What is a Rotary PVC Sole Blow Moulding Machine?
Rotary PVC Sole Blow Moulding Machine
Rotary PVC Sole Blow Moulding Machine can be used for the production of single shoes, cloth shoes, slippers and TPR and PVC soles. It has a professional blowing device and can be used to produce thermoplastic raw materials such as PVC, TPR and PCU.
The quality of the product is light, soft and has a good surface gloss. It is also environmentally friendly and can be mixed with recycled materials without any change in the quality of the finished product. With the ability to use servo motor and automatic mould opening robots, the machine is able to save the maximum amount of labour and energy.
So is a rotary PVC shoe sole blow moulding machine manufacturing products that are injection molded or blow molded?
It’s blow moulding
And what does blow moulding look like?
We should understand blow moulding.
Blow moulding can be divided into three types
1) Extrusion blow moulding
An?extractor uses a rotating screw to break the plastic through the die head that forms the billets around the blow pins. The blanks are extruded vertically between two open half-dies so they can be closed over the blanks and blow pins. Pressurised air flows through the blowpipe, causing the blanks to expand. This is the most common method of blow moulding and is used to manufacture a large number of relatively simple parts.
2) Injection blow moulding
The molten plastic is injected into a core around the mould blank to form a hollow mould blank. When the blank mould is opened, both the blank and core are transferred into the blow mould and firmly clamped. The core is then opened and allowed to expand with compressed?air.
This is the least common approach as productivity is lower, but enables more complex parts to be formed at a higher rate of progress. Injection blow moulding is preferred for small, complex bottles, for example in medical applications.
3) Stretch blow moulding
The profile is molded in the same way as injection blow moulding. However, once transferred into the blow mould. He is heated by the core and stretched downwards before being inflated. This stretching provides greater strength to the plastic. Stretch blow moulding is often used to produce parts that must withstand internal pressure or are very durable, such as soft drink bottles.
Blow moulding versus injection moulding
First:?Injection moulding process
Advantages
The wall thickness distribution of the injection moulding process can be precisely controlled by the injection mould. Thus making the wall thickness of the resulting container more uniform and avoiding the thinning of the corner part of the general blow moulding products. The blanks made by injection can all be blown into the blow mould. Reducing the waste of moulding materials and saving the time of trimming the products.
Disadvantages
Injection moulding and blow moulding must use two sets of molds and a hollow core mould with felling. And the cost of injection molds and core molds are relatively high.?Injection molds have a high temperature, high temperature molds need a long cooling and shaping time after blowing in the injection mould. So that the entire moulding cycle of the product is extended and the production efficiency is reduced.
Injection molds have a high internal stress, coupled with uneven cooling when changing molds. This increases the risk of stress cracking in polyolefin plastic blow molded containers. Two sets of molds must be used for each product, an injection mould and a blow mould. The injection mould must be able to withstand high pressures.?The positioning tolerances of the two molds are high, the cost of the mould increases, the shape and size of the container is limited and it is not suitable for the production of containers with handles.
Second: The blow moulding process
Advantages
Blow moulding machinery, especially blow moulding molds are less expensive. When forming similar products, the cost of blow moulding machinery is about 1/3-1/2 of the injection machinery. The production cost of products is also lower. The residual stress of the product is smaller, and the resistance to tensile, impact, bending and environmental strain is higher, with better performance.
In injection moulding, on the other hand, the melt has to pass through the mould runners and gates at a high pressure of 15-140mpa, which can lead to an uneven distribution of stresses.
Disadvantages
Blow mould design requirements, should be equipped with exhaust grooves.?The bottom design concave, mould body selection of corrosion-resistant carbon tool steel and common alloy steel. Pipe billet temperature and blow moulding temperature. The temperature is too high melt viscosity is low easy to deformation, so that the tube billet in the transfer of uneven thickness. The temperature is too low and the product often has more internal stress, which can easily deform and rupture during use.
Rotary PVC shoe sole blow moulding machine features
1. Rotary mechanical structure
The machine adopts the rotary structure, the equipment structure is reasonable. It can effectively save the occupation space, simple and convenient operation. The operation is safe and reliable. One person one machine operation, baking efficiency is high. Adopting 24-station rotating baking technology, the baking range is wide, the output is considerable and the product colour is good.
2. Adopt PLC/PC intelligent control system
Advantages of PLC intelligent control systems
1) Programmable controllers are different from traditional control systems. Traditional control systems have more hardware relays and contacts. PLC is mainly composed of “soft relays”.
