The principle and process flow of the automatic bottle blowing machine

Bottle blowing machine refers to a machine that blows bottles. The simple explanation is a machine that can blow plastic particles or preforms into bottles through technological means.

Plastic hollow containers are widely used in beverage, medicine, cosmetics, food and chemical industries due to their light weight, low price, and high safety. They have attracted more manufacturers to choose plastic containers instead of glass containers.

Nowadays, the equipment, molds and raw materials of the plastics industry are all presented to us. New technologies and new applications are emerging one after another. Throughout the field of plastic hollow molding, there are also fruitful results. With the soaring world oil prices, the price of plastic raw materials is also high, and the development of alternative products with low energy consumption and low raw materials is also one of the market trends.

At present, most of the blow molding machines are still two-step blow molding machines, that is, plastic raw materials must be made into preforms before blowing. Nowadays, environmentally friendly plastics made of PET are commonly used.

Blowing principle

The blowing process of the bottle blowing machine is divided into two parts.

1. Warm up

The preform (preform) is irradiated by an infrared high-temperature lamp to heat and soften the preform body. In order to maintain the shape of the bottle mouth, the preform mouth does not need to be heated, so a certain cooling device is required to cool it. .

2. Blow molding

In this stage, the preheated preform is placed in the blow mold, and the inside is inflated with high pressure. Blow and pull the preform (embryo) into the required bottle.

The automatic bottle blowing machine combines the two operations of bottle blowing through the operation of the manipulator, eliminating the need for manual process of putting the preheated preform into the blowing mold. Greatly accelerate the rate of production.

The process flow of the bottle blowing machine

The blow molding process of the bottle blowing machine is a two-way stretching process. In this process, the PET chains are extended, oriented and arranged in two directions, thereby increasing the mechanical properties of the bottle wall and improving the tensile, tensile and impact strength. And has very good air tightness. Although stretching helps to increase the strength, it should not be overstretched. The ratio of stretch-inflation should be controlled: the radial direction should not exceed 3.5 to 4.2 times, and the axial direction should not exceed 2.8 to 3.1 times. The wall thickness of the preform should not exceed 4.3mm.

Bottle blowing is carried out between the glass transition temperature and the crystallization temperature, generally controlled between 90 and 110 degrees. In this interval, the PET exhibits a highly elastic state, and becomes a transparent bottle after rapid blow molding and cooling and setting.

The blow molding process includes: stretching-blowing once-blowing twice. The three actions are very short, but they must be well coordinated, especially the first two steps determine the overall distribution of the material and the quality of the blown bottle. Therefore, it is necessary to set the parameters: stretching start timing, stretching speed, pre-blowing start and end time, pre-blowing pressure, pre-blowing air flow, etc. If possible, it is best to control the overall temperature distribution of the preform. The temperature gradient of the inner and outer walls of the preform.

During the rapid blowing and cooling process, induced stress is generated in the bottle wall. For gas-filled beverage bottles, it can resist internal pressure, which is beneficial, but for hot-filled bottles, it must be fully released above the glass transition temperature.

Hisson Plastic Machinery Co., Ltd. is a professional manufacturer specializing in the design and production of plastic molds and PET blow molding machines.

Since its establishment, the company has specialized in designing and producing more than forty specifications and models of blow molding machines, plastic blow molding machines, PET bottle blow molding machines, PET automatic blow molding machines, semi-automatic PET blow molding machines, blow molding hollow molding machines and Various hot and cold runner injection molds, hollow molding molds, bottle blowing molds.

According to needs, we can configure various PET blow molding machines from single cavity to 8 cavities, from hundreds of bottles per hour to 20,000 bottles per hour, and provide a complete set of production from preform production, blowing, filling to final packaging. System, provide the whole plant supporting projects, we have accumulated rich experience in the long-term work, we are willing to use our experience and enthusiasm to provide high-quality solutions for new and old customers, and contribute to your business soaring.

Hisson Machinery is constantly seeking innovation and change in technology, and always welcome friends from all walks of life with high-quality products.