Liquid wallpaper on soft plastic packaging film printing features of In recent years, plastic film packaging of fresh milk, soy milk and many juice drinks, condiments, etc., have an array appears in the market. As milk, soy milk, drinks are fresh beverages, health and temperature requirements are very strict, so the printing on the bags also have special requirements, which makes milk and beverage packaging film printing are different from other printing of the technical features. 1, liquid soft plastic packaging film features Liquid soft plastic packaging film material used mainly for polyethylene film (PE) co-extruded film, it must meet the packaging printing, processing, storage and transportation and health requirements. View from the film’s apparent performance can be divided into three categories: soft creamy white PE film, black and white co-extruded PE film, PE film rigid high-temperature cooking. Soft creamy white PE film are mainly used in milk, soy sauce, vinegar, liquid packaging simple, co-extrusion blown film Masterbatch to LDPE, LLDPE and white material composition. Membrane performance, the relatively poor barrier properties, sterilization temperature does not exceed 90 ℃, short shelf life; generally used in the installation manual or low speed filling equipment. Such as low milk packaging, general shelf life of up to three days, nearby sales. Mostly black and white film layer, up to five, blown film, the increase of the middle layer coextruded barrier made of the parent material. Play black masterbatch inner seal blocking light ultraviolet cut off the role. Since the existence of intermediate barrier layer to EVA, EVAL Deng mother feed composition, built objects longer shelf life, can be maintained at 30 days Yi Shang, Bu Guo Bu Fen in the market have three co-extruded black and white film, Zhong Jian Bing Fei layer is barrier materials with the composition of the parent, so that the same black and white film is the first category. In the three types of film, black and white film is not conducive to printing operations. Black and white film in the film when, with the slippery agent and the maximum amount of brightener to meet the black and white film in high speed automatic filling machine friction coefficient on the request, and the added color printing process oily substance on the extremely unfavorable, greatly reduced ink adhesion properties. In most of the high-speed automatic filling machine, direct hydrogen peroxide with heat sterilization system for sterilization of packaging films. In this case, we should pay attention to sterilization conditions on the layer of ink, because the ink in some of the paint is not very good oxidation resistance. Test showed that the oxidation of hydrogen peroxide with increasing temperature significantly increased, therefore, color printing factory in the provision of packaging materials, the customer must be clear after the processing conditions. Hard PE film high-temperature cooking, mainly used for yogurt, soy milk and other dairy drinks, the contents after sterilization in the filling, the use of ultra-high temperature sterilization process. The co-extruded PE film hard to master material as the main HDPE, LDPE, and add some of the masterbatch, therefore, hard PE film has good high temperature performance to meet the requirements of ultra-high temperature sterilization. As the pressure difference exists sterilization, easy to produce “expansion bag” phenomenon, we asked hard PE film not only have good seal strength and tensile strength properties of films better, color printing manufacturers generally use “throws three meters high” or “Single-foot man” test results. Second, liquid soft plastic used in packaging film printing ink Milk, drinks, liquid packaging film surface printing methods commonly used for printing to polyamides or material modification to connect the majority of such ink is gravure printing ink in China in the first developed, the production technology is relatively mature and improve. The type of ink applied to polyethylene, polypropylene film, ink adhesion fastness, good gloss; but widespread Polyamide ink water resistance is poor, fat intolerance, impatience and other properties of frozen defects, at high temperature summer print this type of ink, prone to sticky, softening, cold winter in the time of printing, will have to Frozen phenomenon. Liquid bag in the filling, such as circulation and stored after processing, to high temperatures or freezing, sterilization techniques, surface printing ink, therefore polyamides inherent defects can not meet the requirements of liquid packaging, color printing factory producing liquid package must be for different types of co-extruded PE film, use of non-polyamide type of surface printing ink, now in the market the most appropriate package of ink is a liquid polyester and modified products are single component and two liquid reaction type ink. (A) safety and health of As the milk and drink for human consumption, so packaging film, printing ink and other packing materials shall also meet the health standards and requirements of food packaging regulations, therefore, requested the printing ink should be used with non-toxic, odorless, low residual solvent, does not contain toxic heavy metals and other requirements. To avoid contamination of milk and drinks, and harm the health of consumers. Based on the above ink performance requirements, must choose a performance more superior ink. General Printing is a dual-component polyurethane-based surface printing inks, and printing ink to be varnished after the treatment, the cost is relatively high and the process more cumbersome. Currently using more extensive and better-quality ink Zhejiang New Oriental Group Co., Ltd. Fu-313A production of super strength and super-type surface printing ink type force table Printing Ink Fu 314, does not require separate treatment on the varnish, just print ink hardener added to quantitative, in print 24 hours after the aging treatment can achieve both water tolerance, resistance to hydrogen peroxide treatment, and can withstand friction. The two ink is for milk and beverage packaging films designed special printing ink, and good compatibility with polyethylene film, ink gloss, good adhesion fastness, its heat resistance, oil resistance, water and other properties are also very good, can be said to drink milk and liquid packaging film printing ink ideal. Fu-313A Super Power inks are alcohol-based polyamide