The multi-color and multi material injection molding technology of hard glue and hard glue,hard glue and soft glue

The multi-color and multi material injection molding technology of hard glue and hard glue, hard glue and soft glue is introduced in detail

1、 Introduction to multi-color / multi material injection molding technology

Also known as multi-color injection molding process, it refers to the injection molding of two or more colors of materials or different materials through a mold with one or more channels. The first is represented by two-color injection molding, and our daily contact is also dominated by two-color products. For example, the handle of the toothbrush we use every morning and evening adopts two-color injection molding. The commonly used material of the handle is PP (hard glue) +tpe (soft glue). TPE is the best material to blend with PP glue, and the coating of soft glue is to improve the grip.

With the increasing complexity of products, the demand for three or even four colors begins to emerge. Generally speaking, there are two types of tricolor machine, one is two position tricolor machine (commonly known as false tricolor), and the other is three position tricolor machine (commonly known as true tricolor). In fact, the difference between the two is not "true or false", but different turntable control methods according to the product structure design (two molds or three molds).

"Two stations" as the name suggests, the rotary table is rotated and positioned in two positions, which is equivalent to the 180 degree rotary table control mode of the two-color machine. In other words, in the three groups of injection molding units of the two station three color machine, two groups are injected into the same mold at the same time. Therefore, if the boundary of two components in the product is not adjacent (it can be designed to inject in the same mold at the same time), only two molds are needed to produce three component products, then the two station three color machine is applicable.

"Three stations" is different. The rotation of the turntable can be positioned at three positions (120 degrees). In other words, the three groups of injection molding units of the three position three color machine are injected into three molds respectively. Therefore, if the boundaries of the three components in the product are adjacent, the three position three color machine is applicable. Similarly, four-color machines can also be divided into "two station" and "multi station" four-color machines. From a technical point of view, the control accuracy of multi station turntable is significantly higher than that of two stations, so the production cost of the machine is also relatively high. Therefore, we should choose the most effective scheme according to the needs of product structure.

2. Working principle of two-color mold

The two-color mold usually has two sets of molds, half of which are installed on the fixed mold fixing plate of the two-color injection molding machine, that is, the side with the injection gate, and the other half is installed on the rotating plate of the moving mold, that is, the side of the mold ejection. The rear dies of these two sets of dies are usually exactly the same, while the front dies are different. When the first material is injected into the first mold, the fixed and moving molds of the injection molding machine are opened, and the rotating plate of the moving mold rotates 180 ° with the rear mold parts of the two molds. At this time, the semi-finished products of the rear mold of the first mold are not ejected, and then the mold is closed to inject the second material (in this process, the first material continues to be injected into the semi-finished products in the second mold). After thermal insulation and cooling, the fixed and moving molds are opened, The moving die of the first die and the finished product of the rear die are ejected. This is a process of forming cycle. In each forming cycle, there will be a semi-finished product and a finished product.

3. Multi color / multi material injection molding product classification

(1) Two or more plastics are injected into one product;

(2) Two or more colors are injected into one product;

(3) One kind of plastic plus one kind of medium is used for injection molding, such as gas assisted injection molding, water assisted injection molding, etc.

4. Advantages of multi-color / multi material injection molding

Two color / multi-color injection molding has become a hot direction in the development of injection molding technology, and its benefits are needless to say. There are many implementation technologies of two-color / multi-color injection molding, such as allowing different hardness and toughness in the same component. Because soft rubber TPE can have color diversity, transparent surface and other interesting features, it is more popular in aesthetic design; Eliminating the installation process, shortening the forming cycle and reducing the processing cost have additional value for the end user (beautiful design, quality, function...).