What pultruded profiles are used for
Pultruded FRP profiles — angles, channels, I-beams, box sections, rods, tubes and grating bars — are used for cable trays, handrails, walkways and gratings, cooling-tower structures, electrical and telecom structures, ladders and building elements, where corrosion resistance, electrical insulation or low weight matter.
What a pultrusion resin must do
The resin must stay stable in an open bath or injection box for a long shift, wet roving and mat quickly as they pass, and then cure fully in the seconds the profile spends in the hot zone of the die. That is a heat-triggered job. Room-temperature cure systems would begin to gel in the bath.
So the key figures for a pultrusion resin are its hot-die behaviour and its cure system, not its room-temperature working time.
Line questions
Share with the enquiry
- Profile cross-section, wall thickness and reinforcement layout.
- Line speed, die length and heating zones.
- Filler type and loading, and any pigment.
- Bath or injection impregnation, and bath volume.
- Service of the profile: corrosive, electrical, outdoor.
Where SPR 401 PT fits
SPR 401 PT is the terephthalic pultrusion grade in the 2026 catalogue. It is specified by a hot-die gel time of 40–80 seconds at 130–140 °C and cured in production with a heat-activated peroxide blend at a total dosage of 1.0–2.0%, added separately during processing. Production MEKP and production cobalt are both 0%.
The catalogue describes the grade as high-strength; no numerical profile properties are published. For profiles in corrosive service, the vinyl ester pultrusion route is the alternative.
Published typical values
| Property | Pultrusion Grade Resin (SPR 401 PT) |
|---|---|
| Chemistry | Terephthalic unsaturated polyester |
| Appearance | Clear, light-straw to amber liquid |
| Viscosity (typical) | 300–600 cPs at 25 °C |
| Gel time / pot life (typical) | 40–80 seconds at 130–140 °C (Hot-Die); 15–25 minutes at 25 °C (Ambient QC) |
| Specific gravity / density (typical) | 1.10–1.14 |
| Styrene content (typical) | 36–42% by weight |
| Reference cure | Heat-activated peroxide blend, total dosage 1.0–2.0% — added separately during processing |
| Source of values | 2026 catalogue; grade TDS |
Typical values, reproduced from each product’s own published data. They describe the liquid resin at its reference condition, not a finished part, and are not guaranteed limits.
Line trials
Die temperature profile, pull speed, filler loading and the peroxide blend interact, and they are specific to each line and profile. Plan trials on the production line: confirm wet-out, cure at the die exit, surface quality, and the profile’s dimensions and properties against its specification before commercial runs.