Industry information

Basic acceptance standards for plastic mold materials and hardness

2021-05-17

Basic acceptance standards for plastic mold materials and hardness

1.The standard mold stand shall be selected in accordance with the standards.

2. Mold forming parts and gating system (core, movable and fixed die inserts, movable inserts, split taper, push rod, gate sleeve) shall be made of materials with properties higher than 40Cr.
3. When forming the plastic that is easy to corrode the mold, the molding parts should be made of corrosion-resistant materials, or the forming surface should take anti-corrosion measures.
4. The hardness of the molded parts should not be less than 50HRC, or the hardness of the surface hardening treatment should be higher than 600HV


 (3) Ejection, reset, core pulling and part taking

1. Ejection should be smooth, no jam lag, no abnormal sound.

2. The inclined top surface should be polished, and the inclined top surface is lower than the core surface.

3. The sliding parts shall be equipped with oil grooves, and the surface shall be nitridated. After treatment, the surface hardness shall be above HV700.

4. All jacking rods shall have stop positioning and each jacking rod shall be numbered.

5. The ejection distance shall be limited by a limit block.

6. The reset spring should be selected as a standard part, and both ends of the spring should not be polished or cut off.

7. Slider and core pulling should have travel limit, small slider with spring limit, spring inconvenient installation can be used wave screw;Cylinder core-pulling must have stroke switch.

8. Slider core pulling generally adopts inclined guide pillar, and the Angle of inclined guide pillar should be 2°~3° smaller than the Angle of the locking surface of the slider.If the slide stroke is too long, the cylinder should be used to pull out.

9. When the end face of the cylinder core-pulling forming part is covered, the cylinder should be equipped with a self-locking mechanism.

10 slider width of more than 150 mm under the large slider should be wear-resisting plate, wear-resisting plate material should be selected T8A, after heat treatment, the hardness of HRC50~55, wear-resisting plate is 0.05~ 0.1mm higher than the surface, and open the oil groove.

11. The ejector should not move up and down in tandem.

12. Add barbs to the jacking rod. The direction of the barbs should be consistent, and the barbs can be easily removed from the products.

13. The fit gap between the jacking hole and the jacking hole, the length of the sealing section, and the surface roughness of the jacking hole should be in accordance with the relevant enterprise standards.

14. Products should be easy for operators to take off.

15. The products are easy to follow the inclined jacking when ejecting, and the jacking rod should be grooved or etched.

16. The top block fixed on the jamming rod should be firm and reliable. The non-forming part around should be processed with a slope of 3°~5°, and the lower periphery should be chamfered.

17. There should be no scraps of iron in the oil hole of the die frame.

18. The end face of the return rod is smooth, without spot welding.Embryo head bottom without gasket, spot welding.

19. The gate plate of the three plate die glides smoothly, and the gate plate is easy to open.

20. The three-plate die limit tie rods should be arranged on both sides of the mold installation direction or on the outside of the die frame to prevent the interference between the limit tie rods and the operator.

21. The oil airway should be smooth and the hydraulic ejection reset should be in place.

22. Open the exhaust port at the bottom of the guide sleeve.

Positioning pin should not be installed with clearance

To be continued