For previous reading, please refer to Injection mold acceptance items and requirements 1.
Injection mold acceptance is our frequent work. How to conduct acceptance and which items to accept can give a more comprehensive understanding of status of a set of molds. Following chapters will give a detailed introduction.

 

1. Cooling or heating system should be unobstructed.
2. Seal should be reliable, system should not leak under a pressure of 0.5MPa, and it should be easy to repair.
3. Size and shape of sealing groove opened on mold frame should meet requirements of relevant standards.
4. Sealing ring should be smeared with butter when placed, and it should be higher than mold frame surface after placement.
5. Water and oil flow channel spacers should be made of materials that are not easily corroded.
6. Front and rear molds should use water collection blocks to deliver water.

1. Gate setting should not affect appearance of product and meet product assembly requirements.
2. Cross section and length of runner should be designed reasonably. Under premise of ensuring quality of forming, process should be shortened as much as possible, cross-sectional area should be reduced to shorten filling and cooling time. At the same time, plastic loss of pouring system should be less.
3. Cross section of three-plate mold runner on the back of front mold plate should be trapezoidal or semicircular.
4. Three-plate mold has a 3mm deep step recessed into gate plate at ball head on gate plate.
5. Ball head pull rod should be reliably fixed, which can be pressed under positioning ring, fixed with a headless screw, or pressed with a pressure plate.
6. Gate and runner should be machined according to drawing size requirements, and manual grinding is not allowed.
7. Point gate and gate should meet requirements of specification.
8. There should be an extended part at the front end of runner as a cold material hole.
9. Z-shaped undercut of pull rod should have a smooth transition.
10. Runner on parting surface should be circular, front and rear molds cannot be misaligned.
11. Surface of latent gate on ejector rod should not shrink.
12. Diameter and depth of cold material hole of transparent products should meet design standards.
13. Gate is easy to remove, there is no trace of gate on appearance of product, and there is no residual gate at assembly of product.
14. Two-part insert of hook latent gate should be nitrided, and surface hardness should reach HV700.

1. Wiring layout of hot runner should be reasonable, easy to repair, and wiring numbers should correspond one by one.
2. Hot runner should be tested for safety, and insulation resistance to ground should be greater than 2MW.
3. Temperature control cabinet and hot nozzle, hot runner should use standard parts.
4. Main runner gate sleeve is connected to hot runner with threads, and bottom plane is in contact with seal.
5. Hot runner has good contact with heating plate or heating rod, heating plate is fixed with screws or studs, and surface fits well.
6. J-type thermocouples should be used and matched with temperature control box.
7. Each group of heating elements should be controlled by thermocouples, and position of thermocouples should be arranged reasonably.
8. Nozzle should meet design requirements.
9. Hot runner should be reliably positioned, with at least two positioning pins, or fixed with screws.
10. There should be a heat insulation pad between hot runner and mold plate.
11. Error between set temperature and actual displayed temperature of temperature controller should be less than ±5℃, and temperature control should be sensitive.
12. Cavity and nozzle mounting holes should be penetrated.
13. Hot runner wiring should be bundled and covered with a pressure plate.
14. There are two sockets of same specification, which should be clearly marked.
15. Control line should be sheathed and not damaged.
16. Temperature control joint structure is reliable and screws are not loose.
17. Joint is installed on bakelite board and cannot exceed larger size of mold plate.
18. Wires are not allowed to be exposed outside mold.
19. All places where hot runner or mold plate contacts wires should have rounded transitions.
20. Before mold plate is assembled, all circuits should be free of short circuits.
21. All wiring should be properly connected and have good insulation performance.
22. After mold plate is installed, all circuits should be checked again with a multimeter.

 

1. Front and rear mold surfaces should not have unevenness, pits, rust and other defects that affect appearance.
2. Inserts and mold frame should match, and gap around fillets should be less than 1mm.
3. Parting surface should be kept clean and tidy, without hand-held grinding wheels to avoid air, and sealing part should not be concave.
4. Depth of exhaust groove should be less than overflow value of plastic.
5. Inserts should be ground in place, placed smoothly and positioned reliably.
6. Inserts, core inserts, etc. should be reliably positioned and fixed, round parts should have stoppers, and there should be no copper or iron sheets under inserts.
7. End face of ejector pin is consistent with core.
8. There are no defects such as undercuts and chamfers in the front and rear mold forming parts.
9. Rib position should be ejected smoothly.
10. For products of multi-cavity molds, left and right parts are symmetrical, L or R should be indicated. If customer has requirements for position and size, it should meet customer's requirements. Generally, it should be added in a place that does not affect appearance and assembly, and font size is 1/8.
11. Mold frame locking surface should be well matched, and more than 75% of area should be touched.
12. Ejector pin should be arranged close to side wall, next to ribs and bosses, and a larger ejector pin should be used.
13. For same parts, numbers 1, 2, 3, etc. should be indicated.
14. Each collision surface, insertion surface, and parting surface should be well matched.
15. Sealing part of parting surface should meet design standards. 10~20mm for medium-sized molds and 30~50mm for large molds, and the rest should be machined to avoid air.
16. Leather grain and sandblasting should be uniform to meet customer requirements.
17. For products with appearance requirements, screws on products should have anti-shrinkage measures.
18. Screw columns with a depth of more than 20mm should use jacking tubes.
19. Wall thickness of product should be uniform, and deviation should be controlled below ±0.15mm.
20. Width of rib should be less than 60% of wall thickness of appearance surface.
21. Core inserts on lifter and slider should have a reliable fixing method.
22. Front mold is inserted into rear mold or rear mold is inserted into front mold. There should be bevels around to lock and machine to avoid air.

1. Mold should have stability of injection molding production and repeatability of process parameter adjustment within normal injection molding process conditions.
2. Injection pressure of mold during injection molding production should generally be less than 85% of rated maximum injection pressure of injection molding machine.
3. Injection speed of mold during injection molding production shall not be less than 10% of rated maximum injection speed or more than 90% of rated maximum injection speed at three-quarters of stroke.
4. Holding pressure during mold injection molding production should generally be less than 85% of actual maximum injection pressure.
5. Clamping force during mold injection molding production should be less than 90% of rated clamping force of applicable model.
6. During injection molding process, product and nozzle should be easy to remove.
7. For molds with inserts, inserts should be easy to install and inserts should be reliably fixed during production.

1. Mold cavity should be cleaned and sprayed with anti-rust oil.
2. Sliding parts should be lubricated.
3. Gate sleeve and feed port should be sealed with grease.
4. Mold should be installed with a locking module, and specifications should meet design requirements.
5. Spare parts and wearing parts should be complete, with a detailed list and supplier name.
6. Water, liquid, gas, electricity inlet and outlet of mold should be sealed to prevent foreign matter from entering.
7. Outer surface of mold should be sprayed with paint, and customer should follow requirements.
8. Mold should be packaged in a moisture-proof, waterproof and anti-collision packaging, and customer should follow requirements.
9. Mold product drawings, structural drawings, cooling and heating system drawings, hot runner drawings, details of spare parts and mold material suppliers, instruction manuals, mold trial report, factory inspection certificate, and electronic documents should be complete.