Silicone Umbrella Valve
Silicone Umbrella Valves, also known as Umbrella Valve Seals, Umbrella Check Valve, Rubber Umbrella Valve, Mini Umbrella Valve, Liquid Silicone Valves, Duckbill Umbrella Valve,LSR Valves, Duckbill Check Valves, which is a kind of one-way valve in diaphragm shape to control air & liquid flow in one direction and backflow in the opposite direction, and which usually worded as a rubber flaper valves assembled with medical plastic device for medical resuscitator.
Silicone Umbrella Valve is usually made of solid silicone, fluorosilicone, FVMQ, EPDM, HNBR and Nitrile Rubber by silicone compression molding. While with the development of Liquid Silicone Injection Molding, the good properties of Liquid Silicone Rubber (LSR), and the higher quantity demand of silicone valves, more and more people choose liquid injection molding for production.
Umbrella Valve is a diaphragm shaped seal or umbrella shape that will allow forward flow once the head pressure create enough force to lift the convex diaphragm from the seat, which will allow flow at a predetermined pressure in one way and prevent back flow immediately in the opposite way.
Umbrella Check Valve Design & Size Analysis:
Umbrella Valves' 3 key design and size+2 key diaphragmatic surface demands:
Umbrella Shaped Dameter: bigger than one-way valve holes
Hook Height: same to plastic & metal panel's height
Stem Diameter: same or smaller than assembly holes
Outside Diaphragmatic Surface: EDM process or texture surface to make sure anti dust.
Inside Diaphragmatic Ring Edge Surface: Polish or high-polishing for sealing function.
Liquid Silicone Valves VS Solid Silicone Valves:
Umbrella Valve Seals by LSR material is odorless with high transparency and purity , and is 100% food grade and can achieve meidcal grade. Compared with liquid silicone & LSR materials, solid silicone is less safe because the purity of the materials composition is not high as liquid silicone.
Duckbill Umbrella Valves with good tear resistance and tensile strength. And will not easy to deform and turn to yellow.Compared with liquid silicone, solid silicone valve's tear resistance, tensile strength is not good. And what's more Solid silicone valve tend to turn into yellow easily.
Silicone rubber molded gaskets that will be under compression in heated conditions, the ability of these materials to recover from compression deformation is a crucial consideration. Liquid Silicone Rubber's compression set is consistent over a wide temperature range, from 60- 250.
While for compression mold silicone umbrella valves, generally require post-curing, compression set of typical organic rubbers is relatively low around room temperature, it increases significantly as temperatures rise, so post-curing and selection of a proper curing agent are particularly recommended when using silicone rubber to make molded items for which low compression set is desired. Especially for silicone gasket and seals need good sealing performance, low compression set is important for sealing function. So liquid silicone rubber umbrella duckbill valves usually have better property in sealing performance as the better compression set property.
Silicone Umbrella Valves by LSR Injection Mold, which consist of glue A and glue B, and is controlled to be 1:1 ratio dosing device, and fully mixed by a static mixes and then injected into injection mold chambers & tubes. Liqud Injection Molding Processing is less or not polluted by workers, as the material is controlled by machine, and for compression molding, the material is weighted and cut by workers.
Solid silicone valves by compression molding, which will not fully cured or vulcanized some times, and also easy to polluted by production workers, during silicone mixing, material cutting, added vulcanizing agent, and place silicone materials into mold chambers & cavities before molded.
Silicone Umbrella Valves by Liquid Injection Mold with shorter cycle time and with higher production efficiency, do not need t ake time to prepare material and with no or less rubber flashings, which can save time to trim rubber flashings. While by compression molding, the vulcanization time is longer and in most circumastance, the material can not vulcanize fully, so need to do second vulcanization to make sure fully vulvanization to make sure material safety. And also there are rubber flashing on the valves, need take time to debur. For large quantity project, Liquid Silicone Injection Mold is a better choice.