Injection Mold Approval Standards

Purpose: To establish the criteria for approving molds from three aspects: mold structure, quality of rubber parts and requirements of injection molding process, according to which the quality of molds is evaluated and scored in the hope of continuously improving the quality of molds to ensure that the molds can be put into production normally and produce qualified quality rubber parts to meet the requirements of product design.
 

I. Mold structure part

(1) Mold material

1. The steel used for each plate of mold embryo is not less than 1050 steel. (equivalent to the Japanese King steel)

2. Embryo Division, side nails, back nails, in the Toji, in the Toji side of the material used in the surface hardness of not less than HRC60.

3. ABS, HIPS material front mold and front mold inserts, with super P20 steel (such as 718, M238, etc.). After the die with general P20 steel (such as MUP, M202, etc.), after the die insert with 1050 ~ 1055 steel or better material steel.

4. Beer PC, POM, PE and other corrosive materials before and after the mold and its inserts need to use 420 steel (such as S136, M300, M310, etc.).

5. 420 steel (such as S136, M300, M310, etc.) is used for mirror mold.

6. The surface hardness of the inclined top and pendulum is not less than HRC35, and the surface hardness of the push plate is not less than HRC28.

7. If the customer specifies that the mold steel should be used, the mold factory should meet the customer's requirements.

(2) The mold should have the structure

1. Mold marking: outside the mold embryo should be typed according to the customer's requirements. The mold embryo should be marked with P/N number and rubber part number according to the position specified by the customer, one mold with multiple cavities should be marked with cavity number, and multiple inserts should be marked with insert number according to the design requirement.

2. The mold should be installed with suitable flange ring and open standard code mold pit.

3. Three plates mold should be installed with snap lock and lock nail, as well as should be installed with pulling hook and water mouth plate, first open the spring ring.

4. The bottom plate of the mold should be opened with qualified top stick hole, and the hole position should meet the requirement of ejecting balance.

5. Mold ejector plate should be installed with reset spring, when closing the mold, the front template should contact the return pin first, otherwise the mold should be installed with reset mechanism first (separate requirement for line position structure).

6. Line position structure.

The movement of line position should be smooth, and the contact surface should be opened with oil groove.

The spring that makes the line position pop up should be installed on the line position, and the limit device should be installed.

In the height direction of the movement of the Haff blocks should not exceed 2 / 5 of the length of the guide slot.

7. Ejector mechanism.

The ejector pin should be set so that the plastic parts are not permanently deformed, white, and do not affect the appearance of the plastic parts when they are removed from the mold.

The ejector mechanism should be flexible and reliable, and no wrong action should occur.

When the top surface of the ejector and syringe is not flat, the ejector and syringe should be positioned.

8.Garbage nails should be set evenly on the bottom plate, and the height of garbage nails should be consistent.

9.4545 or above large die should be equipped with middle bracket edge, and the number of sizers in a set of die reaches or exceeds 16 should be equipped with additional middle bracket edge.

10.The diameter and length of runner should be reasonable, shorten the process as much as possible under the premise of guaranteeing the forming quality, reduce the broken area to shorten the filling and cooling time, meanwhile the loss of plastic in the pouring system should be the least. The runner should be equipped with cold material wells in general.

11 . The distribution of cavities should be reasonable, in line with the principle that each cavity should be filled at the same time, the setting of gate should not affect the appearance of plastic parts, meet the assembly of plastic parts, and try to achieve the least amount of gate residue as far as possible under the conditions allowed by the beer.

12. Cooling system.

The surface of the water channel should be divided so that the temperature difference between the parts of the mold surface is within 10℃.

The location of the inlet and outlet holes of the runner does not affect the installation, and the throat size is 13mm.

The inserts on the surface of the cavity, line position, etc. should generally be connected to the water flow, and the battery pocket, handle position, horn position and other inserts must be connected to the water flow.

The mold runners should be leak-free and marked with "OUT" and "IN" at the entrance and exit of the runners. If there are multiple groups of runners, the group number should be added.

13. Battery pockets and other parts of the front mold that produce large clamping force should be evenly increased after the corresponding part of the mold hooks and so on.

14. Mold structure to ensure smooth exhaust.

15. The height of the column position exceeds 20mm, and the height of the bone position exceeds 25mm should be increased evenly according to the design requirements.

16. The mold should be evenly distributed according to the strength requirements to prevent mold deformation.

17. Mold cavity stress center should be consistent with the mold center as far as possible, and its cavity center should not exceed 25% of the mold center at most.

18. The shape surface has the corresponding back mold column position that will cause shrinkage should be added to the crater.

19. The parting surface is one-way bevel and large deep cavity molds, the parting surface should have a reliable self-locking device.

(3) The structure of the mold is not allowed

1. The mold is not allowed to have sharp steel and have a height greater than 2mm, thickness less than 1mm of thin steel.

2. In addition to the BOSS column, the ejector pin is not allowed to contact with the front mold.

3. No abnormal sound is allowed when the mold is opened and closed.

4. The red-dan test is not allowed within 5mm of the edge of the cavity, and the red-dan test on the parting surface is not allowed to be lower than 80%.

5. All fastening screws are not allowed to be loosened.

6. All hooks and needles are not allowed to appear in different directions.

7. No sticky mold phenomenon is allowed in the rubber parts.

8. No unbalanced ejection of the mold is allowed.

9. The mold height direction before and after the template does not allow the lack of drawing holes.

10. The mold assembly does not allow to miss or install the wrong parts.


 

II, the quality of rubber parts part

(1) Basic size

1. The geometry, size and precision of the rubber parts should be in accordance with the official and valid mold opening drawings (or 3D files).

