Glossary of Terms

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

- A

AC Frequency Drives - allows control of the motor speeds. Most stretch wrapper manufactures are still using the oldest technologies: DC motors
and DC drives. The advantages of AC are:
-Easier trouble shooting with digital read out
-No brushes on AC motor like on DC Motors, which require maintenance
-Easy adjustments because it is digital
-Accel & deccel of motor are easily adjustable
-Internal surge protection

Accumulation Conveyor - Any conveyor designed to permit accumulation of packages, objects, or carriers. May be roller, live roller, roller slat, belt, vibrating, power-and-free or tow conveyors.

AGV - An Automatic Guided Vehicle System, or AGVS consists of one or more computer-controlled wheel based load carriers (normally battery powered) that runs on the plant floor (or if outdoors on a paved area) without the need for an onboard operator or driver. AGVs have defined paths or areas within which or over which they can navigate. Navigation is achieved by any one of several means, including following a path defined by buried inductive wires, surface mounted magnetic or optical strips; or alternatively by way of inertial or laser guidance.

Alarm Diagnostic - Indicates the possible reasons why the machine stopped and gives a diagnostic, in order to restart the machine quickly.

Annularly threaded nail - pallet nail with annular (ring) threads rolled onto shank

Arm Conveyor - A conveyor consisting of an endless belt, one or more chains, to which are attached projecting arms, or shelves, for handling packages or objects in a vertical or inclined path.

Automatic Guided Vehicle System - An Automatic Guided Vehicle System, or AGVS consists of one or more computer controlled wheel based load carriers (normally battery powered) that runs on the plant floor (or if outdoors on a paved area) without the need for an onboard operator or driver. AGVs have defined paths or areas within which or over which they can navigate. Navigation is achieved by any one of several means, including following a path defined by buried inductive wires, surface mounted magnetic or optical strips; or alternatively by way of inertial or laser guidance.

Automatic palletizers - Machines that assemble unit loads on pallets or slipsheets. Speeds can reach as high as 150 cases per minute or more. Conveyors integrate the palletizer with other systems.

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- B

Bag-in-box - A package comprising a carton containing a bag that closely fits the carton and contains the product.

Ball transfer table - Another form of gravity conveyor that utilizes balls rotating in sockets over which the load is passed and thereby easing effort of movement. Another form of gravity conveyor that utilizes balls rotating in sockets over which the load is passed and thereby easing effort of movement.

Bar Code - Utilizes a system of printed bars that are able to be scanned and enables the user to identify a part or parcel. Used in conjunction with a laser scanner and serves to increase accuracy and speed of product identification.

Bead seal - A seal in which the two edges of the material are welded together along a very narrow strip without overlap.

Belt Conveyor - A conveyor that utilizes endless belts, made from fabric, rubber, plastic, leather, or metal, energized by drives and operating over those drives, tail ends, bend terminals, belt idlers or slider bed. Handles bulk materials, packages and any object placed directly on the belt.

Belt driven live roller conveyor - A form of powered roller conveyor that is distinguished by a drive motor connected to a wide, flat belt that contacts the underside of the roller surface causing the rollers to rotate and move the load. The load is place directly on the belt, which is supported by the rollers.

Bin - multi-sided superstructure to be mounted on a pallet base, with or without a cover; also known as a box or container.

Blister - A thermoformed clear plastic shape that is used to make a blister pack.

Blister pack - A package which usually comprises a clear plastic shape containing a product, which is heat-sealed to a backing card.

Block - rectangular, square, multi-sided or cylindrical deck or deck-mat spacer, often identified by its location within the pallet such as corner block, end block, edge block, inner block, center or middle block

Block pallet - a type of pallet with blocks between the pallet decks or beneath the top deck.

Blown Film - Indicates the fabrication of a film by continuously pumping the polymer through a circular orifice (die), then filling the tube thus created with air. The volume of air contained within the tube stretches the tube or the bubble out to the desired width. In conjunction with the rate at which it is being pulled away from the die, the desired thickness is created.

Bottom deck- assembly of deck boards comprising the lower, load-bearing surface of the pallet.

Butted deck board- an inner deck board placed tightly against an adjacent lead deck board during pallet assembly to reduce damage to the unit load caused when fork trucks mishandle the pallet

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- C

CAD- computer-aided-design software that allows the design of the "right" pallet at the best value, See Pallet Design System (PDS)

Cantilever -style racks - Racks with arms on one or both sides of the columns to hold stock such as pipe, tubing, and structural shapes. Arms separate SKUs in trays or shelves.

Captive Pallet - A pallet intended for use within the confines of a single facility, a pallet retrieval/recovery system or company. It is designed and dedicated to a given process, system or location/facility. Not intended to be exchanged.

Carton - A container which is made from carton board, generally between 0.25mm and 1.0mm in thickness, and is usually delivered to the user in the form of a carton blank.

Carton blank - An individual carton in the flat after cutting and creasing and with the strippings removed.

Carton tray - A rectangular open carton with sides and ends made from carton board generally between 0.25mm and 1.0mm in thickness and usually delivered to the user in the form of a carton blank.

Case tapers - Machines that automatically seal boxes or cases. Infeed is often automatic by belt or roller conveyor. Sealed containers can be sent to a palletizer or directly to the shipping dock.

Cast Film - Indicates fabrication of a film by continuously pumping the polymer through a straight slot orifice (die), then chilling this hot sheet of plastic immediately after the die by contact with a cooled "chill roll". Film thickness is determined by how fast the casting roll pulls the plastic away from the die.

Chain Conveyor - A form of powered conveyor used to transport heavy unit loads such as pallets and industrial containers. These conveyors can be single or double chain strand in configuration. This chain is not only the driving force but it is also the part which comes in direct contact with the load and provides friction which pulls the load forward. In some cases, free rollers on either side of or between the chain provide additional support to the load. Short sections of double strand chain conveyors are a common means of transferring loads at right angle to/from another straight section of roller conveyor.

Chamfered deckboard - a deckboard with the edges of one or two faces beveled, either along the full or specified length of board or between the stringers or blocks, facilitating entry of pallet-jack wheels and tines of forklift trucks

Chute Conveyor - The chute conveyor is the simplest example of gravity-operated conveyor. Not unlike a child's sliding board, unit simply slides down a straight or spiraling metal or plastic chute to it ultimate destination.

Cling - The characteristics of stretch film that make it stick to itself or other clean, shiny objects.

Closed "loop" or closed distribution system- a shipping system restricted t moving goods between specified plants and facilities.

Closure - A packaging component used to close a container or package

Coextrusion - Fabrication of a multi-layer film by pumping the various materials through separate extruders and then merging the extrudates into a common die assembly. These die assemblies are constructed to maintain distinct material layers with fusion occurring at the boundaries due to the pressures and temperature of the extrudates.

