How To Choose The Polymer

There are thousand of polymers available in market for moulding grade and it becomes quite difficult for designers, engineers and end users to choose perfect material for their application.But it becomes much easier to pick a material when you look into the overall material composition.

These are the top five materials used throughout the industry:

  • Polypropylene (PP)
  • Acrylonitrile Butadiene Styrene (ABS)
  • Nylon
  • High Density Polyethylene (HDPE)
  • Polycarbonate (PC)

There are thousands of subtypes within each material, so to find the right material , we need to focus on the main properties of each of these six categories, focusing on hardness, flexibility, weight, and cost.

Material Hardness

Hardness is defined as a material’s resistance to permanent deformation.The hardness of polymer is often measured by the Rockwell or Shore hardness .Illustrated below are how these top materials stack up regarding how soft or hard they are:

Material Flexibility

A common misconception is that all soft materials are flexible, and all hard materials are stiff. While reality is that material’s flexibility is its ability to bend under stress without breaking easily.Stiffness, however, is the resistance to bending under stress.

A good example of a flexible product is an ABS ruler, even though it is more of a harder material. It would bend up to a certain point before it shows signs of failure. On the other hand, a Nylon ruler would rupture as soon as load is applied to it.

Material Weight

Material weight also plays important role in material selection. Ultimately, the density of a plastic polymer will determine how heavy or light the end product turns out to be.

Material Cost

Material cost is certainly an crucial factor when it comes to manufacturing a plastic injection moulded product.

However, we recommend you to make material decisions based on the product application rather than cost alone. Below is a brief graph of cost comparison between the most common polymers used for injection moulding.

Conclusion

All materials have their own properties, and it is extremely important to look at the overall characteristics that comes with each material category you choose.

Keep in mind that if you believe a material is falling short of some properties, there is always fine tuning through the use of additives and fillers to get the material properties just right.

Check the table below and use the line corresponding to each material to quickly compare where it falls on each of the four different properties we talked about.

If you are having trouble throughout the process of picking the correct material, our team at Plastolin can help.