1. liquid silicone Molding parts
Liquid silicone rubber injection molding is the most recent addition to Hangzhou Bright Rubber Plastic Products Co., Ltd's molding operations. The faster cycle times and improved performance properties of liquid silicone rubber make it a good choice for a variety of molded components.
Liquid silicone rubber (LSR) remains flexible and elastic beyond -70°F and retains its properties up to 450°F which makes liquid silicone rubber a good candidate for gaskets, seals, boots, bellows, medical devices and other applications where outdoor conditions are demanding.
Cured liquid silicone rubber does not out-gas volatiles and plasticizers as other rubber compounds do – which has made it friendly to various assemblies that were formerly required to be ‘silicone free’.
2. LSR Advantages
A key advantage of liquid silicone rubber over gum based molding silicone compounds is the cycle time. Depending on the catalyst and cross-section of the molded component, the cycle times for liquid silicone molded parts range from 30 seconds to three minutes – with our average cure time of 25 to 50 seconds. In contrast, gum base silicones may take from 3 to 5 minutes total cycle time in a traditional silicone mold. Therefore, a single or two cavity injection mold will out-produce a multi-cavity mold. With fewer cavities needed to support production, tooling costs and lead times are reduced as well as part costs.
3. Types of LSR
Besides regular grade LSR with hardnesses between 30 and 80 Sh (A), LSRs are also available with other special properties:
●hygiene: suitable for making components that come into contact with drinking water, food or beverages (FDA, BfR)
●oil resistance: used for components that come into contact with hydrocarbons, often at high temperatures
●oil sealing: used for assembly components
●electrical insulating or conductive: used in electrical and electronic systems
●high transparency: used in lighting systems as lenses or optical conductors
●sterility: used for medical parts (ISO 10993, USP Class VI)
●self-bonding: used for two-component manufacture
Types of LSR are also available with combinations of these properties.
What is LSR Molding?
Liquid silicone rubber, or LSR, injection molding is a thermoset process that mixes two compounds together. This two component compounds is heat cured in a mold along with a catalyst which results in a completed molded part. Liquid Silicone Rubber – LSR – components are produced via an injection molding process comparable to plastic injection molding. However there is a major difference between the two processes in that the material delivery system is cooled and the mold is heated. Liquid silicone rubber injection molding is different from the plastic injection molding process because it centers on mechanical mixing as opposed to pressurized impingement mixing.