Material Insights

How To Shred Plastics


Now that we have collected and separated our plastic waste, it is time to move on to the next step: Shredding the plastics… correctly. Now you may wonder “how should you shred plastics?” and “what steps need to considered?”.  To answer your questions, we have created a seven-step guide for you in which we explain it all!

In our previous blog post, we went over the different types of recyclable plastics that are out there and how you can recognize them. If you missed it, we recommend you checking that out before continuing on with this blog, as it is a very important step to divide your plastics first before shredding them. 



The Seven Step Guide To Shredding Plastics

There are several steps you need to take to be able to shred your plastic waste into consistent regrinds – which you can eventually extrude into filament. 

  1. Clean your plastic waste
    Once you have sorted out your plastic waste and have separated them by each material type. It is of utmost importance to fully clean your plastic waste by for example removing all the stickers, tags, dust, and liquids.  
  1. Store the plastic items
    Once you have cleaned your plastic items, you need to make sure that they remain clean by storing them. When stored correctly your plastics won’t get dusty and won’t get affected by any moisture. 
  1. Don’t mix plastics
    When shredding plastics it is not recommended to shred different materials in one session. Each material reacts differently to heat during the extrusion process, which will lead to inconsistencies in your filament. Some plastic might not even melt thoroughly, which could cause blockage in your extruder. Therefore, to avoid contamination, always shred each material separately. 
  1. Cut / break up the plastic items
    As some plastic items are big in size, it is recommended to first break them up in smaller pieces before feeding them into your shredder. Just like our material expert, Louis Rinaldo states in the video – “Always break larger plastics items into smaller parts before feeding the plastics into a shredder“. By breaking them up in smaller pieces, you avoid overloading your shredder which can cause malfunctions.
  1. Feed the hopper
    Now that you have broken up your plastic waste, you can feed them into the hopper of your shredder. Make sure to add your plastic waste in small batches so you don’t overload the hopper. 
  1. Check your regrinds 
    Once you have grinned up your plastic waste, it is important to go through it and see if there are still some larger parts. Therefore, we recommend to even re-shredding your regrinds so you can be sure that your shredded plastic batch is consistent throughout. 
  1. Store your regrinds 
    Just like we mentioned to store your plastic waste well in step 1, it is as important to store your regrind well too. Make sure that your regrinds are stored in a dust free container and that no liquid can get to it, or else you’ll have polluted regrinds.  

So now we have successfully shredded your plastic waste…what’s next? Time to extrude your regrinds into filament! Eager to learn how? Keep an eye out for next week’s blog and video in which our material expert, Timo van der Laak will show you how to extrude.  

If you are still left with some unanswered questions, feel free to contact us.

Until next week!