Injection mold processing plant Approved standards
Injection mould Recognize the mold standards from three aspects of mold structure, rubber part quality and injection molding process requirements, so as to evaluate and score the mold quality, which can continuously improve the mold quality; Ensure that the mold can be put into production normally and produce qualified rubber parts to meet the requirements of product design.
1. Mold structure
(1) Die material
① The steel used for each plate of the mold shall not be less than 1050 steel. (equivalent to Japanese ace steel)
② The surface hardness of materials used for embryo, side nail, back nail, middle bracket and middle bracket shall not be lower than HRC60.
③ Super P20 steel (such as 718, M238, etc.) is used for front mold and front mold insert of ABS and HIPS materials. General P20 steel (such as MUP, M202, etc.) is used for the rear formwork, and 1050~1055 steel or better steel is used for the rear formwork inserts.
④ 420 steel (such as S136, M300, M310, etc.) shall be used for front and rear moulds and inserts of corrosive materials such as PC, POM, PE, etc.
⑤ The steel used for the beer mirror mold is 420 steel (such as S136, M300, M310, etc.).
⑥ The surface hardness of lifter and swing bar shall not be less than HRC35, and the surface hardness of push plate shall not be less than HRC28.
⑦ If the customer requires the use of mold steel, the mold factory shall meet the customer's requirements.
(2) The mold shall have structure
1. Mold identification: words shall be printed outside the mold according to customer requirements. The mold embryo shall be marked with P/N number and rubber part number according to the position required by the customer, the mold cavity number shall be marked for one mold with multiple cavities, and the insert number shall be marked for multiple inserts according to the design requirements.
2. The mold shall be installed with proper flange ring and standard code mold pit shall be opened.
3. The three plate mold shall be installed with locks and locking nails, as well as pull hooks and nozzle plates, and the spring ring shall be opened first.
4. The mold bottom plate shall be provided with qualified ejector holes, and the hole position shall meet the requirements of ejection balance.
5. The ejector plate of the mold shall be equipped with a return spring. When closing the mold, the front template shall first contact the return pin, otherwise the mold shall be installed with a return mechanism first (otherwise required for line structure).
6. Traveling position structure: the movement of traveling position shall be smooth, and the contact surface shall be provided with oil grooves. The travel position shall be equipped with a spring to make the travel position pop out, and a limit device shall be installed. The total push out height of the Huff block moving in the height direction cannot exceed 2/5 of the length of the guide chute.
7. Ejecting mechanism: the ejector pin shall be set so that the plastic part will not have permanent deformation, white top and affect the appearance of the plastic part when demoulding. The thimble mechanism shall be flexible, reliable and free from wrong action. When the top surface of the ejector pin and the ejector sleeve is not flat, the ejector pin and the ejector sleeve should be positioned.
8. Garbage nails shall be set evenly on the bottom plate, and the height of garbage nails shall be consistent.
9. The large formwork of 4545 or above level shall be provided with intermediate supporting edges. When the number of the sleeves in a set of formwork reaches or exceeds 16, the intermediate supporting edges shall be added.
10. The diameter and length of the runner shall be processed reasonably. On the premise of ensuring the forming quality, the process shall be shortened as far as possible, and the sectional area shall be reduced to shorten the filling and cooling time. At the same time, the plastic loss of the gating system shall be less. The flow passage shall be generally provided with a cold well.
11. The cavity distribution shall be reasonable, which shall comply with the principle of simultaneous filling of all cavities. The gate setting shall not affect the appearance of the rubber part, which shall meet the assembly requirements of the rubber part. The residual amount of the gate shall be as small as possible under the conditions that the beer production allows.
12. Cooling system: the temperature difference of each part of the mold surface shall be within 10 ℃ when the water conveying runner is split. The position of the inlet and outlet holes of the water conveying channel will not affect the installation, and the size of the throat is 13mm. The inserts, rows, etc. on the surface of the cavity should generally be filled with water, and the inserts such as battery pockets, handle positions, horn positions, etc. must be filled with water. The water conveying channel of the mold shall be watertight, and the inlet and outlet of the channel shall be marked with "OUT" and "IN". If there are multiple groups of water conveying channels, the group number should also be added.
