The glue used for crepe paper is starch glue and chemical glue. There are two kinds of starch glue, yellow plastic and white plastic, the domestic carton composite has basically eliminated yellow plastic. The currently used white rubber powder has the advantages of easy availability of raw materials, environmental protection, low cost, and ease of use, but the adhesive force is not strong, easy to mold, dry slowly, and the film becomes brittle after drying;
When used, there are a lot of suspended matters, which are prone to precipitation, and the stability is not good. If you use a large amount of glue to update the frequency, you only need to use a simple stirring device. Before the glue is used, it is required to check the viscosity. In the compounding process, not only the adhesive effect is observed. The quick drying of glue is very important. Due to the high moisture content, the carton has good resistance to pressure after die cutting. The glue must be able to bond and dry completely within 4 hours. Otherwise, the cartons produced tend to collapse and the strength is damaged. The ratio of quick-drying rubber powder to water is generally 1:5, which is adjusted according to different products. After 3 minutes of initial tacking, the moisture content quickly drops to 20%, then drying slows down, and the cardboard moisture should be tested before die-cutting.
Chemical glue includes inorganic adhesive sodium silicate solution (water glass), commonly used for bonding between outer handsheet paper and inner core board, PH is 11-13, is alkaline, easy to contaminate the bonded materials, and absorbs moisture. Poor weatherability; PVA PVOH poor water resistance, adhesive strength is not high; Polyvinyl acetate (PVAc) room temperature curing speed, easy to use, high bonding strength, long storage period, colorless and transparent film after curing It does not contaminate the surface to be bonded, the adhesive layer has toughness, it has little damage to the tool, and it has a certain water resistance to cold water. Lamination 3065LV of National Starch Chemical Co., Ltd. belongs to this category.
The combination of crepe papers is strongly influenced by the work environment. The dampness of the air will cause the cardboard to be soft and soft. Therefore, it is advisable to place the machine in a constant temperature and humidity room.
If the machine is adjusted and the glue is used normally but it still produces degumming, the cause may be raw paper. All wood pulp ox card face paper will be poorly absorbed due to paper density and tightness. The rubber particles are difficult to penetrate quickly into the inner layer of the paper fiber, so that the adhesiveness is not secure. The solution is to try low viscosity glue. Robust corrugation ensures that delamination defects do not occur when the carton is automatically boxed by pulling up the cardboard (stand).
Automatic boxing
Food, beverage, beer, daily chemical, pharmaceutical and other industries are increasingly using automated carton packer packaging to solve the new problems of mass production and rising labor costs. The carton boxing machine is composed of five steps: the box, the vertical box, the folding cover, the bottom spray glue, and the transmission. The steps must be consistent and the beats must be consistent during the work. The automatic packing changed the appearance of the traditional manual box bloated, loose, making it more compact, more beautiful, the structural advantages of the corrugated box to get the best play; Second, the automatic box into a hot melt adhesive to replace the plastic sealing tape, can be effective Prevent white pollution, in line with the concept of environmental protection, is conducive to the promotion of commercial exports.
Automatic packaging was once slow because of expensive equipment promotion. In recent years, China's light industrial machinery manufacturers have developed economical packing machines, equipped with Nordson, and made 40 boxes per minute to complete the carton packaging terminal system. The comprehensive automation not only improves the labor efficiency of the packaging process, but also expands the application function of carton packaging.
The automatic box-packing machine requires high strength, stiffness, and low moisture content. The soft and soft carton box can not guarantee the normal box folding, but also affects the shape of the carton after molding. This happens to be the "soft rib" of the paper-bonding process. .
Eliminating the defects of the carton on the automatic offset carton carton, the first one is to detect the moisture of the base paper (less than 12%); the second is to control the moisture (less than 10%) of the cardboard after the cold glue and tile, and the cardboard from the veneer At least 24 hours after the natural drying time, and then slotted or die-cutting. Offset printing uses partial gloss, but the hot-melt glue coating department does not use clear oil, which helps seal the box fast and securely.