Plastic Injection Molding


Operating since 2010 | AFAQ ISO/TS 16949, UL and ISO certifications,mainly supplying to many 3D Printing Company In the World Now.

At Djmolding we specialize in producing high-quality plastic injection molded parts and mold tools. We mainly supply our plastic injection manufacturing for many 3D print companies in the world. We have 55 machines for robotics and automatic plastic injection manufacturing.We offer all machining and finishing services to make tools from a variety of materials, and can produce 100 to 200k+ finished parts in all major plastics. What truly sets us apart is our advanced material verification, inspection and testing to ensure your parts meet and exceed your highest expectations. Contact our international injection molding experts for a free quote today.

What Is Plastic Injection Molding?

Injection moulding is a manufacturing process for producing parts by injecting molten material into a mould. Injection moulding can be performed with a host of materials mainly including metals, (for which the process is called die-casting), glasses, elastomers, confections, and most commonly thermoplastic and thermosetting polymers. Material for the part is fed into a heated barrel, mixed (Using a helical shaped screw), and injected (Forced) into a mould cavity, where it cools and hardens to the configuration of the cavity.[1]:240 After a product is designed, usually by an industrial designer or an engineer, moulds are made by a mould-maker (or toolmaker) from metal, usually either steel or aluminium, and precision-machined to form the features of the desired part. Injection moulding is widely used for manufacturing a variety of parts, from the smallest components to entire body panels of cars. Advances in 3D printing technology, using photopolymers which do not melt during the injection moulding of some lower temperature thermoplastics, can be used for some simple injection moulds.

Parts to be injection moulded must be very carefully designed to facilitate the moulding process; the material used for the part, the desired shape and features of the part, the material of the mould, and the properties of the moulding machine must all be taken into account. The versatility of injection moulding is facilitated by this breadth of design considerations and possibilities.

Plastic injection molding is by far the most common way to produce large volumes of finished plastic parts for every kind of commercial and industrial use. Molten resin is injected under high pressure into the cavity of a metal die and then rapidly cooled, forming a solid shape. A single cycle to make a finished part may take anywhere from a few seconds to minutes depending on part complexity and size.

Advantages Of Plastic Injection Molding

Among the many advantages of plastic injection molding are the following:

Thousands of plastic resins to choose from for any application.Most cost-effective way to make large volumes of parts fast.A single tool can last for up to millions of cycles.Excellent surface quality and dimensional characteristics can be achieved.Different plastics can be overmolded for even more design options.The process is stable and reliable for predictable result

Injection Molded Plastic Parts

ODM Plastic Injection Case

Plastic Injection Molding Machines

Production Of Injection Molded Parts

How Does Plastic Injection Molding Work?

The thermoplastic injection molding process at is a standard process involving an aluminum mold with no heating or cooling lines running through it, which means cycle times are a bit longer. It allows our molders to monitor fill pressure, cosmetic concerns, and the basic quality of the parts.

Resin pellets are loaded into a barrel where they will eventually be melted, compressed, and injected into the mold’s runner system. Hot resin is shot into the mold cavity through the gates and the part is molded. Ejector pins facilitate removal of the part from the mold where it falls into a loading bin. When the run is complete, parts (or the initial sample run) are boxed and shipped shortly thereafter.

Plastic Injection Molding Process

Once your plastic injection mold tools are ready, the molding process consists of the following basic steps:

Step 1. The plastic resin comes in raw pellets. These are dried to the right moisture content, and then if necessary they can be blended with pigments or master batch colorants.

Step 2. The dried pellets are poured into the hopper of the molding machine. A reciprocating screw inside the barrel of the machine will transport these pellets towards the mold.

Step 3. Within the barrel, the pellets are mixed and heated until fully molten, forming the liquid resin.

Step 4. The heated mold closes automatically and resin, under great pressure, is injected through a gate and into the mold cavity.

Step 5. The mold is cooled to solidify the part inside.

Step 6. The mold opens and the part is ejected to begin a new cycle.

Plastic Injection Molding Tolerances

All plastic material will expand and contract under the influence of heat and moisture. Our tolerance guide will give more general information on the characteristics of most common resin types for typical part features.

We will work closely with you to optimize your designs for manufacturing. We will indicate any areas where poor design may produce thermal stress, shrinkage, warping, etc. Consult our design guide for more information on common defects and how to avoid them.

Unless otherwise specified, we comply with the DIN 16742 standard tolerances for plastic injection moldings. Read about the visual quality standards that we apply to injection molded parts.

Plastic Injection Molding Materials
Djmolding make injection molding tools and dies from Aluminum 7075, P20 and NAK80 semi-hardened steels and H13 fully-hardened steel. Additionally, we offer standard SPI finishes, EDM texturing and a range of etched textures.

Each of these material types will have distinct advantages for certain applications. Considerations include:

Cost of the raw material
Durability and resistance to corrosion or abrasion
Ability to take a high surface polish
Time required for heat treatment
Expected tool life
Contact our technical specialists to learn more about which one is right for you.


Plastic Injected Parts
There are thousands of thermoforming and thermosetting plastics to choose from for your project. In addition, mechanical and chemical characteristics can also be enhanced with additives like glass fibers, UV stabilizers and lubricants. Our materials sheet will give you more detailed information about the standard types and the tolerances to expect with each.


Your choice of resins may depend upon one or more of the following considerations:

UV, chemical, abrasion and impact resistance
Cost of raw material
Mechanical strength
Weight and density
Contact one of our technical specialists to learn more about material properties.

Our injection shop:

Leading plastic injection mold and rapid prototyping service manufacturer

Djmolding is one of the more well-knowm plastic injection molding companies in China. Our injection molding shop is equipped with 50 sets of high precision injection molding machines, ranging from 30 tons to 800 tons, They are mostly imported from Taiwan and Japan,our injection shop run 24 hours a day, 7 days a week ,and provide production services.

We are experienced with various plastic products for many industrial,including :automotive, medical, lighting, sports equipment, home appliances, and agriculture. Djmolding have pass AFAQ ISO/TS 16949, UL and ISO 9001 Certifications since 2010,We also have 15 IPQC people constantly watch our production and check part quality,This ensures our production maintains a highest level of quality. In the last 9 years,Djmolding has established a strong reputation of producing high quality tool and part at a resonable price.We maintain strong business relationships with appx. 50 customers,mainly from the USA and Europe.