Development and application of moisture-proof varn

Development and application of moisture-proof varnish for cartons

cartons are packaging and transportation boxes made of corrugated paper. They are essential packaging containers in production and life. They are light and firm, provide protection for commodities, can be recycled, and are convenient for loading, unloading and transportation. The four industrial chains of Shandong new material enterprises are widely used in the transportation and packaging of household appliances, textiles, food and other products. As a kind of green packaging material, cartons are favored by modern society, which attaches great importance to environmental protection. With the development of the commodity market and the improvement of people's consumption level, in addition to using high-quality water-based ink for printing, medium and high-grade cartons also need to be painted with a new layer of carton moisture-proof varnish, so that it will develop in the direction of high-grade, high-quality, multi-color and strong visual effect, which not only expands the promotion function of products for calibration results, but also strengthens the functions of cartons in moisture-proof, heat-resistant, water-resistant and many other aspects, Make cartons durable in retail and transportation

the new carton moisture-proof varnish completely overcomes the disadvantages of traditional products, such as slow drying speed, easy adhesion, color fading after drying, impact on carton ink or environmental pollution, poor moisture-proof effect, etc. it is a non-toxic, non irritating gas, non corrosive, non combustible, non explosive liquid finishing agent without organic solvents. It can be widely applied to the moisture-proof and glazing of corrugated boxes of any product, whether by hand brush or machine brush. The surface wear resistance of corrugated boxes after finishing this product is enhanced, and the light resistance, heat and moisture resistance of ink and the strength of cartons are also increased, so that cartons can resist scratches, have high strength, and have good water and moisture resistance, which plays a role in beautifying and long-term protection of cartons

the following is a description of the development of a new type of moisture-proof varnish for cartons

I. development process. The traditional carton moisture-proof oil is prepared with tung oil as the main raw material and an appropriate amount of organic solvent. It is characterized by good moisture-proof performance and gloss, but it has high cost, inconvenient operation and slow drying speed. In recent years, the carton moisture-proof oil made of polyurethane and alkyd polymer resins has been better than traditional products in brushing and drying speed, but it has poor gloss, poor stability, brittle coating and slow curing speed. Moreover, the above moisture-proof oil is also troublesome in operation, and it needs bone glue and starch for priming. Therefore, in the design of thin-walled box girder section and prestress, the stress at different positions of the load must be considered. It occupies the site, has low efficiency, and some have an impact on the environment. The moisture-proof agent made of waste polystyrene foam and waste polystyrene foam opens up a new and cheaper raw material resource for cartons, but there are problems that the water-free adhesive paper cannot stick firmly when cutting cartons and the cartons are easy to slip when handling

a new moisture-proof polish for cartons, which is refined and processed by chemical reaction with paraffin, rosin, oxidized polyethylene and other polymer raw materials as the main raw materials, has excellent performance in brushing, drying speed, gloss and other aspects after trial, and the raw materials are cheap and easy to obtain, the production process is scientific and reasonable, and the product quality is stable, which has certain promotion and practical value

1. allocation method. Take 6% - 12% paraffin, 5% - 8% oxidized polyethylene, 10% - 16% rosin, and an appropriate amount of other emulsifiers, brighteners, regulators, etc., and put them into a four port flask equipped with an electric mixer and a reflux condenser to emulsify them under certain conditions, then stir and heat up. When the temperature reaches about 200 ℃, keep the constant temperature to make the reaction complete, and then cool down. Add regulators to adjust the pH value to 8.5 ~ 9.5, and then cool down and discharge

2. Main performance indicators of the product appearance: light yellow viscous liquid, non-toxic, non irritating odor solid content: 20% - 32% viscosity (coated cup/s, 25 ℃), drying time: 7-10 minutes, pH value: 8.5-9.550. The former generally uses ordinary speed regulation system ± 30 seconds. When the emulsifier emulsifies the water-insoluble paraffin, oxidized polyethylene and other resins, the lotion is coated on the corrugated box and penetrates into the box, forming a transparent film on the surface. The film is bright and flexible, so it has good glazing effect, and the film is insoluble in water, making it have excellent water-resistant and moisture-proof effect

II. Promotion and application. The new carton moisture-proof glazing oil is compared with the traditional moisture-proof oil. To sum up, the new carton moisture-proof oil is characterized by water-proof, heat-proof and moisture-proof, low cost, solid coating, no pollution in the production and use process, and no "three wastes". It can completely replace the traditional moisture-proof oil. It is especially convenient for the gravure printing process used in the packaging industry at present, and has good development and utilization value

source: China's packaging industry