Reference
Materials guide
Most industrial fabrication questions come down to four thermoplastics: polypropylene for general chemical duty at temperature, PVC for ambient duties and clear sections, polyethylene for toughness and food contact, and PVDF for aggressive chemistry running hot. The right answer depends on chemistry, temperature and load together — tell us the duty and we will confirm the material.
| Polypropylene (PP) | Working range roughly 0 to 90 °C. Excellent resistance to most acids and alkalis. Welds well (butt-fusion and extrusion). The default for process tanks, scrubbers and benches. |
|---|---|
| PVC-U | Roughly 0 to 60 °C. Very good chemical resistance at ambient temperature; solvent- and hot-air-weldable; clear grades available. Ducting, enclosures and ambient tanks. |
| CPVC | Extends PVC-type duty to roughly 80 °C where hot corrosive liquors rule PVC-U out. |
| HDPE | Roughly −40 to 60 °C. Outstanding toughness and impact strength; food-contact grades available. Hoppers, chutes, bulk storage and transport tanks. |
| PVDF | Roughly −20 to 140 °C. The premium option: resists many duties that attack PP, including hot aggressive chemistry and high-purity work. Specified where nothing else lasts. |
Polypropylene (PP)
The workhorse of industrial fabrication. Excellent resistance to acids and alkalis, good rigidity, and comfortable at working temperatures most process duties demand. The natural beige sheet seen throughout our gallery is PP — most of the tanks, scrubbers and benches we build are made from it.
PVC (uPVC / CPVC)
Rigid, economical and easy to fabricate, with very good chemical resistance at ambient temperatures. Widely used for ducting, enclosures and ambient tanks. Clear PVC provides vision panels and sight sections. CPVC extends the working temperature where needed.
Polyethylene (HDPE)
Extremely tough and impact-resistant with outstanding low-temperature performance, and available in food-contact grades — the usual choice for hoppers, chutes and handling equipment as well as bulk storage.
PVDF
The premium option: exceptional chemical resistance including many duties that attack PP, and a working temperature range well beyond the commodity materials. Specified where aggressive chemistry runs hot — high-purity and semiconductor-adjacent work included.
GRP grating & steelwork
Not everything in a plastic installation is plastic. We fit GRP grating walkways and access platforms over bunds and lined floors, and supply supporting steelwork for scrubbers, stacks and ducting where the structure demands it.
What actually attacks polypropylene
PP handles the great majority of industrial acids and alkalis, which is why it is the default for process tanks and scrubbers. The exceptions are worth knowing, because they are the duties where specifying PP by habit causes an expensive failure. As a general guide, PP is attacked by strongly oxidising acids — concentrated nitric and concentrated sulphuric in particular — and is swelled or softened by chlorinated and aromatic solvents such as trichloroethylene, toluene and xylene. Prolonged UV exposure embrittles unstabilised grades, so outdoor work should use a UV-stabilised material.
Temperature magnifies all of it. A concentration that a polymer shrugs off at 20 °C may attack it at 60 °C, which is why chemical resistance tables are always read together with the working temperature rather than on their own.
HDPE or polypropylene?
They are close cousins and the choice usually comes down to temperature against toughness. PP holds up better as things get hot and is stiffer, which suits heated process tanks and self-supporting fabrications. HDPE is tougher, particularly in the cold, and has a slipperier surface — which is why hoppers, chutes and handling equipment tend to be polyethylene while heated process tanks tend to be polypropylene. Both weld well, and both are available in food-contact grades.
A note on limits
Working limits depend on chemical concentration, temperature and mechanical load acting together, so treat any single figure with suspicion — including ours. We confirm material selection against the actual duty before fabricating.