A hundred years of history of injection molding technology has experienced , with the continuous development of the plastics industry, plastic products, multifunctional composite structure and will become the development direction of green plastics industry , a variety of new injection molding machines and injection molding processes are emerging behind inefficient production techniques bound with the progress of technology and the elimination of injection molding , production companies and only continuously updated or improved production equipment and technology in order to better adapt to market development .

        Mixed blending plastics production technology is actually a co-injection molding technology of injection molding technology systems through multiple injection molding machine , the different colors or different materials or different colors and textures of plastic injection molded simultaneously or sequentially methods. This technology in the early 1970s , it has been proposed British company ICI Garner and Oxley, followed by the company will be applied to the actual production of them , and apply the relevant patents.

        Although co-injection technique is proposed and applied to the actual production of which , but because of its relatively high injection molding machines and special , and even then the demand for complex plastic is not high, it has not been pre- emphasis . Until improve production technology and people to improve the requirements for plastic products , the technology before they get rapid development, especially in two-color injection molding technology , a wide range of applications.

        Two-color molding plastic products generally use two methods: one is to use two mutually independent ordinary injection molding machine, an injection molding machine injection molding plastic insert a color , and then put the insert onto another injection molding machines, then another color plastic injection , to obtain the final color plastic. This approach is more traditional molding methods, devices using a simple , easy method , but it requires a higher labor costs , productivity and the bottom , backward production technology , generally large companies have eliminated the production methods , and the use of the second method , the method is the direct use color injection molding machine , two color or texture of the plastics injection molding in the same injection molding machines. Two-color injection molding machine uses a two separate injection unit , the plasticizing cylinder with different colors and different types of plastic , the intermediate process does not require human intervention , it is possible to automate the production of color plastic products. The use of this method of producing color plastic products, high initial cost of equipment investment , higher equipment maintenance management requirements , it is difficult for SMEs to large-scale introduction of the production equipment.

        Mixed plastics blending is developed on two-color plastic products, not only in different colors , hardness plastic material is also different , greater difficulty in production , but production methods and two-color plastic products , are based on the two production methods. Some small and medium enterprises are still using the first production process , how in the original equipment on a small increase in the case of hardware and software to improve the degree of automation and production efficiency , lower costs , higher efficiency , which is currently in research is less , there is no more typical example for SMEs to improve production processes for reference.