Two-color mold design of the basic principles:
Hard rubber to do 1, soft rubber to do 2 times;
(2) transparent to do 1, non-transparent to do 2 times;
(3) plastic molding temperature to do a low molding temperature to do 2 times;
The above is the basic principle of doing two-color mold, otherwise the mold will do the same; In addition, the plastic seal as far as possible by breaking the plastic, without interrupting the sealant, even if it is recommended that customers modify the product should also try to rely on broken sealant;
1. Die embryo guide bushings must be up and down symmetrical, front and rear mold symmetry.
After the mold to rotate 180 degrees, the former die does not move.
3 product spacing must be based on the distance between the injection molding machine muzzle, some foreign two-color injection molding machine muzzle spacing is adjustable, and some are not adjustable, the domestic can not be adjusted.
4. Two independent ejection system, the top stick is also 2. After the two molds the same product, the thimble is the same, is the rotation relationship, must not be made in translation.
5. Thimble plate can only be reset with a spring, not forced reset with screws, because after the mold to be rotated.
6. Side lock must be in the center of the mold on both sides, and before and after the mold symmetry, or when the mold after the rotation of the former model 180 not match.
7. If the injection point spacing and injection molding machine nozzle spacing is different, the top hole to be made into a waist type, because the injection molding machine spacing is not adjustable top stick Note that most of the domestic two-color injection molding machine injection nozzle can not be adjusted.
8. Pay attention to the direction of the parallel nozzle of the injection molding machine provided by the customer. It is the x-axis or y-axis, in order to determine the layout of the product rankings.
9. Water into the water direction must be in heaven and earth side, and each cycle of water access must be on the same side, not water in the days, the water on the ground, because after the mold to be rotated 180 degrees, pay attention to the mold embryo The size of the injection molding machine can not exceed the height of the sink, or can not pick up the water.
10. The first injection of the product to be placed on the non-operating side, because after the first injection of products to be rotated 180 degrees for the second injection, just turned to the operating side, easy to take products.
11. Exit mode code module bits should be in the operating side and non-operating side, not on the world side, because their products should be fully automatic.
12. Parting surface precautions: After the mold parting surface to be merged after the two products obtained after the parting surface for the mold; the former mold parting surface to take a single product, not desirable after the merger of the product Parting surface.
13. Before and after the flange of the negative tolerance of 0.05mm, the two flange pitch tolerance of plus or minus 0.02mm, top stick and the top of the stick hole gap unilateral 0.1mm, before and after the guide sleeve guide column center distance tolerance for the positive and negative 0.01, the mold frame and depth should be plus tolerance, or when the mold rotation 180 degrees, due to the inconsistency between the level of the production front.
14. If the mold embryo plant has been processed embryo mold, factory to process the nozzle and the top of the stick hole, to 4 guide pin hole guide hole center for the reference number, or too much deviation, easy card Die. Stamper set to be identified when the two-color mold embryo, four guide column guide and frame symmetry, after the mold rotated 180 degrees to match the front mold.
15.If it is a two-color after the mold rotation is much simpler, the same as the two front mold core, while the hard plastic injection. Rotation of 180 degrees (Note that the product can not fall when the turn, the gate can be automatically separated), turn To the other side after the injection of soft plastic, injection molding hard plastic need not be arranged thimble, simply arranged in the soft side of the core mold can be another shrinkage to pay attention to, if the soft plastic completely hard plastic entangled, just put hard plastic Shrinking, if it is the outline of the soft rubber glue should be put shrink water.
16. If it is a set of mold two-color mold, then it is a straight barrel, a 90-degree barrel injection, do not need to rotate, just a mold core, soft and hard plastic separation method by the seal glue.
17. cavity two different shapes, respectively, forming a product, while the core of the two appearances intact.
18. Die before and after the model to the center of rotation 180 °, it is necessary to match. This design must be done when this inspection.
19. Note thimble hole location, the minimum interval of 210mm. Large molds to be appropriate to increase the number of top hole and because injection molding machine itself with the thimble is not long enough, so our mold must be designed to increase the thimble, the thimble grow Mold embryo floor about 150mm.
20. Rear mold base plate must be designed 2 locating ring.
21. The total thickness of front panel plus a plate can not be less than 170mm. Please carefully check other reference data of this type of injection molding machine, for example, the maximum thickness of the mold, the minimum mold thickness, the top hole interval and so on.
