KYmach designs twin-screw extrusion systems for biodegradable plastics, including PLA, PBAT, PBS, PPC, and PHA compounds. Our solutions deliver precise formulation, high-quality pellet production, and efficient processing for film bags, cutlery, and compostable products.
Overview of Biodegradable Plastics
Biodegradable plastics are designed to break down under natural conditions such as soil, composting, anaerobic digestion, or aqueous environments. Microorganisms break these materials down into CO₂, water, and biomass under suitable conditions.
Based on raw material sources, biodegradable plastics are classified into:
- Bio-based biodegradable plastics: PLA, PHA
- Petrochemical-based biodegradable plastics: PBAT, PBS, PPC, PGA
Applications：
Twin-screw extrusion is widely used to compound biodegradable plastics, enabling uniform dispersion of fillers, plasticizers, starch, and additives while maintaining product consistency and process efficiency.
Film Bag Compounds
Typical formulations include PBAT+PLA+starch and PBAT+calcium carbonate. Starch, liquid additives, and other components are fed via vacuum feeders into the batching system, pre-mixed, and then delivered to the twin-screw extruder through loss-in-weight feeders.
Cutlery & Disposable Tableware Compounds
Formulations include:
- PLA+PBAT+Talc
- PLA+Plant fibers+Kaolin
- PBS+PLA+Calcium carbonate
- PBS+Bamboo powder+Starch
- PBS+PLA+Crop residues
- Crop residue+PLA+Talc
- PLA+PBAT+PHA+Talc
These compounds are designed for biodegradable, compostable tableware with high mechanical performance and processability.
Twin-Screw Extrusion Process
Feeding & Batching
Raw materials are fed precisely using loss-in-weight feeders, enabling accurate ratios for each component.
Extrusion & Compounding
Materials undergo:
- Plastification and melting
- Intensive mixing and homogenization
- Vacuum venting for moisture and gas removal
- Pressurization and strand extrusion
Pelletizing & Post-Processing
Extruded strands are cooled on stainless steel air-cooling conveyors, then cut into pellets. Pellets are sieved, dried, homogenized, and packaged under vacuum for storage and shipping.
Equipment options
| Model | Main Motor | Screw Speed | Capacity |
| HK-73 | 160 kW | 40-400 rpm | ~300 kg/h |
| HK-73 MT | 200 kW | 40-400 rpm | ~400 kg/h |
| SK-73 | 250 kW | 40-400 rpm | ~450 kg/h |
Customer Case：
High-Tech Bioplastics Company
Annual PBAT-based compound production exceeds 10,000 tons. Equipment supplied: HK-73 and SK-73 twin-screw extruder lines.
Shandong Biotech Company
Supplied 8 HK-73 and 2 HK-73 MT twin-screw extruder production lines for large-scale biodegradable plastic manufacturing.
Why Choose KYmach for Biodegradable Plastics?
- Accurate, loss-in-weight feeding for consistent formulation
- Uniform compounding of bio-based and petrochemical-based polymers
- Efficient vacuum venting and strand extrusion for high-quality pellets
- Scalable solutions for films, cutlery, and other compostable applications
- Global support for multi-country operations