Collapsible Container - A container (metal or plastic) that may be disassembled or dismantled into separate pieces or folded in order to save storage space. These types of containers can be reassembled or unfolded for future use. A container whose sidewalls collapse.

Collar - fixed, hinged, removable, or collapsible horizontal framing members to tie together vertical elements of pallet superstructure; rail

Connection - the structural junction of two or more members, components, or assemblies, designed to be assembled, with mechanical fasteners, adhesives, welds or interlocks, or a combination of them, to transmit structural forces safely; often identified by location within the pallet as end connection, center connection, corner connection. Colloquially, the term joint is used in place of the term connection.

Conveyor - A horizontal, inclined, or vertical device for moving or transporting bulk material, packages, or objects in a path predetermined by the design of the device, and having points of loading and discharge, fixed or selective.

Conveyor belt - A belt used to carry materials and transmit power required to move the load being conveyed.

Copolymer - A plastic or polymer whose chemical composition consists of more than one basic hydrocarbon type. The materials are chemically bonded and remain in combination, thus influencing the performance by their own distinct characteristics. EVA and LLDPE are copolymers, made by feeding more than one monomer to the reactor.

Corrugated board - A material comprising one or more sheets of fluted paper stuck between flat sheets of paper.

Cost-pass through - a cost-share system where the partial cost of a pallet is passed-through from the purchaser to the receiver of the palletized unit load

Cost-per-trip - average cost of pallet or container use for a single one-way movement of the unit load consisting of four to six handlings

Cycle Counter - This resetable cycle counter will allow the operator to determine how many loads are being wrapped.

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- D

Deck - top or bottom surface of the pallet, consisting of one or more boards or panels, with or without space between the elements

Deck mat - the assembly of deckboard and stringerboards or a solid sheet of material forming the deck of a block pallet

Deck board - a single element or component of a pallet deck, oriented perpendicular to the stringer or stringer board

Deck board spacing - the distance between adjacent deck boards

Deck board span - the distance between deck board supports (stringers, stringer boards, or blocks)

Deflection - the amount of flexural deformation of a pallet or pallet component due to the weight of an imposed load; sag

Die - A device used in extrusion processes to shape the extrudate. We use circular dies for blown products and straight slot dies for cast products.

Dock leveler - A manually, hydraulically, or electrically operated plate, located at the dock entrance that can be raised and lowered to accommodate varying trailer floor heights.

Dock plate - A moveable metal ramp that allows access to a rail car or trailer.

Double-deck pallet - a pallet with both top and bottom decks

Double-face pallet - a pallet with top and bottom duckboards extending beyond the edges of the stringers or stringer boards

Double-wing pallet - a pallet with top and bottom deck boards or decks extending beyond the edges of the stringers or stringer boards

Drive-in racks - Racks that make in-depth multilevel storage of unit loads possible, improving density and providing individual support for each load.

Drive-screw nail - continuously helically threaded or fluted pallet nail

Drive Through rack - This rack is similar to drive-in rack except that the fork truck is capable of driving straight through the structure at any storage location along the aisle.

Driverless tractor trains - Trains that consist of a guided vehicle pulling a train of trailers that hold loads of various shapes and sizes. Some of these systems can automatically load and unload, but most serve simply as materials delivery systems.

Driving Pulley - Small pulley that links the ring bearing gear to the motor and gear box.

Dynamic storage system - A storage system that provides varying means of either mechanically moving storage locations or loads within the systems so as to increase storage density and/or to increase storage, retrieval and order picking throughput.

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- E

Economic life- the number of trips the pallet will make over its lifetime, provided it is properly repaired, which maximizes the return on the investment (an output of the PDS software)

Elastic recovery - The extent to which a material returns to its original shape or size after having been deformed or subjected to strain (e.g. stretched).

Electric hoist - A suspended machinery unit that is powered by electrically driven motors and is used to lift or lower a freely suspended (unguided) load. Generally uses chain or wire rope as its lifting medium.

Elongation at break - The strain or deformation required to break a sample. Generally expressed as a percentage by dividing the strain (distance) at which a sample breaks by the original sample length. While related to ultimate stretch ability, lab conditions generally lead to much higher % elongation than is possible during stretch wrapping.

Empty pallet stacker - A transporter or device used to distribute, move and store empty pallets.

Euro-Pallet - The standard pallet in Europe. It is 1200 mm by 800 mm in dimension and has a wood block design between the top and bottom permitting four-way or four-sided entrance by lifting forks. Although other sizes exist in Europe, they are not nearly as prominent as the Euro-pallet.

Exchange pallet - a multiple-use pallet intended for use among a designated group of shippers and receivers where possession of the pallet is transferred with the ownership of the unit load; pool pallet.

Expendable pallet - a pallet intended for a limited series of handlings during a single unit load movement from shipper to receiver; See limited-use pallet

Extrudate - The molten polymer in an extruder and as it comes out of the die.

Extrusion - The process of feeding, melting and pumping a material such that a desired shape or configuration can be created. It is a continuous process and utilizes a device similar to a "meat grinder."

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- F

Fastener - a device for connecting pallet components such as nails, staples, screws, bolts, lag bolts, adhesives and welds

Fastener shear index - measure of the estimated shear resistance of the pallet fastener relative to the shear resistance of a high-quality "baseline" pallet nail

Festoon - A configuration of small trolleys, support track, and electrical cable utilized to provide power to material handling devices while keeping the power cable out of harm's way. The cable is looped or "festooned" by attaching to trolleys supported on a track. This arrangement allows this cable to be "bunched" in an accordion-like fashion so as to keep the cable from becoming entangled in the movement pattern of the device it serves. Often utilized to "stretch" cable across the bridge of an overhead traveling crane.

Film reel - A continuous sheet of paper, carton board, plastics film, metal foil or flexible laminate wound on a cylindrical core.

Film web - A continuous sheet of paper, plastics film, metal foil or laminate.

Film yield - Generally expressed as the coverage area (in square inches or meters) per unit of weight (lb or kg) of a film at a given gauge. Typical low-density poly ethylenes yield 30,000-sq.in./lb. @ 1.0 mil and 60,000 sq.in./lb @ 0.5 mil. Values are normally reported or unstretched films, but obviously pre-stretch dramatically increases yield or coverage.

Flexible packaging film - A continuous sheet of paper, plastics film, metal foil or laminate.

Flush pallet - a pallet with deckboards flush with the stringers, stringerboards, or blocks along the ends and sides of the pallet

Force to Load - The force or tension at which a stretched film is applied to the load. See Wrap Force.