ink, resistant to boiling below 100 ℃, 60 ℃ less able to withstand hydrogen peroxide sterilization. Fu-314 Super Power India ink is a two-liquid form reactive polyurethane modified ink resistant to 121 ℃ / 40 minutes of cooking sterilization, can withstand 80 ℃, 35% concentration of hydrogen peroxide sterilization. Based on 314 pairs of super-strength liquid reactive Fu ink oxidation resistance experiments, the aging 24 hours at the temperature of the printing film 45 ~ 50 ℃, 35% of the hydrogen peroxide concentration in the soak for 15 minutes, remove and testing, excellent ink adhesion, almost no fading phenomenon can completely meet the liquid milk and beverage packaging requirements. (B) the regulation and control of ink performance 1, the viscosity of ink Viscosity is the most important control ink application index, which directly affects ink transfer performance and print quality, therefore, in the printing process, ink viscosity control is important, the general control of 15 to 20 seconds rooms. Ink viscosity is too low, making it easy graphic part of the pinhole, made false, ink spreading; the other hand, the viscosity is too high, the ink transfer performance is rather poor, prone to paste version, dry version of the phenomenon, and dwell large field portion uneven, thin line breakage failure. ; 2, the drying of ink Ink ink drying performance is a measure of quality and performance of one of the important indicators of good control of ink drying performance is to obtain good results a necessary condition for printing. Ink drying too fast, fault-prone dry version, but slow drying ink will print on the back of sticky dirty place fault. Select ink drying rate of the general principle, is Zai Xian You press conditions, ink into the next printing color in the previously as well as rewinding should be preceded by Nenggouchongfen drying, Danshi in print edition Shangquebuneng drying. Printing ink used in packaging films for the solvent ink, which is mainly determined by drying the solvent evaporation rate, so in actual production in the ratio of solvent must be strict control, can be specific to the ink dried slowly adding an appropriate amount of solvents or drying of solvent to adjust the ink drying speed, to ensure adequate ink to dry, to prevent “fake dry” phenomenon. General use of ultra-Fu 314 pairs of liquid reaction force ink printing, the printing speed of 80 / minutes under normal circumstances, the general control of ink viscosity of 15 seconds or so, according to practice, using the basic ratio of mixed solvent : MEK: toluene: butyl = 4:3,5:2.5, this will ensure better printing quality. 3, liquid soft plastic packaging film printing process for attention (A) select appropriate materials. In actual production, should be based on the filling speed automatic filling machine, sterilization conditions, the length of product shelf-life situation such as to select the appropriate print film and printing inks, and adjusted according to actual situation and control the printing process parameters, standardized process process, to ensure the quality film print. Polyamide surface printing inks because of its water resistance, good resistance to grease, liquid packages generally can not use ink; polyurethane inks have different types to choose when to have targeted the new super power Fuk 313A Oriental ink generally used only for soft co-extruded PE film, while the 314 model is applicable to all kinds of co-extruded PE film. Used in color printing factory co-extruded PE film blowing is usually made on their own, different skills, so be sure to grasp the parent material selection, it is appropriate agent models of female non-slippery material; use of PE film after electric discharge treatment, surface energy minimum to 40 dyne, preferably more than 42 dyne. (B) customers or testing standards after the processing conditions. Color Printing Factory food manufacturers only in the full understanding of the conditions at the time of filling and the subsequent processing of the process, even the liquid bag in the market circulation of details of the requirements to be targeted an idea. The attention of the major points include: filling speed, sterilization conditions, the length of shelf life, preservation requirements. (C) printing process requirements. In order to ensure the quality of liquid packaging film printing, the printing process must also pay attention to tension on the printing, print pressure, print speed and drying conditions of temperature and process control, to develop a reliable process, and standardizing processes, ensure that the scale of production smoothly. In addition, the overall quality printers, ink manufacturers provide technical information, rare material and good quality ring, shop environment, changes in factors that can not be ignored. (D) control the printing environment better. Pressroom changes in temperature and humidity inside the substrate material and ink are some of the performance, the environment is too dry will cause static film, resulting in printing problems; environment is too dry and wet ink will not fully affect the strong degree of ink. Therefore, we should strictly control the temperature inside the printing shop and relative humidity, as far as possible so that it remains relatively constant, and ensure good ventilation to reduce the incidence of printing faults. In general, the workshop of the temperature control in between 18 ℃ ~ 25 ℃ is appropriate, the relative humidity maintained at 60% ~ 70% is appropriate. (E) make finished products inspection. Customer satisfaction is high for each criterion, a printing business and the ultimate desire, it will be qualified to ensure the finished product sent to the customer. This would allow customers to achieve satisfaction, but also to maintain the image and reputation of the company, which is to maintain and develop good customer relations. Liquid package production process, more frequent exchange membrane, likely to cause the performance of different membranes, liquid bag with a little ink, a long time to use the old ink printing ink may also bring performance degradation, therefore, liquid bag can be produced more variable factors. Printing business customers through the use of simulated conditions, to develop an appropriate product testing standards to ensure the production of non-factory failed to avoid unnecessary losses.

Tags: Packaging film, printing environment, printing inks, sterilization conditions, viscosity