Plastic Injection Molding Service

Injection Molding Process


3Diligent's Plastic Injection Molding Service provides customers a cost-effective avenue for pursuing productions runs in the thousands or higher. 


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Process Overview

Traditional plastic injection molding starts with the desired pelletized polymers. These are filtered into a barrel cavity where a reciprocating screw rotates and warms the pellets into liquid, pushing them down the shaft to the injection entrance. The rotating rod quickly jams forward, inserting the liquid into the negative space of the workpiece. Air escapes the workpiece's cavity through microscopic holes, allowing the plastic filament to fully fill the cavity without exiting the workpiece.

This process can be completed through the use of aluminum or steel tools.  3Diligent offers both material options to suit a range of quantities.

Process at a Glance

Common Materials

ABS, Silicone, Polycarbonate (PC), Polyurethane (PU), Polyester (HDPE, and LDPE), Nylon, Polyproylene (PP)

Standard Tolerance


Usual Batch Size

Preferably 500+ (for unit cost savings)

Minimum Wall Thickness

.05 "

Plastic Injection Molding


  • Affordable - Large production runs generate increasingly lower CPPs
  • Strong - Filler options can increase density, strength, and other material properties
  • High tooling lifespan -  Up to 100,000 parts/tool
  • Consistent part quality



  • Hard tooling usually expensive - Steel tooling is usually required for larger production runs
  • Small batches expensive
  • Design limitations - Part design must have features to easily enable injection of parts