Plastic Mold Fabrication Service

Plastic Mold Making
Injection Mold Repair
Prototype Injection Molds
In-House Mold & Export mold

Experienced China Plastic Mold Maker

As an experienced injection mold maker, Sungplastic is committed to providing mold design and plastic mold manufacturing services. At the same time, we provide one-stop services for parts design, mold tooling, injection molding and project management.

Our customers often invite us to participate in the product design process because they know that we can use our experience to help them analyze the rationality of product design and the feasibility of production. The result of this is a correctly designed and built mold that can be used to efficiently produce high-quality plastic parts.

Sungplastic’s mold building ensures the precision to meet product requirements, sufficient service life, and the best cost performance. Send us your CAD or 3D drawings, and we can use them directly for work. Or tell us your idea, we can realize it together. We are glad to service you. let’s get started with your next project.

plastic mold factory

Prototype Injection Molds & Mass Production Mold

We provide high-quality prototyping, small-batch manufacturing and mass production services to support your product needs. Different types of molds can be selected for different production needs. The right choice depends on your project needs.


Steel Mould

Aluminum Injection Mold

Plastic Mold Engineering

Professional plastic mold design engineer team with more than 13 years of experience.
Provide you with engineering design services for complex products or individual components.
Functions include CAD modelling, 3D mold design, DFM (manufacturing design), mold flow analysis.

CAD Modelling (2D, 3D)
Moldflow Analysis
3D Mold Design
Design for Manufacturable (DFM)

Tool Room Equipments

Project leader with over 20 years of industry knowledge and fluency in English communication.
Excellent injection mold manufacturing team and injection molding technicians.
Our tool room is equipped with advanced equipment to provide the precision, hardness, rigidity and thermal stability required for mold manufacturing and mold adaptation. We will manufacture your molds on the best equipment.

6 CNC Machines

8 Drilling Machines
2 Milling Machines
8 EDM Machines
6 Gridning Machines
1 Lathe Machines

A Full Range of Plastic Mold Making Services

At Sungplastic, plastic injection mold making and injection molding production are at the heart of what we do. In order to provide comprehensive services, we also provide support services such as mold design, mold repair, mold export, etc. All services are performed in-house by our well-trained staff to ensure customers receive a quick and accurate response. All services follow our strict quality standards to ensure that injection molds serve the injection molding process smoothly. All services are guaranteed.

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injection mold making

Plastic Mold Making

Creating injection molds is the core of our expertise and our origin. Our experience spans two decades of crafting bespoke injection molds. Whether your needs involve plastic or rubber components, rest assured, we possess the capabilities to craft molds for them. Additionally, we offer specialized mold fabrication for overmolding.

Our expertise extends across multiple sectors, including automotive, medical, agriculture, and more. If you require molded parts, we also extend our services to include injection molding, overmolding and insert molding. Considering these myriad advantages, what reason could there be to choose any tool other than Sungplastic for your mold-making needs?

injection mold repair

Plastic Mold Repair

As a seasoned injection mold manufacturer, we boast extensive expertise in preventive maintenance and restoration. Who better to keep things running than the people who built it, right? Molds undergo wear and tear throughout numerous injection molding cycles, inevitably leading to various molding defects. This is natural and unavoidable, so regular maintenance is required to keep production going.

Our team takes care of it all. For preventative maintenance we perform full mold removal and cleaning. For repairs, we meticulously restore your mold to its original precision specifications. Concerned about the aesthetics of the restoration? Our welding and painting specialists work their magic to ensure that no discernible traces of repair remain.

cnc aluminum molds

Prototype Injection Molds

We stand at the forefront of rapid prototyping injection molding within China. Our profound knowledge of manufacturability and materials empowers us to craft prototype molds suitable for real-world applications. Typical prototype molds are aluminum injection molds.

Whether you’re a visionary entrepreneur or a well-established company exploring a new product, our prototype tooling proficiency is here to assist in validating your designs. In a matter of days, you can acquire tangible prototypes, utilizing a limited quantity of molded components to assess the form and compatibility of elements. This capability facilitates swift design adjustments during the initial stages of product development.

export mold

Export Mold

In addition to manufacturing in-house molds for injection molding production, we offer a mold export service to our customers. This option empowers you to conduct injection molding production within your own facility and realize substantial savings on tooling expenses.

