The wall thickness control of hollow blow molding machine is an important step in the production process of blow molding, which affects the performance of the machine and the quality of blow molding products to a certain extent.
How much do you know about the wall thickness control of hollow blow molding machines?
This article will give a detailed introduction to this problem.
Why should the wall thickness of hollow blow molding machine be controlled?
For blow molding products:
The hollow blow molding technology is to make the plasticized blank close to the inner wall of the mold by air pressure. Hollow blow molding plastic containers for its product strength requirement accurately within the scope of the wall thickness, at the same time, the wall thickness of hollow blow molding product is a main factor to measure the quality of the products, so in the process of production in order to guarantee the quality of the products, hollow blow molding machine wall thickness control system can accurately track the set value, response speed and tracking as soon as possible. On the other hand, the wall thickness of the hollow blow molding product is uniform and stable enough, the product will be strong and wear-resistant, the product will have good impact resistance and not easy to damage, long service life, so as to save the cost of the product.
For plastic machinery manufacturers:
Nowadays, customers have more and more diversified requirements for hollow blow molding products. Such as capacity size, shape, use, the number of layers and so on.
Among them, the requirement of the number of layers is related to the wall thickness control of the hollow blow molding machine.
Why do you say that?
If the customer wants to produce multi-layer blow molding products, it must involve the wall thickness of each layer and the degree of wall thickness uniformity. Naturally, it is necessary to use the wall thickness control technology of hollow blow molding machine.
The application of wall thickness control technology of hollow blow molding machine can improve the product performance of blow molding machine, so that it can meet the diversified market demand.
Therefore, wall thickness control is a very important step in the production process of hollow blow molding machine, whether it is for hollow blow molding machine or blow molding products.
What is the wall thickness control of hollow blow molding machine?
The wall thickness control principle of hollow blowing molding machine is to install a thermal expansion mechanism at the outer die ring of the mouth die outlet. The temperature of the expansion mechanism is adjusted by the heater, and the change of the expansion amount under different temperatures is used to push the deformation of the die ring in the radial direction, change the size of the gap between the mouth die, control the outflow of materials at the mouth die, so as to change the thickness of the film. Generally, a number of thermal expansion mechanisms are installed on the circumference of the die ring. Control the die clearance of each point on the corresponding circumference to achieve the effect of wall thickness control.
How to realize the wall thickness control of hollow blow molding machine?
The control method of wall thickness of hollow blow molding machine is:
The forming process of each billet is divided into several points, and the wall thickness of these points is controlled respectively. The fewer the number of control points, the faster the response speed, but too few points, can not reach the desired wall thickness control precision, and will form a melting joint around the blank; On the contrary, too many points will cause the system response time is too long, the servo cylinder is too late to reflect the received signal, the billet has come out.
There are many ways to control the wall thickness of hollow blow molding machines, for example,
The special mold, the axial wall thickness control technology, the radial wall thickness control technology, including the flexible ring technology, the mouth edge modification technology, the mold temperature difference method, the combination of vacuum blister and extrusion blow molding and so on.
In addition to these methods, a suitable wall thickness controller can be used in conjunction with the hollow blow molding machine.
As mentioned in the above wall thickness control method, it is difficult to master the number of control points, too much is not good, too little is not good, so try to use the wall thickness controller with better control performance to cooperate with the hollow blow molding machine.
Take MOOG controller as an example, many plastic machinery manufacturers use MOOG controller for wall thickness control.
MOOG controller has an independent wall thickness control system, can provide 30 points, 100 points wall thickness controller, can be used to control the wall thickness of storage cylinder type and continuous hollow molding machine. The LCD screen can accurately display the production situation in real time: according to the feedback of the electronic ruler of the storage cylinder, control the opening of the mouth mold. The vertical coordinate of the LCD display the position of the storage cylinder, and the horizontal coordinate display the opening of the mouth mold.
The level of plastic processing machinery largely depends on the level of control. The programmable logic controller (PLC) is widely used in the control system of plastic machinery, and the fuzzy control, statistical process control (SPC), and the control system of remote monitoring and fault diagnosis based on the network are used in some high-precision plastic machinery.
In the design and production of hollow blow molding machine, MOOG controller is used in the wall thickness control to ensure the uniformity and stability of the wall thickness of blow molding products. The world brand Siemens full set of PLC controller, simplified the operation process, the production process is more intelligent, more accurate; The remote monitoring system can monitor the operation of blow molding machine in real time.
In the long run, whether plastic machinery manufacturers or plastic machinery users, it will improve the quality, efficiency, cost, service, sales and other aspects of competitiveness, so as to expand economic benefits.
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