2K Injection Molding & Co injection molding

2K Injection molding is also known as two shot injection molding, twin shot injection moulding, two shot molding, two color injection molding, twin shot injection molding, dual shot molding, double injection molding, double shot molding, co injection molding, and bi injection molding. The 2K injection molding process two different plastics or 2 colors into one integrated part. These plastics can have different structures, colors, properties, and levels of hardness. 2K injection molding process reduces set-up and assembly times in injection molding, integrate functions, combines product properties, and reduces material and work steps. It creates a high-quality connection along with the advantages of two materials with different properties. With the help of co injection molding process, parts can include a transparent window, movable segments, water shields, integrated gaskets, or sound or vibration reduction. The coordination of machine, 2k injection mold, and 2k molding materials is particularly vital in 2K injection molding. The injection units must work in harmony, but must always be independently controllable.

In addition to our 1K injection molded parts, Stebro Mold has become well-known for its 2K moulding capability. Our facilities and expertise enable us to produce complicated 2K parts from two different polymers, especially when it comes to complex geometries. We can help you to optimize the 2K plastic part design, select the best materials that meet bonding requirements for 2K mold design, 2K mold manufacturing, and co injection molding manufacturing, all are under one roof.

2K Injection Molding Example

Here are some co injection molding projects which we made for our customers. To learn if 2k molding technology is right for your project, contact us and our engineers will provide you excellent 2k moulding process.

Two shot injection moulding Part design 

  1. Transitions between wall thickness should be gradual to reduce flow problems, such as back fills and gas traps.
  2. Deep, unventable blind pockets or ribs should be avoided.
  3. Long draws should have a 3-5° draft per side to aid component ejection.
  4. The TPE thickness should be less than or equal to the thickness of the substrate to prevent warpage; this is especially critical for long, flat geometries.
  5. Uniform wall thickness in product is preferred to obtain the best molding cycle time and avoid shrink mark. Wall thicknesses ranging from 1.5 mm-3 mm will ensure good bonding in most overmolding applications. If the part requires the use of thick TPE sections, they should be cored out to minimize shrinkage problems, reduce the part weight and lower cycle time.

2K Injection Mold Design

We insist mold construction design, steel quality and precise manufacturing is the key to achieve molds with excellent performance. Our mold design principle is the mold must be durable, high efficiency and easy to do the maintance and manufacturing.

  1. Shrinkage factor for both materials.
  2. Plastic component wall thickness, uniform wall thickness preferred.
  3. Number of cavities in the mold
  4. Plastic material feeding systems. Runner and Gate
  5. Core and cavity cooling system
  6. Component ejection system.
  7. To avoiding burn mark, air vent is necessary.
  8. Injection Molding Type

Variations of two shot moulding

There are a few variations of two shot moulding, including rotary platen, movable core, and overmold. The first two require a second injection unit, two runner systems, and two processes. The latter, in most cases, involves two separate molds—one for each material—but can also be run with one mold, two runner systems, and pick-and-place part transfer, either manually or with a robot.

2K Mold Manufacturing

To speed up the mold manufacturing process without sacrificing quality, you need the right technology. We use UG to design and manufacture molds. The 2K Mould manufacturing was done toally according to the 3D mold design. For manufacturing the 2K mold, we use different manufacturing machines such as Mikron CNC, AgieCharmiles EDM, Sodick Slow Wire Cut machine, Grinding Machine and Gun Drill Machine. After machining all the components, we have to measure the key size on the CMM machine. It is very important to avoid flash at the parting surface.

2K Injection Mold Trial

Our 2K Engel injection molding machine is not only for the 2K injection molding production, but also for the 2K mold trial.

2K Injection Molding Manufacturing

We offer the injection molding on state-of-the-art injection molding machine Engel with closing force of 130T and rotating table, we are planning to buy another 260T 2K Engel Injection molding machine in 2020.
We offer complete sollutions on the area of 2K technology – from in-house product development, part optimation to two shot mold manufacturing, 2K mold test and serial 2K part production.

Vertical Integration

Single-source, vertically integrated, Stebro Mold makes the transition to injection molding with new tooling easier and more flexible. We can easily handle your T-0, T-1 sample and short run production before the tool’s ships to its’ home location or as many parts as needed to launch your program or fill your future production. Learn more about our in-house 2K Injection Molding.

Advantage, Disadvantage and applications of Two-Shot Molding

Advantage of 2K Injection Molding

  • Stable production processes and high efficiency
  • Lower part cost compared with overmolding and assembly parts
  • Enhanced tactile and cosmetic product features
  • High precision and stable part quality
  • Improve the touch feel
  • Expanded design possibilities
  • Optimum bonding with minimum time and labor

Disadvantage of 2K Injection Molding

  • 2K injection mold and 2K injection molding process cost is higher than single injection molding, but the cost can be covered because of the assembly cost.
  • The combination between 2 plastic materials must be good

Applications of co injection molding:

  • Soft-Touch enhancements, combining thermoplastics and silicone in one component, such as hand tools, writing instruments and toothbrushes
  • Performance improvements, combining different material properties for an Ideal solution.
  • Enhance cosmetics features, permanent graphics through the use of additional colored resins.

Stebro Mold is pleased to advise you as a stong 2K injection mold manufacturing and 2K injection molding partner. We will work with you to optimize the part design, select the suitbale material, choose the cost effective 2K mold and two shot molding solution. We have the Engel 2K Injection molding machine with rotary plate in house for 2K mold trial and 2K injection molding production.

Know more 2 Shot mold solutions, please feel free to contact us.

Quality 2K Injection Molding Manufacturer, From Part Design to Final Delivery, Affordable Price, Fast Delivery, Free Technical Support, Class A services.


Contact Us for Your Co Injection Molding Project