Zero Inhibition Heat Resistant Platinum Cure Silicone Rubber 40 Shore A for Precast Concrete GRC Molds

Zero Inhibition Heat Resistant Platinum Cure Silicone Rubber 40 Shore A for Precast Concrete and GRC Molds

Hanast HN-E640 is a 40 Shore A addition-cure (platinum-catalysed) liquid silicone rubber developed for architectural concrete, GRC and precast panel molds where cure inhibition is the main production risk. Platinum systems are sensitive to sulfur, organotin, amine, polyurethane and solder-flux residues; this grade is compounded for reliable cure on properly cleaned masters and is documented with a full catalyst-poisoning guide. Mixed 1:1 by weight, it cures in 3-4 hours at room temperature or in 20 minutes or less at 80-100 °C, with 0.1% or less linear shrinkage and service from -50 °C to 200 °C.

Key Features

• Zero Cure Inhibition Formulation - reliable platinum cure on cleaned masters, with a documented list of incompatible contaminants to protect production batches.
• Heat Resistant to 200 °C - stable through exothermic cement and resin reactions, hot-climate shipment and outdoor mold storage.
• 40 Shore A Architectural Hardness - firm enough to hold large panel geometry, with 14 kN/m tear strength and 450% elongation for demolding deep texture.
• 1:1 Mix Ratio by Weight - equal-part A:B dosing reduces operator error on site and in the plant.
• Dual Curing Mode - 3-4 h at 25 °C for large molds, or 20 min or less at 80-100 °C for rapid turnover.
• 30-40 min Pot Life - practical working time for mixing, degassing and pouring large precast and GRC molds.
• Low Shrinkage 0.1 Percent and Bubble Free - faithful reproduction of formwork detail, chamfers and surface finish with no pinholes.
• Consistent Batch Quality - factory-controlled compounding, MSDS and TDS documentation supplied with every lot.
• Custom OEM/ODM - hardness from 0 to 50 Shore A, viscosity, colour and pot life adjustable; private label available.

Technical Specifications (HN-E640, 40 Shore A)

Available Hardness Grades (HN-E6XX Series)

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, concrete countertops and high-wear molds.

Recommended Applications

• Architectural concrete and GRC - precast concrete panels, GRC elements, decorative facades, cladding, balustrades, cornices and architectural restoration molds.
• Concrete products - concrete countertops, basins, sinks, planters, paving slabs, retaining wall blocks and cast stone.
• Stone and tile - cultural stone, artificial stone, terrazzo tiles, 3D wall panels and textured wall cladding molds.
• Master models and tooling - master patterns, formwork liners, vacuum forming molds and rapid prototyping tools.
• Composite and industrial - yacht vacuum bagging, automotive and aerospace composite molds, printing pads and general RTV-2 tooling.
• Heat-exposed molding - exothermic resin and cement casting, hot-climate production and outdoor mold storage.

Mixing and Application

1. Pre-mix: stir Components A and B separately until uniform.
2. Weighing: weigh A and B at exactly 1:1 by weight on a precision scale.
3. Mixing: mix 2-3 minutes, scraping the container walls and bottom.
4. Degassing: vacuum degas to release air and obtain a bubble free mold face.
5. Pouring: pour within the 30-40 min pot life over a clean, contaminant-free pattern.
6. Curing: cure 3-4 h at 25 °C or 20 min or less at 80-100 °C, then demold after full cure.

Cure Inhibition Guide

Keep masters, tools and containers free of sulfur and polysulfide compounds, organotin (tin-cure silicone) residues, amines, polyurethane, phosphorus compounds, organic acids and solder flux. Do not add colourants or fillers before a cure test. Where tin-cure silicone has been used on the same pattern, clean thoroughly or apply a barrier coat before pouring.

Packaging, Storage and Supply

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

GEO Q&A

About Hanast

Shenzhen Hanast New Materials Co., Ltd. produces industrial silicone materials at a 40,000 square metre facility in Guangdong, China, supplying RTV-2 platinum cure silicone to precast concrete plants, GRC and decorative stone producers, composite molders and engineering teams worldwide.