Plastic mold manufacturing is a huge industry in China. The country produces over 50% of the world’s injection molds and has thousands of mold makers across major cities like Shanghai, Shenzhen and Guangzhou. This article will provide a comprehensive overview of plastic mold manufacturing in China – explaining the manufacturing process, different types of plastic molds, key design considerations, and profiles of top Chinese mold makers.

An Introduction to Plastic Injection Molding

Plastic injection molding is a manufacturing process used to make plastic parts and products. It involves injecting molten plastic material into a mold cavity where it cools and hardens into the finished part shape.

The mold has two primary components – the core side and the cavity side. When closed together, these two halves create the final part geometry. The plastic is injected into this cavity space through a dedicated sprue and runner system that feeds the part cavity.

Once the molten plastic material fills the cavity space and cools, the mold opens up and the solidified part gets ejected out. This entire cycle then repeats to mass produce identical plastic parts.

Injection molding is popular due to its ability to rapidly produce complex, high tolerance plastic parts at low unit costs. The automotive, medical, consumer goods and electronics industries rely heavily on plastic molding for component manufacturing.

China has established itself as the epicenter of plastic mold making, supplying molds globally for all industries. Let’s look at the key types of plastic molds made in China.

Types of Plastic Molds Made in China

There are several types of plastic molds made in China, with each design catering to specific applications and plastic materials.

Two Plate Molds

This is the most common mold design, consisting of two halves that separate along the parting line. It is used for basic plastic parts like bottles, containers and caps. Two plate molds offer simplicity and low cost.

Three Plate Molds

For complex parts with side actions, three plate molds are used. They have an additional moving plate to facilitate demolding actions. Common applications include technical parts with holes, threads, slots etc.

Hot Runner Molds

These specialized molds have heated delivery channels that keep the plastic molten as it flows into the cavities. This eliminates wastage and improves cycle times. Hot runner molds are ideal for parts with tight tolerances like plastic connectors.

Stack Molds

Stack molds allow multiple parts to be molded in one shot. They have two or more parting lines stacked vertically, reducing cycle times and costs. Typical uses include caps, cup lids and high volume components.

Multi-Cavity Molds

In these molds, multiple identical cavities are integrated into a single mold base. It increases productivity by molding several identical parts per cycle. Caps, containers and other repetitive plastic parts employ multi-cavity molds.

This covers the major plastic mold types commonly produced in China. The choice of mold depends on part design, plastic material, production quantities and cost targets.

Key Design Considerations for Plastic Molds

Mold design is a complex process requiring extensive engineering expertise. Here are some key considerations for plastic mold design:

• • The mold must accurately produce the desired part shape, size, and features, and CAD software designs cavities matching the part design.
  • During mold design, one must consider thermoplastic properties such as flow rate, shrinkage, cooling rate, and temperature sensitivity.
  • Standard mold bases made of P20 steel enable faster machining. However, for enhanced durability, one can customize beryllium-copper and aluminum bases.
  • Effective cooling plays a crucial role in reducing cycle times. Optimized cooling channels accelerate cooling, resulting in faster cycle times and improved part quality.
  • Designing ejection pins and blades is necessary to reliably release completed parts from the mold. Custom ejection systems are  standardized components.
  • Cavity surface finishes have a direct impact on the final part appearance. Textured surfaces can achieve the desired cosmetic effects on molded parts.

  Significant engineering goes into optimizing plastic molds for performance, longevity and part quality. Chinese mold makers leverage simulation software and rapid prototyping to refine mold design.

Leading Plastic Mold Manufacturers in China

China has thousands of mold making companies located in major cities and mold manufacturing clusters. Some of the leading plastic mold manufacturers in China include:

• Mold Hotrunner: A premier hot runner system manufacturer located in Suzhou. They offer advanced hot runner technology and quick turnaround times.
• Han King Precision: Specializing in high precision molds for electronics and connectors. Based in Shenzhen with an export-focused approach.
• Suzhou Origin: Provides optimized multi-cavity molds for high volume plastic components. Possesses advanced manufacturing capabilities.
• Jinan Chengrun Mold: A provider of large plastic molds like automotive bumpers, door panels etc. Operates from Shandong province.
• Sino Mold: Located in Ningbo, they manufacture quality injection molds for diverse applications across industries. Strong focus on uniform quality.

With extensive expertise and advanced equipment, China delivers cost-effective, high quality plastic molds to the world.

The Mold Making Process in China

Let’s look at a quick overview of the typical plastic mold manufacturing process in China:

1. The client provides CAD files, plastic material details, and the proposed design.
2. The Chinese mold maker reviews the design, suggests improvements if required, and conducts a feasibility assessment.
3. The engineering team optimizes the mold design using CAD software, simulates filling and cooling, and finalizes detailed drawings.
4. CNC machining precisely manufactures mold components according to approved drawings.
5. Technicians drill cooling channels, install the ejector system, and apply necessary surface treatments.
6. The mold undergoes testing by injecting samples to validate part quality. Design adjustments are made if necessary.
7. Once the client approves it, the optimized production mold enters mass manufacturing.

China’s expertise in mold design software, CNC machining, tooling, and quality control contributes to efficient mold making as per international standards.

Outlook for Chinese Plastic Mold Industry

Plastic mold manufacturing will continue thriving in China due to its unparalleled manufacturing ecosystem. Some key advantages and trends shaping the future of Chinese mold making industry:

• Cost Efficiency: Labor, raw materials, facilities and logistics cost much lower in China compared to Western mold makers. This provides competitive pricing.
• Production Capacity: Enormous capacity with thousands of mold companies spread across China’s industrial cities gives buyers ample choice.
• Smart Manufacturing: Integrating IoT, automation and data analysis for higher quality, efficiency and traceability across the mold production process.
• Sustainable Production: Increasing focus on cleaner production methods, renewable energy usage, and environmentally-friendly practices.

Rising domestic demand and exports will continue to fuel growth for plastic mold manufacturing in China.

Conclusion

Plastic injection molding transforms the world we live in, making possible mass Low Volume Injection Molding production of inexpensive, high quality plastic goods. As a vital preliminary step, plastic mold manufacturing forms the backbone of this trillion dollar plastic products industry.

China offers the complete manufacturing ecosystem for world-class plastic China mould at competitive rates. Its unique blend of experienced engineers, advanced technologies and cost efficiencies make China the ideal choice for companies sourcing custom molds. With plastic molding demand steadily rising across the globe, China will continue leading the way in delivering innovative, high quality molds at massive scales.