Isophthalic SMC Resin
SPR 301 SMCIsophthalic sheet moulding compound resin for hot-mould processingSPR 301 · Isophthalic Polyester Resins
Isophthalic resin for hot-mould sheet-moulding-compound processing.
Review the official product data sheet for specifications and application information.
Price
Price on Request
Industrial resin pricing varies based on:
- Order Quantity
- Resin Grade
- Current Raw Material Rates
Product details
| Catalogue Code | SPR 301 SMC (combined SMC / DMC entry) |
|---|---|
| Resin Chemistry | Isophthalic unsaturated polyester |
| Compound Type | Sheet moulding compound (SMC) |
| Supply Condition | Non-accelerated |
| Reference Cure System | MEKP 1.5% + Cobalt Octoate 0.4% — added separately during use |
Typical specification
| Appearance | Clear, pale-yellow to light-amber liquid |
|---|---|
| Viscosity | 800–1,400 cPs at 25 °C |
| Gel Time | 12–18 minutes at 25 °C |
| Specific Gravity | 1.10–1.14 |
| Styrene Content | 31–36% by weight |
Typical values from the Samrat Poly Resins product catalogue, 2026 edition. They are not guaranteed specifications or finished-component properties; confirm the current values for your order and trial the grade on your own process.
SPR 301 SMC is the isophthalic sheet moulding compound resin of the SPR 301 family, for hot-mould SMC processing, listed for sheet moulding compound production and hot-mould and compression-moulding processes. The catalogue describes it as having superior properties compared with the SPR 201 SMC grade. It is supplied non-accelerated, with MEKP and cobalt octoate added separately during use.
The catalogue prints one combined entry for the isophthalic SMC and DMC resins: they are separate manufactured products that share one typical specification. The dough moulding compound product is Isophthalic DMC Resin; the orthophthalic SMC/DMC grade is DMC/SMC Resin.
Key features
- Isophthalic resin for sheet moulding compound (SPR 301 SMC)
- For hot-mould SMC processing
- Superior properties compared with the SPR 201 SMC grade, per the catalogue
- Typical viscosity 800–1,400 cPs; gel time 12–18 minutes at 25 °C
Applications
- Sheet moulding compound production
- Hot-mould and compression-moulding processes
Product role
Sheet moulding compound is resin, filler and chopped reinforcement made into a sheet, matured, then compression-moulded in a heated tool. The choice of family is decided by the chemistry the compound needs: the catalogue's selection guide offers SMC resins in the orthophthalic (SPR 201), isophthalic (SPR 301) and terephthalic (SPR 401) families.
SPR 301 SMC and SPR 301 DMC share one typical specification but are separate products for different compound forms. Compound formulation, maturation and moulding conditions are the compounder's; share them when enquiring.
Supply and cure
- Supply condition
- Non-accelerated
- Reference cure system
- MEKP 1.5% + Cobalt Octoate 0.4% — added separately during use
Processes and where this grade fits
SPR 301 SMC is a compound resin. It goes into the SMC paste with fillers and other compound ingredients, and the finished sheet is compression-moulded in a heated tool.
| Process or use | Role of this grade | What to confirm |
|---|---|---|
| SMC paste and sheet production | Listed role | Filler and thickener system, paste viscosity and maturation |
| Hot-mould compression moulding of SMC | Listed role | Tool temperature, press cycle and the compound’s initiator system |
| DMC / BMC compounding | Consider SPR 301 DMC | The separate isophthalic DMC product |
| Open-mould hand lay-up | Not this grade’s role | The laminating grades |
Process-selection considerations
- Choose the SMC family by the chemistry the compound needs: orthophthalic (SPR 201), isophthalic (SPR 301) or terephthalic (SPR 401).
- Share the compound formulation principles — filler, thickener, glass content — and the moulded part. The compound is the compounder’s design.
- The typical gel time, 12–18 minutes at 25 °C, is an ambient quality-control figure; hot-mould cure is set by the compound’s initiator and tool temperature.
- Viscosity is 800–1,400 cPs at 25 °C typical; confirm paste behaviour with your filler loading.
- State the moulded part’s requirement — electrical, appearance, water exposure — so the family choice can be discussed.
Limitations and trial requirements
- The catalogue publishes a combined SMC / DMC entry for the isophthalic pair; SPR 301 SMC and SPR 301 DMC share one typical specification but are separate products.
- No moulded-compound mechanical, electrical or heat data are published; those belong to the finished compound.
- The reference cure MEKP 1.5% with cobalt octoate 0.4% is the ambient QC condition, not a hot-moulding recipe.
- Trial the grade on the real part, mould and shop conditions before production. The catalogue values are typical liquid-resin properties, not guaranteed limits or finished-part performance.
Before you select this grade
- The values on this page are typical. Final selection should be confirmed against your own process, a trial result and the current technical documentation for the grade.
- The Technical Data Sheet linked on this page carries these same typical values. No Safety Data Sheet is published on this site for this grade; request current safety information before use.
- Never mix a concentrated peroxide initiator directly with a cobalt accelerator. Add each to the resin separately, according to the confirmed process.
- Store resin, initiators and accelerators separately, in original sealed containers, cool, shaded and away from heat and ignition sources. Use suitable personal protective equipment and adequate ventilation.
