LS Mtron captivates the injection molding machine industry with customized multi-shot injection molding!

Currently, the injection molding market’s entry level is relatively low in emerging countries such as China and India. However, attempts to improve the value of products by adopting complex plastic surgery technologies are increasing, and plastic surgery techniques to improve productivity are continuously being developed.

Among them, multi-shot injection molding machine is a structure that requires high initial setup costs, including IMM and mold costs, and demanding technical skills for materials and processes. 

In the future, the higher the customer's demand for quality and appearance, the stronger the demand for the injection molding and IMM is expected.

At a time when demand for multicolor molding machines is increasing due to the recent advancement and automation, LS Mtron Co., Ltd. will briefly discuss multi-shot injection that can produce simple household goods, high-end interior/external materials and parts, and introduce our products.

1. The concept of multi-shot injection

Multi-component injection molding, also known as multi-shot, refers to the process of simultaneously injecting two or more colored and raw materials into a mold to form a single jet

2. Type and characteristics

(1) Type of multicolored, multiple injection molding

① Multi-component injection molding

With two substances ejected into different liquids and present at the same time as a sandwich structure, the raw material is injected into concentric circles using the same mold/gate, or by repositioning using gates at different locations.

② Multi-shot injection molding

It means making multiple layers based on the starting axis of the initial mold. In other words, heated materials are inserted into the mold one after another in a particular order, which creates a layering effect between materials while maintaining relatively high energy interactions at the material boundary. This means that interlayer bonding is more powerful in that it is a combination under heated and melted conditions, compared to overmolding being injected into existing cooled parts. This is preferred when various molds(different shapes) are needed.

③ Over-molding

This has the most powerful layering effect. This process is used to add shapes and structures to existing components using melted resin, and is an injection method that is applied when layers with various geometric profiles are needed around the central 'core' structure. 

▲Types of techniques applied to multicolor injection

(2) Type of multiple, multicolored injection

Multi-shot injectin molding can be applied variously depending on the free injection expression and factory installation environment by the customer's product characteristics. In addition, cost can be drastically reduced by omitting post-process processes.

In addition, the defect rate in the post-processing process decreases. During the post-treatment process of heterogeneous/different materials, it is also characterized by a reduction in the number of metachromatic stain and poor bonding.

Also, additional manpower and facilities are not required according to the existing assembly process, and one-stop production can reduce incidental production time to maximize efficiency.

3. Current status and prospects of Multi-shot injection molding

Currently, many companies have entered the multicolor injection molding market, but each has a low share because it is very subdivided. In particular, the degree of competition is not considered to be relatively high because the injection molding process or control of equipment is more difficult than general injection molding. 

Especially, multi-shot injection molding are difficult for manufacturers to access because they require a special design, have fewer suppliers, more expensive machines, and are somewhat limited in supply and demand. Therefore, the higher the customer's demand for quality and appearance in the future, the higher the demand for the injection molding and machine is expected to increase.

Meanwhile, the advantages of multicolor injection molding are attracting more OEMs to multicolor injection molding. It is possible to mold high-precision parts with various color combinations and one injection machine, increasing the value of the product.

Recently, as aesthetic and ergonomic designs have become more important, rubber materials, joining technologies with silicon materials, and seal molding methods are drawing attention. This is also expected to be a positive factor for the multicolor injection molding market(e.g., bicycle handlebars/grips, operating buttons and anti-slip, etc.).

▲Increasing demand for multicolored(material) molders

4. LS Mtron’s multi-shot injection molding solution

Currently, LS Mtron provides multi-shot injeciton molding using LS Mtron's accumulated power-driven techniques to control injection volume, speed through multiple injection and digital precision control which injects two or more materials simultaneously or sequentially. In particular, it is possible to change and combine to suit the customer's needs, providing a customized solution to the special purpose customer, and transport it by axis or vertical rotation using the rotational function provided by the machine or mold.

Next, I would like to introduce the description and features of our multiple and multi-shot injeciton molding.

(1) WIZ-EC

① Pneumatic stopper: Easy to replace the stopper and adjust the position of the taper stopper.

② Best-in-class rotating plate size: the largest gap between the tie bar in Korea and the extension of the length of the shape

③ Rotating plate servo motor drive: Reduce mold rotation time and improve positional precision with index units using AC server

④ Option: Application of ejector pin segmentation type(reduction of extraction time) / Application of magnetic plates

(2) WIZ-ED

① Injection exclusively for LENS

- Large specifications of screws can be fitted to primary and secondary injection units

- Post-molded products by applying longitudinal pressure injection servo(maintenance time of more than 300 seconds)

- Transparent Dedicated Screw Design Applied

- Injection Precision Slow Control

- Reduce cycle time(2-layered molding)

- High-rigid center press plate applied

② Molding characteristics

- Secondary injection system can be installed without restricting injection volume

- Easy to switch into general injection(single product)

- Utilization of floor space is relatively efficient

(3) WIZ-EV

① Vertical structure of a two-liquid injection device: The injection device is mounted perpendicular to the top of the fixed plate and occupies the same space as the standard machine(high-cycle shape high speed application / high-digestion screw applied exclusively for packaging)

② Multi-layer technology applied: Technology that improves the formation of blocking layers(EVOHs) on the surface of the product through multi-stage injection

▲Multi-Layer technology 

(4) WIZ-EPR

① Molding characteristics

- The narrower the gap between the two nozzles, the more space between the four tie bars can be fully utilized to minimize the mold size

- Individual control of two injection units results in different injection sequences and increased molding precision

- European double injection molds or standard molds can be applied

② Core Turn

- By applying core turn(index core), 4 portable plates of servo motor injection molding machine are installed to implement individual and simultaneous operation

- Simplify mold structure and increase productivity

- Fast and accurate core rotation with servo precision control

(5) WIZ-EL

① Mechanical structure

- Additional injection device is located on the semi-manipulated side(determined according to mold structure)

- A structure in which two gates are perpendicular to each other in two types of molds

- 1st injection device: press + 2nd injection device power type

② Scalability

- Applicable to existing injection machines or third-party injection machines

- Up to 5 additional injection devices can be attached

■ Contact: LS Mtron's Injection Molding Machine Division www.lsinjection.com