Since the world's first Tetra Pak aseptic filling machine with hydrogen peroxide sterilization in 1961, aseptic filling technology has developed to the point of perfection, it has become a collection of mechatronics technology, modern chemistry, physics High-tech technologies such as microbiology, automatic control, computer communication and many other high-tech technologies [1], and continue to develop with the advancement of modern technology. In the case of paper-plastic aseptic packaging machines, there are vertical and horizontal, in-line forming cartons and pre-formed cartons, which have also evolved from the earliest polyhedral packaging to brick carton packs and roof packs with different capacities. The style is more novel and fits as much as possible into the psychology of the consumer. PET bottles have developed rapidly due to their light weight, transparency, non-breakability and recyclability. From the hot filling development to the aseptic filling, the advantages of the PET bottle have been fully exerted. The application of the aseptic filling technology reduces the cost of the bottle and the bottle type is more diversified, and the bottle can be directly bottled from the PET material. And aseptic filling on the line, the overall cost is further reduced, the advancement of these technologies and the continuous improvement of the microbial fence system, more based on safety, reliability and environmental protection are inseparable. The Fluorochemicals compound is a new field in modern organic chemistry. It has a special physical and chemical properties, so it is widely used in the earliest development of applied pesticides and rat poison. During World War II it was developed in some countries appliedas antimicrobial agents, there are more and more new research suggests that fluorochemical will play an increasingly more important role in the field of anticancer drugs. We started later in the field of fluorochemicals, but we have a strong sense of his enormous potential, and we are increasing investment to catch up. We will custom product which has potential market prospects from gram and kilogram-class through process optimization, enlarged to the size of ton. Currently we have developed more fluorochemical compounds in the benzoic acid range, the number of products have been more than 2017. Fluorochemicals Organic Fluorochemical Compound,FluorineCompounds,Containing Benzoic Acids Taizhou Volsen Chemical Co., Ltd. , http://www.volsenchem.com
The continuous innovation and improvement of liquid food sterilization technology is an important part of the rapid development of aseptic filling technology and equipment. The application of the fluid control system enables precise and effective control of the sterilization time and temperature of the liquid food, thus ensuring the stability and safety of the product quality. With the pursuit of food nutrition and color, fragrance and taste, it is hoped that the marketed liquid food, juice, beverage and milk will be closer to the original flavor and nutrition of the food. For many years, scientists have been exploring and seeking more advanced sterilization methods, in addition to the classic HTST and UHT using steam as heating medium, microwave sterilization, resistance heating technology, high pressure sterilization, high voltage pulsed electric field, radio. The sterilization techniques of physical methods such as wave and excited state ultraviolet pulse sterilization technology are being studied intensively, and some have been commercialized.
A partition wall UHT system using saturated steam as a heat source
Ultra High Temperature Sterilization System (UHT) consists of a set of tube or plate heat exchangers, material tanks, maintenance tubes, superheated water preparation systems and CIP units [2]. These devices are connected to an organic whole through pipes and valves of varying performance. The entire system is controlled by the PLC for automatic program operation and automatic adjustment of process parameters. The type of sterilizer depends on the type of liquid food. In general, most of the products with good fluidity use a plate heat exchanger as a sterilizer-cooler. Most of the higher viscosity products use tubular heat exchangers, and for higher viscosity products, scraped surface heat exchangers are used. The tube sterilizer is available in multiple sleeves and multi-tube type. The former consists of a set of concentric sleeves with different diameters and corrugations. 3-8 sleeves, heat medium and materials can be made according to requirements. The heat transfer can be carried out through a heat transfer surface or two heat transfer surfaces, and a countercurrent operation can be realized. The multi-tube sterilizer can actually be used as a heat exchange device that couples a plurality of shell-and-tube heat exchangers by a 180° bend. It is equipped with 7-92 straight pipes of φ19-38mm in a large diameter pipe (114-318mm). The pipe length is 3-6m, which can realize multi-flow operation. This is the tube type that is currently used more. The type of sterilizer.
