On the selection of printing consumables and equipment for tissue printing

As a printing method that meets future environmental protection needs, flexographic printing has been increasingly used in packaging in recent years, such as labels, folding cartons, flexible packaging, and cartons. But when it comes to the application of flexographic printing in tissue products, it is still little known in China. There are two main reasons: First, the domestic flexographic printing process started later than abroad, and there are still great aspects in market promotion and equipment use. The gap; the second is the difference in consumer culture. Paper towels are a wide-ranging and artistically interesting design theme in the West. Beautifully printed napkins can be used in different occasions, such as the fairy tale series launched at Christmas and Children’s Day. At the same time, it It is also an affordable form of personalized advertising, which is not uncommon in restaurants or hotels. As people's lifestyles are increasingly developing towards personalization and fashion, personalized tissues have become a trend and trend nowadays, such as weddings, banquets or company annual meetings and other special anniversaries often use specially designed tissue supplies, so In the past few years, tissue printing has developed quite fast.

At present, the single-color printed paper towels used by McDonald's and KFC are mostly seen in the Chinese market, and the patterns are relatively simple. However, we also noticed that in large fashionable supermarkets like IKEA, color napkins imported from Europe have also been prominently placed. The price is much more expensive than pure white products. Obviously, printing has brought more High added value. For printing, this also means a new profit growth point, which deserves everyone's attention.

Tissue material

In tissue printing, the choice of tissue material is very important, and it is also one of the basic elements to ensure the smooth progress of printing. Compared with other packaging materials, paper towel materials are characterized by being very thin, soft, highly absorbent, poor in tensile strength, and easy to stretch. Therefore, paper towel products generally focus on the matching of bright colors, but do not overemphasize the subtle levels and colors Reappearance. In addition, the content of cotton or fiber in paper towel products is relatively high, it is easy to bleed, and there is much paper dust. For folded paper towels, there are also single-layer and multi-layer materials. For multi-layer materials, attention must be paid to the separation of layers, because when printing at high speed (such as 700m/min), the paper towel material has not been embossed. , All levels must ensure that they can be closely combined, otherwise it will cause paper jams during printing and downtime. In addition, during printing, the ink may cause the surface material to expand. If the layers are not tightly bonded, it will also cause the material to wrinkle, affect the printing effect and even cause waste products, increasing material waste. Therefore, in order to ensure print quality, reduce waste, and improve production efficiency, it is necessary to choose good quality tissue materials.

Printing ink

For napkin products, direct contact with the human body, such as mouth, hands or eyes, and food, hygiene and environmental protection are very important. The water-based inks currently used in tissue flexo printing machines are environmentally friendly, pollution-free, and odor-free, fully complying with hygiene and environmental protection requirements. In addition, when many domestic consumers talk about colored napkins, they will all raise such a doubt that the printed ink will not stain the skin or pollute the surrounding environment when using such colorful paper towels. In fact, this kind of worry is not necessary. Tissue printing companies have fully considered these when selecting inks, especially the abrasion resistance, water resistance, and resistance of ink are very important technical indicators. The ink used for tissue printing After repeated skin contact tests, abrasion resistance, and anti-flood tests, especially in home life, there may be many substances that are easy to induce ink bleeding. Therefore, compared with ordinary water-based inks, tissue ink printing formulas are also Some ingredients are added to effectively prevent the ink printed on the paper towel from bleeding or dissolving when it comes into contact with water or strong alkaline substances.

The printing suitability of tissue printing ink is also very important. During the printing process, the pH value, viscosity and other properties must be kept stable, and the drying property is appropriate, which is consistent with the printing speed and post-press processing requirements. The printing speed of the tissue flexo printing machine can be as high as 700m/min or 10,000 sheets/min. During high-speed printing and high-speed folding, the stability of the ink performance is very important. Improper viscosity of the ink may cause breakage; drying is too slow to meet Requirements for high-speed production; drying too quickly will result in dirty plates.

Printing Equipment

The tissue flexo printing machine adopts a layered or satellite structure design, and the whole machine includes unwinding, printing and connecting processing parts. Starting from unwinding, through printing, folding, embossing, fragrance addition, counting to the finished tissue, the entire process is fully automatic. The flexographic printing equipment adopts a combined design, and the configuration is quite flexible. All the orders including the number of printing orders can be increased or decreased. The printing factory can tailor it according to the needs of its own business.

The characteristics of the tissue flexo printing machine are high speed and high output. Taking the tissue flexo printing machine produced by Omit as an example, the format is 500～2740mm, and the printing speed can reach 600～700m/min; the printing order can be configured up to 8 There are several color groups; in the paper output part, according to the size of the output, there are several paper collection methods such as single paper path, double paper path and even 8 paper path.

In the tissue printing process, due to the particularity of the tissue material, the control of printing tension is one of the key factors affecting the quality of the printing. Many high-end flexographic printing equipments have adopted shaftless drive technology. Each unwinding, printing, embossing, folding, etc. are controlled by independent DC motors, and are equipped with digitally controlled multiple floating rollers and pinch rollers, making the equipment The effect of tension control and register control has been greatly improved. Secondly, the drying performance of the equipment is also very important. Paper towel flexo printing machines mostly use infrared, hot air or a combination of the two drying methods, and are equipped with a water-cooled cylinder scheme, so they can achieve better drying results and meet product requirements.

However, there is still a problem in the tissue printing, because the tissue material itself has more paper wool and the surface strength is poor, it is easy to fall off powder and hair, adhere to the printing plate and gradually accumulate, it will cause dirty plates and block plates, must Stop cleaning. In response to this annoying problem, many manufacturers install a vacuum cleaner on the printing list to solve it, or cooperate with a special doctor blade to reduce the incidence of such problems. Omite uses a wheel pressing device, a closed double knife, and a vacuum cleaner to basically eliminate this phenomenon. At the same time, Omite also provides a device for non-stop cleaning of the printing plate, which can reduce downtime ,Increase productivity.

Post-sequence processing is an important part of flexo printing on paper towels. Take folding paper towels as an example. The folding of paper towels is very particular, requiring square sides and sharp edges. In this process, tension control is particularly critical. The folding method of paper towels is flexible and diverse.

Embossing is also a very important part in the production process of paper towels. Embossing can improve the softness and hygroscopicity of paper towels. At the same time, the uneven patterns of different patterns also add a beautiful effect. There are many ways of embossing, such as point-to-point, steel-to-steel, steel-to-paper, steel-to-rubber, etc., and can also be divided into partial embossing and full embossing.

The strong development momentum of tissue flexo printing has attracted people's attention. The US FTA report pointed out that although the official statistics on the North American flexo printing market in 2002 have not yet included the data portion of the flexo printing tissue business, but from Judging from the situation of tissue printing companies that occupy 5% to 8% of its members, tissue printing represents a new and powerful profit growth space, which has attracted considerable attention in the North American flexographic printing industry, which has been in a downturn. Many tissue flexographic printing companies are full of confidence in the current and future tissue printing market. Statistics show that in 2005, the tissue and napkin printing business will grow steadily by 3% to 5% annually.

These market trends can be used as a reference for domestic manufacturers engaged in the flexographic printing industry and those who plan to invest in flexographic printing, to jointly make the flexographic printing market bigger and stronger, and win a broader development space.