Polypropylene Sheet, Copolymer, Textured

Textured polypropylene copolymer sheet in black, sold by the full sheet.

This is the impact-cladding grade: polypropylene copolymer, textured, in black. The copolymer base is what makes it suitable - notched Izod runs to no break where homopolymer sits at 0.9 ft-lb/in, with roughly five times the elongation, and it stays tough at temperatures where homopolymer turns brittle. These sheets are commonly blended with a small percentage of polyethylene for further impact resistance and flexibility.

The texture earns its place rather than being decoration. It adds grip, improves wear resistance, hides scuffing and cuts glare - all the things a smooth sheet does badly on a surface that gets knocked. Ask us to confirm the pattern on the sheet we would ship before you order to a cosmetic spec.

It is sold for van, trailer and commercial-vehicle linings, impact protective cladding, workbench and workstation surfaces, agricultural cladding and feeder systems, die-cutting pads, and storage containers.

Chemical resistance is the reason to buy it. Acids, bases, alcohols, detergents, lower ketones, aldehydes and water-soluble salt solutions are, in the resin producer's words, usually not regarded as antagonistic. Dilute to mid-concentration sulphuric is a documented working envelope - tanks are built in homopolymer for 10 to 40 percent sulphuric from 41 to 158F. Concentration is what decides it, not just the chemical: polypropylene handles 30 percent sulphuric but not concentrated, 10 percent nitric but not 40 percent. Oxidizing acids are where it fails.

What it is not for: chlorinated solvents, aliphatic and aromatic hydrocarbons, ketones and esters are unacceptable; hot water and steam are limited service; and bleach and hypochlorites cause a failure that looks like stress cracking but is actually oxidative attack. Polypropylene is largely outside the stress-crack failure mode that troubles polyethylene, which is worth knowing - but it is not immune to oxidizers, and at 120F the not-recommended list grows substantially.

On temperature, read the load with the number. Continuous service runs 180 to 212F depending on grade. Heat deflection is 210F at 66 psi; at 264 psi the published figures disagree badly across mills, so treat anything above about 190F under real load as something to test. And the number that catches people out: homopolymer has lost about 92 percent of its room-temperature tensile strength by 150F. Polypropylene melts around 320F, but that is not a service temperature and nothing here should be designed near it.

Outdoor use, and this is the one that comes back as a warranty claim. Standard polypropylene is not UV stabilized. Continuous sunlight is rated limited, and exposure causes progressive loss of tensile strength and elongation - polypropylene's peak photochemical sensitivity sits at 370 nm, inside the UV-A band, which makes it the more vulnerable of the two common polyolefins. For outdoor or UV-exposed service, specify a UV-stabilized polypropylene grade or UV-stabilized HDPE. Color alone is not UV protection, black included: the UV-stabilized polypropylene grades actually sold are blue, beige, gray and white, and no mill we can find publishes a UV service claim for black polypropylene.

Joining is by welding, and every mill leads with it. Heated-tool butt welding, hot gas and extrusion welding are all rated excellent, with extrusion welding running 410 to 464F material temperature and 410 to 572F gas under DVS 2207-4. A good weld approaches base-material yield. Use matching polypropylene weld rod - the wrong rod is the one weld defect a supplier can actually prevent, so order it with the sheet.

It cannot be solvent cemented. Polypropylene's surface energy is about 29 mN/m and most adhesives need over 36 to wet it, which is a wettability problem rather than a strength one. Structural acrylic polyolefin adhesives bond it untreated with no surface preparation and are the practical answer; cyanoacrylate works with a polyolefin primer. Flame and plasma treatment work but are easy to overdo - over-treating leaves the bond no better than untreated.

It machines easily - about a 3 on a 1-to-10 scale - with sharp tools, high rake angles and good chip clearance. It is soft and it moves, so expect more spring-back than acetal or nylon and allow for the thermal expansion, which published sources put anywhere between 4.6 and 10.6 millionths per degree F. Hold thin parts gently; clamping marks stay.

Food contact: available in grades compliant with FDA 21 CFR 177.1520, olefin polymers. Compliance attaches to the specific resin and color formulation, not to polypropylene generically - and the regulation bounds density at 0.880 to 0.913, which some published sheet densities sit outside. Request the manufacturer's declaration of compliance for the product supplied if you need it on file.