Frequently Asked Questions
Direct answers to the questions engineers and procurement teams ask most.
What is the difference between thermoplastics and thermoset plastics?
Thermoplastics soften when heated and harden when cooled, allowing them to be remelted and reformed. Thermoset plastics cure permanently through a chemical reaction and cannot be remelted. Most industrial plastic distribution involves thermoplastics — including acrylic, polycarbonate, HDPE, and nylon — because they can be machined, formed, and recycled.
Which plastic has the best chemical resistance?
PTFE (Teflon), PVDF, and polypropylene offer the broadest chemical resistance, withstanding most acids, bases, and solvents. PTFE is the gold standard for aggressive chemical environments, while PVDF balances chemical resistance with better mechanical strength.
What plastic is best for food-safe applications?
HDPE, PP, PETG, and FDA-compliant grades of acetal and nylon are commonly used in food-safe applications. NSF-certified and FDA-compliant grades are required for direct food contact. HDPE dominates cutting boards and food storage; PETG is widely used in clear food displays.
How do I know which plastic to use for outdoor applications?
For outdoor use, prioritize UV resistance and weatherability. Acrylic, HDPE, and PVC perform well in long-term outdoor exposure. Standard polycarbonate degrades under UV unless specifically UV-stabilized. For signage and displays, acrylic is the industry standard.
What is the most machinable plastic?
Acetal (Delrin) is widely considered the most machinable engineering plastic — it cuts cleanly, holds tight tolerances, and produces excellent surface finishes. Other highly machinable plastics include nylon, UHMW, and PEEK.
Are engineering plastics worth the extra cost over commodity plastics?
Yes — when the application demands it. Engineering plastics like acetal, nylon, polycarbonate, and UHMW deliver mechanical, thermal, and chemical performance that commodity plastics can't match. The higher material cost is often offset by reduced part failure and longer service life.
Can plastics replace metal in industrial applications?
Yes. Engineering plastics regularly replace metals in bearings, bushings, wear strips, gears, chemical tanks, and structural panels. Common conversions include bronze bushings to acetal or oil-filled nylon, steel wear strips to UHMW, and stainless piping to PVC, CPVC, or PVDF for chemical service.
What's the difference between cast acrylic and extruded acrylic?
Cast acrylic is produced in batch sheets between glass molds, resulting in higher molecular weight, better optical quality, and superior thermoforming and machining performance. Extruded acrylic is mass-produced in continuous sheets — it's lower cost and more dimensionally consistent, but doesn't machine or polish as cleanly as cast.
What plastic is strongest for impact resistance?
Polycarbonate is the strongest commonly available plastic for impact resistance — roughly 250 times more impact-resistant than glass and 30 times more than acrylic. UHMW and ABS also perform well in impact applications.
How do I request a quote or technical support from Laird Plastics?
Visit the contact page to reach a Laird specialist, or use the locations page to find your nearest branch. Each Laird branch has technical staff trained to help with material selection, fabrication, and sourcing for your specific application.
Does Laird Plastics offer fabrication and CNC machining?
Yes. Laird Plastics offers cut-to-size services and fabrication capabilities at most branches, including CNC machining, sawing, routing, and bending. See the custom services page for details.
Can I download technical data sheets from the Resource Library?
Yes. Material guides include links to manufacturer spec sheets. For specific data sheets not listed, contact your local Laird branch.
