Solid Silicone
Curing without Any Pressure
A new silicone system developed by WACKER researchers adheres to a great many materials without pretreatment. This saves time and helps the environment.
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A novel silicone system adheres without pretreatment to many materials, such as metals
Extruded parts look like spaghetti because the production process is essentially the same: extrusion. You press a molding compound through a die, leave it to go solid and then coil it or cut it into pieces.
Silicone, too, can be extruded. But silicone is not really solid in comparison with organic rubber materials and thermoplastics. Despite its relative softness, though, silicone has such outstanding properties that in many situations it is impossible to do without it.
For this reason, many processors and end users are looking for a rigid, hard support material to which they can bond silicone so that it does not twist out of shape, for example, or is easier to install.
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The new silicones from WACKER can only be separated from the substrate by destroying them
Coextrusion with Silicone
Metals and rigid plastics are generally used for this purpose. Composites of this type are produced by coextrusion.
Generally speaking, coextrusion using silicone tends to be difficult. This is partly because of the softness, but is also due to the chemical makeup of the silicone: it repels other substances and is reluctant to bond with them. This hampers adhesion, which actually ought to take place during coextrusion.
Therefore, adhesion promoters such as primers must be used. This, however, has a drawback: the pretreated parts must be processed as quickly as possible.
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WACKER employees at the production of test strips at the WACKER pilot plant in Burghausen, Germany
Excellent Adhesion
WACKER SILICONES has developed a silicone system that can be processed with coextrusion and has excellent adhesion.
ELASTOSIL® bonds without pressure, on a wide variety of substrates such as steel, brass, copper, zinc, titanium and even drawn steel sheets covered with a film of oil and dirt.
WACKER SILICONES has now started to test the new material in combination with other plastics. The results with polyamide (PA) and polybutylene terephthalate (PBT) are excellent.
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A so-called zebra tubing made of different materials
Patented Technology
Our adhesion technology, for which a patent is pending, forms a chemical bond very quickly right in the heating tunnel. This provides a significant gain in productivity.
Complicated preparation, such as priming or flame treatment, is unnecessary. This not only lowers energy consumption and manufacturing costs, but also reduces the amount of solvent needed.