13. The position where the battery pocket produces greater wrapping force on the front mold shall be evenly increased with needle hooks at the corresponding rear mold position.
14. The die structure ensures smooth exhaust.
15. If the column height exceeds 20mm, the driller shall be used. If the bone height exceeds 25mm, the glue feeding rice shall be added evenly according to the design requirements.
16. The die should be evenly distributed according to the strength requirements to prevent die deformation.
17. The stress center of the mold cavity shall be consistent with the mold center as far as possible, and the center of the mold cavity shall not exceed 25% of the mold center.
18. Volcanic crater shall be added at the corresponding rear formwork column position that may cause shrinkage on the external surface.
19. The parting surface is unidirectional inclined plane and large deep cavity and other molds. The parting surface should be equipped with a reliable self-locking device.
(3) Structure not allowed by the mold
① No sharp steel and thin steel with height greater than 2mm and thickness less than 1mm are allowed in the mold.
② The ejector pin is not allowed to contact the front mold except for the BOSS column.
③ No abnormal noise is allowed when opening and closing the mold.
④ It is not allowed to fail the red lead test within 5mm of the cavity edge, and the red lead test on the parting surface is not allowed to be less than 80%.
⑤ All fastening screws shall not be loosened.
⑥ All crochets are not allowed to be in different directions.
⑦ Adhesive parts are not allowed to be stuck.
⑧ The mold shall not be ejected out of balance.
⑨ The front and rear templates in the height direction of the mold are not allowed to be short of pulling holes.
⑩ Missing or wrong parts are not allowed for mold assembly.
2. Rubber part quality
(1) Basic dimensions
① The geometric shape, size and accuracy of rubber parts shall meet the requirements of formal and effective mold drawing (or 3D document).
② General structural dimension standard.
■ The average glue thickness is generally required for rubber parts, and the non average glue thickness shall meet the drawing requirements.
■ Stud root diameter: M3 screw is φ 6.0+0.2mm, crater diameter φ 10.0mm；
■ M2.6 screw is φ 5.0+0.2mm, crater diameter φ 9.0mm。
■ Fork bone and periosteal root thickness: 1.2+0.2mm.
■ Top thickness of button top RUBBER cross bone: 0.9+0.1mm.
■ Top wall thickness of the driller column: 1.2 ± 0.1mm.
■ The thickness of the glue at the needle position of the rear mold of the battery box is less than 2.0mm.
■ The misalignment of the front and rear molds at the same position as the PL surface is less than 0.05 mm.
■ Face bottom shell fit. The misalignment of PL surface is required to be less than 0.1 mm for the second or third level lip fitting, without scratching; The unilateral clearance of the wrap lip fit is 0.1~0.3 mm, and the larger value shall be taken for complex shape.
■ The horizontal unilateral clearance between the battery door and the battery box is 0.2~0.3 mm.
■ The button fits with the hole. Generally, the unilateral clearance between the button and the hole is 0.15~0.25 mm. The unilateral clearance between the special-shaped button and the hole is 0.3~0.4 mm, and the clearance between the fuel injection buttons should be taken as the maximum. When the button matches with the flower, the matching condition can meet the safety test standard.
■ Insertion and clamping position matching. The fit unilateral clearance between the card inserting door and the face bottom shell is 0.2~0.3 mm. The unilateral clearance between the socket and the plug box is 0.5mm.
■ The axial unilateral small clearance of the four large parts at the rotating shaft position is 0.1~0.2 mm.
■ The unilateral clearance between LOCK and its matching pillow hole is 0.2 mm.
■ The unilateral clearance between the support and its matching hole is 0.1~0.2 mm, and the greater value shall be taken if the length is greater than 150 mm.
