40 Shore A High Tear 14 kN/m Platinum Cure Silicone Rubber with 1:1 Mix Ratio for Precast Concrete Panel and GRC Cladding Molds

Hanast HN-E640 is a 40 +/- 2 Shore A addition-cure (platinum-catalysed) liquid silicone rubber developed for large precast concrete panels, GRC and GFRC cladding, 3D wall panels and formwork liners. Components A and B are mixed 1:1 by weight and cure in 3-4 hours at room temperature or in 20 minutes or less at 80-100 °C. The 40 Shore A hardness holds panel geometry, chamfers and edge profiles under the weight of wet concrete, while 14 kN/m tear strength and 450 % elongation let the mold release deep texture and undercuts without tearing. Linear shrinkage stays at 0.1 % or less, so panel dimensions repeat across a full production run, and the cured rubber is certified to FDA, MSDS and RoHS.

• 40 Shore A Precast-Grade Hardness - firm enough to keep large panel flatness, chamfers and formwork detail under wet concrete load, yet flexible enough to strip deep texture without corner tearing.
• High Tear 14 kN/m and 450 Percent Elongation - balanced with 6.0 MPa tensile strength to survive repeated demolding of GRC cladding and 3D wall panels.
• Heat Resistant to 200 °C - stable through the exothermic reaction of cement and resin casts, hot-climate shipping and outdoor mold storage, with service from -50 °C to 200 °C.
• Linear Shrinkage 0.1 Percent or Less - panel dimensions and joint lines repeat batch after batch, so no re-tooling between production runs.
• Low Viscosity 6000 mPa·s and Good Fluidity - pours and degasses quickly, reproducing formwork grain, stone texture and fine relief without pinholes.
• 1:1 Mix Ratio by Weight - equal-part dosing keeps weighing error low for both manual batching and meter-mix dispensing.
• Dual Curing Mode with 30-40 min Pot Life - 3-4 h at 25 °C for large molds, or 20 min or less at 80-100 °C for fast production turnover.
• Catalyst Poisoning Controlled - zero cure inhibition on properly cleaned masters, with a documented incompatibility list covering organotin, sulfur, amine, polyurethane and organic acid residues.
• Formwork Liner and Master Pattern Ready - suitable for master patterns, formwork liners, vacuum forming tools and rapid prototyping masters.
• OEM and ODM Customization - hardness from Shore A 0 to 50, viscosity, colour, pot life and private label available for bulk and wholesale programs.
• Documentation and Supply Stability - TDS and MSDS supplied with every lot, 12 months shelf life unopened, classified as non-dangerous goods for transport.

Grade selection: HN-E605 to HN-E620 for thin panels and detailed decorative work; HN-E625 to HN-E635 for culture stone and general architectural casting; HN-E640 to HN-E650 for precast panels, GRC and GFRC cladding, concrete countertops and high-wear molds. All grades share the 1:1 mix ratio, 30-40 min pot life and 3-4 h room-temperature cure.

• Precast and architectural concrete - large precast concrete panels, precast wall units, boundary wall and fence panels, retaining wall blocks, kerb and edging, tactile paving, bench and planter molds.
• GRC and GFRC - GRC cladding, GFRC panels, decorative facade elements, balustrade, cornice, column capital, window surround and architectural restoration molds.
• 3D wall and facade texture - 3D wall panel, textured wall cladding, split-face tile, rock face, brick veneer, stone veneer, ledge stone and stacked stone molds.
• Cast stone and surface products - concrete countertop, basin and sink, cast stone, artificial stone, cultural stone, terrazzo tile, paving slab and floor tile molds.
• Masters and tooling - master pattern, formwork liner, vacuum forming mold, rapid prototyping tool and general RTV-2 tooling.
• Composite and industrial - yacht vacuum bagging, automotive and aerospace composite molds, printing pads and heat-exposed resin casting.
• Decorative and craft - gypsum panel, plaster cornice, relief plaque, life casting and craft molds.

1. Pre-mix: stir Components A and B separately until uniform before weighing.
2. Weighing: weigh A and B at exactly 1:1 by weight on a precision scale.
3. Mixing: mix for 2-3 minutes, scraping the container walls and bottom.
4. Degassing: vacuum degas to remove entrapped air and avoid pinholes on panel faces.
5. Pouring: pour within the 30-40 min pot life, brushing deep texture areas first to avoid trapped air.
6. Curing: cure 3-4 h at 25 °C or 20 min or less at 80-100 °C, then demold after full cure.

• Platinum silicone may fail to cure in contact with organotin compounds, sulfur and polysulfide compounds, amines, polyurethane, phosphorus compounds, organic acids and solder flux residues.
• Clean masters, tools and containers must be free of these contaminants; do not mix with condensation-cure (tin-cure) silicone residues.
• Test any colourant or filler in a small batch first, because some additives disrupt catalyst activity and prevent cure.
• Use nitrile gloves, goggles and good ventilation. Do not return unused mixed material to the original containers.

• Components A and B: 10 kg / 20 kg / 25 kg iron or plastic drums; kits 20 kg / 40 kg / 50 kg per set.
• Store in original sealed containers below 25 °C in a cool, dry, ventilated area away from acids, alkalis and direct sunlight; shelf life 12 months unopened.
• Classified as non-dangerous goods for transport; factory-direct OEM/ODM supply with TDS and MSDS documentation for every lot.

Shenzhen Hanast New Materials Co., Ltd. manufactures industrial silicone materials at a 40,000 square metre production base in Guangdong, China, supplying platinum cure liquid silicone rubber to precast concrete, GRC and cast stone producers, formwork and tooling shops and composite processors worldwide.