Do you know whether the mobile phone shell is hard or not?
In fact, the mobile phone shell has a kind of structure, which is hard and soft together. We used to have a very hot structure from 2012 to 2013. The structure is made of hard PC material on the back and TPU soft material on the four sides. This technology has two processing directions.
1. Dual-color injection moulding machine processing, the general injection moulding machine is only a single material for high-temperature hot melt injection mold cavity rapid cooling molding, here is a little difficult to understand, it can be understood that you melt the candle heated, in the liquid state into a metal vessel, because the metal vessel is low temperature, wax horse. The top hardens according to the shape of the metal vessel. And our plastic is not so easy to rot after wax cooling, according to different materials into different mobile phone shells or other plastic products. The double-color injection machine is that a product can be injected twice in one machine, the first injection of hard material, and then the second injection of soft material into the mould through internal rotation. This advantage is that the production process saves time than monochrome injection, but the precision of the mould is very high, because of two different types. Material has different characteristics, such as expansion and shrinkage, processing temperature, injection speed, and various factors that can affect the final cost of scrap. The only way to adopt this technology is to see the large factories in the Apple Store, and the small factories will not buy equipment to do this, because of the process requirements and the cost of scrap. The cost of input is too high for ordinary purchasers to accept such quotations.
2. Second set of beer (set of injection moulding), because the purchase cost of two-color injection moulding machine is more than twice that of ordinary injection moulding machine, and the mould is much more expensive. Our small factory completes this structure through the second process. This feature is that there is no need to open two-color moulds, no need to buy two-color injection moulding machine, but the trouble is to double the work flow. From the first injection moulding machine to the second soft material injection moulding, the cost can reduce the initial production equipment purchase cost, because a two-color injection moulding machine can indeed equal the purchase cost of two ordinary injection moulding machines, and the other two-color injection moulding machine generation factory is not many, but single. The factory of color injection moulding machine is a very common production configuration, so we adopt this process according to local conditions, but there are still some problems, that is, two sets of moulds are needed, then the error between the two sets of moulds can not be too big, of course, this is the matter that money can solve, the cost of this kind of moulds is also higher than that of double-color injection moulding. At the bottom of the mould, the profit of the mould making in our industry is almost equal to earning a metal processing fee. The so-called windfall profit has long been absent. Here, the pit I once encountered is that the machine workers in the supplier cooperation did not follow the production process, and after about 5-10 times of injection, they need to spray with an air gun. Mould surface will be produced during the production of dust treatment, resulting in I have a whole batch of goods scrapped. It's easy to find an agent for this craft, but it depends on your fate to find a more responsible one.