According to the Italian SIG Manzini company, the company cooperated with the University of Parma to study the heat transfer of corrugated pipe and smooth tube structure of the tube sterilizer, and considered that it is a fluid for liquid foods with little viscosity, such as milk or juice. When in turbulent or turbulent flow, the total heat transfer coefficient of the fluid when the bellows and the smooth tube are heated or cooled is relatively close, and the pressure drop of the fluid in the bellows is significantly higher than that of the smooth tube. For the heating and cooling of the viscous material, the total heat transfer coefficient and pressure drop of the bellows are significantly larger than that of the smooth tube when the fluid is in the transitional flow.
Radio wave sterilization technology
According to SIG Manzini, the company has been working with the University of Milan in Italy to commercialize radio waves for liquid food heating. ART30 type device has been used for milk and juice sterilization respectively. Its production capacity is 3300l/h, sterilization temperature is 140°C, radio wave installation power is 100kw, and maximum heat power is 75kw (65000kcal/h). The structure of the whole set is similar to that of the traditional UHT system. The material in the material tank is first pumped into the heat recovery device and then heated to the set sterilization temperature in the radio wave heating unit. The high temperature material is passed through the maintenance pipe, the heat recovery device and cooled to After filling temperature, it is sent to the aseptic filling machine for filling.
The frequency of the radio wave used in the device is 27.12 MHz. The liquid food to be treated is heated by the magnetic field to cause high frequency vibration of the polar molecules, and the heating time is only 1/100 of that of the conventional superheated water heating method. The material in contact with the food is made of polytetrafluoroethylene. The advantage of using radio wave sterilization is that the food is heated evenly, and no dirt is generated on the tube wall due to overheating, and the flavor of the product is closer to the raw material itself. Radio wave sterilization technology can be used for juices, jams, milk and dairy products with bulk materials, as well as juices and pulps that are sensitive to heat.
Microwave sterilization
Microwave refers to electromagnetic waves with a frequency of 300 MHz to 300 GHz, and microwave frequencies for the food industry are 915 MHz and 2450 MHz. The heating of liquid foods with polar molecules by microwaves is the result of the material itself converting microwave energy into heat energy. Microwave sterilization is not only due to the effect of the organism's absorption of energy into a thermal effect, but also by its non-thermal effect. The non-thermal effect of microwave means that the organism does not produce significant temperature rise under the action of electromagnetic waves, but can cause the normal metabolic function of the microbial cells to be disrupted, inhibit growth, and even stop growth or death. Microwave can also reduce the water activity of microbial cells and destroy their living environment. The application of microwaves can kill microorganisms in the material at a lower temperature than conventional heating methods [3].
Pulse microwave sterilization mainly uses non-thermal effect. The method is as follows: 1. Pulse microwave sterilization technology with instantaneous high-power pulsed microwave energy and low average power, so that the object is exposed to high-energy microwave in a very short time to make bacteria and other microorganisms. Loss of viability under the action of extremely high electromagnetic fields to achieve sterilization and other purposes. 2. The continuous wave microwave power is periodically cut off at the millisecond level and the stop time, so that the cell body is subjected to a periodic continuous action, resulting in a resonance state, resulting in bacterial cell membrane vibration causing bacterial death.
High pressure sterilization technology
The high-pressure technology is to place the food in a liquid medium, and process and process it under the pressure of 100-1000 MPa, and inactivate, denature and gelatinize the high-molecular substances such as enzymes, proteins and starch in the food during the processing, and destroy at the same time. The cell membrane of microorganisms achieves the purpose of sterilization [4]. The use of high-pressure technology to sterilize foods avoids a series of processing defects caused by heat treatment and sterilization. It does not destroy vitamins, pigments, aromas and nutrients, does not produce hot odor, and can effectively save energy. Therefore, since the introduction of the research report on the application of high-pressure technology in food in the University of Tokyo, Tokyo, in 1986, it has received attention from some developed countries and made some progress. In 1990, the jam produced in Japan by high-pressure technology was first sold in a supermarket. The processing technique was to pressurize the jam to 400-600 MPa at room temperature for 10-30 min. Japan's POKKA and WAKAYAMA companies sterilize citrus juice with a semi-continuous high-pressure device. American FMC Company and British Kjelda Food & Beverage Company have also established sterilization devices for juice and soy milk [5]. Some colleges and universities and industrial production departments in China are still in the experimental stage of the application of high-pressure technology in the food industry, and have seen reports on commercial applications. The 52 Institute of Ordnance Industry Group carried out high-pressure sterilization test on watermelon juice containing pulp, and the product was stored at room temperature for 6 months. The high-pressure sterilization test of strawberry juice sealed in double-layer polyethylene plastic bag by Hefei University of Technology showed that the coliform bacteria could be completely killed by pressing the strawberry juice at a temperature of 350 MPa for 3 minutes at a pressure of 29 °C. At 40 MPa, the mold and yeast can be completely killed in 10 minutes [6].
