China Plastic Injection Molding Services - Expert Suppliers from a Reliable Factory
Plastic product molding workshop
Mass injection molding production service
Lean production, continuously and stably create value for clients, and ensures reasonable benefits.
Kingsjeng, one of the excellent injection molding service providers, provides one-stop solutions. We are not only skilled in single-color injection molding, but also in the injection molding of treaded products and secondary molding. Regardless of volume or complexity, our professional team is committed to providing high-level and satisfactory professional support for your injection molding needs.

Our Step-by-Step Production Process
RFQ
Your sparkling idea
Product design & Optimization
Our designer will create Intuitive 3D data for your confirmation
Prototype making
Prototype within touch, you can evaluate your idea more intuitively.
Design review
Design for manufacturing can avoid risks and reduce costs.
Stable production
Based on ISO system, built quality in the process.
Delivery
Packed well, the exciting plastic products can be delivered via sea, air or train.
What kind of injection molding services can we provide?
Our most advantageous injection molding service
Injection molding service
Our Plastic injection molding strength
Representative OEM injection molding products - by molding category
Single color Injection molding
















Insert Injection molding









Overmold Injection molding


Threaded part Injection molding

2-color Injection molding


Representative Products - Industries applicable to plastic products
Smart home appliances



Intelligent floor cleaning robot, Blender, Air fryer
Office equipment


Printer parts, Mini thermal printer parts, Teller terminal parts
Medical and health



Massage device, Dental irrigator/impactor, Forehead thermometer, Blood pressure monitor
Beauty and skin care


LED makeup mirror, Hair dryer, Beauty and skin care
Internet of Things




Control box, Router, IoT box, Remote control, Security camera
New energy





Power Cover Drive Assembly, Auto parts, Charging pile components, Charging gun, charging station parts
What is injection molding?
Plastic injection molding is the most efficient way to produce plastic parts in high volumes for commercial and industrial use. Molten resin is injected under high pressure into a metal mold, then rapidly cooled to form a solid part. Here is a schematic diagram of an injection molding machine:

The Plastic Injection Molding Process
Plastic injection molding is the process of filling a mold tool with liquid plastic resin under great pressure. The tool may comprise a single cavity or hundreds of cavities in order to make indefinite numbers of parts. Once the mold tools have been carefully designed and manufactured, 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 to create the correct color for the design.
- Step 2 – The dried pellets are poured into the hopper of the molding machine. A reciprocating screw inside the barrel of the machine is used to transport these pellets towards the mold while at the same time heating them.
- 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 in a short amount of time to solidify the part inside.
- Step 6 – The mold opens and the part is ejected to begin a new cycle.
Advantages Of Plastic Injection Molding
There are many advantages to plastic injection molding. These include the ability to make large volumes of parts quickly, high surface quality, many resins to choose from, color flexibility, and durable tooling that can last for years.
Hundreds of resins to choose from
Economies of scale
Stable and repeatable
Excellent surface quality
Overmolding for more design options
Multi-cavity and family tools
Why can we do well in injection molding production?
Design For Manufacturing
As is well known, the design phase determines 80% of the manufacturing cost of a product, DFM considers manufacturability from the beginning of product development and design, closely linking design and manufacturing to achieve a one-time success from design to manufacturing. At KingSjeng, we will complete a personalized DFM based on your exact needs.
Plastic Injection Molding Materials
Choosing the right resins is extremely crucial for injection molding, as it affects many aspects such as product performance, quality, cost, and production efficiency. For example, suitable materials can ensure product strength meets standards, avoid defects, and optimize cost control.
Color Consistency
The color consistency of injection molded products is very important, as it ensures a coordinated and beautiful appearance, reflects quality, and enhances brand image. Consistent color of the outer shell of a batch of electronic products will give consumers a good visual experience and quality trust.
Visual Quality Standards
The highest visual quality inspection standards are used to verify your plastic injected molded parts.
A diligent and enterprising team
A professional and diligent team is crucial in improving efficiency, ensuring quality, overcoming challenges, driving your project towards success, and realizing your dreams as soon as possible.

Product Road mapping
Follow the product road mapping journey to save time, money and effort on your next project. It is beneficial for team work, smooth production and timely shipment.
Plastic Injection Molding Resources - A well-established supply chain
Frequently-used resins brands
Color master batch
Professional color master batch manufacturers with long-term cooperation in the local area can provide color master batch that meets environmental requirements and color consistency, with color standards based on Pantone or Ral.
Frequently-used resins
- ABS, ASA, PS, AS, PS, HIPS etc.
- PP, PE, HDPE, UPE etc.
- PA66, PA6, PA6T, PA9T, PA12, PA46 etc.
- PC, POM etc.
- PPE etc.
- PET, PBT etc.
- TPEE, TPE, TPV, TPU etc.
- PARA, PMMA, PEEK, PES, PPSU, PEI, PPS etc.
Property of material
- Carbon fiber reinforced, wear-resistant, conductive, thermal conductive, and high rigidity specifications.
- Special composite: aramid AF CF+GF, CF+TF, GF+TF, Equal composite specifications.
- Wide range wear resistance level: including wear resistance specifications such as SI, MoS, PTFE, nano modification, etc.
- High dimensional stability (low moisture absorption, low warping, low shrinkage, low coefficient of thermal expansion).
- Combination of conductivity, anti-static, electromagnetic shielding, and thermal conductivity.
Common surface treatments for plastic products
1. Painting: Endow plastic products with rich colors and appearance effects, such as high gloss, matte, and metal texture.
2. Electroplating: Increase the surface gloss and metal texture of plastic products, and improve the wear resistance and corrosion resistance.
3. Printing: Silk screen printing, pad printing, and other methods to apply patterns, logos, and text.
4. Laser engraving: Capable of achieving fine patterns and marks with permanence and high precision.
5. Vacuum coating: Enable the surface of plastic products to have good decorative and functional properties, such as fingerprint resistance and UV protection.
6. Matte treatment: Make the plastic surface have a matte and rough texture, increase anti-slip properties, and reduce reflection.
7. Polishing: Improve the surface finish of plastic products to make them smoother and brighter.
8. Flocking: Attach a layer of fluff to the plastic surface to increase the soft and comfortable touch.
Applications for Plastic Injection Molding

OEM
According to customers' needs, produce products they need. The products cover many industries, such as small household appliances, electronics, healthcare, home furnishings, beauty care, etc.

ODM
After in-depth exploration of existing advantageous technologies and experiences, as well as market demand research, we successfully developed high-strength plastic materials for water pipe connectors recognized by customers.
The proportion of OEM and ODM in revenue


