A set of high-quality plastic molds requires not only good CNC processing equipment for plastic molds and skilled mold makers, but also good mold design. Especially for complex molds, the quality of mold design accounts for more than 80% of the mold quality. An excellent mold design is to make the processing cost low, the processing difficulty small and the processing time short on the premise of meeting the customer's requirements. What are the CNC processing procedures for plastic molds?
CNC Processing of Automobile Plastic Mold
1、 CNC processing flow of plastic mold:
1. Material opening: (At present, the mold factory does not need the process of material opening when it directly purchases the refined material.)
Front mold material, rear mold material, insert material, line position material and inclined jacking material;
2. Thimble screw hole
Drill thread hole, pinhole, thimble and screw hole
3. Waterway
Waterway processing of front and rear mold kernel
4. Open frame: (When the mold is purchased with a fully processed mold base, it is unnecessary to open the frame.)
Front mold frame and rear mold frame;
5. Bold opening:
Front mold core opening and rear mold core opening
6. Finishing
Front mold core finishing, rear mold core finishing
7. Copper:
Front mold copper pin, rear mold copper pin, parting line corner clearing copper pin;
8. Wire cutting:
Insert parting line, copper pin, inclined top sleeper position;
9. Electric spark:
Front mold thick, copper male, male mold line clear angle, rear mold bone position, occipital position;
10. Slider processing
Row position, row position voltage pole;
11. Clinoform
Inclined roof, inclined roof seat and inclined roof guide block.
12. Processing of mold accessories
① . Jacks, die pits, garbage nails (limit nails);
② . Water nozzle, supporting head, spring and water conveyance;
13. Mold polishing
Front mold, rear mold bone position, sliding block, inclined roof and insert.
14. Additional process for hard mold
Quenching, row position surface nitriding;
15. Mold accessories
Engraving on the surface of the mold, slider, diagonal pin, insert engraving, mold nameplate, etc.
16. Die matching
The front and rear molds are matched.
17. Mold mounting
Overall assembly of the die.
Cnc processing of plastic mould
2、 How to perform CNC processing for plastic molds:
1. Principle of plastic mold processing reservation
① For workpieces requiring heat treatment, 0.25mm grinding machine allowance shall be added on one side of the overall material preparation size before heat treatment;
② For the part of the mold core and insert that needs CNC rough machining, 0.2mm allowance shall be reserved on one side;
③ One side allowance of 0.3-0.5mm shall be reserved for rough milling of the contour by bench milling machine. For workpieces to be machined by grinder after line cutting, 0.05mm shall be reserved on one side of the forming part, and 0.1mm grinding allowance shall be reserved on one side of the contour opening;
④ Mirror polishing is required after CNC finishing and electric pulse, and 0.03mm polishing allowance is left on one side.
2. Requirements for processing accuracy of plastic moulds
The manufacturing accuracy of die size shall be within 0.005~0.02mm; The perpendicularity shall be within the range of 0.01~0.02mm; Coaxiality shall be within 0.01~0.03mm; The parallelism of the upper and lower planes of the movable and fixed mold parting surfaces shall be within the range of 0.01~0.03mm.
After the mold is closed, the gap between parting surfaces is less than the overflow value of the molded plastic. The parallelism of other formwork mating surfaces shall be within the range of 0.01~0.02mm; The fitting accuracy of the fixed part is generally within the range of 0.01~0.02mm; If the small core has no requirements for insertion or has little impact on the size, a clearance fit of 0.01~0.02mm on both sides can be adopted; The fitting accuracy of sliding part is generally H7/e6, H7/f7 and H7/g6.
Note: If there is an insert on the mirror surface that is attached to a step, the fitting should not be too tight, otherwise, when the insert is knocked back from the front, the tool used for knocking is easy to damage the mirror surface. If it does not affect the product size, the bilateral clearance of 0.01~0.02mm can be used for fitting.