Continuous autoclaving is the direct pumping of liquid food into a pressure vessel. The pressure medium is separated from the liquid food by a barrier baffle. The medium pressure is delivered to the product through the separator, and the processed product is pumped into the aseptic tank. In order to prevent pollution, sterile water is used as a pressure medium to achieve continuous operation of high pressure sterilization and aseptic packaging systems [4].
Aseptic filling machine
Since the introduction of the first Tetra Pak aseptic filling machine in the canning factory in 1976 to produce chrysanthemum tea and guava juice, it has been nearly 30 years old. Now there are more than 400 paper-plastic composite packaging sterilized in the country. The filling machine is running. In addition, there are large aseptic filling machines for infusion of concentrated fruit and vegetable juices or puree and aseptic filling machines for composite plastic film packaging. In 2001, Beijing Huiyuan Juice and Tianjin Dingxin Group took the lead in introducing five PET bottle aseptic filling production lines. Since the introduction of 17 such production lines nationwide. The introduction of these aseptic filling production technology and equipment has promoted the promotion and development of China's beverage industry, and made the production technology and equipment of China's beverage industry into the international advanced ranks.
The form of the aseptic filling machine depends on the packaging material. For the key technology for achieving aseptic filling, a fully functional aseptic filling machine should contain sterilized packaging materials, sterile liquid food delivery, Devices such as perfusion and sealing in a sterile atmosphere, in addition to CIP and SIP conditions. There are many ways to sterilize paper and plastic packaging materials. Tetra Pak's paper-plastic packaging material is immersed in a hot hydrogen peroxide solution at a concentration of 35% and then formed into a cylindrical reel. The O3 decomposed H2O2 material is sterilized under high temperature conditions and is filled with O3. The material is filled and sealed inside. PKL's SIG Combibloc sprays the atomized H2O2 into the inside and outside of the carton in the forming carton, and then uses the hot air to sterilize the O3 produced by the decomposition of H2O2, and also creates the O3 atmosphere in a small environment. This filling and sealing. As a large bag of aseptically filled multi-layer film composite bag, the filling port is pre-sealed with a plunger-like plug, and then irradiated with a sufficient dose of CO60 to kill the microorganisms in the bag in the sterile room of the filling machine. Disinfect, remove, infuse and seal the infusion port. Early sterile rooms were sterilized with chemicals such as halogens or peroxides, and now most have been sterilized with saturated steam, with a sterile chamber volume of less than 0.01 M3.
The disadvantage of paper-plastic packaging materials is that it is difficult to recycle, and if it is not specifically recycled, the environmental pollution is self-evident. In recent years, the application of PET (polyethylene terephthalate) bottles in the beverage industry has been rapidly developed. Its advantages, in addition to the convenience of consumption, can also achieve efficient production of bottles and fillings. cycle. The key technologies for achieving aseptic filling of PET bottles are mainly the sterilization of bottles and caps, the maintenance of the sterile atmosphere in the filling and sealing areas, and the filling machine itself should meet the requirements of aseptic filling.
The main method for sterilizing bottles and lids is to use chemicals, and currently used more are hydrogen peroxide, peracetic acid and ethylene oxide. When in use, it is heated, atomized, and sprayed all the way to various parts of the bottle. After a certain reaction time, it is rinsed with sterile water to minimize the chemical residue in the bottle.
The high-speed PET bottle aseptic filling machine is designed to sterilize-flush, fill and seal the bottle into three independent rotary models. It is connected to the combination machine by a star wheel and is contained in a huge one. In the sterile room, the filling-sealing area has a cleanliness level of 100, and the sterile air flows in a laminar flow from top to bottom in a sterile room, which is positive pressure. Sterilize the sterile chamber with a foamed disinfectant before the end of production and before start-up. Many companies have made efforts to reduce the sterile space. For example, SIG Simone West accommodates the filling valve and the bottle conveying channel in a clean area of ​​only 9 m3, using a dynamic liquid seal between the rotating body and the stationary isolator. Maintain positive pressure operation in the sterile field. The advantage of reducing the sterile area is to reduce the amount of disinfectant, save disinfection time, reduce chemical contamination of the operator, and facilitate maintenance of mechanical parts outside the sterile room.
