Application of the most popular aseptic packaging

2022-08-01
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Application of aseptic packaging technology in roof box packaging machine, Suitable for super "Future market shelf sales. However, the aseptic packaging technology has not been applied to the roof box packaging at present. If a set of aseptic processing equipment is added to the existing roof box packaging machine in the dairy factory, the aseptic packaging of the roof box can be realized. This paper discusses the main mechanism, the key technical problems to be solved, and the required additional institutions and equipment for the roof box packaging machine in the dairy beverage factory It provides a certain basis for technical transformation

aseptic packaging of roof box

key technology

sterilization of packaging materials

because the packaging material of roof box is square cylinder sheet paper plastic composite paperboard material with prefabrication line, polyethylene/paperboard/polyethylene, although the temperature of such material during composite processing reaches about 200 ℃, which is equivalent to a sterilization treatment, it will be contaminated by bacteria during printing, square cylinder manufacturing, processing, storage and transportation, Therefore, the packaging materials must be sterilized during packaging

the sterilization methods of packaging materials mainly include physical method and chemical method. Physical methods include heating treatment, ultraviolet radiation, high-frequency electric field treatment, etc. As the roof box is made of paper plastic composite material, heating treatment will damage the polyethylene coating and affect the sealing effect. High frequency electric field treatment is used in the packaging production line, and its safety is not easy to guarantee. Ultraviolet sterilization uses the wavelength of 250 ~ 270 μ M ultraviolet irradiation packaging materials, although can play a certain sterilization effect, but not completely

the chemical method is hydrogen peroxide (H2O2) solution sterilization. Sterilization can be achieved by dipping or spraying the packaging materials with hydrogen peroxide solution. At present, packaging machines that use hydrogen peroxide alone for sterilization generally use hydrogen peroxide with a concentration of 30% ~ 35%, and heat the temperature to about 120 ℃, and H2O2 will be decomposed into oxygen and water. The new ecological oxygen is very active and has strong sterilization ability. However, due to the high concentration, the residual amount of hydrogen peroxide is difficult to control

if ultraviolet irradiation is combined with hydrogen peroxide, satisfactory sterilization effect will be achieved. Low concentration of hydrogen peroxide solution (1%) plus high-intensity ultraviolet light. It can produce a strong sterilization effect only at room temperature, which is much better than when the two are used alone (even with high concentration of hydrogen peroxide at high temperature) after adding hot water to the mineral water bottle

therefore, hydrogen peroxide plus ultraviolet light should be used for sterilization in the roof box packaging machine. As the roof box is a separate sheet carton, it cannot be soaked with hydrogen peroxide like the reel material. Firstly, the sheet carton must be opened into a square cylinder with a vacuum suction cup, and then the bottom must be formed and sealed with a concentration of 0 Spray it with 1% hydrogen peroxide solution and use a certain wetting agent to improve its sterilization effect. Generally, it takes 3 ~ 5S to kill bacteria. At the same time, it is supplemented by sterile hot air injection at 90 ~ 100 ℃, which, on the one hand, enhances the sterilization efficiency of the new state oxygen decomposed by hydrogen peroxide solution, and on the other hand, evaporates the residual hydrogen peroxide solution and water in the roof box. At the same time, a 250 wave length is installed above the carton conveying chain μ M strong ultraviolet radiation sterilizes the inside and outside of the packaging box, so as to ensure the sterility of the roof box

formation of sterile room

after sterilization, if the packaging box is placed in the air, the bacteria in the air will form secondary pollution. In addition, in the process of filling and sealing the top of the box, bacteria in the air will be brought into the box, causing pollution. Therefore, the sterilized carton conveying area and filling area must be sterile. If sterile air is fed into these areas, and the pressure of sterile air in the area is higher than the external atmospheric pressure, the external air cannot invade, thus becoming a sterile room

the air contains a large number of microorganisms and bacteria. The outdoor air in cities generally contains about 103 ~ 105/m3 of microorganisms, most of which are Gram-negative bacilli, bacillus, brown spherical nitrogen fixing bacteria, Staphylococcus aureus, catalase positive cocci, peroxidase negative cocci, etc. The width of bacilli is generally 0 4~1. 0 μ M, length 1 ~ 5 μ m。 The diameter of cocci is generally 0 4~2. 0 μ m。 There are about 10% of molds and yeasts, whose diameters are generally 1 ~ 10 μ m。 These bacteria will pollute the milk and cause corruption and deterioration. The minimum diameter of these bacteria is 0 forty-one μ M. if the friction coefficient of the material can be measured and the coarse, medium and fine three-stage membrane filtration can be carried out on the air, the pore diameter of the fine filtration membrane is 0.25 ~ 0 three μ M, the filtered sterile air will not contain more than 0 three μ M particles, that is, they will not contain microorganisms that contaminate milk. The air is filtered by the blower and then passed through the heater. It becomes hot air and is continuously sent to the sterile room. The sterile air forms a positive pressure of 20 ~ 30Pa in the sterile room, so that the air containing microorganisms outside the sterile room cannot enter. In addition, the hot sterile air accelerates the oxidation of hydrogen peroxide in the roof box. On the one hand, it enhances its sterilization ability and the evaporation of water and residual hydrogen peroxide in the box

