I. Introduction of Pregelatinized Modified Starch Adhesive 

Pre gelatinized starch, as one important type of the modified starch, is made from natural starch through a pre gelatinization process to obtain various adhesive properties. As a ready-to-use adhesive, it saves time and cost, without being dissolved in hot water first as normal starch does. And it avoids the disadvantages of non degradability of the chemical adhesives. Screw extrusion process is an important method to produce pregelatinized starch. Its processing is easy, efficient and continuous, with low energy consumption and equipment investment. Its extrusion machinery provide the best solution to meet the market demand for large quantities of pregelatinized starch.

Pregelatinized starches with different characteristics, normally about viscosity, α-convert, whiteness, pH value and gel strength, can be produced according to the settings on raw materials moisture, temperature, extrusion time, shear force, and crushing precision, etc. They are food grade, construction material grade, fragrance grade, briquet grade, petroleum grade, feed grade, medical grade and other pregelatinized starches.

II. Parameters

III. Features

• Finished Food Quality Ensured: Optimal extrusion solution, premium equipment design, and equipment processing ensure high-level and stable production.
• High Output: High designed capacity; minimal material loss;
• Less Energy: High mechanical coordination, low wear; optimized heating, thermal transfer& insulation details, low heat loss
• Low Production Cost: Flow production, precise control of each process
• Simple and Low Cost Maintenance: Modular structure, easy operation. Lifetime after-sales service
• Safe Material: High-quality food-safe materials for all food contact part
• Failure Rate:  Nearly zero failure as long as preventive maintenance

IV. The General Flow Chart for Pregelatinized Starch Adhesive Production

• Step 1: Mixing
• Step 2: Extrusion
• Step 3: Drying
• Step 4: Crushing
• Step 5: Measuring and packing

Modified starch machine working process:

Natural starch flours (one of a combination of two or more starches such as corn/rice/wheat/cassava, etc.) are mixed evenly with a certain amount of water, and the water content is usually 15-20%. The material is gelatinized to required degree in the starch extruder under the correct temperature, pressure and shear force. The mixture is then extruded through an extrusion die. Extrusion dies are typically small holes of 1-10 mm. Due to the pressure and temperature difference between the inside and outside of the screw, the water in the extrudate evaporates rapidly, and the material expands rapidly. Then, the puffed granules are dried to optimize the moisture content in the starch dryer machine. Then, the drived puffed starch granules are processed into powder with the required precision by a pulverizer/or superfine pulverizer. After all above, we get the final pregelatinized starch adhesive.

V. Components of 200-250kg/h Pregelatinized Modified Starch Adhesive Making Machine

1. High Speed Mixer
2. Twin-screw starch extruder
3. Drying machine
4. Ultrafine crusher
5. Automatic packing system
6. Controlling system (PLC/or instrument control options)
7. Complete conveyors

VI. More

Economy

• During the whole extrusion process, only a small amount of water is added, and the temperature of 120-160 ℃ can be maintained by using internal frictional heat.
• The extrusion process is simple and standardized, requires less time and less personnel, and is very suitable for continuous production.

Flexibility

• The extrusion process of the modified starch machine is suitable for a variety of native starches as raw materials, including grain starches like corn starch, rice starch, wheat starch, and root starches like tapioca starch.
• The modified starch production line can produce pregelatinized starch of different particle sizes, including 60-70 mesh, 80-90 mesh, 120 mesh and above.

Processing Potentiality

• Pre configure the starch extruder barrel with heating and cooling zones, the modified starch production line can produce starch-based buffer material and biodegradable granules by only replacing the appropriate extrusion die in the future.