WPC Profile Extrusion Line

WPC profiles produced by these lines are widely used for:
Outdoor decking & flooring – anti-slip, weather-resistant, low maintenance.
Fencing & privacy screens – UV-resistant, impact-resistant, easy to install.
Railing systems – for balconies, gardens, and public walkways.
Cladding & wall panels – modern architectural facades with a wood-like appearance.
Landscape lumber & park benches – resistant to moisture, insects, and rot.
Real case: A Dutch garden material supplier uses our SJ72 line to produce hollow decking profiles (140×25 mm) with a stable output of 210 kg/h. The line runs 20 hours per day with a scrap rate below 2%, saving 30% in raw material costs compared to solid PVC profiles.

2.1 High Torque & High Filling Capacity
The SJZ series conical twin-screw extruders provide excellent mixing and plasticizing capability.
SJ65 (37 kW) – suitable for small to medium batch production, e.g., narrow decking boards or decorative trim.
SJ72 (45 kW) – optimal balance between power and energy efficiency for standard WPC profiles.
SJ80 (156 kW) – high torque margin for high-filling formulations (up to 60% wood fiber) and large cross-section profiles (e.g., 200 mm wide decking).

2.2 Wide Output Range
From 150 to 350 kg/h, you can select the appropriate model according to order volume. The SJ72 covers the most common range (160–250 kg/h), while the SJ80 meets high-volume production needs with lower energy consumption per kg of product.

2.3 Stable Profile Dimensions
The conical screw design minimizes temperature fluctuations and pressure pulsation – critical for WPC materials that tend to swell or warp. Typical dimensional tolerance: ±0.2 mm for a 40 mm thick decking board.

2.4 Energy-Efficient Drive
All models use AC frequency drives. According to actual field measurements, the SJ72 consumes only 0.22 kWh per kg of finished profile – 15% lower than many single-screw alternatives.

We implement a four-stage quality system to ensure consistent output from every WPC profile extrusion line.

Real case: A Canadian WPC decking manufacturer using the SJ80 line reported that after installing our online pressure monitoring system, the profile warpage rate dropped from 4.2% to 0.8% within one month.

The US customer reported that the SJ80 line paid for itself within 11 months, mainly due to lower material costs (using recycled HDPE + 58% wood flour) and reduced energy consumption.

Product Specifications

Q1: Can I produce both solid and hollow profiles on the same line?
A: Yes. The SJ65, SJ72, and SJ80 can all work with different molds and calibration tables. For hollow profiles (e.g., 4-cavity decking), we recommend the SJ72 or SJ80 because they provide higher melt pressure to fully fill thin ribs. Quick mold change takes about 45 minutes.

Q2: What typical wood-to-plastic ratios can these extruders handle?
A:
SJ65: up to 50% wood fiber (by weight)
SJ72: up to 55%
SJ80: up to 60% (thanks to the 156 kW motor and larger screw channels)
Higher wood flour content reduces material cost but requires better cooling. We equip high-filling formulations with a 12-meter vacuum calibration tank.

Q3: How do you control warpage of profiles after cooling?
A: Warpage is mainly caused by uneven cooling or internal stress. Our lines include:
6-zone vacuum calibration sleeve with independent water flow control
4-meter spray cooling tank with adjustable nozzles
Servo-driven caterpillar haul-off that maintains constant tension (tension range 0–5000 N)
For the SJ80, we also add an online laser straightness sensor that automatically adjusts haul-off speed when deviation exceeds 1.5 mm/m.

Q4: What is the average energy consumption per kg of finished product?
A: Based on customer reports (continuous 8-hour operation):
SJ65: approx. 0.24 kWh/kg
SJ72: approx. 0.22 kWh/kg
SJ80: approx. 0.20 kWh/kg (lower due to higher output, spreading fixed costs)
These values assume a typical WPC formulation: 55% wood flour, 40% HDPE, 5% additives.

Q5: Do you provide complete lines including mixing, feeding, and downstream equipment?
A: Yes. Each extrusion line includes:
Automatic batch mixer (500 L or 1000 L)
Volumetric or gravimetric feeder (±0.5% accuracy)
Extruder + die
Vacuum calibration table (6 m / 8 m / 12 m) 
Spray cooling tank (4 m / 6 m)
Haul-off unit (caterpillar type)
Flying cut-off saw with dust collection
Tilted discharge conveyor
For the SJ80, we also offer an optional fully automatic stacking robot for heavy decking profiles (up to 6 m long, 15 kg each).