Multi-shot and Double-shot plastic injection Moulding
- Our Experience in multi-shot and double-shot moulding
- Why Choose Kore?
- What is Multi Shots Moulding?
- What is Double-shot Injection Moulding?
- Benefits of multi-shot moulding
- Areas it is best applied
- Case Studies
Our Experience in multi-shot moulding or double-shot moulding?
Why Choose Kore
- We have been advocating multi-shot moulding not just for its benefits but also our commitment to the Green Manufacturing
- We are the experts on multi-shot moulding, and the pioneer in multi-shot plastic injection moulding.
Find out more about multi-shot moulding and double-shot moulding below.
What is Multi-shot Moulding?
Multi-shot moulding is the injection moulding process that moulds two or more more materials onto each other in a single injection moulding cycle.
Another term for multi-shot injection moulding is multi-material injection moulding.
The most common multi-shot moulding is the double-shot moulding or what is also known as 2K moulding or two-shot injection.
What is Double-shot Injection Moulding?
Two shot injection is the injection moulding process that moulds two materials onto each other in a single injection moulding cycle.
The process uses specialized plastic injection moulding machinery with two plastic injection moulding units; the primary plastic injection unit for the first shot and a secondary plastic injection unit for the second shot.
Other known terms for double-shot injection moulding are:
- Twin-shot injection moulding
- 2K injection moulding
- 2-shot or Two-shot injection moulding
- Double-colour injection moulding
- Transfer moulding
How its done
First, the substrate is injected into the its respective mould cavity while the over-mould is injected into its own cavity over the substrate from the first half of the injection moulding cycle.
Next, the mould opens and the moving half or the core side of the mould is rotated 180 degrees and closed for the second half of the injection moulding cycle.
The finished two-shot part is finally ejected from the mould for manual or robot pick.
For a double-shot plastic injection moulding to work, the substrate and over-mould plastic material has to be chemically compatible in order to form a solid bond. See chart for chemical compatibility of materials.
In cases where the substrate and over-mould plastic material are not chemically compatible, the substrate geometry has to incorporate mechanical bonding features such as through holes or other similar features.
These features allows the overmolded plastic material to mechanically “grab” onto the chemically incompatible substrate.
Read more about our past case studies of different types of double-shot / multi-shot moulds here
Benefits of multi-shot injection moulding:
- It can significantly improve the appearance and appeal of the product
- Using Two-shot plastic injection moulding technology, a single moulding process can join two parts. This reduces the process costs by eliminating manual assembly or adhesive in cases where the two parts are build using non-two-shot processes
- The two-shot moulding process provides a stronger and more durable product than an assembled product manufactured using two individual moulded components
- Another added benefit of a two-shot injection moulding process is its ability to provide multicolored product. This eliminates the need for secondary process such as painting
- The two-shot moulding can produce complex parts that are capable of extra functions.
- The products injection moulded using two-shot injection moulding are much more functionally robust widely used in dust, shock, and waterproofing applications; e.g. IP68 housings
- Two-shot moulding is ideal for surfaces with maximum friction, i.e. first shot hard plastics with a second shot soft rubber designed to enhance grip non-slip surfaces for industrial hand-held devices and infant products.
What areas is it best applied?
The two shot injection is usually used to mould a soft material onto a hard plastic or non-plastic material.
- They are ideal for buttons and switches, handles, grips and caps.
- The process is also used to produce multicolored products or painted logos.
- Two-shot injection moulded parts are also ideal for parts that function as noise pads and vibration damper.
- Moreover, different industries including aerospace, automotive, medical and consumer industriescommonly apply this two-shot process to build their plastic injection moulded parts.
- From bottles for infants to guns for soldiers, the two-shot injection process is widely used and trusted for its versatility and durability.
Read about our multi-shot moulding case studies here