Choose a grade for the job, not an acronym

Injection Molding Material Selection Guide

Material selection should connect strength, stiffness, impact, temperature, chemicals, appearance, shrinkage, processing and cost to the actual product environment.

Exact grade confirmedGeometry reviewed with resinSupplier evidence scopedTrial material identified

Qualitative Material Comparison

Properties vary by grade, fillers, color and conditioning. This table is a screening guide, not a substitute for a supplier datasheet or application test.

Material family	Typical reasons to consider it	Design and validation cautions
PP	Low density, chemical resistance, living-hinge potential and cost-sensitive products	Shrinkage, stiffness, low-temperature impact and surface/paint requirements
ABS	Appearance, dimensional balance, toughness and common enclosure or consumer uses	UV, heat, chemical exposure and flame requirement by grade
PC / PC blends	Impact, heat and transparent or structural applications depending on grade	Drying, stress, chemical compatibility, wall and processing window
PA6 / PA66	Strength, wear and industrial components, with fillers where appropriate	Moisture conditioning, dimensional change, warp, abrasion and slender features
POM	Low friction, wear and dimensional applications such as moving components	Processing control, shrinkage, bonding/painting limits and exact chemical exposure
PMMA	Optical appearance and weatherable clear or colored parts	Brittleness, stress, drying, polish, gate and scratch protection

What Real Project Records Show

Two PP C-clip material trial variants — **PP choice by sample**Two PP variants were compared for fit and appearance before the buyer selected the production option.

PP and ABS holder samples compared side by side — **PP versus ABS**The organizer project used sample rounds to review appearance, flatness and the selected product direction.

Dense PA6 bristle-block features — **PA6 geometry risk**The material and dense slender geometry were reviewed together for release, venting and deformation risk.

A Better Material Brief

Use environment

Temperature range, moisture, UV, chemicals, cleaning and contact requirements.

Mechanical behavior

Load, stiffness, impact, flexing, wear, creep and failure mode.

Appearance and process

Color, gloss, texture, transparency, printing, painting and weld-line limits.

Commercial evidence

Expected volume, approved grade, supplier data, testing and substitution rules.

Grade boundary: “ABS,” “PP” or “PA6” alone is not a complete specification. Fillers, flame packages, UV stabilization and supplier grade can materially change performance and processing.

Select Material Before Freezing the Mold

Send the drawing and explain the product environment, performance priorities, appearance and target cost.

Get Material Selection Support