Materials Options for Translucent and Clear Injection Molding
Different materials have different advantages in clear plastic injection molding. Here’s a rundown of the qualities of our clear plastics.
Acrylic (PMMA)
Acrylic can be injection-molded into crisply clear and colored plastic products, plus it’s non-toxic, scratch-proof, and UV-resistant, making it a popular choice for use in outdoor equipment. Acrylic’s accommodation and its variety of colorants make it a good choice for lenses, light fixtures, and objects requiring them. On the downside, acrylic can be inflexible and breakable, so it can’t be used in products that must withstand a lot of pressure, and it must be dried after it absorbs moisture, possibly slowing the manufacturing process and causing issues for end-users.
High-density Polyethylene (HDPE)
Like acrylic, high-density polyethylene (HDPE) is UV-resistant, but it is more easily translucent injection molded. HDPE is less brittle than acrylic, and it’s cheaper to produce, but it still breaks under high pressure. These qualities dictate its common use in containers, especially bottles, and pipes. HDPE is formed by applying high heat and pressure to petroleum. These transparent injection molding features, along with being inexpensive, are why it’s used in mass production.
Polycarbonate (PC)
More expensive than acrylic or HDPE, polycarbonate is an alternative to clear plastic injection molding. It’s as transparent and UV-resistant as acrylic but less prone to damage from extreme temperatures. Polycarbonate’s high impact resistance makes it a good choice for products that maintain safety, such as windows, containers, helmets, and safety goggles. However, like acrylic, it must be dried after it absorbs moisture before injection molding can occur.
Polyetherimide (PEI)
In addition to UV resistance, polyetherimide (PEI) is impervious to intense heat, repeated pressure, and acids, making it appropriate for medical and automotive products. It is also often used as a translucent material in aerospace engine components, temperature sensors, and heat shields. PEI is more expensive because a steel mold must be used in manufacturing.
Polypropylene (PP)
Commonly used in textiles, packaging, and containers, the high flexibility of polypropylene (PP) makes it an ideal choice for waterproof fabric for bags and clothing. It also has high electrical resistance, so it is used in electronics, and its nonreactivity with acids and bases makes it a good container for solvents and other corrosive materials. It even works well as a sort of dynamic hinge on non-loadbearing parts.
