Polytek PlatSil®71-11 Silicone RTV

New PlatSil® 71-11 Soft but Tough!

1:1-Mix Platinum Silicone Keeps It Simple


Demolding with new PlatSil®71-11 is a breeze. This gargoyle bracket is easily removed without undue wear or tear on the silicone mold rubber. The smooth, release-free demold of silicone is especially welcome on highly detailed resin parts. The 1:1 mix ratio makes it available to any user—no equipment required!

Simplify your life! How many times have you heard or thought about that? Well, the Polytek® crew also believes there is beauty in simplicity. To make it easier for our customers, we have added yet another 1:1-mix silicone to our lineup. PlatSil® 71-11 is a high-strength, Shore A~15, 1:1 by weight or volume system with physical properties New PlatSil®71-11—Soft but Tough! 1:1-Mix Platinum Silicone Keeps It Simple that won’t disappoint even the most demanding user. This new system joins PlatSil®71-20 (Shore A~25) and PlatSil®Gel-10 (Shore A~10) in the 1:1 platinum silicone systems Polytek® currently offers.

Without a doubt, 1:1 mixes are the way to go whenever possible. Most silicone mold rubbers are mixed 1:10, which obviously requires a scale for accuracy. As with all the 1:1 PlatSil® products from Polytek®, 71-15 can be mixed easily by volume, eliminating the need for expensive scales and the time-consuming process of weighing. Since Parts A and B are similar in viscosity (approximately 15,000 cps), the two components blend easily when mixed. And since one component is blue and the other is green, it is easy to see when the mix is uniform and complete. PlatSil®71-11 has a working time of about 15 minutes and a demold time of about 4 hours, similar to 71-20. Customers tell us they like being able to pour a mold and use it for casting later that same day. For some, a speedy demold is a matter of convenience, but for others it’s a necessity. Since 71-15 is an addition-cure silicone, it can also be accelerated with heat. Demolding within an hour is possible when curing at around 110°F. Not all users have access to an oven or one large enough to accommodate a larger mold, so a room-temperature cure of 4 hours has real benefits.

The physical properties of 71-11 are impressive. Given its lower hardness, it offers a high elongation for demolding very delicate, complex parts. In many softer silicone systems, tear strength is sacrificed. Not so for PlatSil®71-11! With a Die B tear of 110 psi, this rubber can handle repeated casting with objects containing sharp undercuts and edges. Tear strength this high is quite unusual for a silicone rubber this soft.

As with other PlatSil® systems, 71-11 can be poured as supplied or thickened for brushing using Cab-O-Sil® powder or PlatThixTM liquid thickener. Other PlatSil® accessories that can be used with 71-11 are (1) PolySil® silicone fluids for lowering viscosity and softening the cured rubber, (2) PlatSil®71X accelerator for reducing the demold time at room temperature, and (3) PlatSil®71R retarder for extending the working time (and demold time). If your requirements call for a softer, high-performance silicone mold rubber for repeatedly casting resin parts (or even plaster, wax, or concrete) easily and without the need for a mold release agent, consider trying new 1:1-mix PlatSil®71-11.

If you aren’t sure which product is best for you, don’t hesitate to contact us at (800) 628-7296. Remember, 1 + 1 = Easy!

Special thanks to Polytek for providing this content. Copyright © 2003, Polytek Development Corp. All Rights Reserved.

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