Industrial food extrusion and forming machine

01

Set the moisture, screw speed and temperature window

Kantrong and co-authors (Journal of Food Science and Technology, 2018) made rice snacks with 15% oyster mushroom powder on a twin-screw extruder, varying feed moisture from 12 to 18% (wet basis), screw speed from 275 to 425 rpm and barrel temperature from 130 to 150 °C. Bulk density changed significantly with all three, higher barrel temperature raised the expansion ratio, and hardness rose with more moisture and lower screw speed. [1]

Using response surface methodology, they chose 13.5% feed moisture, 425 rpm and a maximum barrel temperature of 130 °C as giving good snack quality at low energy. [1] Editorial note: these settings are for one rice-based formulation on one machine; use them as an example of the window an extruder supplier should demonstrate with your own recipe.

Give the supplier the products and formulations, target throughput, moisture range, temperature profile, desired expansion, density and texture, die shapes and cut lengths, downstream drying or frying, cleaning and food-contact requirements, and utilities.

02

Measure specific mechanical energy and residence time

The same study measured specific mechanical energy (SME) from the extruder's current and voltage with and without load, divided by the feed rate, and found that feed moisture had the largest influence on SME: between 12 and 15% moisture SME fell as moisture fell, while between 15 and 18% it fell as moisture rose. It reports SME values of about 260–350 kJ/kg. [1]

A 2024 review in Frontiers in Sustainable Food Systems on extruded instant flours describes SME and mean residence time as essential process parameters, alongside pressure and torque, and reviews how temperature, screw speed and moisture affect properties such as water absorption and solubility, pasting, colour and bulk density. [2]

Editorial calculation: at 300 kJ/kg and a feed rate of 100 kg/h, the net mechanical power going into the product is 300 × 100 / 3600 ≈ 8.3 kW; ask suppliers to quote motor power with margin above the SME your products need at full throughput.

03

Size the extruder from a maker's model range

ANDRITZ's brochure Advanced extrusion technology for pet food production lists its extruder range by screw diameter, main motor and capacity, and describes its co-rotating twin-screw extruders as suited to recipes with high inclusion of meat slurries or fresh meat, with complete discharge and no residue in the barrel for rapid recipe changeover. [3]

The brochure's feature table lists belt drive on the three smaller single-screw models and gear drive on the others, pinned screws on the single-screw models and splined screws on the twin-screw models, screw push-out and high-moisture meat slurry handling only on the twin-screw models, and water cooling or heating jackets and liquid injection points on all. It describes adjusting pressure at the die plate to raise or lower SME without changing screws, and a microfeed system for pellets down to 2 mm. [3]

Editorial calculation: installed motor power per tonne of rated capacity is 500 / 12 ≈ 42 to 500 / 8 ≈ 63 kW per t/h for the EXTS616 and 315 / 11 ≈ 29 to 315 / 4 ≈ 79 kW per t/h for the EX1021; this is an upper bound, not the specific mechanical energy actually used. [3] [1]

For direct-expanded snacks and breakfast cereals rather than pet food, Baker Perkins gives the nominal throughput of its SBX Master 125 twin-screw extruder as 2,300 kg/h of direct expanded products, against a previous maximum of 1,500 kg/h in its range. It attributes the gain to a motor and gearbox combination with twice the torque capacity of its previous generation, which it says also lets the extruder handle denser materials, and to a high free-volume agitator geometry that sustains output on low-density materials such as bran and fine milled flours. The barrel is modular so its length can be matched to the process and extended later; screws run on splined shafts; the drive is AC; and control is by PLC touch screen with automatic start and stop sequences. Baker Perkins names corn curls, chipsticks, maize rings, whole-grain and multigrain snacks and filled pillows among the products of its Snack Master lines. [4] Editorial calculation: 2,300 ÷ 1,500 ≈ 1.53, about 53% more nominal output; at the 260–350 kJ/kg SME measured for one rice-based snack, 2,300 kg/h would take about 166–224 kW of net mechanical power (SME × rate ÷ 3,600), so check motor rating against your own recipe's SME. [4] [1]

Give the product (kibble, aquafeed, snacks), meat or slurry inclusion, target output and pellet size, and ask for the model, motor power, screw type and the SME range the drive can deliver.

04

Twin-screw snack extruders, puffed-snack lines and pet food extruders on the listed pages

Listings include twin-screw food and snack extruders, puffed-snack production lines and pet food extruders.

05

Feeder, screws, heated barrel, die, cutter and drive on a cooking extruder

The feeder, screw and barrel-zone rows correspond to the three variables Kantrong and co-authors varied (feed moisture, screw speed, barrel temperature); the cutter row has no published value in these sources. [1]

06

Throughput, screw speed, barrel temperature, motor power and die pressure for a food extruder

Published values here come from the rice-snack study (275–425 rpm, 130–150 °C), ANDRITZ's pet food range and Baker Perkins' 2,300 kg/h snack extruder; screw diameter, L/D, heating zones and machine weight are left for the supplier to quote. [1] [3] [4]

07

Send the recipe, product and line data together

Paste it into your enquiry below or into an email to a maker, then replace every bracket.

Products: [snacks; cereals; pellets; pet food]
Recipe: [ingredients; moisture range]
Targets: [expansion; density; texture]
Process: [throughput; temperature; screw speed]
Forming: [die shapes; cut length]
Line: [preconditioning; drying or frying; coating]

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