Chopped Strand Mats (CSM)
300 · 450 · 600 GSM | Emulsion & Powder Binder | Hand Lay-Up · Compression Molding
Chopped Strand Mats
Chopped Strand Mat (CSM) is produced by randomly depositing chopped E-glass strands (typically 50 mm) onto a moving conveyor and bonding them with either an emulsion or a powder resin binder. The result is an isotropic sheet reinforcement with random in-plane fiber orientation that provides equal strength in all directions. CSM is the most widely used glass-fibre reinforcement in the Indian FRP industry, valued for its low cost, ease of handling, fast wet-out with polyester resin and suitability for complex shapes in hand lay-up and spray-up processes.
Key Features
- Isotropic reinforcement — equal strength in all in-plane directions
- Fast polyester wet-out — binder dissolves quickly on resin contact
- Consistent areal weight (±10%) across full roll width
- Available in emulsion grade (standard hand lay-up) and powder grade (pultrusion/heated press)
- Excellent drape over curved and complex mold surfaces
- Produced with silane sizing compatible with unsaturated polyester resin
- Standard roll width 1000–1270 mm; 30–50 kg rolls
Product Overview
Chopped Strand Mat remains the workhorse reinforcement of the FRP industry for good reason: it is inexpensive, easy to handle, accommodates complex geometries without cutting, and produces acceptable glass/resin ratios with modest skill requirements. A single sheet of 450 GSM CSM, when properly impregnated with resin and cured, typically produces a laminate with 25–30% glass content by weight — sufficient for general-purpose structural applications.
The choice between emulsion-bound and powder-bound grades affects processing: emulsion-bound CSM dissolves in styrene-based polyester resins, releasing the fibers uniformly and giving excellent wet-out at room temperature. Powder-bound CSM uses a thermoplastic binder that activates under heat and pressure, making it ideal for compression molding, sheet molding compound (SMC) processes and elevated-temperature pultrusion operations where solvent-based dissolution is not appropriate.
We stock 300 GSM (light lay-up), 450 GSM (standard), and 600 GSM (heavy structural) in both emulsion and powder binder variants. All grades are packed in moisture-proof polyethylene rolls to maintain binder integrity during storage.
Note: We supply multiple grades and qualities to match your application — share your requirements and we will recommend the right product.