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Development of Cryogenic deflashing Technology

cryogenic defiashing technology first Invented in the 1950s. In the development process of cryogenic defiashingmachines, it has gone through three important periods. Follow along in this article to gain an overall understanding.

(1) First cryogenic deflashing machine

The frozen drum is used as the working container for frozen edging, and dry ice is initially chosen as the refrigerant. The parts to be repaired are loaded into the drum, possibly with the addition of some conflicting working media. The temperature inside the drum is controlled to reach a state where the edges are brittle while the product itself remains unaffected. In order to achieve this goal, the thickness of the edges should be ≤0.15mm. The drum is the primary component of the equipment and is octagonal in shape. The key is to control the impact point of the ejected media, allowing for a rolling circulation to occur repeatedly.

The drum rotates counterclockwise to tumble, and after a period of time, the flash edges become brittle and the edging process is completed. The defect of the first generation frozen edging is incomplete edging, especially residual flash edges at the ends of the parting line. This is caused by inadequate mold design or excessive thickness of the rubber layer at the parting line (greater than 0.2mm).

(2)The second  cryogenic deflashing machine

The second  cryogenic deflashing machine has made three improvements based on the first generation. First, the refrigerant is changed to liquid nitrogen. Dry ice, with a sublimation point of -78.5°C, is not suitable for certain low-temperature brittle rubbers, such as silicone rubber. Liquid nitrogen, with a boiling point of -195.8°C, is suitable for all types of rubber. Second, improvements have been made to the container that holds the parts to be trimmed. It is changed from a rotating drum to a trough-shaped conveyor belt as the carrier. This allows the parts to tumble in the groove, significantly reducing the occurrence of dead spots. This not only improves efficiency but also enhances the precision of edging. Third, instead of relying solely on the collision between the parts to remove the flash edges, fine-grained blasting media is introduced. Metal or hard plastic pellets with a particle size of 0.5~2mm are shot at the surface of the parts at a linear speed of 2555m/s, creating a significant impact force. This improvement greatly shortens the cycle time.