Tile mounting techniques of corrugated cardboard boxes

Composite application

Laminating paper compound is the first post-printing process of offset printing color box. The viscosity and pressing directly affect the efficiency and forming effect of the card box. Multi-layer carton (three-layer, five-layer), carton and folding box, U / V type affixed tile / tile affixed tile, double-layered affixed card under 500g can be combined by laminating, the product is used for packaging Beer, liquor, beverages, food, fruits, electrical appliances and cosmetics, etc. Some small carton manufacturers purchase color noodles and mount them on their own. They make moon cake boxes in summer and fruit boxes in winter. Many breweries also use offset-printed veneer boxes. For example, the Venus Beer Carton Branch had purchased three laminating machines in one go. Due to process limitations, the composite efficiency is generally not high, with an hourly speed of 1200mm-1600mm wide width between 2500-7000 sheets. Therefore, the paper-laminated composite process is more suitable for carton and carton packaging with smaller batches and more complicated product structures. Large-volume RSC carton common color register should use flexographic post-printing, dot printing can use flexographic or gravure pre-printing.

Product size restrictions come from equipment. From the paper mounting process itself, of course, small-sized carton is easier to operate, and the quality is more easily guaranteed. Pay attention to the paper grain direction for the multi-layer backing compound. The paper grains of the two papers in the carton are perpendicular to each other, and the paper grain direction of the carton should be perpendicular to the corrugated direction, so as to obtain higher compressive strength and reduce fluting. phenomenon.

The operation of the automatic laminating machine requires high cardboard, the facial paper and the single tile must be dry and smooth, and the proficiency of the operator is also high; the structure of the semi-automatic machine is simple, equipped with a cardboard anti-roller, and the manual operation is more flexible. Not fast. The production efficiency and machine cost of fully automatic machines are almost 2.5 times that of semi-automatic manual machines.

In order to avoid the corrugation height being less squeezed and damaged during the laminating process, on the one hand, the paperboard must not be too soft, and the moisture content should be controlled below 14%; on the other hand, the pressure, angle and speed of the press part should be adjusted to moderate. The effective lamination length of the domestic veneer machine is set at 3.2 meters. The carton factory can request the machine manufacturer to extend it to 3.8 meters. With a longer pressing length, the operator can remove and reduce the 22 pressure feeding rollers under the belt according to product requirements. The automatic laminating machine is equipped with a hydraulic induction system at the pressing part, which automatically raises the height of the drum to adjust the pressure of different paper segments. This user-friendly design can not only reduce the burden on the operator, but also protect the strength of the carton.

Bonding performance

Compression, flat pressure, burst strength and bonding are important physical indicators of corrugated boxes. The strength is related to the processing technology of paper and cardboard, and bonding is inseparable from the composite glue. The veneer bonding directly affects the next process of the carton and the customer's on-line packaging. Gluing becomes an important part of the laminating paper composite process. If the adhesive is uneven, the adhesion is not good, the cardboard surface will blister, and the back of the cardboard will be glued. , Rubber powder can be seen on the corrugation.
The machining accuracy of the laminating machine determines the uniformity of the glue application. The accuracy of the outer and inner circles of the rubber roller requires that the roundness of the roller passes through the outer car and the inner car to be exactly the same. There will be no wheel eccentricity after 2 years of operation and the rubber will be thrown away. The accuracy of the veneer will remain unchanged for at least 5 years. The fully automatic machine adopts a built-in glue tank, a closed pump glue, and the glue quantity is supplied by hydraulic pressure, which is even, safe and hygienic.

The glue water used for mounting paper is starch glue and chemical glue. There are two kinds of starch glue, yellow glue and white glue, yellow glue has been basically eliminated in domestic carton compounding. The white glue powder currently used has the advantages of easy availability of raw materials, environmental protection, low price, and ease of use, but the bonding force is not strong, it is easy to mold, the drying speed is slow, and the film becomes brittle after drying; when it is used, there are many suspended substances, which is easy Precipitation occurs and the stability is not good. If the dosage is large and the glue renewal frequency is required, only a simple stirring device is needed. The viscosity needs to be checked before the glue is used, and not only the adhesion effect is observed during the compounding process. The quick-drying of glue is very important. Due to the high moisture content, the carton has good compression resistance after die cutting. The glue must be able to be completely dried within 4 hours, otherwise the carton produced will often collapse and the strength will be damaged. The ratio of quick-drying powder and water is generally 1: 5, and it is adjusted appropriately according to different products. After 3 minutes of initial sticking, the moisture content quickly drops to 20%, and then drying slows down. The moisture of the cardboard should be tested before die cutting.

Chemical glue includes inorganic adhesive sodium silicate solution (water glass), commonly used for the bonding between the outer paperboard and the inner core board, the PH is 11-13, it is alkaline, it is easy to contaminate the adherend and will absorb moisture, Poor weather resistance; Poor water resistance of polyvinyl alcohol PVOH, low bonding strength; Polyvinyl acetate (PVAc) curing at room temperature is fast, easy to use, high bonding strength, long storage period, colorless and transparent film after curing It does not pollute the bonded surface, the adhesive layer has toughness, little damage to the tool, and a certain water resistance to cold water. Lamination3065LV of National Starch Chemical Co., Ltd. belongs to this category.

The laminating paper is deeply affected by the working environment. The damp air will cause the cardboard to become soft and damp, so the veneer is best placed in a constant temperature and humidity room.
If the machine is adjusted and the glue is used normally but degumming still occurs, the cause may be a problem with the base paper. The tissue paper of the whole wood pulp cattle card will not be absorbed well due to the dense paper and high tightness. It is difficult for the rubber particles to quickly penetrate into the inner layer of the paper fiber, so that the adhesion is not strong. The strong corrugated bonding can ensure that when the carton is automatically formed into a carton, there will be no delamination defects due to the upward suction of the cardboard (stand-up box).
Automatic boxing

Industries such as food, beverage, beer, daily chemical, medicine, etc. increasingly use automatic boxing machines to package commodities to solve the new problems of mass production and rising labor costs. The carton cartoning machine is composed of five steps: box feeding, stand box, folding cover, bottom spraying, and conveying. During the work, the steps must be coordinated at a uniform speed and consistent in beat. Automatic boxing changes the bloated and loose appearance of traditional manual box making, making it more compact and more beautiful, and the structural advantages of corrugated boxes are best exerted; secondly, automatic boxing uses hot melt adhesive to replace plastic sealing tape, which can be effective Preventing white pollution, in line with environmental protection concepts, is conducive to promoting export of commercial outlets.

Automated boxing was once promoted slowly because of the expensive equipment. In recent years, domestic light industry machinery manufacturers have developed economical boxing machines equipped with the Nordson glue spraying machine (Nordson), which packs 40 boxes per minute, completing the carton packaging terminal system The full automation of the package not only improves the labor efficiency of the packaging process, but also expands the application functions of carton packaging.

The automatic box forming machine requires high strength, good stiffness and low moisture content of the cardboard. The softness of the carton can not only ensure the normal folding of the box machine, but also affect the shape of the carton after molding, which is just the "soft rib" of the laminating paper composite process. .

Eliminate the card box defects of the offset printing carton on the automatic machine. The first is to detect the moisture of the base paper (less than 12%); the second is to control the moisture of the cardboard after the cold rubber mounting tile (less than 10%). The cardboard is removed from the laminating machine After coming down, there is at least 24 hours of natural drying time, and then slotting or die cutting. The offset printing adopts local glazing, and the hot melt adhesive coating department is not varnished, which helps to seal the box quickly and firmly.