After the mold processing plastic mold calculates the structure, shape and size of the mold, it also needs to put forward the basic requirements for the processing quality and use conditions of the mold. What are the main requirements? Tell us now what these requirements are. (1) The hardness of the medium W is uniform. After the mold is quenched and tempered, the hardness value HRc is 45-51 (depending on the cable tie mould size of the mold, the larger the size, the lower the hardness required). (2) There is a high enough manufacturing precision, the shape tolerance and dimensional tolerance of the mold meet the requirements of the drawings (generally manufactured according to negative tolerance), and the matching dimensions have good interchangeability. (3)

There is a sufficiently low surface roughness, and the roughness of the table should only be 3.2-1.6Mm. The working surface has a surface roughness of 1.6-o. 4Py', the surface should be nitrided, phosphatized to treat other surface heat treatment, such as multi-element co-infiltration treatment and chemical heat treatment; (4) have good neutrality, the contact rate should be greater than 80%. (5) mold no Internal defects can only be used afterwards. 'Generally, ultrasonic testing and surface quality inspection should be carried out. (6) The transition of the working belt and the transition zone of the cavity of the cavity and the transition of the welding cavity are smooth and evenly transitioned, and no corners are allowed. The number of holes in the porous rod die can be selected according to the following principles: (1) Reasonable extrusion coefficient A. According to the extrusion force of the extruder, the length of the extruder receiving table and the cooling table, the size of the extrusion cylinder, the mechanical and mechanical requirements of the product, the deformation resistance of the extruded alloy, and the like; For aluminum alloy bars, A can take 8-40, where the soft balance takes the upper limit, the hard alloy takes the lower limit c(2), and the mold strength c is used to improve the service life of the die, the distance between the die hole and the die and the die

The distance should be kept at a certain value. For extruders below 50MN, generally take 15-50mm, the small tonnage extruder takes the lower limit, and the large tonnage squeezer takes the upper limit. For large extruders above 80MN, it should be increased to 30-80mm: (3) Good product surface quality: In order to prevent the dirty logistics person on the surface of the ingot from squeezing the product towel, the edge of the die hole and the extrusion tube should be made Keep a minimum distance, generally 10% -30% of the squeezing of the squeezing (the lower limit of the large extruder, the limit of the small extruder), in addition, in order to prevent surface scratches and sprains, reduce 1 : The labor intensity and the amount of waste, the number of plastic mold holes should not be too much.