We support customers to view molds through live or recorded video before delivering finished molds. Trial run will be done in our factory and samples will be submitted to customers for approval. Before packing, the mold will be fully maintained and rust-proofed. It is then carefully packaged for shipment to ensure smooth reception and assembly at the customer’s factory. Apart from the moulds, we will also ship to the customer all the mold design data/NC program data.

Plastic Mould Steels

When selecting materials, please consider material characteristics, functions of different mold parts, mold accuracy, characteristics of injection molding materials used, product appearance, mold life, and processing costs.

  • P-20
  • H-13
  • 1.2738
  • 1.2718
  • NAK80
  • S136
  • S-7
  • A-2
  • 1.2738H
  • 1.2718H
  • S136H
  • 2083
  • 1.2343
  • 1.2344
  • 1.2767
  • 420
  • Stainless Steel
  • Aluminum
mold parts

Surface Treatment for Plastic Mold

Mold steel treatment:

In addition to the high enough strength and willfulness of the mold during work, its surface properties are very important to the working performance and service life of the mold. These surface properties refer to wear resistance, corrosion resistance, friction coefficient, fatigue coefficient, etc. This can be achieved through the surface treatment technology of the mold steel.

  • Heat treatment
  • Thermal refining
  • Annealing
  • Positive
  • Quench
  • Tempering
  • Vacuum Carburizing
  • Vacuum nitriding
  • Carbonitriding

Mold core cavity surface treatment:

Since each plastic product has different appearance requirements, we will do the corresponding cavity surface pattern treatment for the mold.

  • Sand blasting
  • Texturing
  • Electroplating
  • Brush finishing
mold polishing

Take A Tour of Our Manufacturing Process

YouTube video

Mold Testing to Guarantee Injection Molding Quality

Mold testing involves assessing the quality and functionality of injection molds, which are essential for producing a wide range of products made of materials like plastic or rubber.

During mold testing, several key factors are evaluated. First and foremost, the mold’s integrity is checked to ensure it can withstand the pressures and temperatures of the molding process. Precision and accuracy in mold dimensions are crucial to producing consistent and defect-free products. Additionally, mold testing includes examining cooling and ejector systems, as well as assessing the surface finish of the mold cavity, which directly affects the appearance and quality of the final product.

Furthermore, mold testing often involves trial runs to identify any potential issues or defects in the production process. These tests help optimize production efficiency and minimize the risk of costly errors. When a problem is found, the mold is corrected in time, until the trial run gets perfect product samples.

Custom high quality plastic mold at Sungplastic

We consider our in-house tool room to be a key factor that distinguishes us from others. There are several advantages to having a tool room within the same facility:

  • Firstly: Working with the same people “From Conception to Completion” reduces communication lag time with suppliers and eliminates the “Blame Game” often associated with working with multiple companies.
  • Secondly: The people who build the tooling are the same ones who put it into production. This ensures that the plastic injection mold life is designed to coincide with the life of your product, built with the best materials and workmanship available in your price range, and ensures efficiency in mold operation.
  • Thirdly: In-house plastic injection mold making allows us to reduce downtime and cost when production problems arise, saving our customers time and money.

Our mold making process involves true craftsmen using CAD/CAM software, CNC, and EDM equipment. Our meticulous attention to detail guarantees that the plastic injection molds and our plastic injection mold making services meet or exceed your requirements.

How Do We Strat to Work Together?

Bring your ideas and products to us, and we’ll provide a free design evaluation. Based on our evaluation, we’ll recommend either “design for manufacturing” expertise at no cost to fine-tune your product or quote a more extensive re-design to prepare your product for manufacturing. If your product’s design is already complete, then you can skip this step!

  • We offer CAD generation and prototyping services to ensure that your product meets or exceeds your expectations.
  • We both agree to design and manufacture injection molds for a reasonable fee. Want to know how much injection molds cost?
  • Additionally, as long as the plastic injection molds remain with us, we’ll guarantee it for life.
  • If you would like to receive more information about our company or plastic injection mold making, contact us by phone, WhatsApp, or e-mail. We look forward to hearing from you and to be of any service to your company.

Guide of Plastic Mold Manufacturing

What is plastic mould tooling?

Injection mold is a tool for producing plastic products, giving plastic products a complete structure and precise dimensions. Injection molding is a processing method used in mass production.

Injection molds are divided into thermosetting plastic molds and thermoplastic plastic molds according to their molding characteristics. According to the number of mold cavities, it is divided into a single-cavity injection mold and a multi-cavity injection mold. According to the dimensional accuracy of plastic parts, it is divided into general injection moulds and precision injection moulds. According to the mold casting system, it is divided into cold runner mould and hot runner mould.