■ The unilateral clearance between COVER and its mating hole is 0.1 mm.
■ The unilateral clearance between ROLLER and its mating hole is 0.5~1.0 mm.
(2) Surface defects (if the process conditions cannot be met)
① No defects are allowed on the surface of rubber parts.
A. Incomplete glue feeding (or lack of material, stagnant water) B, coke burning C, white top
D. White line E, peak F, blistering
G. Whitening (or cracking, breaking) H, printing I, wrinkles
③ Limited surface defects and acceptance.
1. Watermarks
A. The strength of watermarks can pass the functional safety test.
B. Generally, the length of the water mark on the impact hole is not more than 15mm, and the water mark on the round horn hole is not more than 5mm.
C. The length of water inclusion lines at the fusion of multiple nozzles shall not be more than 20 mm.
D. The water mark on the wrist is not in the middle of the wrist or at the stress position.
E. The outer surface of the rubber part corresponding to the column position is free of water inclusion.
F. The key bracket with fire pattern on the surface is free of water inclusion.
G. There is no limit on the position where the strength is allowed for the water mark of the internal part clamp.
2. Shrinkage
A. Slight shrinkage is allowed at the inconspicuous position on the surface of the rubber part (no dent can be felt).
B. The internal parts may shrink slightly if the size allows.
C. The shrinkage under the condition that the non appearance surface of the rubber part does not affect the size and strength is not limited.
3. Drag white
A. Slight whitening is allowed on the side of the rubber parts with spark lines or sun lines, and can be eliminated by grinding paste processing.
B. The appearance of the rubber part is not white on the first side.
4. Deformation
A. The unevenness of the support foot of the larger bottom shell is less than 0.3mm.
B. The unevenness of KEY support is less than 0.5mm.
C. The rubber part deformation shall be controlled by rack adjustment after plastic injection.
D. Except for the above items, the rubber parts are not deformed.
5. Aeroglyph
A. For rubber parts with PE, PA, PVC, PC and other rubber materials, slight air lines are allowed at the nozzle. The air ripple does not protrude 3.0mm from the nozzle.
B. For doll type rubber parts with thick and uneven wall thickness, slight air lines are allowed at the nozzle position and the carved protruding position.
C. Except for the above two items, the surface of the rubber part is free of air lines.
6. Yellow gas
A. Large bottom shell with water entering in the middle; Slight yellow gas is allowed near the nozzle. The degree of yellow gas should not affect the natural color of the rubber part, but only slightly change the color depth.
B. Except for the above conditions, the rubber parts have no yellow gas.
7. Outlet residue
A. There is no interference in the nozzle position and residues of rubber parts during assembly.
B. There is no glue scum at the nozzle position, and the film at the thimble position dives into the water.
C. The appearance surface of rubber parts after assembly has no traces of water opening.
8. Snakeskin
A. The appearance surface of rubber parts after assembly is free of snake lines.
B. The internal parts or non appearance surfaces after assembly are allowed to have snake lines if they cannot be improved.
9. Sharp and thin rubber parts
Except for piano keys and other rubber parts that are allowed to have specially designed sharp and thin glue positions, other rubber parts have no sharp and thin glue positions.
(3) Surface finishing requirements
① Surface highlight: the highlight surface should be flat and have a mirror effect; The non appearance surface of the front mold surface and the internal parts are allowed to have slight machining traces on the surface. No scratch, rust, spot and other defects are allowed on the high gloss surface.
② Surface decoration (EDM or sunburn). The grain shall meet the design requirements, and the grain shall be uniform and the side shall be consistent with the surface. The grain of each accessory shall be consistent. (except those matched with cores)
③ Surface font. The height of the font on the surface shall meet the design requirements and shall be uniform. The font width, size, density, number of characters and position shall meet the film requirements.
④ CORE surface decoration. Generally, the CORE surface needs to be polished without obvious spark lines and machining tool marks, except for special requirements. The appearance of transparent rubber parts or assembled surfaces shall meet the design requirements.
