Biodegradable

Stainless, electropolished sets for PLA, PHA and bio-resin runs.

Biodegradable — Rootier BY CONDITION component

Product data

NameScrew Barrel Solution for Bio-degradable Plastic Processing
Typical ApplicationPLA, PBAT, PBS, Starch-based blends
Process MethodInjection, Extrusion
Material Recommendation38CrMoAlA
Surface TreatmentMirror Polish, Chrome Plating, PVD
HardnessHV 900 - 1000
L/D Ratio18:1 to 22:1
Max Temperature≤ 220°C (428°F)

Technical Challenges

  • Biodegradable resins are thermally sensitive and degrade quickly under shear and residence time, causing discoloration and loss of mechanical properties.
  • Starch-based blends are abrasive and hygroscopic, wearing screw flights and requiring thorough drying.
  • Narrow processing window makes temperature control and melt homogeneity critical to avoid brittleness.
  • Residual moisture drives hydrolysis, reducing molecular weight and part strength.

Rootier's Technical Solutions

  • 01Stainless, electropolished screws and barrels that resist corrosion and prevent resin adhesion.
  • 02Low-compression, low-shear screw geometry engineered to keep residence time short and temperature uniform.
  • 03Mirror-polished melt channels and chrome plating for clean processing and easy colour changeover.
  • 04Nitrided 38CrMoAlA components with controlled surface hardness for bio-resin service life.
  • 05Optimized L/D ratio (18:1–22:1) balancing plasticising uniformity with gentle shear.

Frequently Asked Questions

  • PLA, PHA, PBAT, starch-based blends, PCL — each with unique thermal and rheological properties.

  • Packaging films/bags, disposable cutlery, agricultural mulch films, medical sutures/implants, eco-friendly consumer packaging.

  • Precise temperature control (narrow processing window), moderate shear design, L/D 20:1–24:1 for gentle processing.

  • Low thermal stability — depolymerizes above recommended temps; excessive shear causes localized heating, reducing molecular weight, mechanical properties, causing discoloration & brittleness.

  • Larger feed zones, lower compression ratios, optimized metering zone flight depth, efficient barrel cooling, and temperature profiles minimizing melt-zone residence time.