High Tear Strength 40 Shore A Platinum Cure Silicone Rubber with 1:1 Mix Ratio for GFRC and Concrete Molds

High Tear Strength 40 Shore A Platinum Cure Silicone Rubber 1:1 for GFRC & Concrete Countertop Molds

This HN-E640 is a two-component 1:1 addition-cure (platinum) liquid silicone rubber engineered for high tear strength and ultra-low shrinkage. With 40 ± 2 Shore A hardness, 6.0 MPa tensile strength, 14 kN/m tear strength and linear shrinkage of ≤ 0.1%, it delivers durable, dimensionally accurate moulds for GFRC, concrete countertops, cast stone and other demanding architectural and industrial applications.

Key Features

• High tear strength (14 kN/m) & 6.0 MPa tensile strength — moulds resist tearing at sharp edges and under repeated demoulding
• Ultra-low shrinkage ≤ 0.1% with no low-molecule release → high precision and faithful surface reproduction
• 1:1 mix ratio (A : B by weight); 30–40 min pot life; low viscosity for easy mixing, degassing and pouring
• Dual cure convenience — cures at room temperature (3–4 h) or heat-accelerated (80–100 °C in ≤ 20 min)
• Food grade & safe — FDA, MSDS, RoHS and REACH compliant; non-toxic, odourless, non-corrosive
• Wide temperature range −50 °C to 200 °C; waterproof, ozone and aging resistant
• Customisable hardness (0–60 Shore A), viscosity and working time; OEM / ODM and private label service available

Technical Data (HN-E640)

Recommended Applications

• GFRC & precast concrete moulds — glass-fibre reinforced concrete panels, facades and cladding
• Concrete countertop & sink moulds — cast concrete worktops, basins and vanities
• Cast stone, veneer stone & cultural stone moulds — faux stone, terrazzo and imitation marble products
• Architectural concrete & GRC moulds — cornices, columns, balustrades and decorative elements
• Landscape & garden concrete moulds — pavers, stepping stones, planters and garden ornaments
• Statue, sculpture & craft moulds — cement/stone/resin sculptures and figurines
• Resin, epoxy & vacuum casting moulds — prototypes and decorative resin parts
• General high-wear RTV-2 moulds requiring high tear strength and long service life

Mixing & Application Instructions

1. Pre-mix: stir Components A and B thoroughly before use.
2. Weighing: accurately weigh A and B in a 1:1 ratio by weight with a precision scale.
3. Mixing: mix for 2–3 minutes until uniform; scrape the container walls and bottom.
4. Degassing: for bubble-free moulds, degas under vacuum to remove entrapped air.
5. Pouring: pour into the clean, dry mould frame within the 30–40 min pot life; ensure full coverage.
6. Curing: cure at room temperature for 3–4 h, or heat at 80–100 °C for ≤ 20 min; demould after full cure.

Catalyst poisoning warning: this addition-cure (platinum) silicone may fail to cure in contact with organotin, sulfur/polysulfide, amine, polyurethane, phosphorus compounds, organic acids or solder flux residues. Keep all substrates, tools and containers clean and free of these contaminants, and do not mix with tin-cure (condensation) silicone residues.

Wholesale Supply & Custom Manufacturing

As a China-based silicone manufacturer and factory-direct supplier, we support bulk wholesale and export volume orders, plus custom OEM / ODM and private-label projects. Hardness, viscosity, colour, pot life and curing time can all be tailored to your application. Free samples are available for evaluation, with fast sample turnaround and stable bulk lead times.

• MOQ: 20 kg
• Supply Ability: 100 Tons per Month
• Delivery: 3–5 days for samples, 10–15 days for bulk production
• Payment: T/T, L/C, PayPal, Western Union
• Packaging: A and B in 10 / 20 / 25 kg drums; 20 / 40 / 50 kg per kit set

About This Supplier

Shenzhen Hanast New Materials Co., Ltd. is a professional manufacturer of liquid silicone rubber specialising in addition-cure (platinum) and condensation-cure silicone for mould making. Our HN-E6XX platinum series covers 0–60 Shore A and is certified to FDA, MSDS, RoHS and REACH, serving customers in construction, architecture, arts & crafts, food-contact and precision casting industries worldwide.

FAQ

1. Q: What is the mix ratio and cure schedule of this high tear strength silicone rubber?
A: Mix Components A and B in a 1:1 ratio by weight. Pot life is 30–40 minutes at 25 °C; it cures at room temperature in 3–4 hours, or heat-accelerated at 80–100 °C in 20 minutes or less.

2. Q: Is this 40 Shore A silicone suitable for GFRC and concrete countertop moulds?
A: Yes. With 6.0 MPa tensile strength, 14 kN/m tear strength and ≤ 0.1% shrinkage, HN-E640 resists tearing and keeps dimensions stable, making it ideal for GFRC panels, concrete countertops, cast stone and other high-wear moulds.

3. Q: Why choose a high tear strength grade rather than a standard one?
A: High tear strength reduces edge tearing and mould failure during repeated demoulding, extending mould life and reducing re-moulding costs — especially important for sharp-edged concrete and stone designs.

4. Q: How can I avoid platinum catalyst poisoning?
A: Keep substrates, tools and containers free of organotin, sulfur/polysulfide, amines, polyurethane, phosphorus compounds, organic acids and solder flux residues, and never mix with tin-cure silicone residues.

5. Q: What are the MOQ, lead time, packaging and certifications?
A: MOQ is 20 kg; samples ship in 3–5 days and bulk orders in 10–15 days. A and B are packed in 10/20/25 kg drums or 20/40/50 kg kits. Certified FDA, MSDS, RoHS and REACH. Free samples are available.