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Air quality concerns during heating

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This topic contains 15 replies, has 12 voices, and was last updated by  Stan 2 months ago.

Emma emmsclaire

Air quality concerns during heating

28/01/2018 at 06:40

Hi! I wanted to start a topic to discuss air quality concerns from heating plastic. Obviously most people have been just using the machines in an open area and hoping for the best. However, I know that we as a community should gather all the information we can about gaseous byproducts from the injecting, compression, extrusion process. If there are any experts on here (@marcelozp ?) please chime in! I’ll be doing my research and will report back with any literature I can find.

Other air quality posts:


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09/02/2018 at 21:19

Yes, please, I’m very interested in this as well!

20/02/2018 at 11:29

Depending on the types of plastics used, and given that the plastic is cleaned properly, it should be relatively safe, for instance if you look at the chemical formula for HDPE, there is not any harmful chemicals like Chlorine (found in PVC) or Flourine.
That said there is the chance of byproducts of the manufacturing process, but in general HDPE,PS and PP are fairly harmless

02/05/2018 at 17:23

Hi, sorry, I just came here today.

In fact lots of polymers are relatively safe (and I guess you will process not too much material) if you have a window near it will be ok.

My only concern is about PVC, in fact, I do not recommend anyone without expertise to try to process PVC at home. Focus on the others types of polymer!

14/12/2018 at 03:34

I’m back and working on an industrial hygiene manual and an open source ventilation system for the entire precious plastic community to use. I’ve got a Slack and a Google Drive if you want to participate in the project!

Topics I’m going to cover:
What gases, vapors, fumes, particulates precious plastic workshops produce
Health effects of those
Industrial Hygiene pyramid: 1) engineered controls 2) workplace controls 3) PPE
Design for a ventilation system
Model of ventilation system working
Test of ventilation system
Proven design and plans including where to buy parts online and cost
PPE protections: respirator use and safety, safety glasses, etc etc

Message me on here if you want to participate.

14/12/2018 at 05:49

@emmsclaire. Some real technical data would be great for this topic. Most polymer companies act like the big cigarette companies and don’t want to admit to the lethality of polymers. In the meantime, just go get one of these dust extraction systems, some more fittings from your local hardware store for venting your clothes dryer and vent the fumes out of your workshop thru the roof or propped door.  Central Machinery® 31810 13 Gallon Industrial Portable Dust Collector13 gal. 1 HP Heavy Duty High Flow Dust Collector  https://www.harborfreight.com/13-gallon-industrial-portable-dust-collector-31810.html

14/12/2018 at 20:10

hey there !

I am also interested in this topic.

where can i find the fumes that are being released when heating PMMA sheet ? (it also have the LDPE coating on it ?
what temperature is considered to be heating and not burning it?

I was thinking around 150 Celsius

does anyone have some helpful information about it ? I searched quite a lot and didn’t get what i was searching for

Many thanks,

16/12/2018 at 05:11

@sheffieldcompany That’s exactly what I’m going to be doing. I’ve started:

1) Identifying and acquiring current scientific literature on the thermal degradation of: PP, PET, LDPE, HDPE, PS. I will not study PVC because we already know it is not recyclable by our equipment (DON’T EVER RECYCLE PVC EVERYONE – it produces hydrochloric acid that will kill you) Reference for PVC producing HCl ->> http://ec.europa.eu/environment/waste/studies/pvc/mech_recylce.pdf on pg 71.
2) Once I know what gases are likely to be produced during the recycling of PP, PET, LDPE, HDPE, & PS I will make a list of them all
3) I will conduct a study using gas detection tubes to see what gases from the list in step 2 are present, using my extruder, in a closed environment.
4) I can use that information to then design an effective ventilation system for precious plastic machines specifically. If anyone is interested, Local Exhaust Ventilation is the method I’ll likely use because that is typical in the plastics industry. Here is a video about Local Exhaust Ventilation ->> https://youtu.be/Ky8y2jDk6i8
5) I’ll build it and test it using gas detection tubes and smoke tubes (test if air is leaking from the ventilation system that shouldn’t be)
6) Make any tweaks and share the plans for everyone to build and use

Anyone who knows polymer engineers, people who have dealt with ventilation or anything like this send them my way! I’ve got a background in hazardous materials and environmental sampling.

