In the manufacture of two-color die, it is usually necessary to conduct die opening evaluation, optimize design and process parameters first, so as to avoid unnecessary errors and meet the high quality requirements of mass production. Common problems of two-color mold opening include: parting, crushing, overflow, obvious glue line, etc.
1、 Exotype
The reasons for the product parting during the opening of the two-color mold are generally as follows:
1. The temperature difference between male mold and female mold is large
2. The gripping force of the male mold is insufficient, and the gripping force of the female mold is large
3. The adhesion of die face is large
4. Abnormal resin shutter
5. The module switching sequence is abnormal.
2、 Crush injury
The reasons for the finished product crushing during the opening of the two-color mold are generally:
1. The amount of second shot preloading is too large
2. Part of the second shot mold core does not avoid the space or the space is insufficient
3. The first shot is deformed, resulting in crushing by the second shot.
3、 Gum overflow
The reasons for overflow of two-color mold during mold opening are generally as follows:
1. Insufficient preloading at the mold core preloading position
2. The molding condition is poor, and the finished product is not full
3. The size of the first shot mold core is not in place, resulting in insufficient thickness of the finished product
4. If the second shot is made of PU, TPE and other soft materials, the material temperature and mold temperature may be too high.
4、 Obvious glue gathering line
The reasons for obvious glue line in the opening of two-color mold are generally:
1. The mold is not vented or the venting is insufficient
2. Poor gate position
3. The molding condition is poor, the material and mold temperature are low, and the injection pressure and injection speed are low.