• Model: Precious Plastic V1 Plastic Grinder
• Manufacturer: Precious Plastic
• Manual: Grinder Operations Guide

This machine allows you to shred plastic into small flakes.

The Tool Safety, Tool Care, Operation, section of this guide are what instructors use to ensure that you can use the equipment according to community expectations.

Plastics clearance or class equivalent is required before use.

⚠️ Always use the plunger to guide plastic into the blades—no hands!
⚠️ Power off the machine before clearing a jam. ⚠️ Always wear safety goggles while operating the grinder.

See the Safety Section for more information.

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

Always cut power the the Plastic Grinder when servicing or putting you hands inside of the hopper.

Always use the plunger when grinding plastic to prevent plastic from shooting out of the hopper.

Only grind known plastics and never grind parts thicker than 1/8“.

When using the Plastic Grinder, Hearing Protection, Closed-toed Shoes, and Safety Goggles are required. A face mask is recommended to prevent the inhalation of small plastic particles and irritants.

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.

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
• Use the plunger to block escaping plastic particles

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

1. Gather the sorted plastic you want to shred
2. Ensure all plastic is thoroughly clean
3. Separate by plastic number and color
4. Check that the mesh is clear

1. Plug in the machine and power on the grinder
2. Load the plastic just a few pieces at a time and guide them using the plunger
3. Occasionally, run the blades backwards to clear any clogged plastic
4. If running the machine with the mesh filter installed, be sure to clear the plastic from the filter if it starts to build-up inside the grinder. This build-up can heat-up and melt if left circulating in the grinder for too long.
5. Check the blades periodically

1. Power off and unplug the grinder
2. Use pressurized air to blast extra plastic out of the grinder blades. Use the provided wooden filter to prevent plastic from aerating
3. Remove the mesh filter (if using), clean, and replace
4. Sweep debris from surrounding area

If you encounter any of the issues listed in the Inspection area or have any other issues with the tool not working properly:

• Update the physical Maintenance Tag at the machine
  • 🟢Green can be used without issue
  • 🟡Yellow can be used withcaution
  • ⛔Red cannot be used without hazard to either the user or the equipment
• Record issues at protohaven.org/maintenance. This notifies our staff and volunteer maintenance crew of any issues.

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

We generally recommend first grinding your plastic with the mesh filter removed, then replacing the mesh filter for a second, finer, grind. The Pelletizer can also be used for this second step.

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.

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

If you are part of the maintenance group please log on to the #maintenance channel of our Discord server to:

• Perform a Maintenance Action
• Request a Maintenance Purchase
• Review complete Maintenance Logs for each machine
• Generally chit-chat about maintenance

The following should be in a Maintenance tool kit for the Grinder…

• item1
• item2

• Every XXX hours of use, replace the oil in the gear box with XXXX. Wear a respirator, gloves, and be sure to do this somewhere with good ventilation