Double Injection Mould Design Requirements
Double Injection Mould: two kinds of plastic materials are injected on the same injection molding machine, which are divided into two parts, but the product is only molded once. Generally, this kind of molding process is also called double material injection molding, which is usually completed by one set of molds and requires a special two-color injection molding machine.
Plastic Over Mold: two kinds of plastic materials are not necessarily injected on the same injection molding machine, and they are formed in two times; after the products are taken out of one set of mold, they are put into another set of mold for the second injection molding. Therefore, the general molding process is usually completed by two sets of molds, without special two-color injection molding machine.
The two-color mold has been popular in the market, and because this process can make the appearance of the product more beautiful, easy to change colors without spraying, it will definitely be the market trend. According to the problems encountered in the design and production of the two-color mold at present, I hope you will follow in the future design work. If not, please refer to the notice of new mold design.
1. The two shapes of cavity are different, forming one product respectively. The two shapes of the core are exactly the same.
2. After the front and back dies of the die rotate 180 ° in the center, they must match. This check must be done during design.
3. Pay attention to the position of the top stick hole, with the minimum distance of 210mm. For large dies, the number of jacking rod holes shall be increased appropriately. Moreover, because the top stick attached to the injection molding machine itself is not long enough, we must design an extended top stick in our mold, which is about 150 mm longer than the mold base plate.Two locating rings must be designed on the back mold bottom plate.
4. The total thickness of front formwork panel plus a plate shall not be less than 170mm. Please carefully check other reference data of this type of injection molding machine, such as the maximum mold thickness, the minimum mold thickness, the distance between the top stick hole, etc.
5. The nozzle of the three plate mold should be designed to automatically demould. Pay special attention to whether the demoulding action of the soft rubber nozzle is reliable.
6. The depth of sprue at the front side shall not exceed 65mm. The distance between the top of sprue on the upper side (large water port) and the center of mold embryo shall not be less than 150 mm.
7. When designing the second injection molding cavity, in order to avoid the cavity inserting (or wiping) damage to the rubber position of the first molded product, part of the cavity can be designed. However, the strength of each sealing position must be carefully considered, i.e. in injection molding, is there any possibility of plastic deformation under large injection pressure, leading to the possibility of batch front in the second injection molding?
8. During injection molding, the product size of the first injection molding can be slightly larger, so that it can be pressed more tightly with another cavity during the second molding to achieve the sealing effect.
9. Pay attention to whether the flow of plastic will impulse the products that have been formed for the first time during the second injection molding, and make their glue position deformed? If this is possible, we must find ways to improve.
10. Before closing the A and B plates, pay attention to whether the front mold slider or lifter will reset first and crush the product? In this way, it is necessary to find a way to close the die first on board a and B, and then reset the slider or life of the front die.