Fork entry - the opening between decks, beneath the top deck and ground or beneath the stringerboards to admit the forks of a lifting device (i.e. fork truck, AS/RS, pallet jack)

Four-way block pallet - a pallet with openings at both opposite pallet ends and sides sufficient to admit hand-pallet jacks; full four-way entry pallet

Four-way entry pallet - a pallet with notched solid stringers to allow entry from both ends and both sides (forklift only through notched stringers)

Free span - the distance between spacers within the pallet; distance between external pallet supports, as in a warehouse rack

FT/MIN - Feet per minute is the way to determine the speed of the conveyor.

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- G

Gantry cranes - Overhead bridge cranes mounted on one or two legs.

Gantry robots - Like gantry cranes, usually designed to travel along one or more tracks and incorporate their own vertical supports. Computer integration is common.

Gauge - A measure of thickness where 100 gauge = 1.0 mil = 0.001". Sometimes used as a synonym for film thickness or film caliper, and expressed in other units e.g. microns(u).

Gear belt - Made of steel and molded in polyurethane - this belt is extra heavy duty and can withstand a max of 2,600 lbs of breaking force. The joint of the belt is again steel welded and molded in uretane. It is FDA approved.

Gloss - The shine or "sparkle" of a surface. In LDPE film, it is described as the amount of light reflected from the surface. A standard technique places a light source and a receiver at 45-degree angles from the surface. The number value produced is roughly the percentage of light reflected from the source into the receiver. Cast films tend to have higher gloss/more sparkle than blown.

Gravity conveyor - Conveyor on which materials are moved by gravity or by a person, as opposed to a conveyor on which materials are moved with powered belts or rollers.

Gravity-lane storage racks - Racks for pallet loads automatically advance materials stored to the picking face and are replenished from the rear. They provide high-density storage.

Gravity roller conveyor - A conveyor that supports the load on a series of rollers with internal ball bearing rings mounted on axles at fixed intervals in a frame. Roller conveyors come in straight sections, curved sections and in various spur and merge sections.

Gravity wheel conveyor - Ideal for light duty handling requirements where the load is flat and smooth, gravity wheel conveyors support the load on a series of skate wheels mounted on a shaft in a frame. The conveyor sections can be either rigid (straight or curved) or flexible. In the latter case, the frame is actually an accordion frame capable of being expanded or curved, making it ideal for temporary applications such as the loading and unloading of over-the-road trucks.

Grocery pallet - a generic reference to the pallets used in grocery manufacturing, distribution and retailing; historically, it meant a "GMA pallet" which was a pallet originally specified by the Grocery Manufacturers Association

Group package - An assembly of products prepared for transit, including cases, crates, trays, shrink wrap packs, bundles and multi-packs.

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- H

Hand (wheel) jack opening - the aperture provided in the pallet bottom deck to allow pallet jack wheels to bear on the ground; window

Hand-held stretch wrappers - Machines that enable workers to manually apply stretch film to packages on a pallet load for greater stability. Tension controls on wrappers are adjustable.

Handling - a single pick-up; movement as a result of picking up, transporting, and setting down of an empty or loaded pallet

Hand truck - Refers to a type of fork truck that is powered but does not carry an operator. Often referred to as a walk behind fork truck.

Hardened-Steel nail - a heat-treated and tempered steel pallet nail with a MIBANT angle between 8 and 28 degrees

Hardwood- a wood from broad-leaved tree species 9 not necessarily hard in texture or dense)

Haze - The lack of clarity of "see through" of a film. It can be induced by process considerations; it can be inherent due to molecular configurations or created by pigmentation. It is measured by determination of the percentages of light not transmitted through a film sample. Cast films tend to have lower haze (clearer than blown.)

Heat Treat - a process that heats coniferous lumber or pallets to a heat treat core temperature of 56 Celsius (133 Fahrenheit) for a minimum of 30 minutes

Heat Treat Stamped - material marked that has met and is stamped and in compliance with the heat-treat requirements.

Helically threaded nail - continuous helically threaded pallet nail; See drive-screw nail

Hoists - Available in two basic designs: chain and wire-rope (cable). Either design can be portable, and either can be manually, pneumatically, or electrically powered.

Impact strength or resistance - The ability of an object or material to resist rapidly applied destructive forces.

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- I

Industrial crane - A machine for lifting and lowering a load, and moving it horizontally. Drives may be manual, power, or a combination of both and utilized totally in an industrial environment.

Industrial scissor lift - A raising/lowering device that is supported or stabilized by one or more pantograph leg sections.

Industrial truck - Wheeled vehicle used in the plant or distribution center, in the dock area (and in some cases also in the yard or on construction sites, to pick up, transport and deposit single loads. May be powered manually, by gasoline, propane or electrically.

Injection molded pallet - Plastic material is introduced in pellet form into a "hopper" positioned at the top of a machine and forcing it along a horizontal chamber or "barrel" of an extruder by means of the rotation of a screw. The plastic material is heated as it moves through the barrel so when it reaches an open cavity, it is a molten mass ready to assume the configuration of the mold. The mold is closed and pressure is applied to form the pallet. Once the pallet is cooled and taken from the mold, it can be further processed into secondary operations such as painting, trimming or fastening.

Ink-jet coders - Coders that can print direct-to-carton alphanumerics and bar codes as conveyors run at speeds up to 60 ft/min. Variable data can be printed and combined with bar codes.

Integrated Systems & Controls - Integrated Systems and Controls (ISC) refers to a product section of the Material Handling Industry of America. An integrated system is a desired state that generally refers to at least one of the three possible characteristics of an installed material handling system. First, although mechanical automation of the material flow properties of a system may be evident, it is the automation of the information flow associated with what is taking place, concurrently with the physical flow, that is the most defining characteristic. Secondly, an integrated system can be characterized by an unbroken, highly coordinated material flow link between successive stages in a manufacturing or warehousing operation where continuous flow is emphasized, and delays, waiting and intermediate storage minimized. Thirdly, an integrated system characteristically interfaces two or more material handling devices in order to form the bridge between work stations or other discrete points of origin and destination within the material flow cycle, with the goal being a high degree of mechanical coordination and the precise timing of movements.

Inner deck board - any deck board located between the end deckboard; interior deck board.

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- J

Jib cranes - Essentially single-girder under-hung cranes cantilevered from a wall- or floor-mounted support and used primarily to service workstations. Capacity is up to five tons.

Joint - See connection

Just-In-Time - The practice of timing inbound material flows so that they can arrive just in time before they are required. This results in smaller inventories. A JIT system requires close links among forecasting, production, scheduling, and purchasing groups as well as suppliers and carriers.

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- L
Layer pad - A sheet of card or corrugated board used to stabilize a pallet or loading unit.

Lay flat tubular film - A continuous tube of plastic film usually supplied wound on a core.

LDPE - Low Density Poly Ethylene - any polyethylene homopolymer whose density is less than 940 kg/m3, which denotes conventional, long chain branched resins made by high pressure tubular or autoclave polymerization of ethylene gas. For recycling, the SPI included LLDPE (and mLL) under their code 4(LDPE).

