Discussion on Traditional Injection Molding, High Speed Injection Molding and Precision Injection Molding

As we all know, the pursuit of injection molding is "high quality, high efficiency and low consumption", that is, the pursuit of profit maximization. However, the development of things needs enough time rather than achieve it overnight. So does the development of injection molding. The emphasis is different at different stages of development.

In the initial traditional injection molding, priority is given to guarantee the delivery time, and the quality can be appropriately relaxed, not to mention the yield and efficiency of production. At that time, the master of technology reflected that other people couldn't adjust the mold of qualified samples, so long as you can adjust it (whether it took you one day plus one night or three days plus two nights), you are a master-hand and a hero. In view of this, the defective rate of the products is high, and many parts are processed by manual work (cutting the nozzle, cutting the front edge, pressing the burr, correcting the deformation with a metallurgical tool, etc.). The production cycle is long, the quality cannot be guaranteed, and the rework is vicious for a long time. Although the traditional injection molding has been greatly improved, the man-machine ratio and labor intensity are still very high.

Compared with traditional injection molding, high-speed injection molding reduces man-machine ratio and labor intensity, and replaces most of human actions with mechanical automation, reflecting the victory of "quantity". This process has high requirements for mechanical automation and assembly line operation. Qualified technical master, not only does well in debugging a good model, but also the stability and operability of production. If you can't meet the set expectation, no matter beautiful your model will be, it will only be an ornamental model, so you can't be a "guide" for mass production.

Precision injection molding is developed on the basis of high-speed injection molding, which is specialized in producing products with higher added value. It refers to an injection molding method which is difficult to meet the requirements by using traditional injection molding machines and conventional injection molding processes, which reflects the "quality" to gain credibility and "quantity" to gain profits. The precision of precision plastic parts includes dimensional precision, form and position precision and surface accuracy, which correspond to dimensional tolerance, form and position tolerance and surface roughness respectively, among which dimensional precision is an important quality index for manufacturing and using plastic parts.

There are many factors that affect the quality and dimensional accuracy of precision injection molding products, such as material selection, mold design and processing, precision injection molding machine, molding process, molding personnel level and production management.

Specific requirements are:

(1) the dimension precision of the part is high and the tolerance is small, that is, there is a high-precision dimension limit;

(2) The weight repetition accuracy of products is high, which requires dimensional stability of day, month and year;

(3) The material of the die is good, the rigidity is sufficient, and the dimensional accuracy and smoothness of the cavity and the positioning accuracy between the templates are high;

(4) Replace conventional injection machines with precision injection machines;

(5) Adopt precision injection molding process;

(6) Select materials suitable for precision injection molding.