Sales: 1-800-645-9110

Differences between Platinum-Cured and Peroxide-Cured Silicone

Apex Packing and Rubber Company provides silicone gaskets in various styles to meet many requirements. They are typically supplied in White Silicone and, for some styles, are also available in Translucent Silicone. These are for use in specialty applications such as in Pharmaceutical or other sanitary applications. White Silicone is Peroxide-Cured, and Translucent Silicone is Platinum-Cured. The curing processes differ in that they produce gaskets with different physical characteristics.

Unlike the traditional Peroxide-Cured (White) Silicone, Platinum-Cured (Translucent) Silicone does not produce peroxides or ketones as part of the catalyzing process which can affect taste tests. As a result, Platinum-Cured Silicone is becoming a more popular choice in medical, food, drink, and dairy applications.

Platinum-Cured Silicone also offers improved clarity, particularly important in translucent products, where it is possible to tint with a specified color to achieve a unique look. A smoother surface finish can also be achieved, which again is important in certain industries. Platinum-Cured Silicone is superior in physical properties over Peroxide-Cured Silicone. In some cases, increases in tensile strength, elongation, and tear strength can be experienced.

Comparison of Physical Properties

PropertyPlatinum-CuredPeroxide-Cured

35 Durometer Elastomer

Tensile Strength (MPa)9.848.21
Tensile Strength (psi)14271190
Elongation (%)1171971
Modulus at 200% (MPa)1.110.97
Modulus at 200% (psi)161140
Tear Strength Die B (kN/m)36.624.5
Tear Strength Die B (ppi)209140

50 Durometer Elastomer

Tensile Strength (MPa)10.169.41
Tensile Strength (psi)14731364
Elongation (%)903596
Modulus at 200% (MPa)2.142.50
Modulus at 200% (psi)311362
Tear Strength Die B (kN/m)45.935.9
Tear Strength Die B (ppi)262205

65 Durometer Elastomer

Tensile Strength (MPa)7.947.59
Tensile Strength (psi)11511100
Elongation (%)890590
Modulus at 200% (MPa)2.823.07
Modulus at 200% (psi)409445
Tear Strength Die B (kN/m)45.542.2
Tear Strength Die B (ppi)260241
Top