With the popularization and application of ultra-clean and aseptic filling process in beverage packaging (fruit juice, tea and sports drinks, etc.), the original hot filling process (85-92°C) is gradually replaced by the aseptic cold filling process. First, the production cost of aseptic cold filling is low, the bottle weight is light, the consumption of compressed air is reduced, and the energy consumption of equipment heating is reduced, so the energy conservation and consumption reduction are obvious; Second, due to normal temperature filling, the loss of nutrients is less, which can maintain the taste, color and flavor of the beverage, and at the same time, the shelf life of the product is more guaranteed.
In order to meet the requirements of ultra-clean and aseptic filling process, the aseptic bottle blowing-filling-capping screwing integrated equipment, the bottle blowing machine uses the aseptic bottle blowing process to produce bottles, reduce the pollution of bacteria to the bottles in the bottle embryo conveying link and the bottle blowing process, effectively kill the bacteria and provide guarantee for aseptic filling (dry or wet sterilization).
Main structure of aseptic bottle blowing process:
1. The mechanism for arranging the bottle blank is totally enclosed.
In order to improve the cleanliness of the bottle blank and prevent dust pollution during the supply, sorting and conveying of the bottle blank, an openable dust cover is designed above the bottle blank tilting bucket. When the number of the bottle blank is less than a certain height, the dust cover opens automatically, and the bucket machine dumps the bottle blank automatically. When there is a certain number of bottle blank, stop pouring the bottle blank and the dust cover closes automatically. Protective cover and transparent window are designed in the process of lifting, arranging and conveying the bottle blank. The bottle blank operates in a closed environment to reduce the contact with the external air, and also reduce the dust absorption caused by static electricity to prevent the pollution of the bottle blank.
2. UV sterilization of bottle mouth.
In the production, storage and transportation process of bottle embryo, due to the influence of temperature, humidity and air and other environmental factors, the surface of bottle embryo will breed bacteria and other microbes. In order to kill bacteria and microbes, a certain number of ultraviolet lamps are installed on both sides of the slideway and close to the bottle mouth. TUV lamps are used to emit short wave ultraviolet (UV-C) to illuminate the bottle mouth to kill bacteria. Under the radiation of ultraviolet, DNA RNA is destroyed and inactivated, preventing cell regeneration and killing bacteria, viruses and other microbes.
3. Electrostatic precipitation of bottle blank.
The purpose of electrostatic dust removal is to remove the dust in the air due to electrostatic adsorption inside the bottle blank. The dust removal system is mainly composed of three parts: (1) bottle blank transmission mechanism, which realizes the up and down movement of bottle blank transmission and air blowing pipe. The transmission system is associated with the heating machine. The star wheel disk is driven by the synchronous belt, and the air blowing pipe is driven by the cam; (2) For the ionisation device, the power controller converts 24V voltage into 4-8KV and 120uA current, and the high pressure discharge needle in the nozzle ionizes the sterile compressed air (2-4bar) to generate positive and negative ions to neutralize the dust electrostatic adsorption on the surface of PET bottle blank; (3) Dust is collected, filtered and discharged by the dust collector generated by the ion dust collector.
4. Flask H2 O2 steam sterilization.
In order to further kill bacteria and other microbes inside the bottle mouth and the embryo tube, considering the heating structure and heating process, the bottle embryo sterilization adopts a certain flow, concentration and temperature of H2O2 steam directly eject to the bottle mouth and the inside of the embryo tube, and the surface of the bottle embryo will form 2-4μm condensation film can destroy the protein of microorganism such as bacteria due to strong oxidizability of H2S; Small surface area of bottle blank and less consumption of H2S solution, which is very suitable for sterilization of PET bottle blank.
5. Sterile high pressure air bottle.
Sterile high-pressure gas is used for the main air blowing and pre-air blowing of the bottle blower to prevent bacteria and other microbes from polluting the bottle during the bottle blowing process. The compressed gas (25-38bar) produced by the air compressor is dried, coarse and fine filtered (filtering accuracy: 3-5um, maximum residual oil content: 5mg/m3), and the air quality cannot meet the sterility requirements, so further treatment is required to effectively filter particles, impurities, water, oil and microbes in the gas; The sterile high-pressure gas is configured with three filters in series: (1) High-pressure precision filter, dust removal, oil removal and water removal, with a filtering accuracy of 0.01um and a maximum residual oil content of 0.01mg/m3; (2) The activated carbon filter absorbs the oil vapor and the maximum residual oil content is 0.003mg/m3; (3) The sterilization filter adopts the sterilization filter element with high flow and high temperature resistance, and the filtration precision is 0.01um, which can effectively remove bacteria and other microbes.
6. High-pressure gas pipeline sterilization.
The main blowing pipeline and pre-blowing pipeline system of the bottle blower are complex, the pipeline connection points and sealing modes are diversified, the dead zone positions and spaces are many, and the compressed air will breed bacteria and other microbes when staying in the dead angle for a long time. Considering the pipe fitting materials, the blowing valve group and the structure and performance of the sealing cylinder, the main blowing pipeline, the pre-blowing pipeline and the relevant pneumatic components shall be regularly sterilized to create a good sterile high-pressure air pipeline environment.
High-temperature steam or hydrogen peroxide steam is used for sterilization of high-pressure gas pipeline. Considering steam condensation and condensation, the blind area of the pipeline will produce condensate and discharge difficulties, and the long-term retention of condensate is not conducive to the sterile environment, this method needs to be further considered and optimized.
7. Sterilization of bottle type adapters.
The working surface of the bottle embryo, manipulator and stretching rod in contact with the bottle embryo as well as the mold cavity and bottle exit star wheel related to the bottle type shall be cleaned and disinfected regularly. The mold cavity, parting surface and manipulator shall be wiped clean with absorbent cotton dipped with 75% alcohol every week/120-150 hours to effectively remove dirt and microorganism on the working surface.
8. Positive pressure environment of bottle blowing area.
As the bottle blank is heated and disinfected with hydrogen peroxide steam, part of hydrogen peroxide steam will be left in the bottle blank tube. After the bottle blank is sent to the bottle blowing mechanism, with the increase of the bottle body and the dilution of high-pressure gas, the discharged gas contains trace amount of hydrogen peroxide. Considering the oxidizability of hydrogen peroxide and the impact on carbon steel parts, two high-efficient fans are designed on the top of the main machine, and the main machine for bottle blowing keeps working under positive pressure to improve the hygiene of the bottle blowing space.