One of the key questions we ask customers is “what is the application?” This question isn’t asked in order to steal your idea but to ensure that the plastic you’re looking for is optimal, or even workable in that application! Industrial plastics are excellent mechanical materials overall; however, like anything they do have both strengths and limitations. This article will review the core line of industrial plastics we carry, give the strengths, the limitations, and common applications/places where the plastic is wrongfully specified.
UHMW Polyethylene
Strengths: Well balanced properties, economical, and readily available.
Weaknesses: Poor dimensional stability
Specification errors: high load bushings, unrealistic tolerances, not compensating for thermal expansion.
Nylon
Strengths: High load bearing strength, diverse formulations, suits a wide variety of applications.
Weaknesses: Absorbs water, poor impact and cold-temperature properties.
Specification errors: Impact parts, marine applications (without accounting for swell), using nylon bushings in high RPM applications.
Acetal
Strengths: High load bearing strength, replaces nylon in “wet” applications, machines to excellent tolerances.
Weaknesses: Impact, temperature (especially steam) resistance.
Specification errors: Using black (copolymer) acetal in food processing applications. It is not food-safe, unlike the blue and white.
Tuffkast
Strengths: Excellent impact, cold weather, bearing, and moisture-resistance properties.
Weaknesses: High cost, elevated temperatures.
Specification errors: Typically in applications that generate high internal heat, such as a hammer cushion for pile drivers. Tuffkast is also softer than nylon, which can lead to increased wear in certain applications.
Polycarbonate
Strengths: Extremely high impact strength.
Weaknesses: Very prone to scratching.
Specification errors: As glass/sight part without upgrading to a anti-scratch version of the plastic.
Acrylic
Strengths: Scratch resistant, economical, stronger than glass, fairly resistant to weathering.
Weaknesses: Difficult to fabricate, prone to cracking.
Specification errors: Using in “Do-it-yourself” projects without proper knowledge of fabrication procedures.
Polyurethane
Strengths: Impact resistance, rebound, good bearing strength (bearing grades only).
Weaknesses: Water saturation degrades the plastic (especially softer grades), vibration degrades the plastic’s composition.
Specification errors: Vibration or moisture applications.
Rubber
Strengths: Lots of choice between properties, cost, wide application variety.
Weaknesses: Polyurethane is superior in many applications, grades must be selected carefully.
Specification errors: Choosing an ineffective grade of rubber for an application to save on cost, assuming the lower grade will still function.
For more information about which plastic is best for your application, please contact us.