AIM Processing Small Plastic Parts Blog

You’ve designed your part, created the tooling, and are ready to begin the plastic injection molding process. But then, there is a change of plans. Rather than using ABS plastic, you will now be making the parts out of nylon. No problem. Just have some nylon shipped to the manufacturer and you’re good to go, right?

Nylon is a synthetic thermoplastic first produced in 1935 and introduced as a fabric during the 1939 New York World's Fair. You will also see Nylon referred to by its chemical designation “PA.” It is commonly available in black, white, and off-white or beige, which is its natural color. Nylon can be produced as fibers, filaments, sheet stock, and films, and also as the raw material for injection molding.

Acetal is the common name for polyoxymethylene (POM), a white semi-crystalline thermoplastic. It is strong, abrasion and impact resistant, and tolerates many organic chemical compounds. It has a low coefficient of friction and durable stiffness, so it is often used in moving parts. Because it is widely available in sheet and block form, many machined prototypes are made of acetal. Examples of items made from acetal include a variety of large and small plastic parts:

Polycarbonates (PC) are a group of strong, impact-resistant, heat-resistant, thermoplastics. They are naturally transparent, with the raw material capable of transmitting light as well as glass—and they are much lighter than glass. While they are clear by default, PC plastics are commercially available in many colors.

 ABS is an acronym for acrylonitrile butadiene styrene. (Now you understand why it goes by its initials!) It is an opaque thermoplastic polymer. The term “thermoplastic” refers to a class of plastics that can be reprocessed after an initial heat cycle; as opposed to "thermoset" plastics that undergo an irreversible chemical change during its first heat cycle. ABS is a common engineering grade plastic and it is used in many products around you, particularly electronic enclosures.

One of the most important decisions you make with each new plastic injection molding project you undertake is determining what type of plastic to use.  The physical characteristics of plastic run the gamut from highly pliable to extremely rigid, clear to opaque, easily reused/recycled or non-recyclable.  Naturally, resin cost and availability can influence your selection as well.