I use vacuum forms for fitting lasts to feet. It’s made of clear PET-G plastic sheets around 0.5mm thick. The key properties are that it needs to be rigid enough to keep the shape of the last (shoe) and clear enough so I can see if there are gaps as well as pressure points.
I’m open to different plastics that have those same properties. PET-G is very clear, which is great, but if it were cloudy, that would be fine too. Some details on how this is used in the fitting process and a picture of the form can be seen here: https://www.exitshoes.com/exit/custom-shoes/
No shop I have seen that uses a lot of sheet material for vacuum forming has a way to reuse the cut-off from forming. The forms themselves are often temporary and used for only one iteration and could themselves be recycled. This is all put in the “recycling” bin which just goes right to the landfill. Then they buy more new sheet stock.
How can we develop a system to make new sheets from the waste?
Long term, can we replace this material with something else?
Hi Jeff ( @shoemaker ),
Very interesting topic. I’m also looking into Vacuum Forming using recycled plastic, but I’m still stuck at the finding a ‘vacuum machine’ stage before I can do some real testing.
The idea is to ‘iron’ flat (using an heat press) cut bottles for use in a vacuum former…
Any advise for where I can look for an affordable vacuum former? Or a DIY build that actually works?
Alternative would be to go for a cheap ‘dental’ machine for testing.
Next step would be to indeed form sheets from pellets/shreds, which the PP V4 is also working on, though not specifically for vacuum forming.
We would definitely want to avoid air bubbles in the feed stock and during the forming process as much as possible. I don’t know enough about plastics forming and extrusion to know how to avoid those issues though…
I suspect the $7k price tag for the hand crank mill is a case of very few competitors and relatively few customers, but those customers NEED the product, and they have the ability to pay a high amount… So, the seller can sell what the market can bear, and the market can bear $7k….
I wonder about the mixing of the shreds, air, etc? Perhaps a melting box with long slot?
After watching some videos of cutting board stock being made at factories, it looks like some kind of melting/extruder thing and two roll mill would do it. The two roll mill I found at OttoBock is a good one, but insanely expensive for what it is.
~$7,000 for the hand crank mill (89-W1) because it’s used in “medical” products, for example making orthotics and prosthetics. That mill is not even heated.
(new to the community, hope you don’t mind if I chime in with random thoughts)
How hard would it be to DIY a roller press with two heavy gauge aluminum or steel tubes (not pipes, tubes)? Perhaps put some heating elements inside the pipes and then feed in feeder plastic from the PP extruder similar to how you would squirt ketchup onto a hotdog bun.
It would have to be oriented so that the pressed plastic sheet would exit from the bottom, and it would have to go relatively slowly so that the plastic extruder could keep up as it sweeps from end to end feeding molten plastic in, but it seems like it could work to me….
Each time we create a custom thermoform plastic package deal for one of our clients, exceptional is constantly our maximum precedence. However, sustainability is certainly one of our pinnacle priorities. After all, we are placed in Portland, Oregon, that’s a middle of environmental innovation.You might have heard the terms “thermoset plastics” and “thermoplastics,” and whilst they sound comparable, they may be pretty extraordinary. At Indepak, we paintings with thermoform plastic or thermoplastic, all of which can be recycled. Used thermoform plastic and thermoplastic scraps can be reused again and again.Thermoset plastic is plastic that cannot be reused. While it’s miles heated and molded further to thermoform plastic, once it has cooled and set, it can’t be melted down again and recycled. In a few instances, humans have discovered ways to re-use thermoset plastics, however they aren’t commonplace by means of curbside recycling programs.However, the thermoform plastics we use to create packaging for our customers are all recyclable. If you are worried with recycling, there are many options that make it clean for you and your customers to recycle the thermoform plastic packaging that we create.There are basically seven different forms of thermoplastic, and every of these forms of plastic is targeted by using a resin identification code. These are those triangles with numbers inside of them that you locate on water bottles and different plastic gadgets. This quantity shows the form of thermoform plastics used to create a package deal, bottle or different plastic object.The thermoform plastics that are diagnosed with quite a number 1 or 2 are almost always widely wide-spread via network recycling programs, making it clean for customers to surely toss those gadgets into their recycling packing containers. The number 1 turned into given to polyethylene terephthalate, that’s used for water bottles, thermoform trays, meals jars and much more. This type of thermoform plastic is also every so often called PET or PETE.High-density polyethylene is the second most commonly recycled thermoform plastic and this is diagnosed with the aid of the variety 2. This also is used for objects inclusive of bottles and milk jugs, in addition to plastic buying bags and shipping containers, to name only some items. Most recycling packages also take delivery of excessive-density polyethylene or HDPE. Among the final five varieties of thermoform plastics, numbers four, 5 and six often can be recycled and increasingly more towns are increasing recycling programs to include additional plastics.Number 3 thermoform plastics are made from polyvinyl chloride or PVC, and even as it is able to be recycled, it regularly is not standard through recycling programs. However, it can be recycled and used to make gadgets consisting of park benches and floors so that you can be used for a very long time. In general, objects crafted from PVC may not be able to be recycled as effortlessly, however they frequently are meant to be used for decades and no longer honestly tossed right into a bin like a water bottle.No rely what sort of thermoform plastic you want to your custom packaging, we are committed to decreasing the amount of waste in standard. We are a low-waste operation and additionally provide many alternatives that consist of recycled content or perhaps Central Vacuums New Zealand. Contact us nowadays and we are able to find a custom packaging answer that is proper in your particular product.
Not on the topic of reusing the sheets, but some good links on building a Vacuum Former and some extra arguments why these should also be part of a Precious Plastics workshop: Alternatives to Metal Fabrication
Also becouse the next step could be blow molding:
Would be fun to be able to reshape existing bottles…
With some tinkering it should be possible to repace the rolls with sand/cement filled pipes in the simpler older models, which often also allow for allignment of the rolls.
Probably easier to build one from scratch though…
For now I however have some old style cold press laminators in the attic that might be suitable for the small scale (a4) testing.
If you can get the material to the right temperature, it strikes me that something like a manual pasta machine (though wider) should be able to roll out sheets of consistent thickness.
The vacuum forming sheets are pretty thin – 0.5mm.
A second hand ‘panini’ press has been added to my shopping list
I also found a heatlamp, even though it’s actually part of a grill plate. Should be enough to do A4 (vacuum) testing. Still looking for the pegboard, but I could always get it in the shop.
KOIN, a local Portland TV station did a story on me in 2013 which shows the basic vacuum form setup. In that video, I’m using an aluminum window screen frame and binder clips to hold the plastic sheet. There is a shopvac down below which you can’t see, but can hear howling in the background. Look for it at 01:59.
I made my own vacuum press using pegboard and a heat lamp. I put the plastic sheets in a picture frame secured with the clips used normally to hold in the foam core backer behind a picture. The frame’s opening slightly smaller than the cut plastic sheet (12″ x 16″) but because the plastic is flexible, it snaps in easily enough. The channel on the inside of the frame is slightly larger than 12″ x 16″
I’ve always wanted to make the heating and frame better, but it’s totally functional.
I’m currently traveling (in the Netherlands!) and won’t be back to my shop for another week, so I can’t make any pictures of my setup, but there are tons of plans on line for the basic box, pegboard, and vacuum rig. I use a decent Miele vacuum because it has strong suction. Some shop vacuums more more air more quickly, but don’t have a strong pull once the vacuum seal has been made.
