What are the acceptance criteria for injection molds?

Thu May 25 15:53:17 CST 2023

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

First. Mould material

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

2, embryonic division, side nails, back to the nail, in the toast division, in the toast 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 mold with general P20 steel (such as MUP, M202, etc.), after the mold 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, beer mirror mold steel used for 420 steel (such as S136, M300, M310, etc.).

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

Second, the mold should have the structureInjection Mold Suppliers

1、 Mold identification: 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、 Suitable flange ring should be installed in the mold and standard code pit should be opened.

3、 Three plates mold should be installed with lock and locking 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 touch the return pin first, otherwise the mold should be installed with reset mechanism first (separate requirement for those with line position structure).

6、Line position structure.

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

b. A spring should be installed on the line position to make the line position pop up and a limit device should be installed.

c. In the height direction of the movement of the Haff blocks can not exceed 2/5 of the length of the guide slots.

7、Ejector mechanism.

a, the ejector pin should be set so that the plastic parts off the mold does not produce permanent deformation, top white, does not affect the appearance of plastic parts.

b, the ejector mechanism should ensure flexible, reliable, no wrong action.

c, thimble, barrel top surface is not flat, thimble, barrel should be positioned.

8、Trash nails should be set evenly on the bottom plate, and the height of trash nails should be consistent.

9、4545 or above large die should be added in the bracket side, a set of die in the number of barrel reaches or more than 16 should be added in the bracket side.

10、The diameter and length of the runner should be reasonable, and the process should be shortened as much as possible under the premise of guaranteeing the forming quality, reducing the broken area to shorten the filling and cooling time, and the loss of plastic in the pouring system should be the least. The runner should be set up with cold material well 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 the gate should not affect the appearance of the plastic parts, to meet the plastic parts assembly, as far as possible under the conditions allowed by the beer to achieve the least amount of residue of the gate.

12 Cooling system.

a. The surface of the runner should be divided so that the temperature difference of each part of the mold surface is within 10℃.

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

c, in the cavity surface inserts, line position, etc. should generally pass into the transport water, battery pocket, handle position, horn position and other inserts must pass into the transport water.

d. The mold runner should not leak, and the entrance and exit of the runner should be marked with the words "OUT" and "IN". If it is more than one group of water runner should also be added to the group number.

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

14 Mould structure to ensure smooth exhaust.

15 The height of the column position is more than 20mm, and the height of the bone position is more than 25mm, and the rubber should be evenly increased 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 should have a crater which will cause shrinkage in the corresponding post-mold column position.

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

Third, the mold does not allow the structure

1、The mold is not allowed to have sharp steel and thin steel with height more than 2mm and thickness less than 1mm.

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、No less than 80% of the cavity edge within 5 mm of the cavity is allowed to be tested, and no less than 80% of the parting surface is allowed to be tested.

5、 All fastening screws are not allowed to be loose.

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、 No lack of drawing holes in the front and back of the mold height direction.

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