40 Shore A Platinum Cure Silicone Rubber with Dual Curing Mode and 1:1 Mix Ratio for Cast Stone Basin Sink Molds

Hanast HN-E640 is a 40 +/- 2 Shore A food grade addition-cure (platinum-catalysed) liquid silicone rubber for cast stone, concrete countertops, basins, sinks and architectural cladding molds where a hard, dimensionally stable tool is needed. 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, so the same material serves low-volume workshops and heat-accelerated production lines. At 40 Shore A the rubber holds countertop edges, sink radii and cast stone profiles under wet concrete load, while 14 kN/m tear strength and 450 % elongation allow stripping without chipping the mold edge. Linear shrinkage is 0.1 % or less, and the cured rubber is certified to FDA, MSDS and RoHS, non-toxic, odourless and non-corrosive.

• 40 Shore A Cast Stone Hardness - firm enough to hold countertop edges, sink radii, chamfers and cast stone profiles under wet concrete load, with 14 kN/m tear strength and 450 % elongation for clean stripping.
• Food Grade and Non-Toxic - FDA, MSDS and RoHS certified, odourless and non-corrosive, so the same grade is approved for kitchen and bath countertop work and food contact molds.
• Dual Curing Mode - 3-4 h at 25 °C for large single molds, or 20 min or less at 80-100 °C for heat-accelerated production lines and fast turnaround.
• Linear Shrinkage 0.1 Percent or Less - countertop dimensions, sink radii and cladding joint lines repeat batch after batch, with no re-tooling between runs.
• 1:1 Mix Ratio by Weight - equal-part dosing keeps weighing error low for manual batching and meter-mix dispensing.
• Low Viscosity 6000 mPa·s and Good Fluidity - pours and degasses quickly, reproducing stone grain, formwork texture and fine edge detail without pinholes.
• Heat Resistant to 200 °C - stable through the exothermic reaction of cement and resin casts, hot-climate shipping and outdoor mold storage.
• Catalyst Poisoning Controlled - zero cure inhibition on properly cleaned masters, with a documented incompatibility list covering organotin, sulfur, amine, polyurethane and organic acid residues.
• Master Pattern and Formwork Liner 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-E600 to HN-E615 for ultra-soft gel and fine art casting; HN-E620 to HN-E630 for artificial culture stone, 3D wall panel and detailed decorative molds; HN-E635 to HN-E650 for thick pavers, precast panels and high-wear production molds. All grades share the 1:1 mix ratio, 30-40 min pot life and 3-4 h room-temperature cure.

• Artificial and culture stone - artificial culture stone, culture stone veneer, faux stone panel, rock face, mushroom stone, split-face tile and stone veneer molds.
• 3D wall panel and cladding - 3D wall panel, textured wall cladding, decorative wall brick, interior feature wall, wall cap and cornice molds.
• Brick and masonry texture - brick veneer, faux brick panel, ledge stone, stacked stone, cobblestone and mosaic tile molds.
• Gypsum and plaster - gypsum wall panel, plaster cornice, decorative relief, column capital, ceiling rose and balustrade molds.
• Concrete surface products - concrete countertop, basin and sink, cast stone, terrazzo tile, paving slab, floor tile and stepping stone molds.
• Casting and craft - resin and epoxy casting, jewellery molds, figurine and sculpture molds, candle and soap molds, wax molds and life casting.
• Food contact molds - chocolate, candy, fondant and baking molds.
• Masters and tooling - master pattern, formwork liner, printing pad, vacuum forming mold and rapid prototyping tools.

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 in stone pores and grout lines.
5. Pouring: pour within the 30-40 min pot life; brush deep relief and undercut 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.
• Masters, tools and containers must be clean and 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 culture stone and wall panel producers, gypsum and concrete casters, mold shops and craft manufacturers worldwide.