Reshape plastic containers

Question

A lot of fruit, vegetables and meat come packed in plastic container boxes - often itself wrapped in further plastic, also bottled water comes in plastic bottles.

I am wondering, is there a way to - sort of melt this plastic so it could be reshaped (e.g. in a mold or some other way of shaping objects) to make other things? Looking mainly for ability to bend, stick together, etc. then harden into the desired shape.

Bonus points if many pieces can be flattened into a single sheet and maintain a good portion of its transparency.

This is largely for environmental purposes, so I'd like a method that doesn't result in polluting plastic fumes being released into the atmosphere.

Answer 1

This definitely exist, It is called Precious Plastic, it is a project started by Dave Hakkens. It is a collection of Open-Source machines designed for recylcing and reusing thermoplastics.

There are phenomenal collections of videos for introduction into plastic recycling and machine building.

So far they already developed 4 DIY machines:

1. Shredder machine,

Plastic waste is shredded into flakes which will be used in the other machines to create new things. You can select the output size of these flakes by changing the sieve inside the machine to create different patterns and processes.

2. Extrusion Machine

Extrusion is a continuous process where plastic flakes are inserted into the hopper and extruded into a line of plastic. These lines can be used to make new raw materials such as 3d printing filament, make granulated plastic, spun around a mold, or used in your own new and creative ways.

3. Injection Machine

Plastic flakes are heated and injected into a mold. It’s a relatively quick process which is well suited for creating small objects repeatedly. You can make the molds completely yourself by using CNC mills or lathes, or by simply welding them.

4. Compression Machine

Plastic is heated inside the oven and slowly pressed into a mold with a carjack. Well suited for making large and more solid objects, the oven itself is also a great machine for prototyping and making plastic tests with.

If you wanna more information about the 4 machines of even want to build one, everything is explained in details with video here.

Answer 2

Here's a simple hack – it works only with individual pieces of PET bottles though, so it's not a generic solution for molding plastic wrapping material into custom shapes, but environmentally, it's a contribution. So here it goes:

The technique exploits the property of blow-molded PET bottles to act like super-strong shrink wrap when heated with hot air (or also by dipping into hot water). That's the reshaping part. One application is tat rings cut from PET bottles can be used as strong joiners for objects with grooves, as demonstrated in this video.