Double shot molding is the mold that two kinds of plastic materials is injection molded on just one injection machine with molded in two times while unmoulded only one time. Generally, this molding process is also called 2K injection, usually completed by a set of mold and requires a special 2K machine. 2K injection technology is a rare production method for plastic product. It originated from Arburg in 1961. After decades of development, the technology has been used in many industries and loved by consumers, such as two-color button, two-color phone case, two-color plastic case. These items are injection molded in the injection molding machine based on the doubt-shot mold.

Doubt shot molding are becoming more and more popular on the market today. In this process, appearance of product can be more beautiful, and it is easy to change colors without spraying, but the cost and technical requirements are high. Non-performing rate of doubt-shot mold is much higher than that of single, because two-color product is closely combined with two materials, and technical requirements are relatively high. Mold maintenance and processing enterprise should first equip each pair of mould with a resume card, detailing and counting its use, care (lubrication, cleaning, rust prevention) and damage to tell condition of damage, degree of wear and tear, finally to provide information on discovery and problem solving, as well as molding process parameters of mold and the materials used in the product, to shorten test time of mould and improve production efficiency.