How to deal with moisture-proof corrugated boxes?- Jiaxing Hengchuang Packaging Technology Co., Ltd.

The corrugated cardboard gift boxes is made of moisture-proof, in addition to protecting the packaging from being soaked by water, it is mainly to prevent water from moistening the box itself.

Because the compressive strength and bursting strength of the carton will be greatly reduced after the carton is soaked in water, which will seriously affect the quality of the packaging. Shenzhen corrugated boxes are manufactured to be moisture-proof, and are usually treated with a method of coating a waterproofing agent. Therefore, the manufacturing methods of moisture-proof cartons can be divided into temporary waterproofing treatment and permanent waterproofing treatment according to the function of waterproofing agent.

Temporary water repellent

After the corrugated cardboard is treated with a temporary waterproof agent in the production process, it has a temporary waterproof function. According to the explanation of JISZ1537: when water falls on it for a short time, it will not get wet and form water droplets, which can prevent water from penetrating the cardboard. Temporary water repellent treatment cardboard technology has been used in major carton factories in my country in the past ten years. This water repellent was originally introduced from Japan, and its Japanese word is puffer agent.

This coating was used on fabric fibers in the early days, and later on the treatment of cardboard. Therefore, most carton factories choose the name of water-pulling agent. The water-removing agent is a wax emulsion with a solid content of 48% to 51%. Its biggest feature is that it can be diluted with about 30 times of water during use, and then coated on the corrugated board being formed. After 150 The temperature around ℃ is dry, and the surface fibers of the paper have low surface tension due to the wrapping of vinegar, forming a surface layer that is not moisturizing to water. When it encounters water, the water does not moisten the cardboard, forming water droplets to roll off, and then achieve the effect of waterproofing. However, the adhesion of wax to paper fibers is not good, especially when the water-pulling agent is diluted 30 times, its solid content is only 1.5+, and the surface fibers of the paper only need to be wrapped in a thin layer of wax. In addition, because the particle size of the wax in the wax emulsion is usually larger than that of the usual polymer emulsion, it is difficult to penetrate deep into the paper fibers. At the same time, the water-removing agent is usually sensitive to chemicals such as alum, and is usually very sensitive to the surface of the paper. The demulsification is quickly broken and the rice is deposited, so most of the wax particles in the water-removing agent only exist in a very thin layer on the paper surface.

Under the action of external conflict, the wax is easily collided, exposing the fibers without wax wrapping, and the waterproof effect is greatly reduced. In order to enhance the adhesion of wax to paper fibers, there are usually rosin derivatives or carboxylated polymer emulsions in the water-removing agent, which not only have good adhesion to paper fibers, but also have good compatibility with wax. In this way, their addition can promote the adhesion of the wax to the paper fiber, and if the wax is modified, such as oxidation and basement, it also has a similar effect, which can increase the adhesion of the wax to the paper fiber. However, it is necessary to point out that even with these measures added, the water-repelling agent is still not a waterproof membrane layer at such a concentration, so in the event of conflicts, such as conflicts during the transfer and stacking of cartons, Often this waterproof appearance is rendered useless. This is why such cartons coated with water repellent are designated as temporary waterproof cartons. Now, the water-removing agent has been widely used in some carton factories and has become a basic process.

The large-scale use of coating water-repellent agents is mainly affected by the following four aspects: the price and machine-coatability of water-repellent agents; The recovery of the carton has no adverse effect; the waterproof effect of the water-removing agent can be fully responsible for the use of the normal carton.

However, it is necessary to point out that, for cartons used in some special environments, such as demand; East warehouse cartons, cartons that need to be stored in a high-humidity environment, and cartons that need to be shipped by sea, be careful when using water-repelling agents . In practice, it has been found that there are cartons coated with water-repellent agent. After being taken out from the freezer, the cartons are deformed, causing economic disputes. Therefore, when recommending what waterproof treatment customers choose, the application environment of the customer's carton should be fully considered.