Choosing the right mold tool for your project is the most important. Because a complete project is generally composed of multiple components. Ensuring that all components are completed and assembled accurately and with high quality is the key to obtaining the final product. Plastic moulds are an important link in the chain that connects the entire process.

What are the structures of the plastic mold?

The basic structure of the injection mold can be divided into seven parts according to its use function: pouring system, lateral parting, guiding mechanism, ejector, cooling and heating system, exhaust system and mold inserts. The analysis of these seven parts is as follows:

  • The pouring system refers to the plastic flow channel in the mold from the nozzle of the injection molding machine to the cavity. The ordinary pouring system is composed of main runner, branch runner, gate, cold slug hole and so on.
  • Lateral parting and core pulling mechanism.
  • In the plastic mold, the guiding mechanism mainly has the function of positioning, guiding and bearing a certain side pressure to ensure the accurate clamping of the moving and fixed molds. The mold clamping guide mechanism consists of a guidepost, a guide sleeve or a guide hole (directly opened on the template), a positioning cone and so on.
  • The ejector device mainly plays the role of ejecting the parts from the mold. It is composed of ejector rods or ejector pipes or pushes plates, ejector plates, ejector rod fixing plates, reset rods and pull rods.
  • Cooling and heating system.
  • Exhaust system.
  • Mold inserts refer to the parts that constitute the mold cavity. Mainly include: punch, die, core, forming rod, forming ring and inserts and other parts.

How to make the best plastic injection mold?

To make a perfect injection mold, these five tips must be done!

  • 1.Process analysis of plastic products.
    Before the mold design, the designer and the mold maker should analyze whether their plastic products conform to the principle of injection molding. Including the geometric shape, dimensional accuracy and appearance requirements of the product, necessary discussions, try to avoid unnecessary changes in mold manufacturing.
  • 2.Mould structure design.
    A set of high-quality molds requires not only good processing equipment and skilled mold making workers but also good mold design. An excellent mold design is: on the premise of meeting the requirements of the customers, the processing cost is low, the processing difficulty is small, and the processing time is short.
    To achieve this, it is necessary not only to fully digest the customer’s requirements but also to have an understanding of the injection molding machine, mold structure, processing technology and the mold factory’s own processing capabilities, so as to improve the level of mold design.
  • 3.Determine the mold material and select standard parts.
    In the selection of mold materials, in addition to considering the accuracy of the product, product quality, and mold life, it is also necessary to combine the actual processing and heat treatment capabilities of the mold factory to give the correct choice. In addition, in order to shorten the manufacturing cycle, use existing standard parts as much as possible.
  • 4.Parts processing and mold assembly.
    Except for the best structure and reasonable tolerance fit in the design, the precision of the mold is very important for parts processing and mold assembly. Therefore, the choice of processing accuracy and processing method occupies an absolutely dominant position in mold manufacturing. In order to reduce mold manufacturing errors, the machining accuracy should first be improved. With the use of CNC machine tools, this problem has been well controlled. In addition, in order to prevent errors caused by mold wear and deformation, the cavity, core and other key parts should be quenched in molds with high processing accuracy and large product output.In order to solve the error caused by uneven shrinkage of the moulded part and the inconsistency between the predetermined shrinkage and the actual shrinkage, 1/3 of the product tolerance is generally selected during mold manufacturing as the manufacturing tolerance of the mold. Large adjustment room to solve the error caused by the molding process.
  • 5.Try out the mold.
    A set of molds only completes 70% to 80% of the entire manufacturing process from design to assembly. For the errors caused by the inconsistency between the predetermined shrinkage and the actual shrinkage, whether the demolding is smooth or not, how the cooling effect is, especially the influence of the size, position, and shape of the gate on the accuracy and appearance of the product, it must be tested by mold trial. Therefore, mold trial is an indispensable step to check whether the mold is qualified and select the best molding process.

