Plastic mold making process 3.26

custom plastic enclosures

As we all know, “Mold is the mother of industry”.Plastic mold is a tool that is matched with plastic molding machines in the plastic processing industry to give plastic products a complete configuration and precise size. Due to the variety of plastics and processing methods, the structures of plastic molding machines and plastic products are complex and simple.

With the rapid development of the plastics industry and the continuous improvement of the strength and precision of general-purpose and engineering plastics, the application scope of plastic products is also expanding, such as: household appliances, instrumentation, construction equipment, automobile industry, daily hardware, etc. In many fields, the proportion of plastic products is increasing rapidly. Bringing different requirements to the plastic mold processing technology.

Hongfa have 20 years experience mold design engineer,It has good advantages in the design and manufacture of plastic molds.Today we mainly talk about the manufacturing process of plastic molds.

The plastic mold manufacturing process can be roughly divided into the following steps: 

  1. Process analysis of plastic products.  

Before designing the mold, the designer should fully analyze and study whether the plastic product conforms to the principle of injection molding. It is necessary to negotiate carefully with the product designer, and a consensus has been reached. This includes necessary discussions on the geometric shape, dimensional accuracy and appearance requirements of the product, and try to avoid unnecessary complexity in mold manufacturing.

  • The mold structure design.

A set of high-quality molds not only requires good processing equipment and skilled mold manufacturing workers, but also a very important factor is to have good mold design, especially for complex molds, the quality of mold design accounts for 80% of the quality of the mold. %above. An excellent mold design is: under the premise of meeting the requirements of customers, the processing cost is low, the processing difficulty is small, and the processing time is short.

  • Processing and production of various parts of the mold

The mold making process is as follows:   

Drawing review – material preparation – processing – mold base processing – mold core processing – electrode processing – mold parts processing – inspection – assembly – flying mold – mold test – production

A: Mold base processing:

1)  Numbering, the numbering should be uniform, and the mold core should also be numbered, which should be consistent with the number on the mold base and in the same direction, and it is not easy to make mistakes when assembling.

2) A/B plate processing: a: A/B plate processing should ensure that the parallelism and perpendicularity of the mold frame is 0.02mm, b : Milling machine processing: screw holes, water holes, thimble holes, machine nozzle holes, chamfering c: fitter processing: tapping , trim the edges.

3) Panel processing, milling machine processing boring machine nozzle holes or processing material nozzle holes.

4) Thimble fixing plate processing: Milling machine processing: the thimble plate and the B  plate are connected with a back pin, the B  plate faces up, and the thimble holes are drilled from top to bottom. The knife is finished in place and chamfered. 

5) Bottom plate processing: Milling: Scribing, Correction, Boring, Chamfering


B: Core processing:

1) Flash: Processed on a milling machine to ensure verticality and parallelism, with a grinding allowance of 1.2mm

2) Rough grinding:For large water grinding process, grind the large surface first, then clamp and grind the small surface with batches to ensure the verticality and parallelism are within 0.05mm, and leave a margin of 0.6-0.8mm on both sides

3) Milling, First calibrate the milling machine head to ensure that it is within 0.02mm , calibrate and press the workpiece, first process screw holes, thimble holes, threading holes, countersunk holes for inserting needles, machine nozzle or material nozzle holes, and taper holes for taps. Make a water hole at the corner, and mill the R  corner.

4) Fitter processing:Tapping, typing code

5) Rough machining.

6) Heat treatment:

7) Fine grinding:The large water mill is processed to minus 0.04mm than the mold frame to ensure that the parallelism and perpendicularity are within 0.02mm

8) CNC finishing,

9)  EDM,

10) Die saving:Ensure smoothness and control cavity size

All aspects of mold production directly affect the service life of the plastic mold and the quality of the injection-molded plastic shell, so it needs to be rigorous and precise from the beginning of the design.

Hongfa provides our customers with high-quality plastic molds and injection molding of plastic products. Feel free to contact us if you are interested.



See our laser and dot peen systems in action in the Factory tour.

Factory Tour


Go beyond our most recent news and learn more about our 20+ years in business.