LLDPE - Linear Low Density Poly Ethylene - actually copolymers of ethylene and other monomers, usually butene, hexane, or octane. Normally made using catalysts in low-pressure reactors.

Length- refers to the stringer or stringerboard length; also refers to the first dimension given to describe a pallet, i.e., 48" x 40", where 48" is the pallet stringer or stringerboard length.

Life to first repair - the number of one-way trips of the pallet prior to requiring any repair (an output of PDS software)

Lift - The maximum vertical distance through which the load hook can travel. The total allowable hook movement between its upper limit of travel and its lower limit of travel.
The term "Lift" or "Lifts" may also refer to lift tables, scissor lifts and personnel lifts.
Lift tables are ergonomic devices utilized to raise, lower or tilt work loads such as pallets and containers. Lift tables are a scissors lift device used to raise, lower, stack, convey and/or transfer material between two or more elevations and not limited to landings. Such movement enables the worker to access the load at an acceptable level so as to not exert undue physical strain while working with the item(s). A scissors lift is a raising/lowering device that is supported or stabilized by one or more pantograph leg sections. Likewise, personnel lifts are used to raise and lower humans to appropriate working heights so that they may work at a safe reaching level and will have benefit of increased movement not afforded by a conventional ladder.

Lift table - A scissors lift device used to raise, lower, stack, convey and/or transfer material between two or more elevations and not limited to landing.

Lifting beam - A solid or fabricated metal or wooden beam, suspended from a hoist/crane or from forks of a forklift, designed to provide multiple lifting points. The lifting beam enables the user to attach the load at more than one point therein securing and controlling the load's movement.

Lifting capacity - The rated load of a material handling lifting device (i.e., scissors lift, hoist) applied as uniformly distributed load.

Limited-use pallet - a pallet designed for an average of up to nine trips, with an average of five handlings per trip in an average environment; single-trip pallet; one-trip pallet; one-way pallet; expendable pallet; shipping pallet

Line load - the weight of a unit load acting along a narrow area across the full length r width of the pallet

Live roller conveyor - The most common conveyor used in large warehouses and distribution centers. Rollers are powered through various means and therein producing movement in needed direction. The load is supported directly by the roller mounted in a frame

Load bearing surface- the interface between pallet top deck and the unit load supported by the pallet; interface between pallet bottom deck and pallet-supporting area

Loading dock - The sorting or staging platform where shipments are loaded or unloaded.

Loading dock equipment - Equipment used to make the loading dock area of a facility more accessible and to provide safe movement of goods in that dock area. Loading dock equipment includes elevating docks, dock levelers, dock boards, dock lights, bumpers, seals, shelters, vehicle restraints and traffic doors.

Loading unit - Generally a palletised load, but including assemblies of group packages which are not on pallets.

Loads Per Hour Display - Allows the operator to see how long it takes for the machine to perform one cycle and anticipate workload and analyze the performance of the system.

Longitudinal seal - A seal made on a package in line with the direction of material travel in the machine.

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- M

Machine Direction - The lengthwise direction of the film.

Magazine - A mechanical assembly designed to hold stacks of cartons, carton blanks, leaflets, labels, lids or stackable containers.

Mandrel - A mechanical assembly around which a bag or carton is formed.

Manipulator - A stationary (does not mean that nothing moves) movement assist device that is often equipped with end effectors for handling different types of loads. End effectors include all forms of grippers, forks, barrel grabs, etc. Manipulators counteract the weight of the load, rendering it almost weightless by way of hydraulic or pneumatic cylinders, or simply by way of counter weights and the exercising of very limited manual control. Most manipulators require manual actuation and control and are therefore manual assist devices. They are mounted to the floor, wall or ceiling. In some cases, manipulators are mounted to a fixed base plate and the entire unit can be moved via a trolley, cart or forklift truck.

Manual Functions - All machine functions requiring manual controls are controllable manually via the operator interface including all conveyors fwd/rev.

Manual palletizers - palletizers that organize and speed the task of stacking containers on a pallet. The containers can be moved to the palletizer by conveyors or other means for greater productivity.

Mast-equipped automatic guided vehicles - (AGVs) serve two functions: transporting unit loads and storing or retrieving pallets and unit loads in racks or on shelves

Material flow - The function of maintaining a constantly available supply of materials needed for production. Such materials may include raw materials, purchased items, or assembled items. The movement of materials to, through, and from productive processes; in warehouses and storage; and in receiving and shipping areas

Material Handling - Material Handling is the movement, storage, control and protection of materials, goods and products throughout the process of manufacturing, distribution, consumption and disposal. The focus is on the methods, mechanical equipment, systems and related controls used to achieve these functions. See also, Supply Chain, Supply Chain Management, Logistics and Third Party Logistics. Note that all of referenced terms are highly interrelated and their definitions are frequently intermingled.

Material Handling Principles - A principle is a general rule, fundamental, or other statement of an observed truth. Over time certain fundamental truths of material handling have been found to exist. The "principles" of material handling are often useful in analyzing, planning and managing material handling activities and systems. At the very least they form a basic foundation upon which one can begin building expertise in material handling.
These principles, that serves as a starting point to identifying potential problems and assessing need, are:
1. Planning
2. Standardization
3. Work
4. Ergonomic
5. Unit Load
6. Space Utilization
7. System
8. Automation
9. Environment
10. Life Cycle Cost

Metallocene, as in m-LLDPE - A catalyst which makes a more uniform and consistent LLDPE copolymer.

Micron - A metric measurement of thickness, also known as a micrometer, abbr. µ or µm. 25.4 µ = 100 guage = 1.0 mil = 0.001".

MIBANT angle - the angular deformation of the fastener shank when subjected to the MIBANT test, providing indication of impact bending resistance and toughness of fastener

MIBANT device (Morgan Impact Bend Angle Nail Tester) - a standard impact nail and staple tester used in the pallet, container, and lumber industry to determine impact bending resistance and toughness of nails and staples

Mil - One one thousandth of an inch, not to be confused with a millimeter or a "mill" (machine/factory). 1.0 mil = 0.001" = 100 guage = 25.4 µ = 0.0254 mm.

Minimum pressure accumulation conveyor - Conveyor minimum pressure accumulation is when product is accumulated and the driving force is not removed. It is called minimum pressure because the pressure of the driving force is kept to a minimum. Pressure will build up as more product accumulates, but can be overcome with controls designed specifically for the application. The advantage to minimum pressure conveyor is a higher discharge or single load release rate than with zero pressure accumulation.

Mobile stretch wrappers - Machines that bring unitizing capabilities to the pallet's location. Film is fed from rolls mounted on manually operated trucks or robots that drive around the pallet.

Modulus - A numerical value reflecting a material's stiffness and resistance to deformation. A film with a high "modulus" is stiff/"crinkly" and initially hard to stretch or elongate.

