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Plastic Grinder

Precious Plastic V1 Plastic Grinder

Tool Guide

The Setup, Operation, and Cleanup Checklists of this guide are what instructors use to ensure that you can use the equipment according to community expectations.

The shredder is the backbone of Precious Plastic, it allows you to shred plastic into small flakes.

Usage Highlights

Precious Plastic Machines Clearance  or Class Equivalent  Required Before Use

==== SAFETY ==== ==== CARE ==== ==== CLEANUP ====
1. Wear appropriate clothing and PPE 1. Wash plastic thoroughly before grinding 1. Power off the machine

2. Always use the plunger to guide plastic into the blades—no hands!2. Always separate plastic based on type 2. Clear debris from both the interior and the mesh
3. Power off the machine before clearing a jam 3. Submit a maintenance request when needed.3. Sweep debris from surrounding area

Personal Protective Equipment

When using the Plastic Grinder, Hearing Protection, Closed-toed Shoes, and Safety Goggles are also required.

Long sleeves must be rolled up and long hair and scarves must be tied back. Avoid any dangling drawstrings or other articles of clothing that may come in contact with the motor and blades.

Tool Anatomy


  1. Power Switch - The lever turns the machine on and off. It can move the blades forward or in reverse to help clear build up.
  2. Hopper - Funnels new material into the blades to be shredded
  3. Plunger - Used to gently and safely guide material into blades
  4. Blades - Grind the material
  5. Receptacle - Removable bin that captures the freshly shredded material
  6. Maintenance Tag - Manually tracks the usability status with Green/Yellow/Red cards

Tool Safety


The most common hazard is flying debris that causes injury to the eye

  • Always ensure safety goggles are on before use
  • Be aware of others in your space at all times

The most significant hazard is getting caught in the rotation of the motor or blades and being drawn into the grinder.

  • Always use the Plunger as a guide while the grinder is operating—never hands!
  • Power off the machine before clearing out a jam
  • Ensure clothes are well-fitted, long sleeves are rolled up to the elbows
  • Verify hair, scarves, drawstrings or hanging articles are tied back and secure

Initial Setup


- Gather the sorted plastic you want to shred
- Ensure all plastic is thoroughly clean
- Separate by plastic number and color
- Check that the mesh is clear

Basic Operation


- Plug in the machine and power on the grinder
- Load the plastic and wait
- Check the blades periodically, gently guiding with the plunger



- Power off and unplug the grinder
- Vacuum the interior and mesh to avoid cross contamination
- Sweep debris from surrounding area
- Note any maintenance needs or concerns on the tag and at


  1. Update the physical Maintenance Tag at the machine
  • Green can be used without issue
  • Yellow can be used with caution
  • Red cannot be used without hazard to either the user or the equipment

Record issues at This notifies our staff and volunteer maintenance crew of any issues



==== Common Issues ==== ==== Possible Causes ==== ==== Resolutions ====
The motor makes a gnarly sound when powering onThe ignition switch is not fully engaged Power off immediately, then restart while making sure that the switch is fully engaged
The blades are not grabbing the plastic Sometimes weight or shape lends itself to needing a helping guide. Use the push tool to move the plastic towards the blade. Never attempt to do this with your hands.
The blades may be operating in reverse Flip the ignition switch in the opposite direction.
Machine stops mid shred There is likely too much plastic. The resistance exceeds the maximum torque of the motor, causing it to stall outPower off and unplug the machine, then remove some of the clogged plastic.

Special Setups

When using plastics other than #5 (Polypropylene), please be extra careful to properly clean up and avoid cross contamination.

We’ve set up our machines to focus on diverting Plastic #5 (Polypropylene) from the landfill, which doesn’t currently have an easy municipal solution! Of course, you are welcome to bring in different Plastic materials to use on our machines.

Additional Resources

The reason we love the global Precious Plastic community is because they provide a wealth of open source community resources! Here are some resources you may find helpful:

Safety and plastic fumes

Oshcut: An Online Metal Laser Cutting Service

Going nerdy on plastic

Good design with recycled plastic

tools/imported/plastic_grinder_tool_guide.txt · Last modified: 2023/03/13 20:08 by jeffbearer