<p>Every time I try melting a scrap piece of plastic it ends up turning brown, smelling, and smoking before even melting down completely. My entire home ends up filled with cancerous fumes and there's no way I'm baking any food in my oven ever again. I've tried different types of Nylon, ASA, and PLA and all of them turned brown before properly melting. I placed the scraps inside a glass jar inside an oven and tried both slowly increasing the temperature, and placing it into the preheated oven.</p>
<p>Absolutely disgusting.</p>
<p><a href="https://i.stack.imgur.com/TaFHz.jpg" rel="nofollow noreferrer" title="Glass jar with burnt melted plastic"><img src="https://i.stack.imgur.com/TaFHz.jpg" alt="Glass jar with burnt melted plastic" title="Glass jar with burnt melted plastic" /></a></p>
<p><a href="https://i.stack.imgur.com/0QNUQ.jpg" rel="nofollow noreferrer" title="Baking pan with burnt melted plastic"><img src="https://i.stack.imgur.com/0QNUQ.jpg" alt="Baking pan with burnt melted plastic" title="Baking pan with burnt melted plastic" /></a></p>
<p>I would like to melt it into blocks or cylinders or planes and further process it with my lathe, my CNC mill, bandsaw... whatever, like this guy: <div class="youtube-embed"><div>
                <iframe width="640px" height="395px" src="https://www.youtube.com/embed/G-HWrDMr0ks?start=0"></iframe>
            </div></div></p>

[{'answer_id': 18637, 'author': 'user10489', 'author_id': 28397, 'author_profile': 'https://3dprinting.stackexchange.com/users/28397', 'pm_score': 2, 'selected': False, 'text': "<p>Plastic in general and 3d printer plastic specifically doesn't really melt so much as get softer in a range of temperatures (in a state refered to as &quot;plastic&quot; rather than liquid).  Below that range, it is a solid.  Above that range, it decomposes and ultimately burns.</p>\n<p>If you want to make a solid block, you need to not only heat it to a specific temperature (which varies by plastic formulation), but also press it into a new shape.</p>\n"}, {'answer_id': 18638, 'author': 'Criggie', 'author_id': 12956, 'author_profile': 'https://3dprinting.stackexchange.com/users/12956', 'pm_score': 1, 'selected': False, 'text': "<p>Your kitchen oven is for food.  I'd strongly recommend using a different heating device for this.  Your oven probably has oils in it that are contaminating the plastic, and the plastic will make your later cooked-food contaminated.  I suggest cleaning your oven before cooking food, too.</p>\n<p>Personally I've had good luck <strong>softening</strong> PLA with a hot air gun, essentially a workshop version of a hairdryer.  I've not tried forming it into shapes though.</p>\n<p>I've been putting all my offcuts, bad prints, brims etc into a 2L icecream tub, and when its full of spidery bits, a 20 second heat with hot air shrivels it all down to 1/4 of the volume.</p>\n<p>However I've not tried to make use of the resulting lump for anything.</p>\n"}, {'answer_id': 18641, 'author': 'Trish', 'author_id': 8884, 'author_profile': 'https://3dprinting.stackexchange.com/users/8884', 'pm_score': 2, 'selected': False, 'text': '<p>PLA starts to char at about 220\xa0°C. However, it also starts to soft at about 100\xa0°C and becomes sloopy (and printable!) at 180\xa0°C. Putting the oven to anything above 180\xa0°C will, with the heating cycle an oven undergoes, result in air that is above the temperature it degrades into burning plastic.</p>\n<p>keeping the temperature at or below 180\xa0°C should prevent charring - you will have to take time though, as the plastic will flow only slowly on its own.</p>\n'}]
['https://3dprinting.stackexchange.com/questions/18634', 'https://3dprinting.stackexchange.com', 'https://3dprinting.stackexchange.com/users/30842/']