Two-Color Mold Design And Injection Molding

- Aug 08, 2018-

23. The depth of the front side SPRUE should not exceed 65mm. The interval from the top of the upper side (large nozzle) SPRUE to the center of the mold is not less than 150 mm.


24. When designing the second injection of CAVITY, in order to prevent CAVITY from inserting (or rubbing) the glue position of the product that was formed for the first time, a partial avoidance can be designed. However, it is necessary to carefully consider the strength of each sealant position, that is, in the injection molding, whether there will be deformation of the plastic under large injection pressure, which may lead to the possibility of a second shot.


25. When injection molding, the size of the first injection molding product can be slightly larger, so that it can be pressed tighter with another CAVITY in the second molding to reach the sealing effect.


26. Before the A and B plates are closed, pay attention to whether the front mold Slider or Lifter will reset and crush the product first? In this case, it is necessary to think of the method of clamping the A and B boards first, and then the SLIDER or LIFET of the front mode is reset.


27. The water transport layout of the two CAVITY and CORE is as full as possible and balanced.


28.99% of the cases are the hard rubber parts of the first injection molding products, and the soft rubber parts of the re-injection products. Because the soft rubber is easy to deform.


29. Pay attention to the plastic injection activity during the second injection molding, will it be the first time to shape the product, so that the plastic position is deformed? Assuming this is possible, we must think of ways to improve.


30. Two-color molds must be carefully selected gate location. It is best to choose a latent glue in one product so that the product and runner can be cut off automatically. Three-plate molds or hot runner molds can be considered when latent feed cannot be used. If the material is a point gate, do a wave, to avoid hitting the secondary material due to one entry residue.


31. Two-color injection molds often use rotary injection molds. The punch/die at two positions of the rotary injection mold requires uniform size and precision, and works well with the die/male. When the ejection mechanism on the two-color injection molding machine cannot be utilized, a hydraulic ejection and release mechanism must be provided on the rotary table.


32. Two-color mold injection molding usually uses the same plastic of different colors, or it can be two different plastic raw materials. At this time, it is necessary to consider the interface effect, shrinkage difference, processing parameters and other aspects of the two materials. Two-color injection molding products are generally made of hard plastics such as ABS and PC, and TPE soft plastics. Due to the cost or application, it is necessary to fully consider the two materials that may be used without good adhesion and fusion. Mold treatment at the joint (generally there will be a phenomenon of embossing the road or need to be used to seal the groove) and thickness of the material and many other problems! In order to make the two plastics "stick" tighter, think about the "stickiness" between the materials and the roughness of the outer surface of the mold. Two-color injection molding has a special TPU material; the smoother the mold appearance, the tighter they stick.