Two - color mold design and injection molding should pay attention to matters
Two-color mold is two kinds of plastic materials in the same injection molding machine injection molding, divided into two molding, usually composed of two sets of mold, after the mold to rotate 180 degrees, while the former mold does not move, but the product only mold once the mold. Generally this molding process is also called double injection molding, and the need for special two-color injection molding machine.
Two-color mold design and injection molding should pay attention to the following matters:
1, two-cavity and the core of the water distribution as much as possible, and balanced, the same.
2, the mold before the mold to the center of rotation 180º, must be consistent with the back mold. Design must pay attention to this point.
3,99% of the situation is the first injection of hard plastic parts of the product, and then injection of soft parts of the product. Because soft rubber is easy to deform.
4, three plate mold outlet can be designed to be able to automatically stripping action. In particular, pay attention to the soft nozzle outlet action is reliable.
5, in the design, please carefully view the two-color mold injection molding machine parameter data, such as the maximum capacity of the thickness, the smallest capacity of the thickness, the top hole distance.
6, injection molding, the first injection molding product size can be slightly larger, so that it can be molded in the second time with another cavity pressure more tight, in order to achieve the role of sealant.
7, the former mold of the two shapes are different, respectively, forming a product. And the two shapes of the mold are exactly the same. (Note: if not the same, to do before the mold block to ensure that the same model)
8, pay attention to the second injection molding, the plastic flow will impulse the first time has been formed a good product, so that the plastic deformation? If this is possible, we must find ways to improve.
9, in order to make two kinds of plastic "sticky" more tight, to consider the material between the "sticky" and the mold surface roughness. Two-color mold injection has a special TPU; and mold surface more smooth, they "sticky" more tight.
10, in the design of the second injection molding cavity, in order to avoid the cavity plug (or wipe) injury has been a good product for the first time plastic bit, you can design part of the shelter. But must be carefully considered the strength of each sealant, that is: in the two-color mold injection, whether there will be a large injection pressure, the plastic deformation, resulting in the second injection may have the potential to produce a batch.