Deflashing

Applied to rubber which has been subjected to prolonged mastication, often carried out with periods of rest between mastication stages such rubber shows little or no elastic recovery. Deflashing... 

Many moulded products can be separated from their excess moulding scrap by use of scissors, cryogenic deflashing or buffing. The latter process has to be carried out with caution for those products which are bonded to metal substrates, because excessive generation of heat will result in loss of the bond integrity and product failure. 

Cryogenic deflashing of rubber is commonly carried out using liquid nitrogen as the temperature depressant, although some smaller units can be operated using solid carbon dioxide as the low temperature medium. 

Correct determination of the required time in the deflashing unit is necessary otherwise the bulk of the product can become brittle with fractures occurring in the mass of the product. 

Deflashing is often required to remove excess trim ( flash ) from the edges of the molded product. This may be done by tumbling in a rotating drum, or by an air-blast grit. 

Liquid nitrogen is used in the cold-trapping of materials such as carbon dioxide and volatile organic carbons (VOCs) from gas streams, as a coolant for electronic equipment, for pulverizing plastics or rubber material, for deflashing of rubber tires, and for simulating the conditions... 

The closures of BFS containers are formed within the automated process by the head mold set which closes around the top of the severed section of parison following filling. The integrity of the container and closure is generally tested by a manual or automated method of leak detection performed outside of the filling environment following removal of excess plastic (deflashing) from the filled product units. 

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