The Top Impact-Resistant Thermoplastics for Injection Molding

Many plastic parts – such as construction materials, outdoor equipment, and prosthetics – must withstand high, repetitious impact and bear significant loads of force. Not using a material that has proven toughness can run the risk of your part breaking, resulting in severe or sometimes life-threatening consequences. Choosing an impact-resistant polymer means finding the right balance between toughness and pliability. We’re here to help you by highlighting the top-impact resistant thermoplastic for injection molding. 

Acrylonitrile Butadiene Styrene: Affordable and Modifiable

Acrylonitrile butadiene styrene (ABS) is a popular choice among manufacturers, as it boasts high impact resistance at a mid-range cost. This thermoplastic is well-suited for injection molding and bonds well with adhesives and coatings. Molders can also manipulate its final properties by heating it at different temperatures: a low temperature will yield more impact resistance, while a high temperature will increase its heat resistance. ABS is commonly used in automotive parts, children’s toys, and power tools. However, it’s important to understand that this polymer is not suitable for use with food and beverages.

Polycarbonate: Versatile and Tough

Polycarbonate (PC) is an astonishingly tough polymer with great manufacturability. It can also be transparent, which makes it an excellent high-impact-resistant alternative to glass. You likely encounter several PC applications in your daily life, from protective goggles and face shields to store-front windows and outdoor signs. In addition to its durability, it also boasts great heat and chemical resistance. PC can also be used as a glaze to protect structures from damage, such as government buildings, medical facilities, and transportation hubs. The downside is this polymer can be expensive to manufacture.

High-Density Polyethylene: Multi-faceted and Inexpensive

High-density polyethylene (HDPE) offers incredible impact resistance and tensile strength. The molecules of this thermoplastic are so densely packed together that it enhances its toughness and rigidity. It also benefits from resistance to corrosion, abrasions, and chemicals. Though, it cannot withstand high-temperature environments. This is a low-cost material that is ideal for marine construction, outdoor equipment, and chemical tanks. Though under extreme pressure, cracks can eventually form, and you will need to work with an experienced molder due to its complex shrink rate.

Polyamide-imide: Durable and Adaptable

Polyamide-imide (PAI) is a tough, stiff, and incredibly durable plastic. This thermoplastic also has good chemical resistance and low thermal expansion and is rated for electrical applications. PAI has both high tensile and compressive strength, so it can adjust itself to forceful impacts. It has tight tolerances, such as resistance to fuels, solvents, and acids, which makes it a great candidate for use in the automotive industry. However, this thermoplastic can be expensive and difficult to process. It also expands when subjected to water, but it will remain dimensionally stable.

Choosing the Right Impact-Resistant Thermoplastic

When choosing a thermoplastic for your impact-resistant part, you want a material with great performance and longevity. The plastics listed above will stand the test of time, all while undergoing long periods of physical stress, but to find the right impact-resistant thermoplastic, you need to consider your part’s application. If you know your part needs to be strong yet transparent, polycarbonate is a preferred choice. If you need to it be safe around food, then avoid ABS. The best way to ensure you’re investing in the right material is to work with an experienced vendor who can give recommendations.

Impact-resistant thermoplastics will ensure your parts remain structurally sound under pressure and are even great alternatives for metal. However, you need to ensure your parts are manufactured appropriately to fully benefit from the material’s impact resistance. At Midstate Mold, our team has several decades of experience prototyping impact-resistant parts and executing quality production. If you’re looking for an experienced injection molding manufacturer for your next project, contact us today.