To make a set of mould which can be called high-rise mould, we should not only have a high level of mould design and precise processing technology, but also have a precise concept of mould development. What is the concept of precision mold development? There are a lot of people who don't think so. They think they have made so many molds. How can they have no precise idea? In fact, the mold does not lie in how much, but in whether your mold development pursues the details of excellence, whether the pursuit of reliable standards, this process does not allow the concept of "almost" exists.

1、 Mold appearance

1. The contents of the mould name plate are complete, the characters are clear and arranged in order.

2. The name plate shall be fixed on the mold foot near the template and reference angle. The nameplate is fixed reliably and not easy to peel off.

3. The cooling water nozzle shall be plastic block water nozzle, if the customer has other requirements, it shall be as required.

4. The cooling water nozzle shall not protrude from the surface of the mold base.

5. The cooling water nozzle needs to be processed with three sizes of counterbore diameter: 25 mm, 30 mm and 35 mm. The chamfer of the orifice should be consistent.

6. The cooling water nozzle shall be provided with in and out marks.

7. The English characters and numbers of the mark shall be greater than 5 / 6, and the position shall be 10 mm below the faucet. The handwriting shall be clear, beautiful, neat and evenly spaced.

8. Mould accessories shall not affect the hoisting and storage of mould. During installation, there are exposed oil cylinder, water nozzle, pre reset mechanism, etc. at the bottom, which should be protected by support legs.

9. The installation of support legs shall be fixed on the formwork through the support legs with screws, and the excessively long support legs can be processed by car, and the external thread columns can be fastened on the formwork.

10. The size of the ejection hole of the mold should meet the requirements of the specified injection molding machine. Except for the small mold, only one center ejection can be used.

11. The positioning ring shall be fixed reliably, with the diameter of 100 mm and 250 mm, and the positioning ring shall be 10 ~ 20 mm higher than the bottom plate. Unless otherwise required by customers.

12. The overall dimension of the mold shall meet the requirements of the specified injection molding machine.

13. For the mould with direction requirement, the installation direction shall be indicated with an arrow on the front formwork or the rear formwork. There shall be the word "up" beside the arrow. The arrow and text are yellow, and the height of the word is 50 mm.

14. The surface of the mold base shall be free from pits, rust, redundant rings, water vapor, oil holes and other defects affecting the appearance.

15. The mould shall be convenient for hoisting and transportation. During hoisting, the mould parts shall not be disassembled, and the lifting ring shall not interfere with the water nozzle, oil cylinder, pre reset rod, etc.

2、 Hardness and die material

1. The standard mold base conforming to the standard shall be selected.

2. The material of mold forming parts and gating system (core, dynamic and fixed mold insert, movable insert, splitter cone, push rod and gate sleeve) is higher than 40Cr.

3. When forming the plastic which is easy to corrode the mold, the forming parts shall be made of corrosion-resistant materials, or the forming surface shall take anti-corrosion measures.

4. The hardness of die forming parts shall not be lower than 50HRC, or the hardness of surface hardening treatment shall be higher than 600hv.

3、 Eject, reset, core pulling and taking out

1. The ejection shall be smooth, free of jamming and 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 provided with oil groove, and the surface shall be nitrided, and the surface hardness after treatment shall be more than hv700.

4. All push rods shall be positioned with rotation stop, and each push rod shall be numbered.

5. The ejection distance shall be limited by limit block

6. The return spring shall be standard parts, and both ends of the spring shall not be polished or cut off.

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

8. Slide core pulling generally adopts inclined guide post, and the angle of inclined guide post shall be 2 ° to 3 ° smaller than the angle of locking surface of slide. If the slider stroke is too long, the oil cylinder should be used to pull it out.

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

10. There should be wear-resistant plate under the large sliding block whose width is more than 150 mm. The material of wear-resistant plate 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 should be opened.

11. The ejector bar shall not move up and down in series.

12. Add a barb on the ejector bar, and the direction of the barb shall be consistent, so that the barb can be easily removed from the product.

13. The clearance between the ejector hole and the ejector, the length of the sealing section, and the surface roughness of the ejector hole shall meet the requirements of relevant enterprise standards.