22. The depth of the front side sprue should not exceed 65mm. The spacing from the top of sprue on the upper side (large spout) to the center of the mold embryo should be not less than 150mm.
23. In the design of the second injection cavity, a cavity can be designed to prevent cavities from being inserted (or rubbed) for the first time in the cavity. However, careful consideration must be given to each location Strength, that is: in the injection molding, whether there will be a large injection pressure, the plastic deformation, leading to the second injection may have approved the possibility of production Feng;
24. In injection molding, the size of the first injection molded product can be slightly larger so that it can be pressed more tightly with the other cavity on the second molding to achieve the encapsulation effect.
25. a, b plate mold before, pay attention to the front mold slider or lifter can reset and crush the product? So, we must think of ways in a, b plate first mold, after the front mold slider or lifet To reset.
26. Two cavity and core of the water layout as full and balanced, the same.
27. 99% of the situation is the first injection of plastic products locally, and then re-injection of soft plastic products. Due to the deformation of soft plastic.
28. Note that in the second injection, the plastic activity will impulse the first time a well-formed product, the plastic deformation? Assuming this possibility, we must think of ways to improve.
29. Two-color mold must be carefully chosen gate position. A product is best to choose the potential into the plastic, so products and flow channels can be automatically cut off. When the potential can not be used when the plastic into the plastic, can be considered three-plate mold or hot runner mold. If the material is a point gate, to be Aberdeen, to avoid entering the point of residue and touch the second material.
30. Two-color injection mold often used rotary injection mold. Rotating injection mold two locations on the punch / die size requirements, accuracy, and with the die / punch well together. When unable to use two-color injection molding machine on the top Stripping mechanism, the turntable must be set up hydraulic ejection stripping mechanism.
31. Two-color mold injection molding is usually the same choice of different colors of plastic, it can be two different plastic materials, this time we must consider the interface between the two materials, shrinkage, processing parameters and so on.
Two-color injection molding products generally abs, pc and other hard plastic with tpe soft plastic-based, due to cost or application, to fully consider the use of two materials may not have good adhesion and fusion between the two materials Between the mold treatment at the junction (usually there will be embossed lines or need to do sealing mold groove) there are many thick material thickness and many other issues! In order to make the two plastic 'sticky' tighter, to think about the material between the ' Sticky 'and the appearance of the mold surface roughness. Two-color injection has a dedicated tpu material; and mold the more smooth appearance, they' sticky more tight.
32. In general, the shrinkage of a two-color mold is dependent on the material at a time, since once the material has already held the contours of the plastic product, the secondary material does not shrink more. As for how to determine the primary and secondary materials, there are Many factors to consider, such as raw material flow, plastic product shape and more.
33. Pay attention to the positioning of the mold before and after; all inserted through the broken surface slope as much as possible, to 0.1mm above.
34. ABS / PC, ABS / PC ABS, ABS / PMMA Two-color injection molding, the need to first injection temperature pc, pc abs or pmma. If it is transparent shell mold most of the flip-mold structure.
35. Transparent large two-color injection molding is a structural design of the need to pay attention to:
a. The reservation of the gate position must be agreed with the mold factory in advance;
b. The thickness of the material is recommended to use more than 0.8mm transparent, non-transparent 0.7mm or more, non-transparent as far as possible the use of light-colored,
c. Transparent parts of the mold surface and the hole width of the same width 0.5mm recommended, smooth surface, to avoid the side view, through a long way, not beautiful, minimize holes;
d. non-transparent pieces of limited thickness, the above ribs and other structures as far as possible in the 0.5-0.6mm, to avoid shrinking;
e. For the moment it is not recommended to do two-color injection with the main lens, mold and product costs are too high, the mold equipment manufacturers and technical level have considerable requirements, to do so, you need to give each other a detailed solution to the process flow For evaluation, the middle part of the need to review;
f. For two-color, large-area injection molded parts, two key tests are drop and thermal shock, transparent and non-transparent parts are easily detached in both tests. Thermal Shock -40 -65, 48 hours .
g. Two-color pieces of the structure as much as possible to simplify, complex with the above pieces, non-transparent pieces of the width as much as possible in the 0.5-0.6, to avoid shrinking.