Overview of shrink film label printing
at present, the printing method of shrink film labels is still gravure printing, and the share of flexographic printing is small. Shrink film labels also have certain requirements for printing equipment, mainly reflected in tension control and heat control
since thin film materials are prone to tensile deformation, the printing tension must be accurately controlled when printing such materials. Some old printing machines or printing equipment specially designed for self-adhesive film labels with base are not suitable for the printing of shrink film labels at all. In the printing of shrink film labels, the heat control of the printing machine is also very important. The printing machine must be able to dissipate and eliminate the heat to prevent the shrink film from shrinking in the printing process. Some new printing machines are equipped with a hypothetical barb cooling roller to take away heat and reduce the temperature of the film
for shrink sleeve printing, a sealing device is also required to turn the sheet-like film into a cylinder, seal the overlapped parts together (forming a seam), then flatten the cylindrical film, and finally roll it up. The sealing quality control can rely on the vertical and horizontal two position system and detection of the outer surface of the oil cylinder with a square level, so as not to affect the subsequent marking process. Generally, no pictures and texts are printed on the sealing part, and it is necessary to ensure that it is clean and free of dirt, otherwise it will affect the bonding fastness
at present, the price of sealing devices is generally between $40000 and $200000, or even higher. Some high-priced sealing devices are also equipped with detection devices. If the detection device is purchased separately, the price is $30000 to $50000
labeling equipment and adhesive
shrink sleeve labeling generally requires special labeling equipment to cover the printed sleeve label on the container. First, the labeling equipment will open the sealed cylindrical sleeve label, which may sometimes need to be punched; Next, cut the sleeve label into appropriate sizes and put it on the container; Then, steam, infrared or hot air channels are used for heat treatment to make the sleeve label tight. Polyurethane materials have been used for medical attachment to the surface of containers
shrink wrap labels can be labeled with traditional labeling equipment, and adhesives and higher temperatures are required in the labeling process. In the process of shrinkage, because the adhesive at the overlapping part of the film will produce stress, it is better to use hot melt adhesive. In some cases, solvent based adhesives can also be used. Although UV adhesives once attracted much attention and are expected to be widely used in the labeling of low shrinkage film labels, no breakthrough has been made so far
at present, shrink wrap labels are usually made of PP film. Due to the low shrinkage of PP film, which is generally within 20%, hot melt adhesive is more suitable for labeling. If solvent based adhesive is used, it may cause PP film wrinkles. Due to the high shrinkage temperature of PP film, hot air is mainly used for heat treatment, which can reach a higher temperature than steam heating
nowadays, high shrinkage film labels are used more and more, and greater stress will be generated in the heat sealing part during the shrinkage labeling process. In order to withstand this shrinkage stress, the demand for solvent based adhesives will be increasing in the future
successful cases of shrink film printing
sleeveco has been focusing on the printing of shrink sleeve labels and stretch sleeve labels since its establishment in 1988. According to Mr. Martin Wilson, deputy manager of the company's sales and marketing department, the reason why the company can cooperate with some internationally renowned consumer goods manufacturers on many challenging projects is also inseparableIn addition to the prepress and printing departments, sleepeco also began to extend downstream to the process and manufacture all kinds of labeling equipment. When processing complex shrink labels, every process link, from design to labeling, must be accurate, and sleeveco can provide all the professional technologies required for the whole process
1. Sleveco produces high-quality shrink sleeve labels
sleveco is aimed at some markets that have very strict requirements on product labels, including automotive aftermarket, cosmetics market, consumer goods market, greening and garden products market, etc. When printing shrink sleeve labels, sleeveco uses solvent based inks. The substrate materials suitable for gravure printing include PVC, high shrinkage PVC, PETG, OPS and OPP films, while PP films are mainly used when printing on flexographic printing machines
because sleeveco has both gravure printing machine and flexographic printing machine, it has high flexibility in production and can choose the appropriate printing method according to the product situation. Flexographic printing machines are suitable for printing bills, coupons, lotteries, etc. that require 100% complete recycling of materials, and labels that prevent leakage and pollution of chemicals in containers. In addition, it is also suitable for drum packaging with a printing volume of 8 ounces to 55 gallons, and can select the ink color and the number of lines added according to the requirements of image color concentration
with gravure printing, sleeveco can also provide photo quality images, and can print with special inks (including metal ink, pearlescent ink, mixed ink and matte oil). Some labels with translucent effect look like labels without labels
2. Practical experience
because sleepeco is an enterprise specializing in label printing, it processes a wide range of moving parts, from ordinary label to more complex label, and even some innovative new products. If necessary, the company will spend several months on research and development to make all indicators of products more perfect, such as size, deformation rate and image quality, Therefore, many packaging users came here one after anotherMr. Wilson highlighted the case that the company spent several months developing shrink labels for some gasoline containers in PENNZOIL Quaker State. He said, "the shape of the gasoline bottle is similar to that of a racing car, and other companies in the industry believe that this product should not use an overall shrink label. In order to make the label shrink and just cover the outside of the car shaped bottle (the wheels and canopy on the label must be able to closely match the wheels and canopy on the bottle body) , the designers of the prepress Department of our company have correctly deformed some parts of the label. In addition, our company also cooperates with bottle manufacturers to make the density of bottles suitable, and has developed a special system for pasting such labels "
another challenging project over time is the successful development of shrink sleeve labels for blue coral's black magic series products. Blue coral wants to use an integral shrink sleeve label for its spray gun bottles. The main challenge is the deformation of the bottleneck. Sleeveco has developed a solution that can provide the correct shrinkage rate in both the small cap and the large bottom
the successful application of shrink labels and special inks has greatly improved the company's business. Mr. Wilson said, "our customer white rock distilleries plans to change the product packaging from the original frosted etched glass to an integral shrink sleeve label, which can also achieve the original effect after matte polishing. This saves a lot of costs for the company, and the inventory of bottles is also reduced"
3. Opportunities and challenges
although sleepeco is facing the growing packaging and printing market, it still faces some severe testsMr. Wilson said, "the biggest problem comes from the end-users' requirements for speed and timeliness. The market and major retailers (such as Wal Mart) require suppliers (that is, our customers) to shorten the delivery cycle, and the amount of supply required each time is gradually reduced. The key to our company's success is to correctly formulate the initial project plan for these problems, so that we can help customers quickly enter the market." 。
despite various challenges, Mr. Wilson believes that the development prospect of shrink sleeve label is bright. He said, "with the further development of shrink sleeve labeling technology and the deepening of people's understanding of shrink sleeve labeling, plastic container blow molding enterprises are now able to produce all kinds of strange bottles, which are more attractive and humanized. Although the cost of shrink sleeve labeling is slightly higher than pressure-sensitive labels and paper labels, it can bring higher added value to products"
information source: Printing Technology