The filling machine is the core of aseptic filling. The bottleneck is used to clamp the bottle on the mechanical components. The filling port is not in contact with the bottle, and is measured by electromagnetic flowmeter or weighing method. In addition, in particular, the high stability of the machine operation is ensured so that it does not substantially cause significant mechanical or control failures in tens of hours of continuous operation. This means that high demands are placed on materials, manufacturing, heat treatment, and inspection of other parts.
Bottle machine and filling machine
In order to minimize the bacterial contamination that may occur during the filling process and the logistics of the packaging materials, more and more enterprises use the production method of bottle and filling. At present, the combination of the Xipa bottle machine and the Bokma aseptic filling machine introduced in China, the PET sheet injection and the blowing bottle are completed on the same machine, and the bottle is directly sent to the aseptic filling machine through the air flow. The SIG Group's Cobras and Simonazzi, and the Tetra Pak-Sidler Group's COMBI system are prefabricated preforms, which are directly connected to the filling machine and can be inserted into the production line. Plasma coating equipment to increase the barrier properties of PET bottles. In order to ensure the hygiene and safety of PET bottles, Tetra Pedestrian's ultra-clean aseptic filling system pre-sterilizes the preforms sent to the heating furnace, ie sterilizes the preforms with UV rays and reuses 0.3 MPa of sterility. The air is purged and vacuumed. The blower and the filling machine are combined into one unit. Sterilization and rinsing of the bottle is done during the transfer of the wheel train consisting of 4-9 star wheels. The bottle is repeatedly disinfected and cleaned by the star wheel. The disinfectant is sprayed to various parts inside and outside the bottle with high pressure pulse, and then the hot air is activated by 120 °C. The advantage of multi-station disinfection is Individual nozzles are blocked and there is no possibility of bottleneck disinfection. Several star wheels are arranged almost in a straight line and are contained in a hundred-stage purified sterile air flowing in a laminar flow. The sterile space of the entire system is only a dozen cubic meters.
The advantages of in-line production are obvious. It first reduces the transport and storage of the package, minimizing bacterial contamination while minimizing intermediate costs.
Progress in domestic aseptic filling technology and equipment
Aseptic filling of liquid foods is one of the most promising areas of packaging technology. New aseptic packaging products, new aseptic filling machines, and new packaging materials for expanding their application range are numerous. Research work is being carried out for the development of this field.
In 1990, the large bag aseptic filling system successfully developed by the Institute of Aeronautics and Crafts Technology marked the beginning of the independent design of aseptic packaging technology in China. Since then, Guangdong Far East Food Packaging Machinery Co., Ltd. has launched a 2500 CPH brick-type paper-plastic aseptic packaging machine. The Hangzhou Zhongya and Aviation Group Technology Research Institute has separately developed an aseptic filling device for plastic film packaging of UHT sterilization milk. In 2001, Mei Xing Shunfeng reported that the 36000 BPH PET bottle aseptic filling machine jointly developed by the factory and Guangdong Robust Group has been put into trial operation. Hefei Zhongchen, Nanjing Light Machine, Langfang Packaging Equipment Manufacturing and Lehui Group have also accelerated. The pace of development, its design, manufacture and testing is carried out in a very rigorous atmosphere.
The development and development of aseptic filling machines must firstly improve the design and manufacturing precision of the various components of the filling machine, improve the stability and high reliability of the machine operation, and make the mechanical structure design meet the requirements of aseptic filling. It is not about building a sterile area to suit the needs of the machine. In addition, attention should be paid to peripheral equipment such as sterile water, bactericides, preparation of sterile air, and cleaning and disinfection of sterile rooms. The aseptic filling technology and equipment with excellent performance is a concentrated expression of modern technology, modern manufacturing and control technology, and also a comprehensive performance of the overall technical level of the enterprise. We are convinced that in the near future, we will expect the aseptic filling technology and equipment of domestic liquid foods to be rapidly promoted and used in China's beverage industry, so that the level of domestic beverage equipment manufacturing in China will be raised to a new height.