In the world of resins and injection molding, there are thousands of options available. Some resins offer strength, thermal stability and chemical resistance, and yet others offer electrical resistance and ease of printing. Perusing several online databases, such as the UL Prospector (formerly IDES), MAT Web, and The British Plastics Federation, can offer a starting point, but picking one from the massive lists is a challenge. If you’re just starting on a concept, you may just need to consider something commonly used. These are options we use frequently in our daily operations that may be a great option for you:
Acrylonitrile Butadiene Styrene (ABS)
ABS is a common resin that you can find in many applications needing a tough exterior and thermal stability. It is a thermoplastic that is a lower cost option available. It’s easily machined and shaped to specific designs while also able to be colored to match specific applications for many different industries. It is a strong material offering resistance in many environments.
Frequent Applications: ABS is a versatile option that can range from the automotive industry to piping used in commercial and home manufacturing. It is an amorphous resin and has no specific melting point because it can be varied in composition easily with many different additives. You can also find it used in applications needing minor chemical and electrical resistance.
Not Recommended Applications: ABS, while thermally stable, isn’t the best option for extreme temperatures above 200 F. Beyond temperatures, ABS isn’t a great choice for applications needing flexibility. It is a hard plastic that can break before it bends. Lastly, ABS does not have superb chemical resistance. It can withstand some chemical exposure, in extreme environments it may not last as long as needed.
Nylon has been around for 80 years and has numerous applications and variations. It’s one of the often semi-crystallin resins frequently used in fabric, applications like carpet and flooring, food packaging, and automotive parts. One of the first uses after development was Ladies nylons, which is where the name of the product stems from.
Frequent Applications: Nylon has many uses from toothbrushes, women’s stockings, to parachutes. Beyond these areas, food packaging is prevalent with clear nylon film. For clothing, nylon is mixed with other fabrics like cotton, polyester, and spandex to make a material that is durable, strong, and has the ability to wick away moisture. It is highly recyclable, so that is an added benefit to its use.
Not Recommended Applications: Nylons should not be used when it can come in contact with sulfuric acid or other harsh acids. Beyond that it can produce toxic smoke if it comes in contact with fire.
Polypropylene, another semi-crystallin resin, is on the list of the most common used and manufactured plastics in the world. It has many properties, such as chemical resistance, flexibility, and insulation. While it can be flammable, and degrade in UV exposure, it is still a popular choice in many applications.
Frequent Applications: Polypropylene offers resistance to chemicals and electrification, which make it a strong contender for environments needing chemical resistance and electrical use. In order to be used heavily in automotive applications, it requires an additive to meet FMVSS guidelines. Beyond automotive, it is heavily used in packaging, electrical manufacturing, household appliances, toys, and medical items.
Not Recommended Applications: Polypropylene is flammable in some variations and can degrade in UV exposure unless it is specially blended with additives to make it non-flammable or UV protected. It can be used in many harsh environments, but only with additives chosen for the application.
HIPS (High-Impact Polystyrene)
HIPS offer’s good impact resistance, dimensional tolerance stability, a hard surface that is good for machining, and a good surface for applications needing aesthetic properties. HIPS offers the ability to be printed on, which makes it a good choice for signs. It can be glued or bonded together, and other materials can be added for more opportunities to change the decoration of the end product. It is low in cost, which also makes it a favorite choice for injection molding.
Frequent Applications: Due to its impact resistance and thermal stability, HIPS is frequently used in printing applications, appliances, children’s toys, and drinking cups (both hot and cold). You may also find it used with computer peripherals and components.
Not Recommended Applications: HIPS can be flammable depending on the variety of material used. There are non-flammable resins available, so be sure to check your application and environment for the material before making the material choice.
Polycarbonate is another amorphous resin that offers strength and a lower medium cost. It is a high-grade thermoplastic that also is naturally transparent. That makes it a great option for safety wear.
Frequent Applications: Polycarbonate, being strong and transparent, is a great option for safety eye wear, bulletproof glass, and medical uses including test tubes, beakers, and pipettes.
Not Recommended Applications: Polycarbonate doesn’t work well is environments that require it to be flexible. Due to the natural transparency, it does not mix well for dies or finished colors. In order to use it in food grade materials, it must be BPA-free.
Just knowing five common resins will help with an idea. You know what basic properties you want in a new project. What you may not know specifically is whether you need an amorphous or semi-crystalline resin, a commodity or high-performing option, or just something in between. Don’t feel overwhelmed trying to determine the best option available. We’re here to help. If you need more advice, or are ready to start your next project, give us a call at (425) 339-0288 or email us at email@example.com.