How to Adjust Expansion and Puffing in Twin screw fish feed making machines？

 

Screw speed: One of the core adjustment parameters. The screw speed of a twin-screw pet feed extruder directly determines the shear strength and residence time of the raw material in the extrusion chamber, significantly affecting the degree of puffing. With other parameters remaining constant, increasing the screw speed (250-400 r/min) generates stronger shear forces through the meshing of the two screws, intensifying friction between the raw material and the screws and extrusion chamber, leading to a rapid temperature increase. Simultaneously, increasing the speed shortens the residence time of the raw material in the extrusion chamber (from 30 seconds to 15 seconds). If the speed increase is moderate, combined with the addition of an appropriate amount of steam, the puffing effect can be enhanced, increasing the degree of puffing. However, if the speed is too high and the residence time too short, the starch in the raw material will not gelatinize sufficiently, resulting in a decrease in the degree of puffing. Adjustment Techniques: When producing high-expansion, buoyant feed (such as bass feed), adjust the screw speed to 350-400 rpm to enhance shear heat generation and expansion force; when producing low-expansion, sinking feed (such as grass carp feed), adjust the speed to 250-300 rpm to reduce shear strength and ensure compact pellets.

 

Steam Addition Amount and Temperature: The Core Guarantee for Precise Temperature Control. The amount of steam added to the twin screw pet pellet making machine directly determines the temperature and moisture content of the raw material within the extrusion chamber, and is a key auxiliary parameter for adjusting the degree of expansion: Increasing the steam addition (0.5%-3%) will raise the temperature within the extrusion chamber (from 120℃ to 160℃) and the moisture content of the raw material (from 12% to 15%), accelerating starch gelatinization, enhancing the expansion capacity of the raw material, and thus increasing the degree of expansion; decreasing the steam addition will lower the temperature and moisture content, resulting in insufficient starch gelatinization and a decrease in the degree of expansion. Adjustment Techniques: Coordinate steam addition with screw speed adjustment. At high speeds, increase steam addition appropriately to compensate for insufficient gelatinization due to short residence time; at low speeds, reduce steam addition to prevent excessive raw material moisture from causing loose particles. Simultaneously, precisely control the temperature of each section of the extrusion chamber (feeding section 60-80℃, compression section 100-120℃, expansion section 120-160℃) using a segmented temperature control device to ensure temperature stability and provide a foundation for precise adjustment of the degree of expansion.

 

Raw Material Moisture and Die Orifice Diameter: Auxiliary Adjustment Parameters. Raw material moisture has a direct and significant impact on the degree of expansion. The optimal expansion effect is achieved when the raw material moisture content is controlled at 12%-14%. Excessive moisture (above 15%) reduces the pressure within the extrusion chamber, leading to insufficient expansion; insufficient moisture (below 11%) causes excessively rapid frictional heating of the raw material, easily resulting in over-expansion or excessively hard particles. Adjustment Techniques: Before production, adjust the initial moisture content of the raw material to the optimal range through drying or humidification, and precisely control the final moisture content in conjunction with the amount of steam added. The orifice diameter of the die affects the degree of expansion by changing the pressure relief rate: the smaller the orifice diameter, the faster the pressure relief rate when the raw material is discharged, the stronger the expansion force, and the higher the degree of expansion; the larger the orifice diameter, the slower the pressure relief rate, and the lower the degree of expansion. Adjustment techniques: When producing small pellet feed (1-2mm for fish fry), use a small-diameter die, combined with high speed and appropriate amount of steam to achieve high expansion; when producing large pellet feed (3-5mm for adult fish), use a large-diameter die, combined with low speed and less steam to reduce the degree of expansion in the Twin-Screw fish feed extruder machine.

 

 

 

 

MIKIM's fish feed pellet production lines and supporting machinery offer excellent value for money. Not only are they affordable, eliminating middlemen markups and allowing small and medium-sized enterprises (SMEs) and fish farmers to purchase complete sets of equipment at reasonable costs, but they also boast exceptional efficiency. The fully automated process, from raw material crushing and precise ingredient mixing to extrusion pelleting and maturation, is completed in one continuous flow. This results in high starch gelatinization rates and uniform pellet formation, significantly improving production efficiency and feed quality, truly achieving "low cost, high output." Choosing a MIKIM fish feed pellet production line means enjoying comprehensive pre-sales and after-sales service, including 24-hour online customer support, a one-year warranty on the entire machine, professional on-site installation, commissioning, and maintenance, and a stable supply of spare parts. Customers can buy with confidence and use with peace of mind, with both excellent value and service quality!!!

 

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1. What is the price of the Twin screw pet food extruder?

The price ranges from approximately $1,500-$55,000

2. Do you provide maintenance services for your customers?
Yes, we offer comprehensive after-sales maintenance services to our customers.

 

If you would like to learn more about MIKIM machinery, please contact us. We offer one-stop service and welcome your inquiries!!!

 

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