Multiple-use pallet - a pallet designed for repeated uses for more than one unit load with an average minimum life-to-first repair of ten trips or more, with an average of five handlings per trip in an average handling environment; multiple-trip pallet; returnable pallet; reusable pallet' warehouse pallet; permanent pallet; general purpose pallet; special-service pallet; through-transit pallet

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- N

Nail - straight, slender, wire fastener made from endless wire by cutting the point and forming the head at the shank end opposite the point, designed to be driven, to hold two or more pieces of a pallet or container together

National Wooden Pallet and Container Association - an international association with the goal of promoting the design, manufacture, distribution, recycling, and sale of pallets, containers, and reels

Neck down or Neck in - Occurs when film is stretched in the MD direction resulting in decreased TD width. The "narrowing" tendency of a film is when it is being stretched or pulled.

Non-reversible pallet - a pallet with a dissimilar top and bottom deck configuration or without a bottom deck

Notch- filleted cutout in lower portion of the stringer to allow entry for the fork tine, usually 9" in length and 1-1/4" to 1 ½" in height

Notched stringer- a stringer with two or more notches spaced for fork-tine entry (partial four-way entry)

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- O

On Pallet Stretch (or On the Load) - The extent to which a film was increased in MD length from its initial length on the roll to its final length on the pallet/load, expressed as a % increase in length, i.e. if you draw marks on the film roll one inch (1") apart and they end up three inches (3") apart on the load, you ended up with a {(3"-1")/1"} x 100 = 200% O.P.S. is usually slightly less than the % PS (Pre-stretch) due to elastic recovery between the pre-stretch head and the load, depending on wrap force.

Opaque - Virtually impervious to light. 100% haze level. Opaque white or black stretch films are used to block out light either to protect the content from damage or to deter pilferage by hiding the contents.

Opening height - the vertical dimension measured between decks, from the floor to the underside of the top deck, or from the floor to the top of the stringer notch

Operator Interface - Replacing the push buttons allows the operator to select wrap parameters and operate the systems.

Overall height - the vertical dimension measured from the pallet bottom to the pallet top

Overhang - the distance the deck or deck board extends from the outer face of the outer pallet stringer, stringer board, or block; wing; lip; cantilever; distance the unit load extends beyond the deck

Overhead conveyor - A form of conveyor consisting of a continuous chain running beneath a continuous, stationary, flanged rail. Individual carriers spaced equidistant along the length of the conveyor are suspended from the chain. The chain pulls the carriers. Vertical support is derived from the fact that the carriers are also connected to a small trolley with wheels that roll cross sections, trolleys and carriers. A few common carriers include a tray, platform or simple hook. A less common alternative to the chain drive is a worm drive.

Overhead traveling crane - A crane with a single or multiple girder (bridge girder) bridge carrying a movable or fixed hoisting mechanism and traveling on an overhead fixed runway structure.

Overlap - The overlap is the amount of film overlapping as the load is being wrapped - meaning where the film layers are touching.
Overlap seal - A seal in which the two edges of the material are joined together inner surface to outer surface.

Overwrap - The overwrap is the length of film required after or before the load which means if a product is 40'' long, we could have 5'' overwrap in front and at the end.
This function is adjustable from 0'' up to 15''.

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- P

Package - A term embracing all types of packages e.g. bottles, cans, cartons, bags etc.

Packaging material transport mechanism - A mechanical assembly that transports packaging material through the Packaging Machine.

Pallet- a portable, horizontal, rigid, composite platform used as a base for assembling, storing, stacking, handling, and transporting goods as a unit load, often equipped with a superstructure

Pallet Design System (PDS)- a reliability-based computer-assisted design CAD program for wood pallets for determination of the safe load-carrying capacity, performance and economic life of wood pallets

Pallet dispenser - A pallet feeder is a device used for feeding empty pallets. It is often known as a pallet dispenser.

Pallet life - the period during which the pallet remains useful under given maintenance conditions, expressed in units of time or in the number of one-way movements of the pallet

Pallet lifter - A below-the-hook lifting device that utilizes forks in its design and serves to take the role of forklift forks while utilizing the capabilities of a crane and/or hoist. Generally, counterweighted at its top and attached via a bail and hook arrangement.

Pallet jack- hand-propelled, wheeled platform contrivance equipped with a lifting device for moving palletized unit loads

Pallet performance - The performance of a pallet as expressed in terms of durability, stability (lateral), degree of stiffness or rigidity, and strength.

Pallet size - overall dimension of a pallet stated in terms of length followed by width and height; for example, a 48" x 40" pallet is 48" long and 40" wide; has 48" stringers or stringer boards and 40" deck boards

Pallet truck - A manually powered fork truck. The operator physically pushes the forks into the opening on the pallet and "jacks" the racheting lift mechanism so as to raise the pallet off the floor. Once lifted, the load can be manually moved from place to place.

Palletizers - Palletizers are special machines capable of building a complete unit load on a pallet. Although the most common application is for cases, some palletizers can also handle sacks and bags. A less common palletizer application would be for special products such as sheet stock. There are two general methods employed for automatically building a full pallet. One makes use of a fixed position or overhead gantry robot with end effectors suited to the individual loads, such as vacuum lifts or a gripper. The other method employs more complex mechanisms for forming pallet layers off line, one at a time, and then shifting or transferring each successive layer onto the pallet as it is lowered via a lift/lower table.

Panel-deck pallet- pallet constructed with composite or structural panel deck or decks

Partial four-way stringer pallet- a stringer pallet with notched stringers and block pallet with overlapping bottom stringer board and deck boards

Pass Height - This is the top height of the roller on a conveyor. On the horizontal wrapper, the pass height is higher than normal machines and if a lower pass height is required there are two possible solutions: 1st pit mounting the machine frame or 2nd selling an elevating conveyor.

Pass-through stretch wrappers - Machines that unitize loads at high speeds. The load passes between two rolls of film. Conveyors can be used to transport the load to the machine.

Pendant station - Also referred to as a "pushbutton station". An electrical control device consisting of pushbutton-operated contacts in an enclosure used by the operator for control of the powered motions of the crane, hoist and other auxiliary equipment.

Platform/Fork length - The platform or fork dimension of a tilter as measured perpendicular to the hinged edge (tilt axis). This is considered the side of the platform or fork.

Platform scales - Scales that weigh heavy or bulky objects to 0.025% accuracy. Units with capacities up to 15 tons or more are available. Rugged designs take lift-truck punishment.

PLC - PLC (programmable logic controller) is the brain of the machine. Sensors and switches provide inputs to the PLC and based on these inputs, the PLC energizes outputs which tells the machine what to do - this is a simple way of explaining what a PLC is. Serving to replace hard-wire and relays, the PLC can be changed (programmed) without changing wiring and tends to be highly reliable and fast-acting. Industrial environments do not require fans, air conditioning or electrical filters to operate the PLC. The PLC is relatively easy to program or change applications and is reusable and troubleshooting is self-diagnosed.

