Plastic Manufacturing Processes

Flashcards covering key concepts in plastic manufacturing processes and materials.

Thermosets are materials that __, while thermoplastics __.

cannot be remelted; can be remelted

The heat deflection temperature (HDT) is the temperature at which the material starts to lose its __ under a load.

mechanical properties

The process of __ involves melting the resin, injecting it into a closed mold, cooling it, and ejecting the part.

Injection molding

Cooling the resin in injection molding takes the __ time.

longest

A core is the of a molded part while a cavity is the .

underside with ribs; outside

Joining plastics without adhesives or fasteners can be done by or methods.

friction; chemical

Fiberglass is made of polyester resin and is classified as a __.

thermoset

Pressure forming has better detail due to but has higher tooling costs due to .

pressure; design complexity

An energy concentrator is used in __ welding to focus melting on a specific area.

ultrasonic

The nominal wall of an injection molded part affects the and of the final product.

thickness; draft

PVC is commonly used for swimming pool plumbing components due to its __.

chemical resistance

Light pipes are used to guide light from a __ to the housing.

PC board

A __ is added during the fiberglass manufacturing process to be the outside of the part.

gel coat

The term __ refers to the crack or mark that can form after the plastic melt flows around a hole in the mold.

knit line

The difference between low pressure structural foam and RIM is that low pressure uses while RIM uses .

thermoplastics; thermosets

In the context of injection molding, a preform is a __ part made through injection molding, useful for precise threads.

premade

The process used to create large hollow plastic parts without stress is __.

rotomolding

The part that allows for easier ejection of a molded part is known as the __.

ejection plate

A soft-touch grip is an example of __ in the manufacturing process.

overmolding

The energy for the injection molding process is supplied by the __ in the machine.

reciprocating screw drive