Injection molding materials

Commercial-grade polymers for injection moulding:

Here at "Micromolds" warehouses we keep wide variety of plastic materials including recycled plastic and elastomers (TPEs). When choosing polymer for your part one should evaluate some of crucial design constraints:

Mechanical properties of a polymer (e.g. UV resistant material);
Compatibility with injection moulding (even almost every polymer is suitable for injection moulding, compatibility is still important when part has high resolution features and is used for micro moulding or when overmoulding processes take part;
Cosmetic appearance like color and surface finish are things to consider of no less importance;
Final but not the least design constraint is the cost of material.

You are always welcomed to use your own materials. Please inform us about that in online quoting form and feel free to supply it for us.

Thin wall injection capabilities

In order to avoid cosmetic defects like flash, sink, warp, knit lines and maintain uniform part structure in plastic injection moulding it is recommended to evaluate wall thickness for various part cross-sections. Here is the list of recommended ranges from min. to max. of wall thicknesses for most often used polymer materials in injection moulding*:

ABS injection moulding: 0.143mm - 3.556mm;
Acetal injection moulding: 0.762mm - 3.048mm;
Acrylic injection moulding: 0.635mm - 12.7mm;
Nylon (polyamide) injection moulding: 0.762mm - 2.921mm;
Polycarbonate injection moulding: 1.016mm - 3.81mm;
Polyester injection moulding: 0.635mm - 3.175mm;
Polyethylene injection moulding: 0.762mm - 5.08mm;
Polypropylene injection moulding: 0.635mm - 3.81mm;
Polystynene injection moulding: 0.889mm - 3.81mm;
Polyurethane injection moulding: 2.032mm - 19.05mm.

*Based on https://www.manufacturingcenter.com/web/home.php

Material bonding guide for overmoulding, 2K, inserts

For good mechanical or chemical material bonding and adhesion in overmoulding, 2K shot moulding and insert moulding processes various combinations can work out. Enormous amount of materials out there leads to a struggle when looking for right match for the substrate material. It is best to refer on recommendations of materials' manufacturer. In research, it is good to have in mind that materials can bond in two ways: mechanical or chemical. Below some recommendations** are indicated to guide you through the selection process of materials.

Personal care:
- Substrate: Polypropylene;
- TPEs: Dynaflex, Kraton, Versaflex CL, Versalloy XL;
Household:
- Substrate: ABS, PC/ABS;
- TPEs: Versaflex OM, Versollan OM;
Consumer electronics:
- Substrate: Polycarbonate
- TPEs: Versaflex OM, Versollan OM;
Hardware:
- Substrate: Nylon 6 and 6/6;
- TPE: Versaflex OM;
Healthcare:
- Substrate: Propionate, Copolyester;
- TPE: Versaflex OM.

**Based on: https://www.avient.com

Plastic materials for micro moulding

In micro injection sometimes material choice can lead to moulding process adaptation and sometimes the process can lead to different material choice. This correlation exists because injection gates should be sized correctly to avoid heat stress on polymer injecting to the cavity. Some of the most used materials for micro moulding are: