Plastic Application Guides — Best Material for Every Use Case

Selecting the right plastic for an application requires weighing load, speed, temperature, chemical exposure, regulatory requirements, and cost simultaneously. These 12 guides each answer one central question — "what is the best plastic for [application]?" — with a comparison table ranking candidate materials across the dimensions that matter most for that use case, followed by per-material tradeoff analysis and a clear decision framework.

Each guide links to all featured material hubs so you can drill into grades, sizes, and machining parameters once you've made the selection.

Wear & Motion Applications

Plastic Bushings & Bearings

Best materials: Delrin, Nylon, PEEK, PTFE/Teflon, PET/Ertalyte, UHMW, PAI/Torlon, Vespel

The bushing and bearing guide covers eight candidate materials across five dimensions: PV rating (pressure × velocity), coefficient of friction, temperature limit, machinability, and FDA compliance. Acetal (Delrin) is the default starting point for most dry-running bushings — tight tolerances, low moisture absorption, and FDA status. PTFE compounds dominate where chemical resistance or non-stick is required. PEEK and Torlon carry the highest temperature and load, used in aerospace and compressor applications. The guide includes a decision matrix by application type (oscillating, rotating, linear, high-load) and links to bushing-specific machining notes for each material.

Wear Strips & Guide Rails

Best materials: UHMW, HDPE, Delrin, Nylon, PTFE

Wear strips and guide rails live at the interface of moving product in conveyor and material-handling systems. UHMW is the most common choice — abrasion resistance six times that of nylon, self-lubricating, and food-contact compliant. HDPE (Marine grade / Starboard) serves outdoor and marine guide-rail applications where UV resistance matters. The guide covers attachment methods (T-slot, bolt-through, adhesive-backed UHMW tape), acceptable temperature ranges, and the cases where acetal or nylon is preferred for tighter-tolerance guide applications.

Plastic Gears

Best materials: Delrin, Nylon, PEEK, PEI/Ultem, PET, Phenolic

Plastic gears replace metal in applications requiring noise reduction, corrosion resistance, or self-lubrication. Acetal (Delrin homopolymer in particular) is the default — excellent fatigue resistance, dimensional stability, and machinability. Nylon absorbs moisture and swells, which matters when gear mesh clearance is tight. PEEK and Ultem handle elevated temperatures. Cotton and linen phenolics have served industrial gear applications for decades — oil-impregnable and dimensionally stable. The guide compares pitch-line velocity limits, fatigue strength, and oil or grease compatibility across all six candidates.

Fluid Handling & Chemical Containment

Manifolds & Fluid Handling

Best materials: Delrin, Polypropylene, PVDF/Kynar, PEEK, PVC

Manifold selection depends on the fluid: water and mild process fluids (acetal, polypropylene); acids, bases, and solvents (polypropylene or PVDF); aggressive halogens and oxidizers (PVDF or PEEK); high-temperature process streams (PEEK). The guide covers machined versus fabricated manifold construction, thread engagement limits, pressure ratings, and chemical compatibility tables for the top four candidates. PVDF is the preferred upgrade from polypropylene in semiconductor and chemical plant environments.

Chemical Tanks & Containment

Best materials: Polypropylene, PVC, HDPE, PVDF/Kynar

Fabricated tanks, secondary containment vessels, and process baths. Polypropylene is the workhorse — light, hot-gas weldable, resistant to most acids and bases at ambient to 180°F. PVC (Type 1) adds structural stiffness for larger vessels. HDPE is preferred where impact toughness and food-contact compliance are both required. PVDF serves the highest-chemical-duty applications (concentrated HCl, HF, chlorine, and bromine environments). The guide covers welding methods, liner options, and the wall-thickness sizing approach for structural tanks.

Optical & Safety

Machine Guards & Safety Shields

Best materials: Polycarbonate/Lexan, Acrylic/Plexiglass, PETG

The defining choice between polycarbonate and acrylic for machine guards: polycarbonate (250× the impact strength of glass) where safety glazing must stop projectiles; acrylic where optical clarity, UV stability, and scratch resistance matter more than impact rating. PETG occupies the middle — better thermoformability than polycarbonate, better impact than acrylic, but lower optical quality than either. The guide covers OSHA and ANSI Z87.1 references, polycarbonate abrasion-resistant coatings, and standard glazing thicknesses by guard type.

Regulated & Specialty Applications

Food-Zone & FDA-Compliant Plastics

Best materials: UHMW, Delrin, HDPE, PET/Ertalyte, PEEK, Nylon FDA, PVDF

UHMW and acetal POM-C (Acetron GP) are the workhorses of food-contact machinery. UHMW for wear strips, star wheels, and conveyor guides; acetal for precision wear parts, valve seats, and manifolds. HDPE for cutting surfaces and marine/food-storage boards. The guide covers 21 CFR 177.1520 (polyolefins), 21 CFR 177.2470 (nylon), NSF 51 (food equipment), and USDA approval categories. PET/Ertalyte and PEEK are appropriate for demanding wear applications in food processing; PVDF for high-temperature or chemical sanitization environments.

Electrical Insulation Materials

Best materials: G10 and FR4, Paper Phenolic, Glass Phenolic, G7, G9, PTFE, Ultem/PEI

The laminate family — G10 and FR4, cotton/linen/paper phenolics, G7, and G9 — forms the backbone of electrical insulation for switchgear, transformers, and motor components. PTFE sheet and rod serve high-frequency and high-temperature insulation where dielectric loss must be minimal. Ultem/PEI handles structural insulators requiring both high temperature and UL94 V-0 rating. The guide covers dielectric strength (V/mil), arc resistance (sec), CTI, and UL94 ratings across all seven candidates, plus guidance on NEMA grade selection.

Aerospace Interior Components

Best materials: PEEK, Ultem/PEI, PPS/Ryton, PAI/Torlon, G7

FAA-qualified plastics for aircraft interior and structural components. Ultem/PEI is the most common — it meets FAR 25.853 heat release and smoke requirements inherently (no additive required), autoclave-processable, and available in certified stock. PEEK and PPS serve higher-temperature and higher-load structural applications. PAI/Torlon for extreme-load bearing components. G7 (glass silicone laminate) for insulating brackets and spacers in high-temperature zones. The guide covers FAA-approved material documentation requirements and typical form factors.

Semiconductor & Wet-Bench Plastics

Best materials: PEEK, PVDF, PTFE, PFA, Polypropylene

Semiconductor fab environments combine ultra-pure chemicals (HF, H₂SO₄, HCl, H₂O₂, SC-1, SC-2), elevated temperatures, and strict particle and contamination requirements. PVDF is the standard structural material for wet benches and chemical delivery lines — excellent chemical resistance, weldable, and cleanroom-compatible. PEEK handles higher temperatures and mechanical loads. PTFE for seals, gaskets, and chemical-resistant liners where mechanical load is low. Polypropylene for lower-duty ductwork and secondary containment where cost matters. The guide covers particle generation, outgassing, and purity considerations.

Marine & Outdoor Plastics

Best materials: Marine HDPE/Starboard, UHMW, Polycarbonate-UV, PVC

Outdoor and marine applications require UV stability, moisture resistance, and in most cases some combination of impact toughness and chemical resistance. Marine HDPE (Starboard) is the benchmark — UV-stabilized, FDA compliant, easy to fabricate, and available in a wide color range. UHMW serves dock fender applications and wear-intensive boat components. UV-stabilized polycarbonate for windows, hatches, and guards. PVC for structural and chemical-ducting applications below decks.

Medical & Sterilization Plastics

Best materials: PEEK, Ultem/PEI, PSU/PPSU, PVDF, Acetal Medical

Medical-grade plastic selection depends on sterilization method. Steam autoclave: Polysulfone (PSU) and PPSU (Radel) are the most autoclave-durable thermoplastics — PPSU survives 1,000+ cycles at 134°C. Ultem/PEI handles 2,000+ cycles but is amber-colored. PEEK for implantable and structural applications with USP Class VI compliance. EtO and gamma radiation: PEEK and medical-grade acetal (POM-C) are radiation-stable. The guide covers USP Class VI, ISO 10993 biocompatibility, and typical sterilization cycle limits for each candidate material.

How to Use These Guides

Each application page is structured to get you to a material selection in one pass:

1. Comparison table — 4–8 candidates ranked across the application's key dimensions
2. Per-material section — tradeoffs, best fits, grades to specify, and forms available
3. Decision framework — flowchart or matrix to confirm the choice
4. Sizes & forms — standard stocked dimensions for the top candidates
5. Links to material hubs — for grades, machining specs, and compliance data

If your application isn't listed here, use the comparisons index to compare the two or three materials on your shortlist directly.