How to improve the moisture resistance of paper gift boxes

Why does this happen

   From the perspective of packaging material testing, this is mainly related to the structural properties of paper. Paper is mainly composed of plant fibers and accessories. It has a porous structure and has strong hydrophilicity. When the relative humidity in the air is too high and the environmental humidity is inconsistent with the water content of the paper, the paper contacts the air and absorbs the moisture in the air. After the paper absorbs moisture, local or overall deformation occurs, resulting in ruffled or crepe paper.

How to make paper waterproof and moistureproof

Physical waterproof and moisture-proof

 Paper products and packaging

1. For the rainy season, based on the testing of packaging materials, it is necessary to improve the water absorption control standard of the base paper, strengthen the detection of the moisture content and water absorption of the base paper, and strengthen the sizing degree of the base paper;

2. The roll paper is protected by wrapping film, and the outer packaging is coated with film; the flat paper is sealed with heat-shrinkable film, which can effectively reduce the effect of weather on softening.

Storage environment

1. The storage environment of paper should be ventilated, clean and dry;

2. The paper can not be stacked close to the wall, and can not be placed directly on the ground. It should be more than 1 decimeter away from the ground. It is generally recommended to use a wooden backing board, which can absorb the moisture on the ground;

3. Pay attention to the mutual gap between the paper stacks during storage, so as to facilitate ventilation and heat dissipation;

4. Under the conditions, the relative humidity of the paper warehouse and production workshop should be maintained between 50% and 65% as much as possible;

5. Quicklime can be wrapped in cloth or sacks and placed in various places in the paper warehouse, which is conducive to keeping the air in the warehouse dry;

6. Pay attention to the rainproof facilities. Usually, there should be a canopy in the warehouse.

Chemical waterproof and moisture-proof

   It can be seen from the relevant content of packaging material testing that corrugated cardboard can also be waterproof and moisture-proof from a chemical point of view, mainly by adding water-resistant components or post-coating process to the pulp to carry out waterproof treatment, and then passing the continuous anti-water leakage test to verify Waterproof effect. For example, the anti-leakage time of paper less than 80g/m² should not be less than 72 hours, and the paperboard above 300g/m² should not be less than 200 hours. The water-repellent treated paper has little effect on the printing process.

   Waterproof and moisture-proof paper products can be used to replace plastic products in a considerable range, and its waste can be recycled. The analysis of packaging materials can meet the requirements of current low-carbon economy and sustainable development.

transport environment

1. In the process of automobile transportation, there are common open-top trucks and vans. The latter can protect the paper products better than the former, and avoid and reduce the softening of paper products;

2. When encountering rainy weather, the logistics shunting will take the flying wing door truck as the priority;

3. For ordinary trucks, the following three protective measures are generally taken to prevent paper products from getting wet:

1) The car box board is covered with wooden boards, and a layer of rain cloth is placed on the wooden board to prevent rainwater from splashing into the car from the bottom of the car, causing the paper products to be wet;

2) Use corrugated cardboard for vehicle protection. Corrugated cardboard can not only effectively prevent paper products from getting wet, but also prevent paper products from being collided and damaged;

3) In rainy weather, the carrier vehicle is covered with three layers of rain cloth to prevent rainwater from infiltrating and causing wet conditions;

Processing technology of paper gift box

   The cardboard should enter the next process as soon as possible after it comes off the cardboard assembly line. The longer the cycle, the easier it is for the cardboard to absorb moisture in the air and soften.

In addition, when printing, especially multi-color printing or bulk solid printing, it is easy to cause the carton to be soft due to the pressure of the printing plate. Minimize the residence time of the carton in the production and processing process to avoid softening after being exposed to the humid air for too long. The workshop should also be moderately isolated from the outdoors to avoid direct blowing of water vapor into the workshop.

The testing data of packaging materials show that the hardness of corrugated cardboard should be ensured as far as possible before printing, and excessive pressure should be avoided during printing. The die-cutting process should try to avoid using the circular die-cutting process that does great harm to the flat pressing of the cardboard.

 In short, the problem of carton softening is still a moisture problem in the final analysis. Experienced packaging material inspectors suggest that only by doing everything possible to prevent the carton from absorbing moisture during the storage of base paper, corrugated cardboard processing, carton processing, storage and transportation, the cardboard can be hardened.