14. The product should be easy for the operator to remove.

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

16. The top block fixed on the top bar shall be firm and reliable, the non formed parts around shall be processed with a slope of 3 ° to 5 ° and the lower part shall be chamfered.

17. There should be no iron debris in the oil hole on the mold base.

18. The end face of return rod is flat without spot welding. There is no gasket at the bottom of embryo head, spot welding.

19. The gate plate of the three plate mold slides smoothly, and the gate plate is easy to pull apart.

20. The limit pull rod of the three plate die shall be arranged on both sides of the die installation direction, or a pull plate shall be added to the die base to prevent the interference between the limit pull rod and the operator.

21. The oil passage and air passage should be smooth, and the hydraulic ejection reset should be in place.

22. The bottom of the guide sleeve shall be provided with an air vent.

23. There should be no clearance in the installation of locating pin.

4、 Cooling and heating system

1. The cooling or heating system should be fully unblocked.

2. The sealing shall be reliable, and the system shall be free of leakage under the pressure of 0.5MPa for easy maintenance.

3. The size and shape of the sealing groove on the mold base shall meet the requirements of relevant standards.

4. The sealing ring should be coated with grease when it is placed, and it should be higher than the surface of the mold base after it is placed.

5. The spacer of water and oil passage shall be made of materials that are not easy to be corroded.

6. The front and rear moulds shall adopt the centralized water supply and drainage mode.

5、 Gating system

1. The gate setting should not affect the appearance of the product and meet the requirements of product assembly.

2. The cross-section and length of runner should be designed reasonably. On the premise of ensuring the forming quality, the flow should be shortened as much as possible, and the cross-section area should be reduced to shorten the filling and cooling time. At the same time, the plastic loss of gating system should be the least.

3. The section of the three plate formwork runner on the back of the front formwork shall be trapezoidal or semicircular.

4. The three plate mold has a material breaking handle on the gate plate, the diameter of the gate entrance should be less than 3mm, and there is a 3mm deep step concave into the gate plate at the ball head.

5. The ball head pulling rod should be fixed reliably, which can be pressed under the positioning ring, fixed with headless screw, or pressed with pressing plate.

6. The gate and flow channel shall be machined according to the size requirements of the drawing, and manual polishing machine is not allowed.

7. The gate of the point gate shall meet the requirements of the specification.

8. There should be an extended part at the front end of the shunt channel as the cold material hole.

9. There should be smooth transition for Z-shaped buckles of draw bar.

10. The porthole on the parting surface should be round, and the front and rear die should not be misplaced.

11. The latent gate on the ejector bar shall have no surface shrinkage.

12. The diameter and depth of cold hole of transparent products should meet the design standard.

13. The material handle is easy to remove, there is no gate trace on the appearance of the product, and there is no residual material handle at the assembly place of the product.

14. For hook type submerged gate, the two inserts should be nitrided, and the surface hardness should reach hv700.

6、 Hot runner system

1. The wiring layout of hot runner shall be reasonable and convenient for maintenance, and the wiring number shall be corresponding one by one.

2. Safety test shall be conducted for hot runner, and the insulation resistance to ground shall be greater than 2MW.

3. Temperature control cabinet, hot nozzle and hot runner shall be standard parts.

4. The main flow sleeve is connected with the hot runner by thread, and the bottom surface is in plane contact and sealed.

5. The hot runner is in good contact with the heating plate or heating rod, the heating plate is fixed with screws or studs, and the surface fits well.

6. J-type thermocouple should be used and matched with temperature control meter.

7. Each group of heating elements shall be controlled by thermocouple, and the thermocouple position shall be arranged reasonably.

8. The nozzle shall meet the design requirements.

9. The hot runner shall have reliable positioning, at least two positioning pins or screws.

10. There should be heat insulation pad between hot runner and formwork.

11. The error between the set temperature and the actual display temperature should be less than ± 5 ° C, and the temperature control is sensitive.

