688N is double components liquid silicone rubber, injection moulding type, with the excellent resistance of high and low temperature, excellent weather resistance, outstanding transparence, high shear strength and good tensile strength, also with good resilience and anti-yellowing feature.
They are widely used in making food grade product, such as nipple, cake mould, shovel and diving apparatus etc.
Mixing: mix A and B components at a weight ratio of 10:1 or 1:1, it can be finished by hand or equipment.
Defoaming: the product need to be defoamed after mixing. The volume of sealant will be 4-5 times during the defoaming process, so the container should be 4-5 times bigger than the volume of mixing sealant, after about 10 minutes, when no bubble come out of the surface, the job is finished and the volume of sealant change to be normal instead of much bigger.
Surface treatment: liquid paraffin or surface active agent can be used as mold release agent on the contact surface of molds or materials.
Curing and mold releasing: curing temperature and time are depended on the process conditions.