2) Traditional control systems have more mechanical contacts, which reduces the reliability of the system. PLC without mechanical contacts is currently used for logic operation of advanced electronic technology, good reliability, operation of small wear and tear, and therefore a longer service life.
(3) PLC is mainly through the programming of circuit control, the traditional control system is mainly dependent on the hardware wiring between the components.
The advantages of PC intelligent control system
First:?System cost is greatly reduced
Compared to microprocessors and PLC and other human-machine interfaces (HMI). PC has a great cost performance. Moreover, compared with PLC, DCS, FCS,?and so forth. PC control systems are incomparable not only in terms of data processing speed and mass storage. For simple devices that are not intelligent and digital, they can also be connected directly to the PC and communicate with it using analogue signals.
Second: The processing speed and communication speed is very fast, the information storage capacity is large
The PC has high processing speed, a reliable operating platform, massive storage, networking, intelligence and other related advantages. the storage capacity of the PC is very large and the system-related data can be accessed very easily. In terms of data communication, with the development of network technology, the high-speed processing speed based on the PC level is quite mature. communication technology of the PC, whether it is inter-PC communication or communication between PC and I/O components, the communication speed is very fast, and if the load of the communication line is too large, it can be controlled by multiple PC segments and then network communication between individual PCs. This also greatly ensures the stability of the entire system. Parts that go wrong can also be quickly isolated from the system.
Third:?Easy integration of process control, batch control and motion control
The PC can collect and process a large number of analogue, digital, pulse. And switch signals through specially designed multi-channel input and output boards. Than through the high-speed processing of the PC, the process control of a production line, the motion control of an actuator, and the batch control and logic control of several components on site can be carried out at high speed. Batch control and logic control of multiple components on site. With its high-speed processor, large memory, multi-threaded processing and high-speed communication, the PC has the advantage of controlling relatively large systems. It allows for better integration of all relevant systems, better coordination and faster processing speeds.
Forth:?system design, commissioning and maintenance is simple, access to upper level information is very easy and faster, better design of the entire control system.
Because of the PC’s friendly human-machine interface, very simple interfaces and good versatility of components.The commissioning and maintenance of the whole system is also very simple. It is also due to the PC that access to information in the system is very easy, and communication with other upper layers is also very simple. Then?relevant information can be made clear at a glance.
Fifth: Good portability of the system software
Although PCBCS offers significant cost savings in terms of hardware, it has become relatively difficult to compile in terms of software. However, the software of PCBCS system is portable, only when doing a new project there are difficulties in the preparation of software.?If there are other related software for reference or upgrade on the basis of existing software, then the preparation of software will become very simple, it is easy to develop new or upgrade software. Based on the existing PCBCS, software development is also no longer a problem.
Finally:?control, human-machine interface and programming functions are easy to integrate.
As the PC has a good human-machine interface, various relevant information is displayed one by one during the control process, making it easy for the operator to operate the whole system and achieve overall control. The disadvantages of total control are eliminated and the control task is completed. Moreover, the operator can also carry out real-time programming to achieve functions that cannot be done by some other systems
3. Environmental protection and energy saving
The machine can be mixed with recycled materials, the quality of the injected products can be comparable to the new material injection products
?
4. Rotary PVC shoe sole blow moulding machine motor selection
Servo motor VS ordinary motor
(1) servo” is “follow” the meaning of the control signal, servo motor can do precise control. It can control how much to let turn on how much. And it also has a feedback device, can realize the closed loop. That is, the encoder can feedback whether to turn the number. so the servo motor is more accurate.
(2) Servo motors and ordinary motors in the maintenance is also different, servo motor maintenance trial needs special equipment. Servo motor closed-loop feedback control components are encoders, but generally encoders are corresponding. It can not be used interchangeably, so more trouble.
(3) Servo motors will also have more types of faults than ordinary motors. Servo motors mainly deal with signal attenuation, communication interruptions, unstable speeds, lost pulses and other problems, all of which require electronic maintenance skills to deal with.
(4) Servo motors are also different from ordinary motors in terms of the motor rotor and feedback device. This is because there are powerful magnetic steel sheets on the servo motor. So the servo motor can precisely control the position of the rotor with the magnetic field generated by the stator coil. And the acceleration and deceleration characteristics of a servo motor are also higher than those of an ordinary motor.
In summary, the machine has a unique design, relatively accurate programming, stable operation, relatively high speed and a high yield. With this machine, you will certainly be able to meet your production needs.