The principle of hot flow path and system components - Union star packaging machinery

The principle of hot runner is 1. Cold runner and hot runner is compared with the cold runner mold gate entrance and products between the parts. Plastic by injection pressure in the flow passage and its heat flow state and flow channel as part of the molding material, but it does not belong to the product. So when we design the mold should not only consider filling effect, and to consider how to save material by shortening, narrow passage, ideally in this way, but in practical application, it is difficult to achieve the best of both worlds. Hot runner is also called the free port is to point to in every time after the injection port of the plastic is not frozen, plastic products mold release, he don't need to port the runner out. Due to the flow of the plastic without coagulation, so the next time the injection port is still open. Briefly, hot runner is an extension of the injection molding machine nozzle. 2. The characteristics of the hot runner mold why will have this kind of hot runner technology appear? Hot runner technology and can bring us what benefits? Familiar with injection molding process engineers know, conventional injection molding often has the following disadvantages: a. Fill the difficulties; b。 Thin-walled parts easy to deformation; c。 Runner waste of raw materials; d。 The multimode cavity mould do not match the quality of injection molded parts. The emergence of hot runner technology, gives these problems is the perfect solution, generally speaking, the hot runner has the following advantages: 1. Shortening the period of stamping shape because there is no limit to the gating system, cooling time, stamping shape after curing can be out in a timely manner. Many small parts with hot runner mold production of thin-walled molding cycle can be under 5 seconds. 2. Save the plastic raw materials in the hot runner mold because there is no cold runner, so there is no material production costs. This was particularly significant for the application of plastic expensive project. Main hot runner manufacturers in the world, in fact, both oil and plastic raw materials is expensive in the world s got swift and violent development, because of the hot runner technology is an effective way to reduce waste to reduce raw material costs. 3. To reduce waste, improve product quality in the process of forming mould of hot flow path, the plastic melt in the runner system to get accurate temperature control. Plastic can be more uniform state into the cavity, the result is consistent with the quality parts. Gate of hot runner molding parts are of good quality and low residual stress after demoulding, part deformation is small. So a lot of high quality products on the market are produced by hot runner mold. 4. To eliminate the follow-up process, be helpful for production automation parts after molding mould of hot flow path is the finished product, don't need to trim the gate and recycling processing cold runner and other processes, production automation. Many products manufacturers at home and abroad are combined hot runner and automation to greatly improve production efficiency. 5. Expanding the scope of the injection molding process application composition of hot runner system even though there are many hot runner manufacturers in the world and a variety of hot runner products series, but a typical hot runner system is composed of the following a few most: heat flow but, nozzle, temperature controller, auxiliary parts. A successful application of mould of hot flow path projects require multiple links be guaranteed. One of the most important two technical factors: one is the plastic temperature control; Second, the plastic flow characteristics of control. 1. Plastic temperature control in the application of hot runner mould plastic temperature control is very important. Many found in production process and product quality problems arising directly from the hot runner system, temperature control is not good. Such as using the torpedo type hot runner injection molding product gate mouth poor quality problems, valve type hot nozzle needle valve fully closed time molding difficult issues, and parts of multi-cavity mold filling time and the quality is not consistent with the problem. If possible, should choose as far as possible to have more regional segmentation of hot runner system, temperature control to increase the flexibility and resilience. 2. Plastic flow control plastic flow balance in the hot runner system. Gate will open at the same time make plastic synchronous filling the cavity. For the parts weight difference to balance runner design. Otherwise there will be some parts molding pressure is not enough, but some parts molding pressure, flash too poor quality problem. Design of the hot runner gating size must be reasonable. Size is too small molding pressure loss is too big. Size is too big, hot runner size is too big, plastic stay too long in the hot runner system, damage material performance and cause parts forming can't satisfy the use requirement.