The blow molding process is a bidirectional stretching process. In this process, the PET chain is bidirectionally extended, oriented and arranged, thereby increasing the mechanical properties of the bottle wall , improving the tensile, tensile, and impact strength. Good air tightness. Although stretching helps to increase strength, it cannot be over-stretched. The stretch-blow ratio should be controlled well; the radial direction should not exceed 3.5-4.2 and the axial direction should not exceed 2.8-3.1. The wall thickness of the preform should not exceed 4.5mm. Bottle blowing machine is carried out between the glass transition temperature and the crystallization temperature, generally controlled between 90-120 degrees. In this interval, PET appears as a high-elasticity, rapid blow molding, cooling and shaping to become a transparent bottle. In the one-step method, this temperature is determined by the length of the cooling time in the injection molding process of the PET plastic bottle blowing machine , so it is necessary to connect the relationship between the injection and blowing two stations. During the blow molding process: stretching-one blow-two blows, the time of the three actions is very short, but it must be well coordinated, especially the first two steps determine the overall distribution of the material, and the quality of the blow molding machine. Therefore, it should be adjusted well; the stretching start timing, stretching speed, pre-blowing start and end timing, pre-blowing pressure, pre-blowing air flow, etc., if possible, can control the overall temperature distribution of the preform. Temperature gradient. During the rapid blow molding and cooling process, there are common problems and solutions in the induced stress in the bottle wall. 1. Upper thickness and lower thickness: delay the pre-blowing time or reduce the pre-blowing pressure to reduce the air flow. 2. Lower thickness and upper thickness: contrary to the above. 3. There are wrinkles under the bottleneck: the pre-blowing is too late or the pre-blowing pressure is too low, or the billet cooling is not good here. 4. Blushing at the bottom: The preform is too cold and overstretched, the pre-blowing is too early or the pre-blowing pressure is too high. 5. The bottom of the bottle has a magnifying glass phenomenon: too much material at the bottom of the bottle, the pre-blowing is too late, and the pre-blowing pressure is too low. 6. There are wrinkles in the bottom of the bottle: the temperature at the bottom is too high, the cooling at the gate is not good, the pre-blowing is too late, the pre-blowing pressure is too low, and the flow rate is too small. 7. The entire bottle is turbid: opaque, and insufficient cooling. 8. Local whitishness: Over-stretching, where the temperature is too low, or pre-blowing too early, or touching the stretch rod. 9. Eccentricity of the bottom of the bottle: it may be related to the temperature of the preform, stretching, pre-blowing, high-pressure blowing, etc. Reduce the temperature of the preform, speed up the drawing speed, check the gap between the draw bar head and the bottom mold, delay pre-blowing, reduce the pre-blowing pressure, delay high-pressure blowing, and check whether the preform is eccentric. Production speed adjustment of blow molding machine By increasing the exhaust time and increasing the saturation time to slow down the speed, while reducing the overall temperature of the lamp box, the overall temperature of the lamp box needs to be reduced by 1% for each increase of 0.1S. Increasing the speed is opposite to reducing the speed. (The exhaust time is very low at 0.8S, and if it is lower than 0.8S, there will be a bottle skipping phenomenon due to the exhaust is not timely.) No matter the speed is increased or decreased, it should not be too fast. The bottle quality should be adjusted after the bottle quality is stable. Every time you adjust the speed, you must carefully observe the quality of the bottle and adjust the temperature of the light box at any time. Each 0.1S change of the bottle blowing cycle changes the bottle output per hour by about 50. The bottle blowing machine should adjust the bottle blowing speed reasonably according to the speed of the filling machine.

One area where hollow blow molding products are growing rapidly is industrial components, especially automotive components. Such as automobile fuel tanks, bellows, collars, windshield washer tanks, dashboards, air ducts of various shapes, and various complex hollow parts around generators. The combination of co-extrusion and three-dimensional (3D) blow molding is the main way to make such products. 1. Automotive Fuel Tanks Since the production of automotive plastic fuel tanks in 1973, automotive plastic fuel tanks are currently the largest production of blow-molded automotive parts. By 2000, plastic fuel tanks have accounted for 90% of the market share. The rapid development is because the hollow blown fuel tank can have complex geometries to make full use of the installation space, which is well adapted to the space requirements of automotive design, and is lighter in weight, low in manufacturing cost, high in economic efficiency, non-corrosive, and resistant to Strong deformation ability. Until the end of the 20th century, the fuel tank was mainly hollow blown from high-molecular-weight polyethylene single-layer extrusion. However, with the increase in environmental protection requirements, the use of multilayer barrier hollow blow-molded fuel tanks with higher barrier properties has become the development of automotive fuel tanks. trend. Due to the continuous change of automotive design and the requirements for the shape of the fuel tank, the design and production of automotive fuel tanks is a constant challenge for hollow blow molding processes and even plastic processing manufacturers. Kind of promotion. 2. Other Plastic Injection Molded Automotive Parts : using improved materials and processing technology, hollow blow molding technology can be used for a variety of new products. For example, door covers, instrument panels, seats, etc. for transmission oil filter, engine covers and large hollow blown automotive parts. In addition, many complex-shaped pipes on cars are increasingly produced using three-dimensional blow molding processes. The pipes that have been developed so far include 6 layers of co-extrusion blow-molded filler pipes, various air pipes and cooling medium pipes. Windshield washer tanks and ducts are also produced by blow molding.

The packaging of the goods is exquisite in different forms, which not only protects the goods inside, but also gives us great visual enjoyment, in this way, we can feel the pleasure of purchasing commodities. It can be said that packaging has largely promoted the rapid development of China's commodity economy. With such exquisite packaging products, we have to mention the vacuum packaging machine .In the continuous innovation of technology, the type of packaging machinery is constantly increasing, among which the appearance of particle packaging machine, is favored by many industries. Particle packaging machine in the face of high temperature in summer, how to deal with high temperature weather in summer? First of all, the machine is best used in a ventilated and dry environment. It is an electromechanical equipment, and some products will melt under high temperature and high humidity.So after each use of the pure water filling machine should be put out of the pellet packaging machine hopper, so as not to melt and stick to the hopper. Secondly, the summer humidity is large, particle packaging machine electrical box to often use compressed air to blow the dust inside, otherwise dust moisture will cause circuit board short circuit, but also corrosion of electronic components. Finally, the operator had better wear gloves to operate, or hand sweating, sticking to the manual sealer machine is easy to corrosion particles packaging machine.