Plast Injection Molds Design Inspection Points

Building high quality plastic injection molds need high level plastic injection mold design, that's why we need to find out which key points are so important while checking plastic injection mold design, firstly we should check whether plastic thickness is even, if not uniform, it will cause shrinkage and affect the appearance.


Mold opening direction
Determine parting surface and draft angle
1. Select the maximum value of projection of parting surface in direction of mold opening as simple as possible
2. Penetration position: try to choose the rear mold, if you want to touch the front mold, it is easy to walk, affect the appearance, and use flat contact.
3. Pillow position: Pillow 5-8 mm, and then level with the large parting surface, pull the glue part 3 degrees, pull 3 degrees behind or avoid the air.
4. Insertion position: use the side to work, pull out 3 degrees, usually as an insert.


Drafting principle
1: Draft in the direction of reducing glue.
2: The largest end of the shaft is the product size, and the smallest end of the hole is the product size.


2D mirror
2D must pay attention to the mirror image and shrink, if you forget this step, most of the mold will be scrapped.


Shrinkage calculation
Products with small shrinkage rate (below 5 ‰) can be shrunk according to experience, and products with large shrinkage rate, such as a product that can hold 18 ‰, 20 ‰ or even 22 ‰, must first seek the opinion of the person in charge before releasing. So as not to match size of supporting products.


Coaxial computing
The eccentric KO should be coaxial


Line point
1. Generally, the inclined guide column is used as the power, and the T-shaped groove is used for the relatively small core-pulling distance, and the oil cylinder is used for the core-pulling when it is larger than 30mm.
2. The angle of the inclined guide column is 2-3 degrees smaller than the angle of the shovel.
3. The rear die row extends into the front die by more than half of the total height, which can save the shovel and use the front die processing surface as the pressing surface.
4. The width of the row position is greater than 100mm, try to use 2 oblique guide columns, and a guide slot in the middle of greater than 150mm.
5. Row positioning: try not to use Bozi marbles (the force is not strong enough), use screws to position.
6. When the row position is at the TOP position, the spring must be placed, otherwise the row position is opened and the mold cannot be returned to the position due to gravity, resulting in crash.
7. Projection direction projection, if there is a slanted top or thimble under the row position, the first reset mechanism should be set, otherwise there may be interference between the row position and the slanted top or thimble.
8. Walking position and walking, walking beer handle, covered rubber position, straight out.
9. The stroke of the line position should be greater than the buckling position by 2 to 3mm, and the stroke of the cylinder should be greater than the buckling position by 10mm.
10. In order to increase the firmness of the backhoe, try to do backhoe as much as possible.


Inclined roof design
1. The inclined top is generally 3-8 °, not more than 15 °.
2. The ejection stroke is generally greater than the buckling position 0.5-1mm.
3. Ejection direction: The glue position should be flat or upward, otherwise delayed oblique topping. When the width of the inclined top is relatively small, a rack is added to the thimble plate to reduce the height of the inclined top to ensure strength.

Ceeto mold company has been dedicated in design and manufacture high level plastic injection molds over ten years and a group of skilled tooling designers with rich experience in plastic injection moulds design like cooling lines analysis, oil lines layout design, hot runner system layout in mold and mold assembly factors etc. Therefore, checking mold design is also key steps while building high quality plastic injection molds.