Filament Winding Grade Resin data sheet (PDF)Ask for a quote
Filament winding in brief
Filament winding builds a cylindrical or rounded part by pulling continuous glass roving through a resin bath and winding it onto a rotating mandrel. The winding angle and number of passes set the wall’s strength in the hoop and axial directions. Once the wall is complete and cured, the mandrel is removed.
Pipes, tanks and pressure-bearing vessels are made this way because continuous fibres placed in the direction of load give a strong, efficient wall.
What a winding resin has to do
Roving spends a short time in the resin bath, so the resin must wet it quickly and completely. That calls for a low viscosity and no thixotropy. The resin must then stay workable while the whole part is wound and consolidated, which can take a long time on a large tank.
SPR 301 FW, in Samrat Poly Resins’ isophthalic SPR 301 family, is catalogued for exactly that: non-thixotropic, typical viscosity 200–400 cPs at 25 °C and a long gel-time window of 20–60+ minutes at 25 °C.
Why isophthalic for wound products
Wound pipes and tanks generally carry water or process liquids, and the catalogue positions its isophthalic family for laminates in water and chemical service. The medium, temperature and pressure still decide suitability, and the catalogue publishes no cured mechanical or chemical data for SPR 301 FW.
Many wound products also have an inner liner — a resin-rich corrosion barrier — that faces the medium. The liner resin and the structural winding resin do not have to be the same, and aggressive services may call for vinyl ester in one or both.
Cure and bath life
The catalogue’s reference cure is MEKP 1.5% with cobalt octoate approximately 0.4%, each added to the resin separately. On a real line the useful bath life also depends on bath temperature, bath volume and how quickly the resin is consumed and replenished, so the working window should be established on the line.