Pneumatic pusher - An air-powered conveyor sortation device. This device utilizes a ram and cylinder configuration and its movement is programmed to redirect packages and materials on a conveyor line.

Pneumatic puller - An air-powered conveyor sortation device. This device is used to redirect packages and materials on a conveyor. Pulling device travels beyond the object to be redirected and retracts, therein pulling the object in the desired direction.

Polymer - Means "many member." A structure generated by the repetitious joining of many of the same elementary units. Natural polymers are cotton, wood, or protein. Synthetic polymers are polyethylene, polystyrene, Nylon®, PVC, etc.

Pop-up chain sorter - An in-line diverter conveyor that has wheels that pop up between the rollers of a powered roller conveyor or between belt conveyor segments and direct sorted items onto a powered take-away line. Fairly high speed sorting, in the range of 120 cases per minute, can be achieved.

Post pallet - a pallet fitted with fixed or detachable columns or posts as a part of its superstructure

Post stretch - Any additional stretch (usually undesirable) occurring between the pre-stretch head and the load.

Power and free conveyor - A variation of overhead chain conveyor is "power and free". They are highly versatile conveyors that can be designed to operate overhead or as floor-mounted units. They offer good operating flexibility. In a conventional overhead conveyor the carrier is permanently fastened to the drive chain, in the power and free case the carrier can mechanically disengage from the drive chain and essentially idle while the chain continues to move. Power and free conveyors can also be inverted so that they can be mounted to the floor, in which case the carrier or tray rides on top of the guiding rail as opposed to being suspended beneath it.

Powered conveyor - Conveyor of any type that's movement is driven by motors and drives. Power may be electrical or pneumatic.

Powered monorails - Monorails that travel on an overhead track and can be computer-integrated or manually controlled. Some systems carry conventional hoists. Monorails offer design flexibility.

Pre-made bag - A pre-formed flat or gusseted flexible container longitudinally seamed and closed at one end made from paper, plastics film, foil, laminate or a woven material etc.

Pre-Stretch - The extent to which a film is increased in MD length within the pre-stretch head. Ideally, in the absence of film slippage on the pre-stretch rollers, or other problems, it is determined by the relative surface speeds/gearing of the pre-stretch rollers. Note that in order to achieve 200% stretch, the second roller must turn three times (3x) as fast as the first roller.

Programmable logic controller - Serving to replace hard-wire and relays, the PLC can be changed (programmed) without changing wiring and tends to be highly reliable and fast-acting. Industrial environments do not require fans, air conditioning or electrical filters to operate the PLC. The PLC is relatively easy to program or change applications and is reusable and troubleshooting is self-diagnosed.

Puncture resistance - The relative comparison of a material's resistance to failures caused by penetration; i.e., how easily does your finger (or a sharp pallet corner) poke through a film sample?

PVC - Abbreviation for Poly Vinyl Chloride. In film form it is used as a deli/meat or produce wrap, a high clarity shrink-wrap for consumer or retail packaging, or rarely as a stretch/pallet wrap. PVC is not compatible with LDPE for recycling.

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- Q

Quality- consistent performance of a uniform product meeting the customer's needs for economy and function, normally represented in terms of conformance to predetermined, agreed standards

Quality control - The use of sensors to detect the presence of an object's component part, fill level, or dimensional tolerance for the purposes of providing process quality control.

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- R

Rack - A single or multi-level structural storage system that is utilized to support high stacking of single items or palletized loads

Racked across deck boards (RAD) - output of the PDS evaluation software describing the maximum load-carrying capacity and deflection of a wood pallet and is decks, where the warehouse racking frame supports the pallet only at the deckboard ends

Racked across stringers (RAS) - output of the PDS software evaluation describing the maximum load-carrying capacity and deflection of a wood pallet and its decks, where the warehouse racking frame supports the pallet only at the stringer or stringerboard ends

Recycled pallet- pallet with damaged components replaced with new or recycled components, in order to reuse it

Remanufactured pallet- a pallet manufactured from recycled lumber and built to a customers specific requirements (Remans)

Rental pallet - A pallet owned by a third party, different from the actual user.

Repair - to remake in order to use again

Repaired pallet- pallet with damaged components replaced with new or recycled components, in order to reuse it

Reset - Brings all the machine components to their original position in order for a new cycle to be started.

Returnable/reusable pallet- a pallet designed to be used for more than one trip; multiple-use pallet

Reversible pallet- a pallet with identical or similar top and bottom decks, to allow either one to support the unit load

Rigid container - A term embracing bottles, jars, drums, barrels, kegs, pails, cups, tubs, ampoules, vials, cans and composite cans.

Ring Bearing Gear belt - The ring bearing gear belt is well known in the industry for its durability, accuracy and for withstanding rough environments - low maintenance.

Roller belt conveyor - A powered form of conveyor where the transporting belt is supported by rollers spaced along the frame, not unlike a gravity roller section. Power and forward motion is transferred by utilizing a moving belt powered by a pulley and motor configuration at one end of the section. Capable of handling rather heavy loads.

Roller conveyor - A series of roller supported in a frame over which objects are advanced manually, by gravity, or by power.

RPM - Rotations per minute.

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- S

Scissors lift - A raising/lowering device that is supported or stabilized by one or more pantograph leg section.

Selective rack - Steel storage racks arranged in either single or back-to-back (double) rows. Each of the rows offers a bay or number of bays in the down aisle direction. Pallets are generally positioned side-by-side in the down-aisle direction at each level of the bay. The advantage to this configuration of rack is that all pallets are accessible from the facing aisle.

Shelving - A storage system designed to accept and store non-palletized loads, placed thereon, either manually, semi-automatically or automatically such as by an automated retrieval mechanism. In its basic open form, shelving is comprised of upright posts, the desired number of formed steel sheet panels, which constitute horizontal shelves, and end and back braces. Sheet steel back and side panels may be substituted for bracing to form enclosed shelving units.

Shelving side panel - A sheet steel panel attaches to the front and rear post to enclose the side of the unit, or as a partition between units placed side by side.

Shipping pallet- a pallet designed to be used for a one-direction movement of the unit load from shipper to receiver; it is then recycled or disposed; See limited use pallet

Shoe sorter conveyor - The conveying surface consists of continuously linked slats. The linked slats move in a manner similar to a belt. Between each slat, along one side, there is a shoe that moves along with the slats. Each shoe is capable of simultaneous independent lateral movement from one side of the conveyor to the other at the same time as it continues to move forward. At the appropriate time, controls sequence as many shoes as necessary, depending on the size of the load, to move from one side of the conveyor to the other, contacting the side of the load, thus directing the load to one of multiple discharge or take-away lanes. The take-away lanes can be powered by gravity. At the end of the run, after the last take-away lane, and on the return (remember the main sort lines move like a belt), the shoes are all reset to their original side. Such sorters are capable of higher sort rates in the range of 150 cases per minute. Another name for this type of sorter is surfing sorter.

