Factors influencing bottle making machine

Preform and its heating, pre blowing (position, pressure and flow), stretching rod, high pressure blow (pressure, position) and the mold, which is the process of the bottle blowing machine.

1 bottles

The preform is also called parison, PET grain by injection molding, it requires recycling material recovery ratio can not exceed 10%, not more than two times. Bottle blank after injection molding preform or heating and then cooling must be above 48h, and the bottle blank use storage time should not exceed 6 months, different production date, especially the bottle blank can not mix the interval is too long, the main reason is two times the proportion of the material residual preform the raw material type, mixed and bottle the compact inner stress caused by the different, and these factors on the forming of bottle blowing technology have a great impact, should be treated according to the actual situation of the specific.

2 heating

The heating of the preform is completed by a heating furnace, which is manually set and automatically adjusted. The height of the heating furnace is about 25mm, which is about 19.6mm from the conveying wheel. The bottle blank is continuously running through the whole oven on the conveying wheel, so that the preform is heated uniformly and can be formed better. The utility model overcomes the defects of uneven heating of the prior bottle blank and manual rotation. But if the improper adjustment of heating furnace, will cause the bottle wall thickness blowing on the uneven distribution (such as light weight, big mouth), stiff neck and other products exceed the standard defects, even failure caused by the mechanical components of the torque. The temperature of each region can be adjusted according to the specific conditions of the product, while taking into account the opening of the oven lamp. In addition, the heating setting of preform oven output power of the output will have a great effect, which controls the entire oven heat. When the term does not boot, boot again when the initial output power should be set higher, the normal production process and then gradually decreased to the normal state, the output power is generally about 80% is appropriate, especially the ambient temperature is below 5 DEG C, the effect is more significant.

Blowing bottle production process and the production environment temperature also has a certain relationship, the ambient temperature is generally at room temperature (22 degrees Celsius) is appropriate. If the temperature is too high, then the product easy to appear point agglomeration; the temperature is too low, the machine starts when the product performance is not stable, according to the actual situation and experience to adjust to the specific operation.

3 pre blow

The role of pre blow in the blowing process is to make the preform shape, while the longitudinal tensile strength of the longitudinal tensile strength. The whole process is pre blow cam in the blowing process of the three-way valve onto pre blowing position, and with the completion of the one-way valve. The pre blow position, pressure and flow can affect the quality of the bottle.

Position: pre blow ahead of the position, will appear at the bottom center of the bottle point deviation, thinning, foot wall unevenness and white light, stiff neck, heavy, and even the bottom penetration defect; pre blow position after the fault occurs, under the light weight, the center point of the thickened, depression and other defects.

Gas flow pre blow flow controlled by the one-way valve, generally open 3-4 ring is appropriate. At the bottom of the gas flow is large, heavy, thin, partial foot center, white wall thickness unevenness; gas flow is small, the center thickness and weight exceed the standard section.

Pressure: preblow pressure in 0.8-1MPa. The pressure is high, may cause heavy, center deviation, foot wall unevenness, white and so on; pressure is low, the bottom is not fully stretched, heavy, thick center.

The shape of the bottle and the central point of the bottle has the greatest impact on the quality of the bottle, which is often caused by improper adjustment.

4 draw rod

The stretching rod in the pre blow at the same time with the pre blow device of bottle stretch after heating, it before the exhaust pressure blown, after reset. Stretching rod must be in the process of blowing the bottle can move vertically up and down, the driving pressure is 0.55-0.8MPa, and the gap between the bottom mold is 2.3-2.5mm, that is, the thickness of the bottle 1 / 3-1 / 2. The gap is too large, it will cause the bottom of the bottle center offset; clearance is too small, the center of thin.

5 high pressure blowing

The role of high pressure blowing is to make the full extension of the material, close to the mold wall, so that the full shape of the bottle, while the lateral tensile, improve its lateral strength. The main influencing factors are location and pressure.

High pressure blowing pressure is 3.7-4MPa, which is determined by its forming characteristics and filling (carbon dioxide) determined by the nature of the. Its location is two, which is a high pressure air exhaust position and the position between the two time for the forming of the pressure holding time has great influence on the stability of the time of bottle capacity. Lack of high pressure gas, easy to make the wrong shape of the bottle, foot blowing, etc..

6 mold

Mold is one of the important factors affecting the blow molding. The bottle to die, the bottom of the bottle blowing mould is independent, typical. In the production process, must maintain the mold constant temperature, clean, the vent hole unimpeded.

Die heating and cooling system failure, there will be the bottleneck of the bottle slanting, tilt, volume, height, weight and other defects at the bottom; maintain the mold temperature can also prevent condensation of mold surface.

PET forming shrinkage rate is generally 1.8%, after the addition of glass fiber reinforcement slightly reduced, but still up to 0.2%-1.0%. Under normal circumstances, high mold temperature shrinkage rate, low mold temperature shrinkage rate, in order to maintain the stability of the volume of PET bottles, mold temperature must be strictly controlled. General requirements of the bottle body temperature slightly higher, 20-45 C, the lower requirements for 6-15. The bottom of the high temperature will make the bottom weight, the center of the thick.

In actual production, such as nozzle will affect the formation of PET bottles.