Formulation and manufacturing technology of the ho

Formula and production technology of starch adhesive

the formula and production of starch adhesive is an extremely exquisite process. If the formula is wrong or the production process has problems, it will have a considerable adverse impact on the production of paperboard. Therefore, according to my own experience, I will make a brief introduction here

single sided corrugating machine and corrugated board production line can appropriately improve the raw material formula, material proportion and production process on the basis of the two-step production of finished starch adhesive currently used. The specific use, proportion and production methods of raw and auxiliary materials are as follows

raw materials and formulas:

first, starch (wheat starch, potato starch or potato starch)

when using starch adhesives in the production line, different starches are used, and the transparency, bonding strength, viscosity, gelatinization temperature, etc. of the adhesives are different. As long as we master the properties of all kinds of starch and the role of other chemical raw materials in making adhesives, and further adjust the formula reasonably, we can make ideal adhesives. Under the same conditions, in order to improve the speed, wheat starch and cassava starch with low gelatinization temperature can be selected; In order to improve the adhesive strength, cassava starch and potato starch with strong adhesive force can be selected

the amount of starch can be appropriately changed according to the specific requirements of the bonding object, such as:

① the production of single-sided corrugated board has low requirements for adhesives, and the amount of starch is 150 ~ 170kg/ton glue

② in the production of three-layer corrugated board, single-sided corrugated board is compounded with face paper, and the requirements for adhesive are slightly higher. The amount of starch is 170 ~ 200kg/ton glue

③ in the production of five layer and seven layer corrugated board, corrugated board is compounded with facial paper. The requirements for adhesives are relatively high, and the amount of starch is 200 ~ 300kg/ton

II. Special desiccant for automatic line (hereinafter referred to as raw desiccant)

Special desiccant for automatic line is polymerized by a variety of salts and organic compounds. In the production process of adhesive, as long as the dosage is appropriate, it not only accelerates the speed of adhesive film, shortens the carton drying time, but also improves the drying speed, hardness and bonding strength of paperboard by about 30%, and increases the thickness by 0.1 ~ 1mm; Using 3 ~ 5kg of glue per ton can reduce the amount of starch by about 20% or reduce the gram weight of corrugated paper by 10 ~ 20g/m2. All performance indexes are better than the national export standard. Later, it was found that the construction of this project was very difficult. The dosage of drying agent in the adhesive was less than 2kg per ton, which could not play its due role, while the dosage of glue per ton was more than 8kg, which was easy to produce the phenomenon of cardboard embrittlement. Therefore, the dosage ratio should be strictly controlled, and the normal dosage standard is 3 ~ 6kg/ton of glue

III. gelatinizer

industrial caustic soda (NaOH, the content of this technical requirement is more than 96%), the amount of caustic soda is added to the starch solution, and the viscosity of the adhesive is adjusted after the carrier body is mixed and stirred evenly. Under the same conditions, the greater the amount of caustic soda, the higher the viscosity, and the adhesive does not produce precipitation and stratification during storage; The smaller the amount of caustic soda, the lower the viscosity. The dosage of caustic soda should be observed and adjusted according to the viscosity requirements

IV. crosslinking agent

the addition of borax or boric acid to the adhesive can make the short chain starch form a complex with its hydroxyl or hydroxyl and boron atoms. Through these irregular crosslinks, it forms a like structure, which has the function of crosslinking and viscosity increasing, vigorously developing the environmental protection industry, which is conducive to improving the initial adhesion and accelerating the drying speed, and also plays the role of corrosion prevention and seepage prevention. The amount of borax is adjusted according to the corrugated paper and facial paper used in the production of corrugated board. The paper quality is poor, and the amount of borax should be appropriately increased; The paper is good, especially the imported sizing paper, which can be used without or appropriately reduce the amount of borax

v. water resistance enhancer

water resistance enhancer is an additive used in the production of water-resistant paper products such as coated paper, white paperboard, double offset paper, carton board, etc. it is added to the paper pulp or carton starch adhesive to improve the dry and wet strength, water resistance, and prevent the lint and powder of the paper and carton; Use 5 ~ 10kg of glue per ton, and keep the paperboard in normal temperature water for 12 ~ 72 hours without glue opening and corrugated deformation; Directly add the water-resistant reinforcing agent to the size or raw starch glue, and stir it for 20 minutes. When it is better than the original performance index, it can reduce the amount of starch and the gram weight of corrugated paper. (since this product is easy to use without changing the original production process and formula, the detailed formula is not listed here.)

formula and production process: (unit: kg)

process flow 1:

carrier (water + starch 1. Dietmar Leeb + caustic soda) + main body (water + starch + desiccant for automatic line raw rubber + borax)

1. Add the raw materials to the agitator in sequence and react for 10 ~ 20 minutes

2. Add the raw materials from the lower kettle into the lower stirring kettle in sequence and stir for 10 ~ 20 minutes

3. Slowly add the upper kettle colloid to the lower kettle and stir for 20 ~ 40 minutes

process flow II:

according to the special circumstances of some enterprises, one mixer can be used for production without main body and carrier production equipment. According to the formula in the above table, the carrier is processed in the reactor first, and then the water in the main body is divided into two parts; First, take out water with the same weight as starch and mix it with starch, desiccant and borax for standby. Add the remaining water into the reactor and stir it evenly. Then add the standby mixture into the reactor and stir it for 30 minutes

precautions:

1. After adding the special desiccant for raw rubber in the automatic line, the viscosity will be appropriately reduced. During the production process, pay attention to adjusting the amount of caustic soda, and rely on caustic soda to control the viscosity. If the glue is too thin, increase the amount of caustic soda, and if it is too thick, reduce the amount of caustic soda

2. The viscosity of single-sided machine and three-layer line shall be controlled within 20 ~ 50 seconds

3. The linear viscosity of five and seven layers shall be controlled within 50 ~ 90 seconds. In special cases, the viscosity of adhesive shall be adjusted according to requirements

4. If the corrugated board produced by the three-layer and five layer automatic lines has degumming and 1 ~ 2cm on both sides of the board is not firmly bonded, please check ① whether the amount of glue is too small; ② Whether the viscosity of the adhesive is too low

5. All production enterprises can also add special desiccant for automatic line raw rubber according to the raw rubber process of the original production line. After the primary rubber is made, the special desiccant for raw rubber is directly added to the finished rubber, and it can be used after stirring for 20 minutes. The special desiccant for raw rubber is acidic. After mixing with the primary rubber, the viscosity of the rubber will be appropriately reduced. In the application, the amount of caustic soda in the process formula of primary glue should be appropriately increased, and about 0.5kg caustic soda should be used for each ton of raw starch glue. (text/chenbaoyuan)