cip cleaning system

it is very important for the CIP cleaning system of sterile packaging. The roof box is mainly packed with milk, fruit juice, beverages, etc. these materials are particularly easy to breed bacteria. After each production, the equipment must be thoroughly cleaned, especially the material cylinder and filling valve. According to the selected best cleaning process, the cleaning program is preset and input into the PLC controller. After the production is completed, the machine will automatically run the cleaning program. In order to ensure clean cleaning, the following cleaning procedures are adopted for the pipeline, material cylinder and filling valve of the sterile packaging machine: 1) pre rinse with water for 5 ~ 8min, and eject the remaining milk or beverage in the pipeline, material cylinder and filling valve

2) rinse with 75 ~ 80 ℃ alkaline detergent (1.2% ~ 1.5% sodium hydroxide solution) for 15 ~ 20min

3) rinse with water for 5min

4) rinse with 65 ~ 70 ℃ acid detergent (0.8% ~ 1.0% nitric acid solution or 2.0% phosphoric acid solution) for 15 ~ 20min

5) rinse with water for 5min

steam shall be used for sterilization after each cleaning. After the parts at the filling head are cleaned, they shall be immersed in 50% ~ 70% alcohol solution for storage

before the start of production, first wipe the carton frame, spindle, bottom shaper and other parts with disinfectant or alcohol, then steam sterilize the pipes, material cylinders, filling valves, etc. shortly after the Haizheng polylactic acid project was officially put into the market, and then spray sterilize the entire sterile area with hydrogen peroxide, so as to ensure the sterility of the whole machine before the start of production

work flow of roof type aseptic packaging machine

the ordinary roof type packaging machine is transformed into a roof type aseptic packaging machine. The executive parts and work flow are as follows:

1) box storage rack. The prefabricated sheet paper boxes are stored in the box rack composed of several columns, waiting for the suction cups to be removed

2) open the box. The vacuum suction cup removes the box piece from the box frame and opens it into a square cylindrical box, and then pushes it into the spindle by the push plate

3) spindle. Insert it into the carton and move it intermittently to the bottom sealing parts of the carton to complete the bottom sealing of the carton

4) bottom heating. The hot air heated to 550 ℃ extends from the air outlet box to the open box at the bottom, and heats and melts the polyethylene film on the four walls inside the box bottom (without heating the rest of the box)

5) bottom folding forming. When the shaft turns to the bottom shaper, the push hook and the forming plate fold the bottom of the box from the vertical and horizontal directions respectively

6) bottom sealing. The indenter presses the formed and folded box bottom, and applies certain pressure to bond the melted polyethylene at the bottom of the box together to complete the sealing of the bottom of the roof box

7) take the box and put it into the chain channel. The vacuum suction head will remove the roof box whose bottom sealing has been completed from the spindle and put it into the chain channel

8) conveyor chain. The sealed box at the bottom is transported forward intermittently to the sterile area, which is filled with hot sterile air with a certain positive pressure

9) hydrogen peroxide spray. The sprinkler sprays the mixed solution of hydrogen peroxide solution and wetting agent inside the roof box to sterilize the roof box

10) the first ultraviolet sterilization. Certain wavelength of ultraviolet radiation sterilizes the interior of the roof box

11) the second ultraviolet sterilization. Ultraviolet continues to sterilize the box. Meanwhile, the hot air in the sterile area accelerates the decomposition of the hydrogen peroxide solution in the box and evaporates the water in the box

12) top pre folding. The folding device folds a certain mark on the top of the box for top sealing

13) filling head. The piston valve pushes the milk out of the piston cavity and pours it into the sterilized carton. In order to prevent the milk from generating foam in the box during the filling process, polluting the top of the box, and generating a burnt smell during heating, there is a filling follow-up device under the filling valve. During the filling process, the top box drops with the rise of the liquid level in the box, maintaining a certain distance between the liquid level in the box and the filling head throughout the filling process, reducing the generation of foam

14) top heating. Blow the hot air heated to about 500 ℃ to the inner wall of the box top, and melt the polyethylene layer on the inner wall surface of the box top

15) top sealing and date printing. The melted roof box at the top of the box is tightened and sealed by the sealing pliers, and the date is stamped here by the date printing pliers. In this way, the whole packaging procedure of the roof box is completed. The finished products are sent to the sterile area for packing and warehousing

16) feeding cylinder. Store the milk to be filled and keep the liquid level in the feeding cylinder basically constant

17) CIP cleaning pipeline. After production, the material cylinder, filling valve and pipeline shall be cleaned to prevent the breeding of microorganisms

it can be seen from the above process that a sterile area is generated by adding a sterile air filter to the existing roof type packaging machine, and the sterile packaging of the roof box packaging machine is realized by adding hydrogen peroxide spray and ultraviolet irradiation sterilization. This eliminates the need for cold chain storage, transportation and sales, and greatly extends the shelf life

reprinted from: China Packaging News

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