2k Injection Molding Service

SeaskyMedical is one of the reliable automotive injection molding companies based in China.

2K Injection Molding Service

2k injection molding is also known as 2-shot injection molding or double-shot injection molding. It is a manufacturing procedure of molding two separate substances or colors into a single plastic item. By utilizing a 2k injection molding machine, this plastic molding technology combines two substances or two distinct colors into a single finished plastic object. 

To create flawless final products, 2K injection molding combines two distinct materials, such as hard and soft substances. The foremost substance that was injected is known as the base material, and the second material that was injected is known as the overlay material. SeaskyMedical is a top-class plastic injection molding company, and we offer a one-stop 2k injection mold service. 

Benefits Of 2K Injection Molding

The following are the advantages of two-shot injection molding

  • The final products made using 2 shot molding process become more robust and long-lasting as a result of the vigorously molded and fitted components.
  • Chemical connections are used to combine various plastics into a single component to improve quality and robustness.
  • The product appearance has a high aesthetic value or level of beauty since numerous colors can be combined during the two shot molding process.
  • It is possible to test out numerous designs with 2 shot molding, even tiny intricate designs. 
  • The foamed substance is encapsulated to increase quality by decreasing the sink and warpage and enhancing the resilience-to-weight ratio.
  • As all production processes are finished during the injection step, there are lower expenses.
  • By automating the majority of the 2k molding procedure, one can save money and acquire precision robots that can complete the exact task 10 times faster and more accurately.
  • It requires a simple setup, less complex operation, and supports easier functioning. 
  • Custom products that can be tailored to the specifications of the client are simple to make.
  • There will be fewer maintenance costs due to simple retrofit and maintenance. 
  • The 2 shot mold process is environmentally beneficial because there is little waste.
  • A multifunctional plastic product can be finished in one injection molding step, minimizing subsequent processing.

Application Of China Two Shot Injection Molding

The 2k injection moldingprocess is used to produce a wide range of products that are designed for a variety of applications in different industries.

Utilized to enhance feel in hand-held devices like toothbrush grips, tool handles, spanners, etc.

Utilized in medical device molding for making syringe piston seals, medical devices houses, stem connectors, IVD cartridges, sealings, etc.

Used to fulfill the requirements of partial light suggestion or light transmission in cell phone keys, power switches, automobile switches, etc.

Used to items that must be waterproof in order to meet the water-resistant criteria. 

Types of Thermoplastic Materials

High-Quality Materials Used In Two Shot Injection Molding

SeaskyMedical is a top-notch 2k mold maker company that uses only high-grade raw materials sourced from credible companies.


For two-shot injection molding, we use a wide range of materials like Rubber, Thermoplastics, Nylon, Thermosets, Acrylonitrile styrene acrylate, Polyvinyl chloride, Polycarbonate, Fibre-reinforced plastic, and many more.


We maintain a decent stock of medical-grade materials and allow custom injection molding material selection for a customized 2k molding process

10+ Year Experienced As A 2k Injection
Molding Company

With over 10 years of industrial experience and skilled injection mold designers, SeaskyMedical is a Chinese-based medical plastic injection molding producer and a worldwide 2k injection molding product supplier. 

ISO Class 8 Clean Room

Our 2k molding production facility is equipped with a reliable ISO Class 8 clean room where everyday disinfection is performed. The clean room molding ensures dust-free manufacturing, and we have automatic production equipment. 

Precise Injection Molding Machines

At SeaskyMedical, precise and high tolerance 2 shot molding process machines are used, which will be upgraded once every three to five years. We have high-end CNC machines, EDM machines, along with advanced measuring instruments. 

Competitive Price

SeaskyMedical makes the best quality and affordable two shot molding products using sterile raw lights and advanced machines. Even bulk quantities of 2 shot mold products can be acquired at a competitive price. 

High Injection Molding Technology

We make use of several injection molding technology machines to manufacture precise 2 shot mold products that are durable, meet the quality criteria, and last longer. 

High Quality Control

At SeaskyMedical, we rigorously abide by the ISO 13485:2016 quality management system. We only use premium raw materials and offer ISO10993 biocompatibility reports and COC factory certificates. All the 2-shot injection molding products will undergo strict quality inspections. 

