A device for recycling and granulation of bio based biodegradable polymers (PBAT)

PBAT (Polyadipic Acid/Butylene Terephthalate) is a biodegradable aliphatic aromatic copolyester, polymerized from terephthalic acid (PTA), adipic acid (AA), and butanediol (BDO). It combines the flexibility and ductility of PBA (polybutylene adipate) with the heat resistance and mechanical strength of PBT (polybutylene terephthalate), and can be decomposed into carbon dioxide and water through microbial action under composting conditions. Mainly used in biodegradable products such as packaging films, agricultural films, disposable tableware, etc., it conforms to the trend of environmentally friendly substitution of traditional plastics. The production process adopts two stages of esterification reaction and condensation reaction, requiring catalysts (such as tetrabutyl titanate). It needs to be blended and modified with materials such as PLA to improve performance. Compliant with biodegradation standards such as EN13432 and GB/T 38082-2019.

This device is used for the recycling and granulation of biodegradable polymers (PBAT). Due to the hygroscopicity of the material, it adopts low-temperature plasticization extrusion and air-cooled granulation structure instead of traditional water cooling process, meeting the performance requirements of the material while saving floor space. It is easy to operate and suitable for the recycling and reuse of waste materials such as films, sheets, injection molding, compression molding, and foaming.

The advantage lies in:

1. The machine barrel is automatically controlled for low temperature in sections, and each section is equipped with an independent fan cooling control to ensure that materials do not decompose due to high temperatures inside the barrel.
2. The extruder adopts the principle of high torque and low speed. The screw is equipped with compression and shear sections to ensure uniform heating and plasticization of the material while reducing solute cracking and decomposition caused by prolonged residence time in the barrel.
3. The head mold adopts a circular hole ring structure to concentrate the melt pressure in the discharge section, forming a high-pressure fluid to improve fluidity and fusion. The surface of the mold mouth is vacuum quenched and tempered, which has wear resistance.
4. The cutting device is equipped with a circular blade holder, which is installed with three tungsten steel blades. It is driven by a motor to rotate in a circular manner and precisely fits the mold discharge port. It is also equipped with a buffer spring mechanism to ensure the fitting and operation of the blades with the mold mouth, while improving the durability of the blades,
5. The recycling device is equipped with a high-pressure fan, pipeline, and storage tank. After cooling and shaping the circular particle raw materials from the cutting device, they are sent through the pipeline and into the storage tank,
6. The storage tank is equipped with weighing control, weighing sensors, set weight values, and automatic discharge for easy statistical measurement.

The process flow of the equipment;

• Raw material pretreatment
  Filter dust removal
  Drying and dehumidification
  Mixing and stirring
• Melt extrusion
  Screw conveying of raw materials
  Heating plasticization
  Homogenization treatment
  Adjust temperature/speed parameters
• Mold head strip
  Constant pressure extrusion
  Strip shaped shaping
• Air-cooled cooling
  Forced air cooling system
  Synchronous temperature control
  Adjust the air supply volume/angle
• Cutting and granulation
  Rotating cutter cutting
  length control
• Screening and collection
  Vibration classification
  Finished product packaging