Waterproof principle of waterproof paperboard
Waterproof board function and waterproof coating brief introduction: waterproof board is the floorboard that has the carton that resists water to destroy carton intensity. It is usually on the corrugated cardboard brush coated with a waterproof coating, made by drying. Waterproof coating in the box after brushing quickly drying film, its film transparency, gloss, coating smooth, non adhesion, no impact on the carton printing ink. The general corrugated carton after finishing waterproof coating, the surface wear resistance, anti scratch, carton reinforced high strength, moisture resistance and water resistance, good strong, to beautify and long-term protection for carton up.
This is because the packing is cooler than the outside when you remove the corrugated boxes from the freezer. Just as cold water is injected into the cup during the summer, the drop on the surface of the cup is the same. This is the dew point phenomenon. Generally in the corrugated cardboard surface dew, in a short period of time can be dried noodles cardboard absorption, increase the carton water, make carton strength reduced. Using hydrophobic paperboard, the dew can be reduced to water droplets and to prevent penetration into the interior without reducing the strength of the paperboard. But as a long time on the outside, or from the freezer repeatedly get in and out, because only in the surface hydrophobic treatment processing board, the hydrophobic effect is gradually reduced, water increased up to a certain time and general strength of corrugated board is reduced to consistency. On the other hand, because of the hydrophobic surface of the cardboard processing, surface wear of cardboard Hanging noodles increased greatly, can prevent the carton in the process of circulation between each other repeatedly friction surface peeling cardboard and paper produced at the end. Water resistant corrugated cardboard (water proof corrugated board), water resistant corrugated cardboard, also known as water blocking corrugated cardboard, this kind of cardboard for a long time and water contact, basically do not make the water through. If on the other hand, although it can prevent water immersion, but once the water into the inside, corrugated cardboard water resistance will all disappear.
The waterproof coating are: oil soluble and alcohol soluble and water-soluble waterproof coating, these three kinds of waterproof coating compared to water soluble coating, waterproof coating moistureproof performance is better than that of oil soluble and alcohol soluble waterproof coating. Water soluble carton waterproof coating is usually in paraffin, polyethylene oxide as main film-forming agent, and stabilizer and dispersing agent, thickening agent, brightener, regulator, water and other additives with water-based emulsion formed. The utility model has the advantages of no poison, no smell, good water resistance, good combustion resistance, good stability and good adaptability between cold and hot temperatures. The utility model has the advantages of safe use, low cost, good waterproof and dampproof performance and convenient use (spraying, coating and Shua Junke).
In the process of corrugated board bonding, waterproof coating is coated with waterproof or roll coating on the surface of the paper, so the board has good water resistance. If both sides of the paper are coated, then the waterproof performance of cardboard better. The representative method for making this kind of corrugated board is curtain coating. As shown in Figure 1, the curtain method is waterproof coating melt film as a curtain. Let down spraying, make corrugated cardboard (or have printed corrugated cardboard) by a method of forming a coating film on the surface of the corrugated cardboard (positive and negative by one or two mounted film device can both act processing).
At present, the demand for waterproof cartons is increasing, especially in the fields of vegetables, food, household appliances and industrial products. In particular, the export of water resistant carton consumption increased rapidly, greatly promoted the development of corrugated box manufacturing industry.
