Silicone sponge, or closed cell silicone sponge, is derived from a skinny sheet of uncured silicone gum. The silicone gum compound is blended with pigment and different elements throughout a rigorous mixing course of. The nonetheless uncured silicone is then rolled into skinny sheets and warmth cured in a excessive temperature press or comparable process.
At this level within the course of, the silicone expands. The product is then usually submitted to an extra 4 hour post-curing course of at 480°F in a hot-air, circulating oven to reinforce the compression set properties and scale back the incidence of out-gassing within the ultimate meeting.
Sometimes, the silicone is cured on a Teflon-coated, fiberglass bleeder fabric. Doing this enables gasses to flee because the sponge expands throughout the curing course of. With out the bleeder fabric, massive air pockets would type that may have an effect on the sealing properties of the gasket materials. That is additionally what produces the positive, material floor end on the cured sponge, attribute of all closed cell silicone sponges.
‘Closed cell’ signifies that the cells are non-interconnecting, subsequently not permitting water or air to leak by the sponge at low pressures. Usually, the superior mechanical properties of closed cell silicone sponge present higher weatherproofing than open cell silicones. It offers wonderful sealing properties for merchandise topic to rain and harsh out of doors circumstances. One draw back of closed cell silicone sponge merchandise is the shortcoming to attain flame scores past UL94HB.
Silicone foam is often thought of to be an open cell, light-weight product forged from low-viscosity, liquid silicone elements. These elements are catalyzed, quickly blended, and forged onto a easy, plastic liner.
The forged foam is disbursed in a managed thickness onto the plastic liner. It’s then handed by a curing oven, and post-cured to drive out residual moisture or vapors. The completed product sometimes has a smoother floor.
The decrease density grades of forged silicone foams are sometimes not as profitable in harsh-environment testing, reminiscent of wind-driven rains. Air and moisture can go by low density open cell Custom Silicone Baby Feeding Ma silicone foam except the design permits for intensive deflection of the gasket.
Larger density silicone foams have been developed lately that allow good climate sealing with medium and agency density silicone foam merchandise. These larger density silicone foam merchandise are literally composed of many closed cells. A significant good thing about the liquid silicone foam product is the truth that it’s flame-retardant, with many merchandise assembly the UL94V0 score.