Reach Us

Do not hesitate to contact us if you have any inquiries. You receive a quick response within 12 hours.

Guide On 2K Injection Molding

Numerous substances are injected under precise and automated control during the 2k injection molding process. Two similar moving molds that fit two distinct fixed molds are the most typical arrangement of a 2k mold maker


Comparing the 2k molding process to single injection molding, there are numerous benefits for more complicated product designs. It efficiently lessens assembly, lowers expenses, mixes substance qualities, and creates a solid bond between 2 shot molding components.

2K injection molding

Design Guidelines For 2 Shot Molding

To ensure the precision of the 2k injection molding process, there are certain design guidelines that need to be followed, which are listed in the below two-shot molding design guide. 

Interior Bonding Surface

There are many elements that affect how well the base substance and cover substance adhere to one another in the 2k injection molding process. These include the bonding surface, compatibility of the substances, order of molding, temperature, and the interior bonding surface’s mechanical interlocking design. 


To boost bonding resilience, the surface of the bonding area must be enhanced. If the interior bonding area is relatively tiny, mechanical interlocking configurations can be created in addition to grinding on the bonding surface to improve roughness. 

Cosmetic Mating Surface Design

Particularly in two-shot injection molding of soft and hard plastics, the cosmetic mating surface design at the foremost and second injection is absolutely difficult and needs to offer enough bonding resilience. 


If not, there is a high chance that burrs, gliding edges, rumbled edges, and flaking can arise instantly. Stepped and fluted cosmetic mating surface patterns are some common types.

Consistent Thickness And Deterring Sharp Corners


Undoubtedly, the 2k injection molding process is a kind of plastic injection molding. 


As a result, 2-shot injection molding is subject to the same DFM design principles as injection molding, like deterrence of pointed corners, consistent wall thickness, precise transitions, and many more. 

Draft Angle


The draught angle is crucial for the 2k molding process as it decides which mold the item is linked to during the cycle. The component must be fastened to the moving mold for the foremost injection, and the ejector side of the mold must be fastened for the next injection.

Difference In Weight


The weight difference between the base substance and the cover substance should not be too different, according to the two shot molding design guide. If not, it will have an impact on the injection pressure and 2k molding cycle.

2 Shot Molding Working Process

In order to maintain the viscous state required for injection to take place, the 2k injection mold substances are put into the injection canisters and subjected to high temperature and pressure there. While the other crate will still be sealed, the first molding crate will be unlocked, and the initial injection will be inserted into it.

  • The foremost crate’s press will be unlocked, and the newly produced item from the foremost injection will be swiftly moved to the next mold. As a result, the first chamber will be once again open and available for the second injection.
  • The second injection will be delivered into the first compartment until it is loaded, similarly to the first one, after the push on the second chamber is sealed. This will guarantee that the final items will be consistent.
    The second half will be once more moved there utilizing automatic arms after the second chamber has been reopened. This 2 shot molding process goes on as quickly as it can till the necessary quantity of mold products is produced.
2k Injection Mold Machine And Products

2k Molding Vs. Overmolding

The following are the primary differences between 2k injection molding and overmolding. 

  • Utilizing a standard injection molding device, overmolding involves removing the product from one mold and placing it in another mold for another injection molding. Coming to the 2k injection molding, two polymers are injected at the same time in a specially designed two-color 2k mold maker machine. 
  • In the process of overmolding, the substance that was utilized to mold should become colder in order to be extracted. However, the polymer will be typically hot and elastic during the 2K injection molding process, allowing for additional operations.
  • In comparison to 2k injection mold, which is significantly used for larger production scales, overmolding is used for manufacturing products on a small scale. 
  • In contrast to 2k injection molding, when an item is created by overmolding, it bonds chemically with the other materials to produce a mechanical lock.
  • A broad variety of materials can be utilized in two-shot injection molding either as the molding substance or as the surface to be formed on. Regardless, one can only overmold a metal with rare instances of a plastic and a plastic while overmolding.
  • In contrast to overmolding, 2k molding does not need insert injection, leading to faster, more effective mold cycles and robust parts.
  • The tolerance will not be the same as the 2k injection molding technique because the overmolding procedure involves transporting the initially molded substrate item to another over mold. 

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