PET Plastic Recycling Workflow

Basics

• PET (Plastic) undergoes hydrolysis when even slightly damp at it's melting point
• THUS it is best to store it at least moderately dry, and/or dry pre-use (in some process/machine integrated dryer)

To Do

• Specific data on water level vs degradation (a graph of water g/kg vs tensile strength or something?)
• Find Methods of in-machine drying (fluidized in hot air, like a hot air corn popper?)

Research Paper Trashcan

• Hydrolytic and thermal degradation of PET fibers and PET granule: The effects of crystallization, temperature, and humidity -seems spot on on what is needed, need to read
• Article on Drying PET
• Moisture Content vs Melt Flow Index

Workflow

Conventional Recycling

1. "Raw" plastic recycling in
2. Shredding
3. "Basic Drying" via being spread thin on a sheet, and left out (in a non-humid area with good airflow)
   1. Can be stored as is, and do only drying pre-use (ie integrated before the hopper etc)
4. IF NOT "Machine Dry" using some sort of device such as a hot air food dehydrator, etc
5. Storage in a sealed container with either an attached dehumidifier, or internal package of dessicant
6. (If stored dry, this is optional-ish) "Post Storage - Pre Use" Machine Dry
7. Use Flakes in any Precious Plastic Machine or the Open Source FDM Filament Maker

PET Pulltrusion

1. Bottle Sourcing
2. Bottle Washing (Although pre-rinsing recycling is HEAVILY encouraged)
3. Bottle Drying (Re 3D Printed Bottle Drying Stand / Open Source Bottle Drying Rack / Bottle Drying Rack )
4. Bottles are Sorted By Color/Brand (Minor Batch Variations+Colors such as Green Sprite Bottles etc)
5. Bottles are Peeled into Strips (Some can be diverted for weaving strips/making plastic rope (albeit compared to a solid brick etc, Plastic Textiles do generate more MNPs so short of when required, use of non-biodegradable plastic textiles isn’t advisable)
6. If not done so via the peeling machine, strips are fed onto Spools
7. Optional HEAVY Drying of Cut Strips akin to FDM 3D Printing Filament Drying
8. Bottle-Strips are Fed Through a PET Pulltrusion machine such as the Recreator3D or the PETamentor

Internal Links

• Filament Maker
• Precious Plastic
• PET (Plastic)

External Links

• The Wikipedia Page on PET Plastic
• A Section of the Page "PET Bottle Recycling" on the need for proper drying