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Essentials of Manufacturing

Information, coverage of important developments and expert commentary in manufacturing.

3D Scanners

A white paper to assist in the evaluation of 3D scanning hardware solutions.

Negotiate Your Salary

Learn the best principles to negotiate the salary you deserve!

CNC Machining Design Guide

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Plastics vs. Metals

From an engineering point of view, plastics differ from metallic materials in the following ways:
  - Plastics tend to have pronounced non-linear time-dependent stress/strain behavior. Below the yield point, metals typically have elastic behavior which is nearly linear.
- Instead of a single melting point, plastics typically have a
Glass Transition Temperature (TG). Metals typically have a clearly-defined melting point.
- Plastics in general exhibit pronounced creep. Metals undergo creep to a certain extent, but for most engineering configurations their creep is insignificant.
- Plastics tend to degrade or denature (due to heat) rather than corrode within a typical atmosphere. Of course, chemical degradation can occur when reactive chemicals are present. Plastics impregnated with organic fillers can be subject to bacterial infestation. Metals can corrode even in a benign atmosphere from reaction with oxygen and water, but are not affected by bacteria.
Plastics vs. Plastics

AMORPHOUS POLYMERS: e.g., PVC, Polystyrene, Acrylic, ABS, PPO, PC, Polyetherimide have
  - a wide melting range,
- low shrinkage after molding,
- better impact and lower chemical resistance than crystalline polymers,
- moderate heat resistance,
- dimensional stability,
- and superior cosmetics of outer surfaces.
CRYSTALLINE POLYMERS: e.g., PPS, PBT (Valox), Polypropylene (PP), have
- a sharply-defined melting point,
- high shrinkage after molding,
- low impact strength,
- high heat resistance,
- good fatigue endurance,
- good lubricity; wear resistance,
- good chemical resistance,
- and the ability to flow in thin-walled sections.
Glossary
Essentials of Manufacturing

Information, coverage of important developments and expert commentary in manufacturing.

3D Scanners

A white paper to assist in the evaluation of 3D scanning hardware solutions.

Negotiate Your Salary

Learn the best principles to negotiate the salary you deserve!

CNC Machining Design Guide

Optimize your designs, reduce machining time, and lower your costs.