Shook- cut-to-size lumber pallet components, such as deck boards, stringers, stringer boards, or blocks, to be assembled into pallets

Shook grade- the classification of the quality of pallet components relative to their performance characteristics based on size and distribution of defects, independent of wood species

Shrinkwrapping - A process in which a package is wrapped in a thermoplastic film that is then heated so that the film shrinks to closely fit the package.

Single-wing pallet- a pallet with the top deck boards or deck extending beyond the outer edge of the stringers or stringer boards and with the bottom deck boards or deck, in any, flush with the outer edges of the stringers or stringer boards

Side loader truck - An industrial truck with lifting capabilities and able to accommodate the narrowest of aisles, depending upon the model and type, all the way down to the 5 foot range. Trucks operating in this range are sometimes called very narrow aisle (VNA) trucks. With the exception of the platform type sideloader, the fork and/or the entire mast on a VNA style truck is capable of rotating or swiveling 90 degrees left or right within the aisle from the down aisle orientation. Some manufacturers have models that can stack in storage racks 10-12 pallets high.

Side seam seal - The longitudinal seal, which is made by stitching, heat sealing or applying adhesive, when a carton blank is formed into a flat carton.

Single deck pallet - A pallet possessing one load bearing deck.

Skate-wheel conveyors - Conveyors with a series of skate wheels mounted on common shafts or on individual axes between parallel frame members. Movement is manual or by gravity.

Skid- a pallet without bottom deck boards or deck

Slave pallet- rigid pallet or platform; single, thick panel used as a support base for a palletized load in warehouse rack-storage facilities or production systems

Slat conveyors- Constructed of one or more strands of chain to which steel or thermoplastic slats are attached to convey a variety of parts or packages. Load capacities vary widely.

Slider belt conveyor - A simple and inexpensive form of powered conveyor. A single section will have a large roller at both ends, one of which is powered by a pulley type belt connected to a motor. The belt is literally slide over a flat surface therein conveying the load on a horizontal plane or carrying loads up an incline.

Slip Ring - The slip ring is used to bring electricity from a fixed point, the control panel to a moving part - the carriage. The slip ring is of extreme high quality, manufactured by WAMPFLER it is made with dual brush systems, which ensure constant contact. The brushes performance: on a load of 96'' long - 50% overlap - 60 loads per hour and on a 60'' ring it is 70 days none stop 24 HRS, which means that after having wrapped 100,800 loads the brushes would need to be replaced.
The brush has a lifetime of a max of 26 260 000 feet. This slip ring is also conformed to UL, CSA - the slip ring is completely safe and conforms to all safety regulations.

Soft nail - pallet nail with a MIBANT angle equal to or greater than 47 degrees

Softwood- wood from coniferous or needle bearing species of trees ( not necessarily soft in texture or of low density)

Solid deck pallet- a pallet constructed of a single or multiple components without space between the deck boards or components, See panel deck pallet

Span- the distance between supports

Start - By pressing the start button if a load is present on the infeed blocking a photoeye, the conveyor will index the load in the wrap zone. If is there is no load on the conveyor, the machine will be waiting for a signal from the existing conveyor to start.

Stevedore pallet- a pallet designed for use on seaport shipping docks; normally a large pallet of heavy-duty, double-wing construction

Stiff-stock steel nail - pallet nail made of medium-high carbon steel without heat treatment and tempering with a MIBANT angle between 29 and 46 degrees inclusive

Storage/retrieval (S/R) machines- Machines that ride on floor-mounted rails, with top support also provided.

Strapping - A load stabilizing and securing methods wherein a variety of materials can literally be used to wrap or tie down a load or individual item for movement and protection. These materials include cold rolled low and medium carbon steel, hot roller high tension steel, polyester, nylon and polypropylene. Each of these materials has special properties that need to be closely matched to the load requirement.

Strapping (pallets) - thin flat bands used t secure the unit load to the pallet

Strap slot - recess or cutout in the upper edge of the stringer or the top or bottom pallet deck, designed to allow tie-down of a unit load to the pallet deck with strapping or banding; strap notch; banding notch

Stress relaxation - Primarily it is the phenomenon of force decay as a function of time. It means that the "rubber band" effect holding a stretch wrapped load together may exert less force as time passes. This rate of decrease varies greatly with different polymers. PVC has an early decay, which is much greater and more rapid than that of LLDPE (whose load holding force can actually increase with time when applied using power pre-stretch.)

Stretch - See On Pallet Stretch, Post Stretch, and Pre-Stretch.

Stretch film - This is popular method of securing loads, especially the irregularly shaped unit load and loads that cannot tolerate the strain of being strapped. This film is tensioned and stretched mechanically as it is unwrapped from its rolls. The tension is released as it is wrapped around the load. The result is greater holding power.

Stretchability - A combination of factors related to the ability of a material to be stretched or elongated; i.e., how easily does a film stretch, how much will it stretch?

Stretchwrapping - A process in which a package is wrapped in a thermoplastic film, which is pulled tightly around the package. The film may be formulated to stick to itself on contact.

Stringer- continuous, longitudinal, solid or notched beam-component of the pallet used to support and space the deck components, often identified by location as the outside, interior, or center stringer; bearer; runner

Stringer board- in block pallets, the continuous, solid board member extending for the full length of the pallet, perpendicular to the deck board and placed between the deck boards and blocks, to serve as support of deck boards or deck

Supply Chain Management - Supply Chain Management is the integration and coordinated execution of all the business processes used to plan and execute the flow of material, goods, products and related information between the many sources and points of use throughout the supply chain in order to achieve the best overall, system wide performance in terms of total cost, on-time (just-in-time) delivery and minimum in-process inventories across the network of suppliers, factories and trading partners that comprise the supply chain. See also, Supply Chain, Logistics, Material Handling, and Third Party Logistics. Note that all of referenced terms are highly interrelated and their definitions are frequently intermingled.

System Integrator - A System Integrator is a company that possesses the resources required to provide a full set of engineering services needed to take a project from the problem definition stage all the way through to implementation and system acceptance by the end user. In some cases, but not always, a company that defines itself as a system integrator may also manufacture equipment and controls. A system integrator will also assume financial responsibility for system performance.

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- T

Tack - An adjective used to describe a film's resistance to slide against itself or another surface or its resistance to separation from itself. Similar terms are surface adhesion or cohesion, surface "seal", "wetting" of film layers, blocking, or cling.

Tackifiers - Chemical substances added to increase the "tack" of the parent or base material.

