For any kind of custom plastic injection molding project that’s carried out, one of the vital factors involved will be the kind of plastic resin that’s used. There are various factors that determine the type of raw plastic resin that’s used during injection, and making the right choice is a key factor in achieving the desired final product.

At EnviroTech Custom Injection Molders, we’re happy to explain all the factors that play a role in determining your injection molding resin, plus identify the ideal resin to use for your desired product. Generally speaking, there are two categories of resins to consider: Commodity resins and engineered resins (the latter may split into sub-categories in some cases). Here’s a primer on each of these categories, plus some of the common resins found within each and the processability and other qualities they carry.

Commodity Resin Examples

Commodity resins describe the more affordable resins that are simpler to process and can be created in high quantities. They’re used in a huge variety of applications, from packaging and clothing areas to containers, medical trays and various retail consumer products.

Some examples of commodity resins include:

  • ABS: Short for acrylonitrile butadiene styrene, ABS is a low-to-medium-strength resin that has excellent resistance impact. It’s easy to process and has a good surface finish, plus resists both chemicals and flames. It’s often used for toys and similar consumer items.
  • Acrylic: Acrylic resin is moderately strong, though it has poor resistance to impact. It’s great for weatherability and insulation, though, so it’s often used for glass replacement or various casing formats.
  • HDPE: Short for high-density polyethylene, HDPE is great with food and is often used for buckets or kids toys.
  • PP: Polypropylene has fantastic material flow and is easily processed, so it’s regularly used in consumer goods.
  • PE: Simple polyethylene resists shrinking and warping extremely well, plus is corrosion resistant and low-weight.
  • PS: Polystyrene is used in product casings and packaging due to its flame retardation and expandable qualities.
  • PVC: Polyvinyl chloride is soft and flexible, often used in fencing, containers and even plumbing.
  • SAN: Styrene acrylonitrile is chemically resistant and has good weatherability, so it’s often found in electrical or automotive industries.

Engineered Resin Examples

Engineered resins, on the other hand, are materials with specific thermal or mechanical properties that make them valuable for a given application. They are generally high in strength and resistant to wear, temperature or corrosion, and used for industrial and related needs.

Engineered resin products range from acetyl and various polybutylene, polyether and related products to nylon, thermoplastics and others. They are often used in high-stress environments like automotive areas, engineering, electrical, medical and other similar areas, including some resins that are mixed together to provide the best processability. They may be costlier than commodity resins, but their benefits tend to make up this gap and then some.

For more on various plastic resins for injection molding and their processability and other qualities, or to learn about any of our custom injection molding services, speak to the staff at EnviroTech Custom Injection Molders today.