I. Appearance, Size and Coordination of Molded Products

1. No defects are allowed on the surface of the product: lack of material, burning, whitening, white line, drape, foaming, whitening (or cracking, breaking), drying, wrinkles and other defects.

2. Weld marks: generally, the length of circular perforation weld marks is not more than 5 mm, and the length of irregular perforation weld marks is less than 15 mm. The strength of weld marks can pass the functional safety test.

3. Shrinkage: No shrinkage is allowed in the visible part of the exterior surface, and slight shrinkage is allowed in the invisible part (no dent is felt).

4. Generally, the planar roughness of small products is less than 0.3 mm, and assembly requirements should be guaranteed.

5. Appearance can not be marked, material flowers, products generally can not have bubbles.

6. The geometry and size accuracy of the product should meet the requirements of formal and effective open-die drawings (or 3D documents). The product tolerance should be based on the tolerance principle. The axle dimension tolerance should be negative tolerance, the hole dimension tolerance should be positive tolerance, and the customers should meet the requirements.

7. Product wall thickness: product wall thickness generally requires average wall thickness, non-average wall thickness should meet the requirements of drawings, tolerance should be - 0.1mm according to die characteristics.

8. Product coordination: shell and bottom coordination: the surface dislocation is less than 0.1 mm, there can be no scraping phenomenon, there are matching requirements of the hole, shaft, surface to ensure the matching interval and use requirements.

2. Mould Appearance

1. The contents of the nameplate are complete, the characters are clear and arranged neatly.

2. The nameplate shall be fixed at the foot of the die near the template and the reference angle. The nameplate is fixed and reliable, and is not easy to peel off.

3. Cooling nozzles should be made of plastic blocks. Customers have other requirements as required.

4. Cooling nozzle should not extend out of die base surface

5. Cooling nozzles need to process sinking holes. The diameter of sinking holes is 25 mm, 30 mm and 35 mm. The chamfering of the orifices should be the same.

6. Cooling nozzles should be marked for entry and exit.

7. Marking English characters and numbers should be greater than 5/6, located 10 mm below the nozzle, and the handwriting should be clear, beautiful, neat and even spacing.

8. Mould accessories shall not affect the lifting and storage of the mould. When installed, there are exposed cylinders, nozzles, pre-reset mechanism and so on below, which should be protected by supporting legs.

9. Installation of support legs shall be fixed on the die base by screw through the support legs, and over-long support legs shall be fastened on the die base by lathe-processed external thread posts.

10. The size of the ejection hole of the die should meet the requirements of the specified injection machine. Except for small-sized moulds, the ejection hole of the die can't be ejected with only one center.

11. The positioning ring should be fixed and reliable. The diameter of the ring is usually 100 mm and 250 mm (depending on the type of the machine), and the positioning ring is 10-20 mm higher than the bottom plate. Except as otherwise requested by customers.

12. The shape and dimension of the mould shall meet the requirements of the specified injection moulding machine.

13. Moulds with direction requirements should be installed on the front or back templates with arrows indicating the direction of installation. The words "UP" should be next to the arrows. The arrows and words are yellow and the word height is 50 mm.

14. There should be no pits, rusts, excessive rings, water vapor, oil holes and other defects affecting the appearance of the die base.

15. Moulds should be easy to hoist and transport. Mould parts should not be dismantled during hoisting. Rings should not interfere with nozzles, cylinders, pre-reset rods, etc.

3. Die material and hardness

1. The standard die holder that meets the standard should be selected for the die holder.

2. Mold forming parts and gating system (core, movable die insert, movable insert, shunt cone, push rod, gate sleeve) are made of materials with properties higher than 40Cr.

3. When moulding plastic which is easy to corrode, the moulding parts should be made of corrosion-resistant materials, or the moulding surface should adopt corrosion-resistant measures.

4. The hardness of moulded parts should be no less than 50HRC, or the hardness of surface hardening treatment should be higher than 600HV.

IV. Ejection, Reset, Pull and Insert Core, Take Parts

1. Push out smoothly, without stuck, no abnormal sound.

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

3. Sliding parts should be equipped with oil tanks, and the surface should be nitrided. After treatment, the surface hardness is over HV700.

4. All ejectors should be positioned to stop rotation, and each ejector should be numbered.

5. The ejection distance is limited by the limit block.

6. The reset spring should be made of standard parts. The two ends of the spring should not be polished or cut off.

7. Slider and core-pulling should have travel limit, small slider should be limited by spring, wave screw can be used when spring is inconvenient to install; cylinder core-pulling must have travel switch.

8. Slider core-pulling usually adopts oblique guide pillar, and the angle of oblique guide pillar should be 2-3 degrees smaller than the angle of locking surface of slider. Cylinder pumping should be used for long stroke of slider.

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

10. There should be wear-resistant plate under the large slider whose width exceeds 150 mm. The wear-resistant plate material should be T8A. After heat treatment, the hardness is HRC50-55. The wear-resistant plate is 0.05-0.1 mm higher than the large surface, and the oil groove is made.

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

12. The direction of the barb should be consistent when the barb is added to the ejector rod. The barb can be easily removed from the product.

13. The matching clearance between the ejector hole and the ejector rod, the length of the sealing section and the surface roughness of the ejector rod hole shall be in accordance with the requirements of relevant enterprise standards.

14. The product should be good for the operator to take it off.

15. When the product is ejected, it is easy to follow the inclined ejection, and the ejector rod should be grooved or corroded.

16. The top block fixed on the ejector rod should be firm and reliable. The non-forming part around the ejector rod should be machined with a slope of 3 5 and the lower part should be chamfered.

17. There should be no iron debris in the oil passage holes on the die holder.

18. The end face of return rod is flat and spot-welded. There is no gasket at the bottom of embryo head, spot welding.

19. The guide of the gate plate of the three-plate die slides smoothly and the gate plate is easy to open.

20. Limiting rod of three-plate die should be arranged in the direction of die installation.