Plastic mold design and analysis

Fourteen steps of mold design and analysis:

  • 1. Product analysis and summary. Lock the mold opening direction and product structure.
  • 2. Product DFM report production. Analyze and review the product structure, processing, and molding problems, and clarify the specific plan.
  • 3. Product parting. Create a parting surface, separate the front and rear molds, and then structure the product shape to lay out the approximate frame of the waterway and the thimble, and then lock the mold core size.
  • 4. Mold structural design. The slider design is carried out in combination with the product structure, and the slider frame is designed based on the mold core.
  • 5. Mould base design.
  • 6. The design of the product ejection structure. Confirmation of ejection height and determination of inclined roof.
  • 7. Design of runner system. If there is a hot runner, first determine the position of the glue feeding point and the style of the hot runner, and then customize the hot runner.
  • 8. The design of inserts. Analyze the risk of processing or size of the product for insert design.
  • 9. Waterway design. Design the water circuit in combination with the overheated or easily deformed area of ​​the product during molding.
  • 10. Positioning system design. Combining the accuracy of the product with the life of the mold, the precise positioning of the mold is designed.
  • 11. Layout and optimization of accessories. Layout design of mold prying angle, support column, trash top, limit block, etc.
  • 12. The design of the exhaust system. Under normal circumstances, the front and rear mold core parting surfaces and the sliding block parting surfaces need to be designed with exhaust grooves.
  • 13. Organize the BOM. Combine the 3D drawings of the mold to make the bill of materials.
  • 14.2D drawing. Make 2D machining drawings of each mold part.

The impact of molds on injection molding

  • 1.Mold design affects product quality at least 70% of the influencing factors of the quality of injection products are in the mold. For the appearance of the product, the skin texture surface mainly depends on the skin texture effect of the mold, and the smooth surface and mirror surface mainly depends on the polishing quality of the mold cavity surface. In addition to the impact of product shrinkage and injection molding process, the most direct impact is the dimensional accuracy of the mold. The higher the dimensional accuracy of the mold, the higher the dimensional accuracy of the product.
  • 2.Mold design affects molding cycle
    In the mold design, the gate location and waterway layout will affect the molding cycle of injection molding. The short molding cycle directly improves the efficiency of injection molding production and increases the production capacity of the injection molding machine, which also means a reduction in production costs.
  • 3.Other influence
    The design of the mold runner system will affect the weight of injection molding waste, which is actually an increase in production costs.When designing the mold, it is necessary to consider the realization of injection molding production automation, such as smooth ejection, no need for post-processing, stable production and no quality risk. If the mold cannot meet the requirements, it will inevitably increase labour costs and increase the instability of product quality.The mold design is reasonable, and the product meets the requirements, without post-processing, such as flash repair, gate cutting, orthopaedics, and full inspection.

How to choose a reliable plastic mold factory?

1. Don’t just focus on product design and ignore plastic mold manufacturing.

When you develop a new product, please contact the mold factory in advance after the product design plan is initially determined. It can ensure that the designed product has a good forming process. The mold maker can prepare the mold design in advance. The supply and demand sides cooperate closely to ultimately reduce costs and shorten the cycle.

2. Don’t just look at the mould price, but from the full range of quality, cycle, and service.

  • Choose different types of molds according to different requirements of parts materials, physical and chemical properties, mechanical strength, dimensional accuracy, surface finish, service life, economy and so on.
  • High-precision molds need to be processed by high-precision CNC machine tools, and mold materials and forming processes have strict requirements. CAD / CAE / CAM mold technology is also required for design and analysis.
  • The manufacturer should have CNC, EDM, wire-cutting machine tools and CNC copy milling equipment, high-precision grinders, high-precision three-coordinate measuring instruments, computer design and related software.
  • When choosing a cooperating manufacturer, you must understand its processing capabilities, as well as management level, processing experience and engineering support.
  • Reasonable mold cost is necessary. Mold manufacturers, like you, must make reasonable profits in their business. Ordering a set of molds with a much lower quotation is likely to be the beginning of trouble. Please proceed from your own requirements and comprehensively measure.

3. Avoid multi-head collaboration, try to make plastic molds and product processing through one-stop.

  • With qualified molds (the test piece samples are qualified), it may not be possible to produce batches of qualified products. This is mainly related to the selection of the part processing machine tool, the forming process (forming temperature, forming time, etc.) and the technical quality of the operator.
  • With a good mold and good injection molding processing conditions, it is best to cooperate with the factory in one-stop. This is conducive to unified management, efficient communication, and time and costs savings.

Find More about Sungplastic

Sungplastic is a full-service parts manufacturer providing high-quality mold making, plastic injection molding and CNC machining services. We are committed to helping you and your projects succeed, focusing on speed, quality and cost. Find more manufacturing capacities for your project.

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