2. General structure size standard.

The general requirements of the rubber parts to achieve the average rubber thickness, non-average rubber thickness should be in line with the requirements of the drawings.

Stud root diameter: M3 screw is φ6.0+0.2mm, crater diameter φ10.0mm.

M2.6 screw is φ5.0+0.2mm,crater diameter φ9.0mm.

Thickness of fork bone and root of perimeter bone: 1.2+0.2mm.

Thickness of top RUBBER crossbone of button: 0.9+0.1mm

Thickness of the top wall of the cylinder column: 1.2±0.1mm.

The thickness of the adhesive at the hook and pin position of the battery box rear mold is less than 2.0mm.

The misalignment of the front and rear mold at the same PL surface is less than 0.05 mm.

Face and bottom shell fit.

A, secondary or tertiary stop fit requires PL surface misalignment less than 0.1 mm and no scratching.

B. The unilateral clearance of the package stop fits is 0.1~0.3 mm, and the larger value is required for complex shape.

The unilateral clearance between battery door and battery box in horizontal direction is 0.2～0.3 mm.

Knob and hole fit. General geometry button and hole unilateral clearance of 0.15 ~ 0.25 mm. shaped button and hole unilateral clearance of 0.3 ~ 0.4 mm, oil spray button clearance should be taken as a large value. When the button and the flower boy fit together, the fit can meet the safety test standard.

Insert the card position with. The gap between the card door and the bottom case is 0.2~0.3 mm, and the gap between the socket and the box is 0.5 mm.

The minimum axial clearance of the four major parts is 0.1~0.2 mm.

The unilateral clearance between LOCK and its mating pillow position hole is 0.2 mm.

The unilateral clearance between the bracket and its mating hole is 0.1~0.2 mm, and the larger value is taken if the length is more than 150mm.

The clearance between COVER and its mating hole is 0.1 mm on one side.

ROLLER and its mating hole unilateral clearance is 0.5 ~ 1.0 mm.

(2) Surface defects (if process conditions cannot be met)

1. No defects are allowed on the surface of the rubber parts.

A, uneven glue (or lack of material, stagnant water) B, burnt C, top white

D, white line E, phi peak F, blistering

G, pulling white (or pulling crack, pulling off) H, baking marks I, wrinkles

2. Surface restricted defects and acceptance degree.

<1>. Water clamping pattern

A. The strength of the water-clamping pattern can pass the functional safety test.

B, general touch through the hole pinch waterline length is not more than 15 mm, round flare hole pinch waterline is not more than 5 mm.

C. The length of the water clamping pattern at the fusion of multiple water outlets is not more than 20 mm.

D, wrist at the water clamping pattern is not in the middle of the wrist or stress position.

E. The outer surface of the corresponding plastic parts of the column position is free of water trap.

F. The key holder of the surface sparkle pattern has no water trap.

G. The internal parts of the water clamping pattern is not limited in the position of strength allowed.

<2>. Shrinkage

A. Slight shrinkage is allowed in inconspicuous position on the surface of the rubber parts (no dent in the hand).

B. The internal parts can have slight shrinkage under the size allowed.

C. The shrinkage of the non-appearance surface of the rubber parts without affecting the size and strength is not limited.

<3>. Dragging white

A. Slight white dragging is allowed on the side of plastic parts with sparkle pattern or sun pattern, and it can be eliminated by abrasive paste processing.

B. The appearance of the glue part has no white dragging 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 bracket is less than 0.5mm.

C. Deformation of rubber parts should be controlled by rack adjustment after beer molding.

D. In addition to the above, no deformation of the rubber parts.

<5>. Air pattern

A. For PE, PA, PVC, PC and other rubber parts, a slight air pattern is allowed at the water outlet. The air pattern does not protrude from the water outlet 3.0mm.

B. For the plastic parts with thicker and uneven wall thickness of doll, slight air lines are allowed at the water outlet and the carving projection.

C. In addition to the above two items, there is no air pattern on the surface of the plastic parts.

<6>Yellow gas

A、Large size and water in the middle of the bottom shell; slight yellow gas is allowed near the water outlet, the degree of yellow gas should not affect the original color of the plastic parts, only slightly change the color depth.

B. In addition to the above situation, there is no yellow gas in the rubber parts.

<7>. Water outlet residue

A. There is no interference between the location of the water outlet and the residue of the rubber parts during assembly.

B. No glue shit flower in the water outlet position and no film diving into water in the ejector position.

C. The appearance surface of the glue parts after assembly is free of water outlet traces.

<8>. Snake pattern

A. There is no snake pattern on the appearance surface of the assembled parts.

B, internal parts or non-appearance surface after assembly is allowed to have snake pattern if it cannot be improved.

<9>. Sharp and thin plastic parts

Except for the keys and other plastic parts which are allowed to have specially designed sharp and thin plastic bits, other plastic parts have no sharp and thin plastic bits.

(3) Surface finishing requirements

1. Surface highlighting.

High gloss surface should be flat and have mirror effect.

The non-appearance surface of the front mold surface and internal parts are allowed to have slight processing traces on the surface.

The high-gloss surface is not allowed to have defects such as scratches, rust stains and spots.

2. Surface decoration pattern (EDM or sunburst pattern)

The grain pattern meets the design requirements, and the grain pattern should be uniform and consistent with the surface on the side.

Mutual parts require the same grain pattern. (Except for those with old parts to match)

3. Surface fonts.

The height of the surface font meets the design requirements and should be uniform and consistent.

Font width, size, density, number of words, location in line with the requirements of the film.

4. CORE surface finishing.

General CORE surface needs to save light, no obvious sparkle pattern and processing knife marks, except for special requirements.

Transparent adhesive parts or the appearance of the assembled surface meets the design requirements