Market for a new wave of demand for waterproof carton
In recent years, with the people's living standards improved, increasing demand for packaging products. Corrugated packaging container as a commodity, not only to guarantee safety in the transportation of goods, but also play a beautification products, increase of added value, promote sales role. Especially in recent years appearing on the market a variety of printed cartons exquisite new moisture-proof coating, in large part to improve product quality, packaging cartons, and a fundamental solution of the carton packaging Yi Chao, easy to mold, easy to loss issues. Corrugated to withstand wet or grease penetration, the intensity will rapidly decrease. Shape, stiffness owing to the damp change. Because after the carton box by water infiltration, compressive strength, bursting strength will be greatly decreased, which would seriously affect the quality of packaging. For example: at 95% relative humidity environment, the corrugated boxes will lose 2 / 3 of the original rhyme strength, corrugated box will be the collapse of the entire cross. Currently boxes with waterproof properties of the market demand is growing, especially in the vegetable, food, household appliances, industrial products, packaging, application of a gradual increase. Export products, especially the rapid growth of water-resistant carton usage, which greatly promoted the development of corrugated box manufacturing industry.
Waterproof cardboard is resistant to water damage the strength of the general term for cardboard. Production of corrugated box for moisture, in addition to protection against water, wet packing, the main is to prevent infiltration of water on the box itself.
Moisture-proof, waterproof corrugated board development concern. As the corrugated box to absorb moisture, or water-absorbent stacking strength will result in significant decline, has become a carton manufacturing enterprises need to be solved important issues. The most common way is to pull in the original paper coating agent. Was first painted in cardboard boxes on the use of tung oil in order to achieve water-proof, moisture-proof effect. Chitosan acetic acid solution after impregnation and acetic anhydride treatment, converted into chitin, apply the original paper and also has good moisture-proof, waterproof effect. The use of paraffin wax, microcrystalline wax, polyethylene wax, beeswax, white wax, carnauba wax, montan wax and other animal and plant wax, apply on board by the emulsion can be moisture-proof and waterproof on the same due to low cost, is currently the most widely used approach to . However, this method of surface characterization of anti-poor, low-gloss, you can join the propylene-based polymer, phenolic resin, epoxy resin, amino resins, poly amide, poly-amino acid alcohol and high-linked thermoset polymers such as polyvinyl chloride , made of composite structures of the pull agent for the impregnation cardboard, can greatly improve the cardboard waterproof and moisture resistant. Waxing corrugated board is not conducive to recovery, the EU has begun to limit the use of. Another pull aqueous chromium trioxide is used in the alcohol - hydrochloric acid solution, restore, and stearic acid with is made of both anti-mildew, anti-pollution and other features. At present there are different formulations on the market pull agent to sell. If the resin, starch or plastic type moisture-proof agent to join the pulp caused by moisture within the copy paper, carton of natural right to produce the most convenient, although this number to increase the cost of base paper, but the total cost is still cost-effective. Toyo Steel Co., Ltd. has made to develop 0.02mm ~ 0.05mm thick pure iron foil by zinc, nickel or tin anti-rust treatment, and kraft paper, polyethylene film extruded with the compound into a composite board, used to make cartons, not only waterproof, moisture-proof, but also electromagnetic shielding, anti-static, especially for aquatic products, fruits and vegetables, electronic instrumentation, semiconductor devices and machinery and electronic products packaging. Aluminum PVC film and the kraft paper cartons post-production, also has a waterproof, moisture-proof function.
Moisture-proof packaging technology
Air humidity is caused by corrosion products, deterioration of the important factors. Wet products and other items of industrial hazards mainly to make metal rust, so that non-metallic products taken place mildew into deliquescence. Some organic materials, the surface moisture swelling, deformation, blistering, not only affect the appearance, but also to mechanical performance. In order to prevent items in the production, transportation, storage, use a qualitative change in the course of damp to take protective packaging, as moisture-proof packaging.
Packaging materials or containers depends on the moisture resistant material or container moisture penetration. Packaging material moisture permeability means: per unit area within the unit, asked by the weight of the water vapor. Water vapor permeability of packaging materials and material types, processing methods and material thickness. In order to improve performance, moisture-proof packaging materials, reducing its moisture permeability is often a different soft multi-layer composite material, made of composite film. Commonly used packaging materials and composite packaging material moisture permeability in the table below.
The moisture-proof packaging in general there are four: the first one is being packaged in order to prevent loss of moisture water products to ensure product performance and stability, using a certain humidity, moisture-proof transparent packaging materials packaging; the second is to prevent the packaged product moisture absorption of moisture in the containers placed a certain amount of desiccant to absorb the package into the package when the water will keep humidity within a certain range. Desiccant commonly used are: silica gel, molecular sieve, activated alumina. This method requires that the container can be sealed, so that the container interior space with the outside air isolation. This method is suitable for small packing cases; third is accused of space through continuous or intermittent moisture detection and control of space will be charged to maintain the humidity within a certain range, achieving the purpose of supplies and equipment dry and sealed . This method is suitable for large products, moisture-proof packaging (such as large equipment, automobiles, airplanes, etc.), can be used such as recycling dehumidification drying and condensation control methods; The fourth is through sealed containers within the vacuum method of realization of moisture