Eight aspects of the hottest dairy products packag

Dairy packaging (VIII)

printing ink for printing milk packaging film

polyamide surface printing ink is generally used for printing milk packaging film. This kind of ink has good affinity with polyethylene film, good gloss of ink layer, high adhesion fastness, heat resistance, grease resistance, water resistance and other properties. Milk packaging film is usually printed by surface printing. In addition to the general technical requirements of surface printing ink (such as hue, fineness, viscosity, dryness, etc.), due to ultra-high temperature instantaneous sterilization (UHT) and hydrogen peroxide sterilization in the process of automatic filling, this special sterilization condition puts forward special requirements for the performance of ink, Here, we need to pay special attention to the following aspects of performance:

1 It has strong adhesion to polyethylene film. As the surface of the plastic film is smooth and the ink cannot penetrate on the surface, it is required that the adhesion between the ink and the plastic film is very strong, that is to say, the ink used to print the milk packaging film should have high affinity and adhesion to the substrate material polyethylene film, strong adhesion and good printing fastness, which is the prerequisite to ensure high-quality prints and good printing effect

2. Strong wear resistance and scratch resistance. As the surface printing ink is printed on the outer surface of the film, it will be affected by friction in the process of commodity circulation, which requires that the printing ink used must have strong wear resistance and scratch resistance. After printing, the surface strength of the ink film is high, the firmness is good, and the friction resistance is good. Otherwise, the ink layer will fall off, resulting in incomplete printing patterns and affecting the appearance and quality of products

3. It has excellent water resistance. During the process of ultra-high temperature instantaneous sterilization (140 ℃/1 ~ 3 seconds) and hydrogen peroxide sterilization, the surface of milk packaging film will contact with water or steam, so the printing ink used must have excellent water resistance and will not fade in case of water

4. Excellent heat resistance and freezing resistance. The printing ink used for milk packaging film must have certain heat resistance to ensure that the ink will not soften, become sticky, and the imprint will fade and change color after being sterilized at a high temperature according to the national standard. In addition, the milk after filling generally needs to be refrigerated at low temperature in the links of storage, circulation and sales, so the printing ink used must have good freezing resistance, and the ink layer will not freeze and fall off at low temperature

5. Outstanding oxidation resistance. Most high-speed filling machines are equipped with hot hydrogen peroxide sterilization system, which is used to sterilize the packaging film. Hydrogen peroxide has strong oxidation, and its oxidation increases significantly with the increase of temperature, which puts forward higher requirements for the oxidation resistance of printing ink. If the oxidation resistance of pigments in ink is not very good, ink fading will occur, affecting product quality

dairy packaging machinery

Tetra Pak packaging system

Tetra Pak products are a common form of high-end packaging in China's dairy market, while in the North American dairy market, this old packaging structure can no longer meet the market demand. The dairy packaging box represented by Tetra Pak packaging has become a popular packaging form. This kind of packaging can be reopened after opening, which can not only better meet consumer demand, It has better shelf effect

Canadian farmers dairy company first installed and put into operation a set of high-speed continuous molding filling sealing system in North America, which can produce 250 ~ 1000ml liquid milk packaging boxes. The remarkable difference between this kind of packing box and traditional Tetra Pak brick is that there is a plastic screw cap on the top, which can be sealed repeatedly, and this capping process is directly extruded on the forming filling sealing production line. The processing and production of this new dairy packaging box will be introduced in detail below

in order to better improve the original Tetra Pak roof packaging, the new Tetra Pak crown packaging production system has been put into use, that is, Tetra Pak's TT3 horizontal forming filling sealing system. This system is composed of double-layer lines, with a production efficiency of 9000/h, and two filling hopper devices are installed on the top of the closed packaging system. Based on the design of double-layer production line, this forming filling sealing system can produce two different products or two different specifications at the same time. At farmers dairy, two production lines can produce basic and medium-sized packaging boxes at the same time. The specifications of basic products are large, such as 1000ml and 500ml packaging boxes; Another production line is suitable for the production of 250ml, 375ml and 500ml packaging boxes

farmers dairy company has become the first dairy company in North America to feature a molding filling sealing production line due to the installation of TT3 system and production line driven by servo motor. A striking feature of the system is the application of injection molding technology and cover forming unit (LFU). The polyethylene end cap produced by this unit is composed of a spiral nozzle and an additional spiral cap. This system provides dairy merchants and consumers with a personalized design, especially the unique design of the sealing system

carton molding

farmers dairy company adopts the pre printing method, first uses the web gravure printing machine to print the packaging box, and the printing color is 4 ~ 5 colors; The composite packaging material used is a three-layer paper plastic composite structure, which is composed of polyethylene layer, paper layer and polyethylene layer. At the beginning of the forming filling sealing system, the composite material roll printed with color graphics and texts is loaded on the feeding shaft. The roll is 11 inches wide and driven by a servo motor. It is continuously and bottom-up transported from the feeding end to the forming filling sealing production line

