{"id":8856,"date":"2026-07-25T11:56:22","date_gmt":"2026-07-25T03:56:22","guid":{"rendered":"https:\/\/topsilsilicone.com\/?p=8856"},"modified":"2026-07-25T12:02:26","modified_gmt":"2026-07-25T04:02:26","slug":"how-to-choose-platinum-silicone-for-polyurethane-vacuum-casting-molds","status":"publish","type":"post","link":"https:\/\/topsilsilicone.com\/es\/how-to-choose-platinum-silicone-for-polyurethane-vacuum-casting-molds\/","title":{"rendered":"How to Choose Platinum Silicone for Polyurethane Vacuum Casting Molds"},"content":{"rendered":"

Two platinum silicones<\/a> can both be listed as Shore A 25 and still perform very differently in the same polyurethane casting project.<\/p>\n\n\n\n

One may release deep undercuts easily but deform around a large flat housing. Another may provide better dimensional support but tear along a thin cut line. A third may look excellent on its technical data sheet but remain sticky against an inadequately prepared SLA-printed master.<\/p>\n\n\n\n

This is why silicone selection should not begin with the largest tear-strength number or the lowest viscosity.<\/p>\n\n\n\n

It should begin with four questions:<\/p>\n\n\n\n

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  1. What may damage the mold?<\/li>\n\n\n\n
  2. Where is the mold most likely to fail?<\/li>\n\n\n\n
  3. What must the operator complete before the silicone begins to gel?<\/li>\n\n\n\n
  4. What defines an acceptable polyurethane casting?<\/li>\n<\/ol>\n\n\n\n

    The right platinum silicone is selected from the polyurethane system, part geometry and production process backward\u2014not from the silicone TDS forward.<\/strong><\/p>\n\n\n\n

    A poor match can lead to cure inhibition, difficult demolding, cut-line tearing, dimensional rejection, premature mold replacement or repeated sample trials.<\/p>\n\n\n\n

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    Respuesta r\u00e1pida<\/h3>\n\n\n\n

    The choice between the two chemical systems comes down to your primary production driver:<\/p>\n\n\n\n

    Choose Cura de esta\u00f1o<\/a> if your priority is Volume & Budget: Requires maximum raw material cost-efficiency for large-scale, forgiving geometries (like architectural concrete or plaster) on a busy shop floor.<\/p>\n\n\n\n

    Choose Cura de platino <\/a>if your priority is Technical Precision: Requires near-zero shrinkage (<0.1%), long-term library storage without warping, or strict FDA<\/a>\/LFGB compliance for skin and food contact.<\/p>\n<\/div>\n\n\n\n

    Quick Answer: What Platinum Silicone Is Best for PU Vacuum Casting?<\/strong><\/strong><\/h2>\n\n\n\n

    The best platinum silicone for polyurethane vacuum casting is a low-shrinkage RTV-2 grade whose usable working time and mixed viscosity fit the complete mold-making process, and whose hardness, tear strength and elongation match the part geometry and local demolding stress.<\/strong><\/p>\n\n\n\n

    Buyers must also confirm compatibility with:<\/p>\n\n\n\n