Thursday, August 11, 2011

Used Plastic Sheet Lines: Purchasing Guide

Plastic sheet lines are used to form a variety of products including plastic cups, food containers, automotive pieces, truck bed liners, appliance parts, and packaging. The equipment used to make plastic sheet lines has not changed significantly in recent years and used plastic sheet lines offer a high return on investment. The typical life of new equipment from a reputable manufacturer is 20+ years. Its life can be extended if properly cared for and maintained. The most important considerations when buying new or used plastic sheet line equipment are cost, quality and delivery time.

Plastic Sheet Lines

Plastic sheets are formed when plastic pellets are fed into an extruder, melted, and conveyed through a melt pump. The molten plastic is worked through a sheet die to form a continuous flat sheet before being cooled on a roll stack. When cooled, it is either wound onto a spool on a roll or cut to length with a shear. The plastic sheets are made in a variety of widths and thicknesses.

Equipment Components

When creating plastic sheets, several pieces of equipment are required. The first is the extruder. When purchasing a used extruder, consider the make, type (AC or DC) and horsepower of the motor, barrel venting, types of controls, type of feeder, condition of the barrel and overall appearance of the used extruder.

Extruder accessories include the melt pump and static mixer. When purchasing a melt pump, ensure the horsepower of the motor is correctly sized for the rate of the extruder. Manufacturers include Maag, Luwa, LCI, and Zenith. It's important to note if the static mixer (a short stationary screw housed inside the barrel) is included. This unit adds additional mixing to the material before entering the die.

When purchasing a sheet die, consider the width, brand, model, and thickness range. Manufacturers include Extrusion Dies Inc (EDI), Cloeren, Johnson, Production Components, Allied Dies, and Egan.

When purchasing a roll stack, ensure it is wide enough to cover the width of the sheet. Sheet take-off rolls need to have enough surface area to cool the plastic sheet. Check the finish of the take-off roll because it affects the final texture of the sheet. There are also up-stack or down-stack configurations. Two types of drive system are available: chain or individual roll drive. An individual roll drive is preferable because it can be independently adjusted. The type of actuation of the sheet take-off rolls can be pneumatic or hydraulic. Hydraulic is preferable because more pressure can be applied to control the thickness of the sheet. The width and diameter of the pull rolls is important and some include a temperature control system. A thickness gauge is helpful: consider the width, brand and type of gauge: beta or laser. Thickness gauge manufacturers include NDC, Measurex, Indev, and Honeywell.

When purchasing a winder, consider the width and diameter of the rolls to ensure the sheet fits onto the winder. The number of turrets determines if an operation can be continuous or not. Manufacturers are Parkinson, Glouster, Welex, Johnson, Sano, and Egan.

If using a shear, consider the width, brand, and gauge rating. The two most common gauge sizes are ten and twelve. Manufacturers include Wysong and Famco.

Used Sheet Lines

When purchasing used plastic sheet lines, consider the quality of the equipment and configurations. Choices include melt pump or static mixer, up-stack or down-stack configuration on take off rolls, whether roll drives are individually driven, and whether it's hydraulic or pneumatic actuation. When purchasing used sheet lines consider equipment age, manufacturer, capacity and features. The advantages of buying used plastics sheet lines include immediate installation and competitive price. Choose a reputable brand with maintenance records.


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Perry Videx has the largest inventory of used processing equipment in the world. It has used machinery for the chemical, pharmaceutical, food, plastics, sugar, pulp and paper industries. With more than 75 years of service, Perry Videx is the proven market leader in the process industries. To see the inventory, visit http://www.perryvidex.com


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