The Methods of Reducing Injection Mould Development Cost

With the rapid development of plastic moulding manufacturing industry, how to reduce the long development cycle and high cost of injection moulds has become a new goal that everyone is pursuing.

Product design
1. Plate selection
Under the premise of satisfying the all of the intensity requirements, plastic injection moulding companies should adopt the more common and mature technologies in the market. For example, one type of anti-collision beam inner panel materials of our company used the Swedish knife-cut material DOCO860. Due to the high intensity of plate, after moulding of mould of developed according to the general process, the opening rebounded up to 8 mm, and the arc rebounded up to 15mm. For these problems, we can only conduct multiple tests through rebound compensation. This not only results in a long cycle but also material waste.

2. Product structure
When developing moulds, more consideration should be given to the versatility of product. In addition, the product must be simplified in structure to avoid increased mould operations or complicated mould structures.

3. Application of synchronous engineering
Stamping Synchronization Engineering (SE) is that in the product design stage, stamping process technicians involve in early product process property analysis, in the design stage, eliminate errors and defects, so as to shorten the injection mould development cycle. The use of simultaneous engineering omit the a process, allowing the tooling production to begin in the shortest possible time, providing sufficient time for plastic moulding manufacturing.

Production Process
There are two types of production lines currently used by Chinese injection moulding companies: manual production lines and automatic production lines. In terms of automatic production lines, in order to ensure the automatic slippage of production waste, the angle between the slide plate and the table must be greater than 20°, and the automatic line mould feeding height requirements are consistent, in order to ensure that the waste material can slide freely, must increase the height of all moulds . However, for the whole vehicle, reducing the height of mould is an effective way to save the mould development cost. If use manual production lines, there are no issues involved. Each plastic injection moulding company can choose the production method and production equipment according to its own situation, and ultimately achieve small input and large output.

1. Moulding process

• Consider the blanking process first, and then consider the drawing process. With the application of high-strength steel plate in automobile production, in order to ensure the high-strength sheet can be formed, the forming method with blanking has a higher chance of success. Compared with drawing, the blanking has no blank holder, so the material utilization is greatly improved. However, the drawing process is easy to ensure product quality, and the debugging cycle can be shortened. Therefore, both should be considered in combine to develop the optimal process.
• Blanking production using nesting process. The scraps after blanking of some injection moulded parts can be used again to produce small parts of the same material.
• Maximize the way to achieve left and right parts clamping or one mould and multiple chambers. If the left and right parts are to be moulded and produced, it is only necessary to increase the dimension of the symmetry part on the dimension (length) of the single part, which is the new process mould. In comparison, a set of guide mechanisms can be saved, and the weight of the overall mould can also be reduced. For narrow and long parts, it is recommended to use a mode of multi-cavity production.

2. Mould design

• Some structures are redundant in the design of inejction mould structures. For example, in order to ensure the smoothness of the pickup, the pneumatic top loading device is often reserved on the mould, which is hardly used in actual production. The requirements of service life of injection mould directly affects the material selection of injection mould. General requirements for the service life of injection mould is 500,000 punches, but in the current multi-species, medium and small batch production, the service life of injection mould continues to press the requirements of 500,000 punch times is some what unreasonable. The mould wall thickness can be appropriately reduced to reduce costs.
  
  

Now China has a low level of casting and it is difficult to achieve mixed casting. For the flanged moulds, high hardness and wear-resistant materials such as GM series, MoGr alloys, and air-cooled steels are generally used in the working part materials. By adopting a mosaic structure and satisfying the high life requirements of injection mould, an integral insert or an integral insert can be selected according to the size of the parts required in the working part.