What Factors Affect the Energy Consumption of Single Screw Extruders in Thermal Break Production?

As a thermal break strip manufacturer with R&D experience since 2006, we know that single screw extruders are irreplaceable in polyamide thermal break production—twin screw extruders only work for granulation, not strip forming. The energy consumption of single screw extruders directly impacts production costs, so optimizing these factors is critical for customers. Through our one stop service, which includes custom single screw extruders, high quality granules and technical guidance, we help customers reduce energy use while maintaining efficiency.

Screw Design: The Foundation of Energy Efficiency

Length to Diameter Ratio (L/D)

The length to diameter ratio of a single screw extruder’s screw determines how well it melts and mixes polyamide. A poorly matched L/D wastes energy: too short (e.g., L/D <20:1) means insufficient melting time, forcing the extruder to use more heat to fully melt granules; too long (e.g., L/D >28:1) increases friction between the screw and barrel, raising motor load. Our custom single screw extruders use an L/D ratio of 24:1—ideal for glass fiber reinforced polyamide (our main raw material). This ratio balances melting efficiency and friction, reducing energy consumption by 15% compared to extruders with L/D 20:1 or 30:1.

Screw Groove Depth and Flight Design

Groove depth affects how much material the screw can convey and how much energy is needed for melting. Shallow grooves (≤3mm) require higher motor power to push material, increasing energy use; deep grooves (>5mm) lead to uneven melting, as heat can’t reach the center of the material. We design our single screw extruders with variable groove depth: deeper grooves in the feeding section (to move granules quickly) and gradually shallower grooves in the melting section (to increase heat transfer efficiency). The screw flights also have a 15° lead angle—this optimizes material flow, reducing the force needed to push polyamide through the barrel and cutting motor energy use by 10%.

Material Properties: How Granules Impact Extruder Energy Use

Quality of Twin Screw Granulated Polyamide

Our polyamide granules are made with twin screw extruders, which disperse glass fibers evenly into the polymer to form a strong network structure. This uniform dispersion is key for single screw extruder energy efficiency. Granules with uneven fiber distribution (from low quality single screw granulation) create “hard spots” that the single screw extruder must work harder to melt—this can increase energy consumption by 20%. Our twin screw granulated granules have a consistent density (1.13-1.15 g/cm³) and fiber content (25-30%), so the single screw extruder melts them evenly without extra energy. As part of our one stop service, we supply these granules directly, ensuring compatibility with our single screw extruders.

Granule Moisture Content

Moisture in polyamide granules forces the single screw extruder to use more energy for drying and melting. Wet granules (moisture content >0.2%) create steam during extrusion, which disrupts melting and requires higher temperatures to remove. Our one stop service includes pre drying support: we recommend customers use our hot air dryers (paired with single screw extruders) to reduce granule moisture to ≤0.1%. This simple step cuts the single screw extruder’s heating energy use by 8%—and also prevents surface bubbles in thermal break strips, reducing scrap.

Operating Parameters: Fine Tuning for Lower Energy Use

Temperature Control

Single screw extruders use multi zone heating to melt polyamide, and overheating is a major energy waster. Setting temperatures too high (e.g., >260°C for PA66) doesn’t improve melting but increases energy consumption; too low () leads to incomplete melting, forcing the screw to work harder. Our single screw extruders have 4 zone temperature control (feeding, compression, melting, metering) with precision of ±1°C. We provide customers with optimized temperature curves: 230-235°C in the feeding zone, 240-245°C in the melting zone, and 235-240°C in the metering zone. This balance ensures full melting with minimal energy—reducing heating energy use by 12% compared to unregulated temperatures.

Screw Speed and Extrusion Pressure

Screw speed directly impacts the single screw extruder’s motor load. Running the screw too fast (e.g., >60 rpm) increases friction and pressure, raising energy use; too slow ( production output without saving energy. Our technical team helps customers find the “sweet spot”: 40-45 rpm for our single screw extruders. At this speed, the extruder produces 3-4 kg/h of thermal break strips (ideal for medium scale production) while keeping motor energy use at 5-6 kW/h. We also adjust extrusion pressure—our single screw extruders maintain a stable pressure of 18-20 MPa, avoiding pressure spikes that waste energy and damage the extruder.

Equipment Maintenance and One Stop Support

Regular Screw and Barrel Maintenance

Worn screws or barrels increase the single screw extruder’s energy consumption. A screw with worn flights (depth reduced by 1mm) requires 15% more motor power to convey material; a barrel with scratches (roughness >Ra 1.6μm) increases friction, raising heating energy use. As part of our one stop service, we provide maintenance plans: monthly inspections of screw flights, quarterly barrel polishing, and annual screw replacement (for high use extruders). We also supply replacement parts (screws, barrels) tailored to our single screw extruders, ensuring they fit perfectly and maintain energy efficiency.

Integrated System Optimization

Our one stop service doesn’t just focus on the single screw extruder alone—we optimize the entire production line. For example, we match the extruder with our precision rolling machines (used for strip flatness) to ensure the extruder doesn’t work harder to compensate for rolling machine resistance. We also integrate the extruder with our mold design (developed with our partner) —our molds have low flow resistance, so the single screw extruder doesn’t need extra pressure to push material through. This system wide optimization reduces the single screw extruder’s total energy consumption by 20% compared to customers who source equipment from multiple suppliers.

For thermal break strip manufacturers, reducing single screw extruder energy consumption is a mix of good design, quality materials and proper operation. Our 17 years of experience, custom single screw extruders, twin screw granulated polyamide and one stop service give customers all the tools they need to cut energy costs. We don’t just sell equipment—we partner with customers to build efficient, low energy production lines that boost profitability and sustainability.