The terminal movement support product is shown in Figure 1. The maximum size of the product is 143.34 mm x 115.00mm x 13.30 mm, the average thickness of the plastic part is 2.00 mm, the material of the plastic part is ABS, the shrinkage rate is 1.005, and the weight of the plastic part is 26.58 grams. The technical requirements for plastic parts are that there must be no defects such as peaks, dissatisfaction with injection molding, flow lines, pores, warpage deformation, silver streaks, cold materials, jet lines, etc.
The structure of the plastic part is a rectangular hollow flat shell, and the structure of the plastic part is shown in the attached 3D drawing. The movement bracket, as the name implies, is to provide fixing and positioning components for the PCB board in the instrumentation. The technical requirement of the movement support is that the plastic part is flat, free of deformation and warpage, and stable in size after long-term use. Another technical requirement of the movement support is high dimensional accuracy, and the installation position is generally marked with dimensional and geometric tolerances. The characteristic of the mold design of the movement bracket is that the mold structure is simple and there is no complicated mold structure. A well-designed exhaust is required to avoid deformation of the plastic parts.
The characteristic of the movement bracket and the mold design is that there is little difference in the packing force of the front and back molds on the front and back of the plastic part, and accurate judgments need to be made during mold design. This judgment is usually called mold opening direction analysis. The mold opening direction analysis is the basis of the mold parting surface design. If the mold opening direction analysis is wrong, the mold is easy to stick to the front mold, and poor mold design will occur.
Based on the judgment of the mold opening direction, the design of the parting surface is carried out. The parting surface of the movement support is not a flat surface, and there are many steps and scratches in some parts. The parting surface design needs to consider the tool processing, and design the pillow position as much as possible, and do not design the rubbing position.
A key point in 3D parting is the design of the draft angle. The movement bracket is a flat plastic part, with more bones and shallower bones. Any bone position with a depth of more than 1mm must be designed with a draft angle. The shallower the depth, the larger the draft angle can be selected. Specifically, the difference between the size and the end of the plastic part's bone position is more than 0.1.
The mold design cavity rank is 1 out of 1, the mold base is the standard mold base CI3050, the gating system is designed as a latent gate, and the mold is injected after 1 point. For flat plastic parts, the plastic process is longer, the injection pressure is large, and the clamping force required by the mold is large. Therefore, the mold parting surface pressure is required to be large, and the ideal state is to adopt a hard mold design to increase the design life of the mold. This set of molds adopts NAK80, a pre-hardened steel with higher hardness. The exhaust of the front and rear mold cores on the parting surface cannot be ignored, otherwise the injection pressure will increase and cloaks will easily appear.
Both the front and back molds are designed with cooling and water transportation circuits, and all adopt direct water transportation design to improve cooling efficiency. The ejector of the plastic part is ejected by a thimble, and all the thimble holes are cut out by wire cutting.
ABIS MOLD TECHNOLOGY CO.,LTD
Daisy Wang (Sales Engineering)
M: +86-150 1652 6799
E: daisy@abismold.com
A: Building B#,YingKeli Industrial Part, LongDong Community, LongGang District, Shenzhen, China 518116
WhatsApp: +86 136 8261 9739
Skype: daisymold@outlook.com