Starch binder manufacturing method

Starch binder is a modified starch. It oxidizes the starch with an oxidizing agent to oxidize the methylol on the carbon at the 6-position of the original starch chain glucose unit to an aldehyde group and a carboxyl group, thereby improving the binding force between the starch and the paper, and at the same time improving the antiseptic and mold proofing capabilities. Very good, it is the adhesive of corrugated carton paste.

The main raw materials are corn starch, sodium hypochlorite or hydrogen peroxide, sodium hydroxide, nickel sulfate, borax, sodium thiosulfate, tributyl phosphate and water.

Equipment equipment oxidation reaction equipment set, stirrer, storage tank.

Production methods are sodium hypochlorite and hydrogen peroxide two.

Sodium hypochlorite method: First add 600 kg of water to the reaction kettle and add 56 kg of sodium hypochlorite (effective chlorine content 8%) under constant stirring. Continue stirring, after fully dissolved, add 200 kg of starch and mix well. The mixture was further mixed with 45 g of a previously prepared solution of nickel thiosulphonate at a concentration of 0.5%, and stirred for about 5 minutes so that the above materials were uniformly dispersed. Under stirring, 54 kg of 30% liquid caustic soda was formulated as a 10% lye to the above-mentioned reaction kettle to gelatinize the starch liquid. The thickening of the material began. Since the starch was oxidized, the degree of polymerization decreased and the material gradually thinned. About half an hour later, the viscosity can be measured as appropriate (tested with a No. 4 cup viscometer). When the viscosity is about 60 seconds, the degree of oxidation can be considered as acceptable. Then, 200 kg of water was added to the reaction boiler, and the mixture was stirred until the viscosity was 25 to 30 seconds. Prepare 8 kg of borax prepared as a 20% solution at 70°C, add it to the reaction kettle, add it while stirring, and measure its viscosity at 50 seconds. In the meantime, for long-term storage, 1.2 kg of sodium thiosulfate can be formulated as a 10% solution and added to the reaction kettle. An antifoaming agent tributyl phosphate may be suitably added to the reaction mass while stirring.

Hydrogen peroxide method: First, 400 kg of water, 9.3 kg of hydrogen peroxide (content 30%) were added to the reaction kettle, and the stirrer was turned on to fully stir it. Then add 200 kg of starch to make it evenly dispersed. Another 150 g of ferrous sulfate was added to prepare a 0.5% solution, which was added to the reaction kettle under stirring. After the addition was completed, stirring was continued for 5 minutes so that the above materials were uniformly mixed. Then take 54 kg of 30% liquid caustic soda and mix it into a 10% solution, then add it to the reaction kettle with stirring. When the reaction is carried out for about 1 hour, add a suitable amount of defoamer as appropriate, until most of the foam disappears. After adding 200 kilograms of water, the required oxidation degree can be achieved when the viscosity is 60 seconds. Next, add 200 kg of water to the reaction kettle and measure the initial viscosity of about 30 seconds. The 4 kg borax is mixed into a 20% solution with hot water of 70° C., and added to the above reaction material under stirring, and the final viscosity thereof is measured to be 50 seconds. Another 1.3 kg of sodium thiosulfate was added to prepare a 10% solution, which was added to the above reaction material under stirring to terminate the reaction. The terminator may also be added before the addition of borax as the case may be.

The above methods, such as the poor quality of the paperboard, can increase the final viscosity to about 80 seconds. If the quality of corn starch is poor, the amount of oxidizing agent can be appropriately increased.

Process flow

Sodium hypochlorite method:

Add 600 kg of water to the reaction pot (flour mix) → Add 56 kg of sodium chlorate (mix) → Add 200 kg of corn starch (mix evenly) → Add 0.5% nickel sulfate solution (stir) → Add 10% lye (stirring) → Add 200 kg of water → Add 20% borax solution (stirring) → 10% sodium thiosulfate (stirring) → Add appropriate amount of defoamer → Finished product.

Hydrogen peroxide method:

Add 400 kg of water + 9.3 kg of hydrogen peroxide (stirring) to the reaction kettle → Add 200 kg of starch (stirring) → Add 150 g of ferrous sulfate (0.5% solution) (stirring) → 10% caustic soda solution (stir) → Appropriate Add defoamer (stirring) → add 200 kg water (stirring) → add 20% borax solution (stir) → add 10% sodium thiosulfate (stirring) → finished product.

Source: 21st Century Fine Chemicals Network