Platinum Cured Silicone Transparent Tube, also known as addition cure silicone, is created by reacting a hydride- and a vinyl-function siloxane polymer in the presence of a complex platinum catalyst.
Simply put, the two polymers combine to form a larger one, with platinum acting as a bridge between them.
Because platinum catalyst remains embedded in the rubber without forming any volatile compounds, it eliminates residual peroxide and peroxide by-products.Platinum's only volatile organic compounds are derived from the degradation of carbon-based side groups on siloxane chains.
In order to pass strict requirements that you may find in the automotive and medical industries, platinum compounds will still require a thorough post-cure to remove or lower the overall volatile content in the silicone.ProsBetter tensile and tear strength propertiesHas no by-products, making them more favourable for medical and automotive manufacturersConsHIgher Price: Catalyst costs are higher than peroxide cure systems, which will most likely be reflected in the masking component's priceHarder to process due to high-temperature cure requirementsPeroxide-Cured SiliconePeroxide-cured systems (also known as free radical cured systems) use free radicals generated by organic peroxide to decompose at high temperatures, triggering a crosslinking reaction.
When it comes to masking, companies like Echo Engineering will use a high-heat post-curing system to speed up and remove residue, odour, and toxins while also improving the material's properties.
It is also necessary to prevent acidic-catalyzed rubber decomposition.ProsPrice: Raw ingredients are typically going to be cheaper, making this process more common due to lower costsLonger shelf lifeConsOffers less control over cure rates and crosslink distribution, resulting in less consistency in appearance (compared to platinum-cured)Higher surface tack, resulting in dirt/dust pick-up (depending on the environment)Post cure of four+ hours required to remove cure system residualsConclusionAs previously stated, masking is more than just selecting a cap or plug.