Take-it-or-leave-it pallet- a pallet fitted with fixed, spaced, solid or notched cleats on the top deck boards or deck to permit fork-truck tines to pass beneath the unit load and remove it from the pallet

Tear resistance - The resistance of a film to being torn. This is measured as the force required to propagate an initiated tear in the MD or TD direction.

Tear tape - A plastic tape, which is sealed to a packaging material, usually plastic film, to assist opening of the pack.

Tensile @ yield - This is a stress level, measured in psi (pounds force per sq. inch of cross-section), beyond which permanent deformation occurs. This term "tensile" indicates that the specimen is pulled or "tensioned" rather than compressed. Up to this stress or applied force level, a release of the force will result in the specimen returning to its original size. Pulling with a higher force will result in a permanently elongated sample even after the force is removed.

Tensile ultimate or Tensile strength at break - This is a stress level, measured in psi, beyond which the specimen will break. It is the laboratory measured, maximum stress (applied force) that the material will withstand. The "tensile" indicates that the test is conducted with a pulling or tensioning type of loading.

Tension - Tension on the film can be adjusted from the operator interface - which will apply more force to load.

Thermal transfer label - Labels printed using a direct thermal printer that does not use ribbons.

Thermoformed pallet - Thermoforming takes place when a thick plastic sheet is clamped onto a frame and heated, then this softened, pliable sheet is forced by either pressure or vacuum to adapt to the shape of a pallet tool. Once the sheet has formed to the configuration of the tool and it has cooled down, it is removed from the frame. The outer perimeter of the pallet is trimmed off to yield the finished part. Twin-sheet thermoforming is a variation of this process whereby two separate sheets of plastic are heated in two separate sets of tooling and then fused together under pressure to yield a pallet with a hollow section or sections.

Thermoplastic film - A plastic film that shrinks when heated.

Thermoformable material - A material which when heated can be formed by pressure and/or vacuum.

Time and Motion - A work measurement process that takes into consideration time to perform a task in a normal or variant effort or pace. The time and effort needed to accomplish a task.

Top cap- a panel placed on top of a palletized unit load to facilitate stacking and tight strapping without damaging the unit load

Top-deck of pallet- the assembly of components comprising the upper load-carrying pallet face

Top load carton - A one piece carton which is erected by first interlocking or gluing the side members to the body part and having a lid with side flaps which can either be tucked or glued to the carton body to close the carton.

Toughness - Measurement(s) of the overall energy required to destroy a sample which takes into account both the amount of force and the amount of elongation a sample can withstand. A "tough" material will resist breakage by absorbing a large amount of energy by both resisting the force and by elongation. A "brittle" material (e.g. glass) will resist force, but will break instead of deforming; hence, it has low toughness. LLDPE, which is "plastic" or "tough", resists and elongates, hence is tougher than glass. The rate (speed) of force application has a significant effect on 'toughness', thus comparisons must include testing data.

Tow-line conveyors - Conveyors that use a chain in the floor to pull carts. Carts have tow pins, allowing them to be disengaged, if necessary, from the chain.
Pallet racks boost storage density and minimize product damage with multi-level storage and separation between loads.

Transverse Direction (or Cross Direction) - The width-wise direction of the film.

Transverse seal - A seal made on a package at right angles to the direction of material travel in the machine.

Trip- a series of four to six handling of a pallet, required to move a palletized unit load from the shipping point to the receiving point

Trolley conveyors- Conveyors that transport loads in a series of trolleys attached to a chain and supported by or within an overhead track.

Two-way entry pallet- a pallet with unnotched solid stringers allowing entry only from the two opposite pallet ends; a pallet without notches in stringers

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- U

Ultimate strength - See Tensile Ultimate.

Uniform standard for wood pallets- a comprehensive standard for the manufacture and repair of wood pallets that's available through NWPCA; also outlines "best practices"

Unit load- the assembly of goods or a single item on a pallet for handling, moving, storing, and stacking as a single entity; it includes the supporting pallet

Unit Load AGV - A unit load AGV is a powered, wheel based transport vehicle that carries a discrete load, such as an individual item (e.g. a large roll of paper, coil of steel or automobile engine) or items contained on a pallet or in a tote or similar temporary storage medium. AGVs operate under computer control without the need for human operators or drivers.

Unit Load AS/RS - A type of automatic storage and retrieval system that handles large loads (500 to 1000 lbs. and up) that are often placed on pallets or contained in pallet size plastic, wooden or industrial metal containers. Certain large loads, for example steel coils or paper rolls, may also be handled without a pallet base or container.

Unit load picking - The act of removing unit loads from stock or storage

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- V
Vertical reciprocating conveyor - A conveyor that moves perpendicular to the floor and provides intermittent operation of a single load-carrying platform or cage which travels up and down on steel rails or guide ways. There are many configurations of vertical reciprocating conveyors (VRCs) including those with a single mast, single rail, double mast, double rail and even models which offer incline travel versus strict vertical travel. There are also numerous platform configurations ranging from a simple flat steel surface to a powered roller conveyor deck with controls that are integrated with the controls of powered feed and take away conveyor lines at the different levels.

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- W
Warehouse - A facility utilized to store, protect and secure items for inventory or staging for shipment.

Warehouse Management System - An execution system used to manage people, inventory, time, and equipment related to picking and processing customer orders. The Warehouse Management System receives orders from the Order Management System or the Transportation Management System, then relies on rules and priorities established by the user to optimize the space and work within the four walls of the warehouse.

Warehouse pallet- a double-deck, flat, multiple-use, returnable pallet intended for general warehouse use

Wing- overhang of deckboard or deck end from the outside edge of the stringer or stringerboard, to increase unit-load area, to add pallet load-bearing capacity, to reduce deck board-end splitting by fasteners, and to facilitate the lifting of a pallet with bar slings hanging from a crane

Wrap Force - The force or tension at which a stretched film is applied to the load. See Force to Load.

Wrap ON/OFF - When wrap OFF is selected, the loads will be passing through the wrapper without wrapping.

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- Y

Yield strength - The guaranteed minimum yield point stress of the material as specified by the steel supplier. See Tensile @ Yield.

- Z

Zero pressure accumulation conveyor - A type of powered conveyor accumulation. Zero pressure accumulation is that which occurs when the driving force is completely removed form the load. This is usually accomplished by way of sensors in combination with various mechanical means such that when a load is stopped on a sensor, the driving force in the zone behind the stopped load is dropped away. When the next load is driven into the now dead zone, it too will stop, causing a like chain reaction upstream, or until such time that the first stopped load is released and moves on. Discharge from an accumulation point can be either one load at a time or a so-called slug discharge, where a pre-specified number of loads are released at one time.

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Glossary Courtesy of Modern Material Handling at www.mmh.com and Material Handling Industry of America at www.mhia.org