the composite material is vertically driven by five traction rollers and transferred to the forming mechanism, which folds one side of the material; During the conveying process, the material belt must pass through an electronic eye device that recognizes the regular positioning (the device is located at the edge of the paper head of the reel material), and then the electric eye sends a signal to the cutting knife to cut the reel material into sheets corresponding to the packaging volume

as a wholly-owned subsidiary of Wanhua Chemical Group Co., Ltd., because the forming filling sealing system is a dual channel, two servo motors need to be used to control the cutter head for independent box blank cutting, and each motor controls one channel. Farmers uses the GS30 brushless servo motor of exlar company. The whole packaging system is controlled by six servo motors, two of which are used to control the cutting head, and the other four are used to control the filling part. GE FANUC system installed with versapro software controls the whole forming filling sealing system, product transmission device and capping device through PLC

after the reel materials are cut into independent box blanks, the conveyor belt located above will vertically transfer them to the vertical sealing machine. The conveyor guide device controls the folded box blank to align both sides and facilitate sealing; Among them, the longitudinal sealer uses the hot-melt technology to seal the longitudinal joints after heating and melting. The sealed box blanks are flattened and transported to the temporary bench, where they are collected and transported to the forming process in pairs

in the forming area, two rotating arms transport the flat box blank from the bench area to the central axis positioning mechanism through the vacuum suction cup. In this process, the suction cup will open the flat box blank. Facing the central shaft positioning mechanism are two eccentric rollers, which extend from the central shaft shell and rotate in a counterclockwise direction; The two box blanks that are opened are moved to the central shaft by the cam and then transferred to the cover forming unit. The forming process is shown in Figure 1

filling and box sealing

while the box blank is transported to the eccentric roller in the cover forming unit, a certain amount of polyethylene resin is extruded by the external device. At this time, the heated elastic metal mold on the forming roller acts together with the external device on the cover forming unit to make a plastic cover, and then the cover and the paper-based box body are sealed together by heating and pressurization to achieve the effect of "fusion". This plastic cover has an internal safety blocking device, allowing inverted filling. During the forming process of the cover, the inverted box top is still not finally formed and remains tubular. In the six-year development cover molding device, the sealing time between the plastic cover and the carton is only a few seconds

after installing the plastic cover, the two cartons slide down to the vertical stainless steel tray through the central shaft, and the tray moves on the oval conveyor belt in the filling and sealing area

the tray carries inverted cartons through the filling area and sealing area, and finally placed in the unloading area. The cartons are sterilized in the filling and sealing areas, which are in a closed space, and sterilized with a sterile air system equipped with a standard high-efficiency air filter to ensure that the cartons are not in contact with the outside air. Before the carton is filled, it must be washed by spray of hydrogen peroxide and sterilized by ultraviolet light

in the filling area, inverted cartons and pallets are pushed onto the filling head. The filling system uses two sets of filling hoppers, which can carry out different filling work. The flexibility of the dual channel system and two sets of filler buckets is that it can produce the same product on two production lines at the same time, or only on one production line. The production capacity of each production line is 4500 pieces/hour

after filling, the inverted box is immediately sealed by ultrasonic heating, and then the bottom sealing device above it folds the box bottom. First fold out the triangular wing, and then apply glue to the folded bottom. At this time, the tray carries the newly formed, inverted carton and continues to move along the oval track. In the unloading area, the product is upright and sent to the unloading conveyor belt

the conversion of medium and ordinary packaging products can be fully automated in the molding filling sealing production line, and the operator can complete it only through touch screen control

cover

the filled cartons arranged on the conveyor belt should be sent to the coding station before covering, and the box cover should be coded with the set data. The coding equipment is mainly domino C6000 inkjet printer. After coding, it is sent to Tetra Trepak capping production line. The resealable plastic cover uses Tetra Pak 38mm low-density polyethylene threaded cover. After that, the variable speed output conveyor belt starts to turn left and finally winds back to the capping area. Next to the capping machine is the packing equipment. The cartons are first sent to the stacking and sorting area, and then packaged by Tetra Pak's cordboard packer 70 film cartons machine

packing

the inverted cartons and pallets are sent up to the packing filling head, the vacuum suction cups send the flat corrugated cartons to the forming area, and the corrugated carton packaging machine slides the cartons into the carton forming equipment every four lines. The forming machine wraps the corrugated box on the outside of the product, and uses a glue applicator to glue and paste the top swing wing. The packed cartons are transported to the conveyor belt of the inkjet coder, where the trademark, product number, date of manufacture, product introduction and other information are printed and sent out. The packaging is complete

the new liquid milk filling machine is more fresh-keeping

at present, most domestic dairy packaging enterprises use low-level conventional equipment, and there are only a few machinery manufacturers with independent innovation ability and R & D ability, among which Zhejiang Wenzhou Tianlong plastic enterprise group and Nanjing Haosheng Packaging Machinery Co., Ltd. are a few enterprises with leading R & D technology in China

Tianlong plastic enterprise group company has recently successfully developed