Yongte is professional manufacturer for wood plastic composite machine, for our WPC decking production line, we equip parallel twin screw extruder for our WPC granulation machine to make high quality WPC granules with high capacity. The core issue is that wood-plastic composites are difficult to blend, melt, and disperse. Only parallel twin-screw extrusion can achieve 'strong mixing + strong degassing + strong conveying'.

1. Superior mixing capability performance-The key lies in achieving thorough dispersion and uniform distribution of wood powder, plastics, and various additives

The formula of wood-plastic composite has the following characteristics:

· High in starch content, lightweight, and resistant to wetting

· High proportion of fillers (e.g., inorganic fillers such as calcium carbonate)

· Although the total amount of additives is small, extremely high dispersion uniformity must be achieved.

The advantages of twin-screw extruder are as follows:

· The threaded components can be flexibly combined according to process requirements.

· Equipped with high-strength shear blocks and specialized mixing elements

· can achieve complete dispersion and full encapsulation of wood powder, matrix resin, and additives

The final result is:

· The granules exhibit regular morphology and homogeneous composition.

· no white spots caused by undispersed wood powder or pitting due to filler agglomeration

· It is conducive to the smooth and beautiful surface of the extruded flooring

In contrast, the conical twin-screw was inferior to the helical twin-screw in mixing strength and dispersion performance.

2. Powerful conveying capacity, effectively preventing slippage and material discharge fluctuations

The high content of wood flour and plant fibers results in low bulk density of raw materials, making them prone to puffing and bridging phenomena.

The parallel twin-screw equipment adopts:

· Fully meshing forward conveying design

· Unfazed by lightweight materials and high-fiber content systems

· Ensure smooth feeding and production continuity

The conical twin-screw is limited by its structure:

· The rear screw groove is deep, while the front screw groove is gradually shallower.

· Slipping and unstable handling are prone to occur when the wood powder content is high.

3. Superior multi-stage exhaust performance — effectively removes moisture and volatiles, eliminating floor bubble defects

Wood flour exhibits strong hygroscopicity and readily releases water vapor and low-molecular-weight volatiles during processing.

Parallel twin screws can be configured:

· Multiple vacuum-exhausted sections

· capable of efficiently excreting water, metabolic byproducts, and other gases

If volatile components are not effectively removed during the granulation process, the final flooring product may develop bubbles, voids, or even cracks.

4. Precise and reliable temperature control, particularly suitable for processing high-density wood-plastic systems

Wood-plastic composites are sensitive to thermal history, and local overheating may cause charred wood powder.

Parallel twin-screw has:

· segmented cylinder temperature control

· The heat generation from shearing is controllable and uniformly distributed

· Specifically suitable for material mixtures with high filling ratios (wood powder content up to 50%–70%)

In summary, parallel co-rotating twin-screw extruders are essential for wood-plastic composite pelletizing. Their superior mixing and dispersion capabilities, stable conveying performance, efficient exhaust performance, and precise temperature control ensure uniform particle size, bubble-free products, and thermal degradation-free materials. This significantly enhances both the surface quality of flooring products and production stability.