ABS Acrylonitrile Butadiene Styrene:  Pits caused by moisture in the sheet are the biggest concern with this material.

Angel hair:  Thin strands of plastic along the cut edge created in the trimming process.  Angel hair usually needs to be wiped from the part and can typically be minimized or eliminated with a sound process.

Blister:  A plastic part that is heated and typically sealed to cardboard.  The blister holds the product securely in a retail or pharmaceutical environment.  The blister pack really needs good detail or cold forming will occur causing the blister to not seal properly.

Clamshell:  A formed part that is hinged and folds over to enclose the product.

Clean job:  A food or medical job that requires white coats and gloves, and is typically run in clean rooms.

Clean room:  A certified area where most of the food and medical jobs are run that require high levels of sterility and particulate removal

Craze marks:  White marks that result from the plastic part sticking to the mold or from the knife being off center.

Crushed part:  A defect in which parts are crushed, usually by the knife.

Cycle:  Parts that move in a group, usually the length of the mold.  A tooling seal line separates one cycle from the next.

Denest:  The process end users use to separate individual parts from the row.  This is usually accomplished by utilizing a denest lug, stacking lug, or silicone.

Denest Lugs:  Parts that have protrusions to aid in denesting.  Stacking lugs have an alternating pattern, and denest lugs have a straight-up pattern.

Extrusion:  Department where the plastic resin is converted from pellets and rolled into sheets for use in thermoforming machines.

FDA: Typically food and medical jobs that require heightened regulations.

Flange:  The area of flat plastic around the outside of a trimmed part.  These are typically the seal areas for secondary operations.

Flow Lines:  Lines on the sides of the formed plastic that are caused from stretching the plastic.

HDPE High Density Polyethylene:  The most common use for this material is milk jugs.  Thermoforming companies use this material as well.

HIPS High Impact Polystyrene:  This is typically a colored material often used for cheese molds, candy molds, and a variety of other applications.

Herringbone:  Tractor-tire pattern on the roll that occurs in the extrusion process.

Matched Metal:  Parts are separated from the web using a trim press and automatically stacked (also called punch and die).

Mold:  The cavity or form that is used to shape the plastic sheet.

OPS Oriented Polystyrene:  A very brittle material typically used for food applications.

Orange Peel effect Pock mark pattern in the material from the extrusion process due to moisture forming pits in the material.

Ovens: The part of the thermoforming machine where the plastic is heated before being formed to its ideal temperature.

PET: Polyethylene Terephthalate:  A clear, very versatile material.

PETG: Polyethylene Terephthalate glycol modified:  Usually a clear material that is sticky and typically requires stacking lugs or internal denest measures.  Other colors are smoke and blue tint.

PP: Polypropylene:  A versatile material that can withstand extremely high and cold temperatures, depending on homopolymer or copolymer characteristics.

PVC:  Polyvinyl Chloride:  A material that often appears to be a clear, or clear/blue color.  This material is good for heat sealing options.

Plug marks:  A mark on the plastic caused when a plug assist feature in the pressure base portion of the tooling rubs on the part, causing an abrasion.  A plug mark is usually rough and white in color.

Poly bag:  A bag that is used within a box to keep dirt and other foreign material out of food and medical jobs.  Poly bags may also be used to prevent abrasions.

Poor detail:  Improper forming that lacks crisp lines, corners, and shapes.

Quality control:  A department that assists in assuring the final parts meet specifications.

Rewind:  Scrap material that is wound around the rewind spindle after the parts have been picked.  This rewind is recycled

Robot:  Automatic picking machines designed to improve efficiency and alleviate repetitive motion injuries.

Roll:  Plastic material wound on a cardboard core and used to feed the thermoforming machines.

Samples:  Also called retains.  These are the parts that are taken during a production run and used for a visual comparison when the job is run again to provide consistent quality.
Shim:  Adding layers on a trim sheet that allows the part to be precisely extracted from the skeleton.

Skeleton:  The plastic that remains after the parts have been picked; also called web.  This material is collected and recycled.

Stacking lugs:  Parts that have 2 or 3 different protrusions that holds parts separate so they denest easily; each cycle must be picked in the same order so the pattern of stacking lugs stays consistent.

Steel rule:  Parts are trimmed (cut) by a knife, but remain attached to the web by a few small pieces of plastic called notches.  The parts are then extracted manually or robotically.

Tears:  Ripped plastic that is usually caused by inadequate shimming or notches.

Thermoforming:  Process of forming plastic.  A thermoplastic sheet is heated, pulled down onto the mold surface, cooled, then trimmed from the web.

Thermoplastic:  Material that will repeatedly soften when heated and harden when cooled.

Tooling:  Knives, molds, air boxes, striker plates, die sets, etc.

Tri-fold:  This type of part has two hinges and three parts that fold so it can sit on the middle section.

Trim:  The finished size of a trimmed parts flange.  This size must meet customer specifications and must be monitored for deformities, wavy flanges, uneven distances from front to back or side to side, angel hair, large notches, bows, etc.

Utility Grade:  A cheaper grade of material that can contain up to 100% regrind.

Virgin Material:  The highest grade of material that contains no recycled plastic.

Web:  A defect in the thermoforming process that looks like a fold in the plastic which may cause the product to fit improperly in the part.