The production process of corrugated board is ever-changing, and the situation is changing rapidly. Carton manufacturers often need to adjust the adhesive formula to improve the adhesion of cardboard. This requires the glue making personnel to have a clear understanding of the characteristics and functions of the ingredients in the ingredients. Next, the micro-editing of "Packaging Zone" will explain to you in detail the characteristics and functions of various ingredients in tile starch adhesive. 1. Water First of all, water mainly serves as a carrier for biochemical reactions, and functions as dilution, penetration, uniformity and diffusion. The adhesive is transferred to the corrugated paper to be processed through the carrier, and then penetrates into the corrugated paper. Secondly, water is necessary during the expansion of the starch granules that give the adhesive stickiness. The water quality required to prepare the adhesive is tap water. Well water or ground water cannot be used. 2. Starch Starch is the main body of biochemical reaction. Starch is a natural carbohydrate extracted from plants containing chlorophyll. Many industries prefer to use starch as a binder, because starch is relatively low in cost, and is biodegradable, and can be extracted from renewable raw materials. After the corn starch is dried, the weight composition of various components is roughly as follows: Starch and carbohydrate-80% Protein-10, 7% Grease-4, 5% Fibre-2,5% Ash-1% Impurities-0, 5% The composition of other starches is also roughly the same. The starch raw materials generally contain about 80% of starch, and impurities other than starch are basically eliminated during the starch manufacturing process. The pure starch content after drying should be more than 99%. 3. Sodium hydroxide Sodium hydroxide (NaOH, also known as caustic soda) is an oxidant in biochemical reactions. It mainly plays a role of gelatinization in adhesives, and also has the function of infiltrating and softening cardboard fibers, and can improve the penetration of adhesives. Too much caustic soda will reduce the gelatinization temperature of the adhesive and increase the PH value of the adhesive; too little caustic soda will make the adhesive gelatinization temperature higher, the starch cannot be completely gelatinized, and the penetration force is poor , The moisture of corrugated cardboard is higher, and the physical index is lower. In the SteinHall gum making process, caustic soda is used to gelatinize the initial starch paste to enhance its viscosity. In a barrel-type glue making process, adding caustic soda when the starch expands can also increase the viscosity. 4. Borax The scientific name is disodium tetraborate decahydrate (Na2B4O7 * 10H2O), which mainly plays the role of crosslinking, complexing and thickening in the adhesive. Too much borax will make the cohesive force of the adhesive too strong. After coagulation, it will be rubbery and lose its adhesion, resulting in delamination of the cardboard. If the borax is too little or not used, it will not achieve the complexing and thickening effect. Increase the moisture of the cardboard. In addition, the effect of borax and cooked starch can change the viscosity of the adhesive, affect its fluidity and permeability, and use with caustic soda can also improve the initial adhesive strength and shear stability. The amount of borax is adjusted according to the corrugated paper and facial paper used in the production of corrugated board. The quality of the paper is poor, and the amount of borax is appropriately increased; the quality of the paper is good, especially the imported sizing paper. 5. Additives There are mainly two kinds of cross-linking agent (or bridging agent) and stabilizer (terminating agent). The use of additives can effectively improve the adhesion and moisture resistance of corrugated cardboard, and make the adhesive hard to be emulsified after curing, thereby improving the edge pressure strength, flat compression strength, and burst strength of corrugated cardboard. Under the premise, the basis weight can be appropriately reduced; the use of additives can effectively reduce the adhesive gelatinization temperature, increase the speed, and improve the flatness of corrugated cardboard; the use of additives can appropriately reduce the amount of starch under the premise of ensuring the bonding effect. In addition, there are preservatives and water resistance enhancers. Boiled starch paste and swollen starch molecules are prone to bacterial degradation. Preservatives help to avoid contamination and prevent paste from growing bacteria and causing viscosity to decrease. Traditionally, preservatives such as formaldehyde are often used, but in recent years they have been gradually replaced by some more environmentally friendly and safer products. Basket Supplies,Toy Packing Bucket,Stacked Storage Basket,Multifunctional Fruit Plate Taizhou Baiying Commdity Co., Ltd , https://www.baiyingplastics.com
June 04, 2021