16/12/2018 at 05:14

Also a dust collector definitely won’t do the trick – dust isn’t the concern. Oxygenated hydrocarbons, aromatic hydrocarbons, aliphatic hydrocarbons, CO, and CO2 are primarily what is released when polymers like polypropylene are broken down, in addition to any contaminants that are incinerated.

17/12/2018 at 09:51

Only the person that made the plastic knows for sure whats was in that batch of plastic.Items not meant to ever be eaten get mixed into our food supply daily, sometimes, even on accident.Anyone that tells you drinking water from a plastic cup is safe means to say, it is safe depending on what the plastic was made from.And whats in the water….Never remold kitchenware from recycled plastic.. It’s just not worth the risk. In many parts of the world people burn trash, melting plastic can’t be as bad as that, so just use caution.

And likewise, only God knows what has been poured in the plastic bottle after it was empty but before you decided to melt it, Its kinda pointless to try to figure out what a bucket full of of shredded plastic pieces once contained… Just wear gloves and hold your breath and run away if the fumes seem toxic….Run Forrest Run

17/12/2018 at 12:32

I am working on the V4 sheet press design and I’m melting 10kg of plastic at a time with chances of burning and while using release agents and polluted plastics. Currently, we don’t know how toxic everything is but I play it safe and bought a Gas mask with an ABEK1P2 filter, it filters a broad range of gases and both dry and wet particles.
I think you can never know exactly what you are inhaling since the plastics are unknown and polluted and contained chemicals when used as containers.
Better safe than sorry.
But I think the smaller machines can be granted some lea way since they don’t burn the plastics and process way less.

for the sheet-press we now built a tent around it from which we suck the air out and pump it through a filter.

21/12/2018 at 00:43

I have this complete article in PDF if anyone wants it. It is just talking about PET but it could be interesting for someone.
It is from my teachers at the university. They also told me that for the temperatures and the plastics we usually use it could be enough with an active carbon filter. Because we are not producing real fumes, just another type of particles. Which ones that are really difficult to identify because depend a lot of the additives (difficult to know which ones have each plastic). Also the amount of this particles is very low.

27/12/2018 at 12:22

Hey @emmsclaire. The first time I discovered Precious Plastic, I immediately feel triggered to run health and safety assessment to each machine for better improvement. I think i really want to know if i can help anything regarding IH assessment/ measurement in order to put the best reccomendation for the machine. (The LEV!)

I’m an occupational health and safety student, i might as well want to discuss further research with my prof regarding HSE analysis for the PP machines. Currently i’m approaching my local community to see if there’s actual accident finding (both health and safety aspects). I also have summarized people’s confusions about safety in this forum (i’ll share them later)–> my initial data to make sure I must do this.
There’s so much to learn and discover but i’m so excited.


05/03/2019 at 11:11

Hi everyone,
I am searching a place for Precious Plastic machines. I am in discussion with a great place but they are not equiped with a ventilation system at all. They have visitors, and I would like to get visitors too. So I should be totally safe and should be able to prove it. Do you have idea of material I could add/buy to complete the machine? I will begin with the extrusion one as only warming machine.
Thanks in advance for your help.
Kind regards,

06/03/2019 at 21:31

@annel Unfortunately, the PP V-4 activities have not reported on any project looking at the safety and fumes issue. In the meantime, I would consider building an enclosure/fume collector around the extrusion machine and use fans/flexible ducting to get it to a nearby window. An insert in the window should make for a visually acceptable setup. If you make it with a couple of well placed access doors you should be able to fill the hopper and attach molds with the fume extraction functioning.
If there is a laser cutting/engraving shop nearby that cuts plastic, go see what they set up. It is a similar problem.
Good luck, please post what your solution ends up being

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