Special Extrusion Die Technology for Biodegradable PLA Nonwoven Solves Melt Breaking & Uneven Fabric Defects

Against the global carbon neutrality trend, PLA biodegradable nonwoven fabric has seen surging demand for disposable packaging, hygiene and medical materials. Yet PLA’s special melt rheological properties bring persistent production challenges: frequent melt breakage during spinning, severe fabric thickness unevenness, low finished product yield and high waste rates. Our independently developed customized extrusion die for PLA nonwoven lines completely addresses these two core technical bottlenecks, verified by multiple bio-based fabric production projects across Europe and Southeast Asia.

Traditional universal dies are designed for PP raw materials, failing to match PLA’s narrow stable processing temperature window and high melt viscosity sensitivity. Minor pressure fluctuation inside flow channels directly triggers filament breakage during high-speed spinning. Our PLA-specific die adopts optimized coat-hanger flow channel simulation design via fluid finite element analysis, balancing melt pressure and temperature distribution evenly across the full width of the die lip, eliminating local material accumulation and dead zones that cause broken filaments. Equipped with four-way hydraulic automatic backfill structure, the die realizes non-stop screen replacement without halting the whole line, cutting filament breakage downtime by over 80%.

Uneven fabric thickness, another major defect of PLA production, originates from inconsistent melt output along the die width. The new die integrates micro-adjustable flexible die lip screws with high-precision CNC integrated machining, controlling thickness tolerance within ±3% across the whole fabric width, far better than the ±8% error of standard dies. High-temperature corrosion-resistant alloy steel extends die service life by 40% under long-term PLA melt contact, reducing frequent polishing and maintenance cycles.

The die matches full-range PLA spunbond, meltblown and composite production lines, supporting fully biodegradable nonwoven bags, disposable wipes and medical protective base materials. It drastically lifts finished product yield above 97% and cuts raw material waste by over 22% for biodegradable manufacturers.