12. The cavity and nozzle mounting hole should be through.

13. The wiring of hot runner shall be bound and covered with pressing plate.

14. Two sockets of the same specification shall be clearly marked.

15. The control line shall be protected from damage.

16. The structure of the temperature control cabinet is reliable and the screws are not loose.

17. The socket shall be installed on the bakelite board and shall not exceed the maximum size of the formwork.

18. Wires are not allowed to be exposed outside the mold.

19. The hot runner or formwork shall have fillet transition at all places contacting with wires.

20. Before the template assembly, all lines are free of open circuit and short circuit.

21. All wiring shall be connected correctly with good insulation performance.

22. After the formwork is installed and clamped, all circuits shall be checked again with a multimeter.

7、 Forming part, parting surface and exhaust groove

1. The surface of front and rear die shall be free from unevenness, pits, rust and other defects affecting the appearance.

2. The insert should be matched with the mold frame, and there should be a gap of less than 1 mm around the fillet.

3. The parting surface shall be kept clean and tidy without hand-held grinding wheel, and the sealing part shall be free from depression.

4. The depth of the exhaust groove should be less than the overflow value of the plastic.

5. The insert should be in place, placed smoothly and positioned reliably.

6. The insert block and core should be fixed in a reliable position, the round part has a stop rotation, and the copper and iron pieces are not padded under the insert block.

7. The end face of ejector is consistent with the core.

8. The forming part of the front and rear mould has no defects such as undercutting and chamfering.

9. The reinforcement shall be pushed out smoothly

10. The left and right parts of the multi cavity mold should be symmetrical, indicating L or R. if the customer has requirements on the position and size, it should meet the customer's requirements. Generally, it should be added in the place that does not affect the appearance and assembly, and the font size is 1 / 8.

11. The locking surface of the mold base should be in place, and more than 75% of the area should be touched.

12. The ejector bar should be arranged near the side wall and beside the rib and boss, and the larger ejector bar should be used.

13. For the same parts, number 1, 2, 3, etc. shall be indicated.

14. The contact surface, insertion surface and parting surface shall be researched and matched in place.

15. The sealing part of parting surface should meet the design standard. The mould below medium size is 10 ~ 20 mm, the mould of large size is 30 ~ 50 mm, and the rest parts are machined to avoid space.

16. The dermatoglyph and sandblasting shall be uniform and meet the requirements of customers.

17. For products with appearance requirements, the screws on the products shall be provided with shrink proof measures.

18. Pipe jacking shall be used for screw column with depth more than 20 mm.

19. The wall thickness of products should be uniform, and the deviation should be controlled below ± 0.15mm.

20. The width of the reinforcement shall be less than 60% of the wall thickness of the exterior surface

21. The insert core on the inclined top and sliding block shall be fixed reliably.

22. When the front mold is inserted into the back mold or the back mold is inserted into the front mold, there should be inclined planes around to lock and machine to avoid space.

8、 Injection molding process

1. The mold should have the stability of injection production and the repeatability of process parameter adjustment within the range of normal injection process conditions.

In general, the maximum pressure of injection molding machine should be less than 2. 85%.

3. The injection speed of three-quarters of the stroke of the injection molding production shall not be less than 10% of the rated maximum injection speed or more than 90% of the rated maximum injection speed.

4. The packing pressure of injection mold should be less than 85% of the actual maximum injection pressure.

5. The clamping force of the injection mold should be less than 90% of the rated clamping force of the applicable model.

6. In the process of injection molding, it is easy and safe to take out the product and nozzle material (the time is generally less than 2 seconds).

7. For the mould with inserts, the inserts should be installed conveniently and fixed reliably during production.

9、 Packaging and transportation

1. The mold cavity should be cleaned and sprayed with antirust oil.

2. The sliding parts should be coated with lubricating oil.

3. The feed port of the gate sleeve shall be sealed with grease.

4. The die shall be equipped with locking plate, and the specification shall meet the design requirements.

5. Spare parts and wearing parts shall be complete, with detailed list and supplier name attached.

6. The water, liquid, gas and electricity inlet and outlet of the mould shall be sealed to prevent foreign matters from entering.

7. Spray paint on the outer surface of the mould, if required by customers.

8. The mould shall be packed with moisture-proof, water-proof and bump proof packaging. If the customer has requirements, it shall comply with the requirements.

9. Die product drawings, structural drawings, cooling and heating system drawings, hot runner drawings, details of spare parts and die material suppliers, operation instructions, die test report, factory inspection certificate and electronic documents shall be complete.