Maybe you experienced, maybe you didn’t but it is quite difficult to use PET to work with Dave’s machines… Also there are a lot of tutorials on the internet which shows some easy way to work with plastic bottles to get some strings or to use it as connectors… The purpose of this topic is to share these experiments and see if we can go further !
1 Plastic bottle string :
I found three kinds of DIY plastic bottle cutter :
This compagny is selling its own plastic bottle cutter, the video is interesting because it gives quickly examples about how you can use the string you do:
How to make a strong rope with several plastic bottle strings :
I did some tests using our new string for basketry. I think there is a real potential to get some lightweight and strong item ! (furniture for instance)
I did some frames in metal and tried different ways to weave around.
In a second time I used a heatgun to stretch the strings and get a surface smoother and stronger.
However I noticed 3 bad points:
– When I used the heatgun, the plastic shrinks and it twisted the metal frame !
if i do not use the heat gun, the result is to rough.
– On the pyramid picture, the faces were full but after the plastic shrank, i got some space at the bottom.
– the knots I did when I need to attach a new string ( to change the color for instance) are too fat, I burnt them with a lighter to get them smaller, but still they are.
@snowpoff I have no problem sharing, I followed this video to get the idea and I just made it bigger. https://www.youtube.com/watch?v=sRJLAac86hg I cut the bottles to make a thick string so it would not break with the footballs. Joining new string was easy as well when the string got too short, just include another string in the last knot you can make with the one that is getting too short and you can extend it as much as you want. Hope it helps. My students are thinking about making an instructable about it but it won’t be posted for a while, maybe a few weeks.
Instead of buying nets for the improvised football goals at our school, we ( Green Team, a ecological club) made them from bottles. 20 bottles for each net approx 2×2 meters. No shrinking needed for this application, just hours of tying knots. It is a great thing to have in the middle of the playground to help students see something our group has worked on.
Here’s a handheld bottle rope stripper that I built as a smaller part of a topic for my Design Academy Eindhoven portfolio about half a year ago. It cuts bottles into 8mm rope.
I found some other characteristics about the PET bottle shrinking:
– First : Do not stay to long at the same place with the heatgun, PET is melting quite fast and it is becoming opaque and bubbly quickly ! ( especially at the bottom which is thicker )
– If you thermoforme several bottles around the same shape, it won’t fuse, so then you can get sizes fitting one inside the other.
-It’s easy to fold PET, so it can be a way to get clean closures.
HEATING BOTTLES FOR NEW SHAPES USING HEAT GUN (I CALL IT “BALLOONING”)
here is an idea i have:
i made a collapsable/pocket shape made from a “reusable oven liner” made from PTFE coated non stick fabric which withstands temperature upto 260°C.
i used black duct tape to join the shapes together to make a new hollow bottle shape which is smaller than the bottle.
then i insert it into the larger bottle and keep it hanging using a long screw which goes through the bottle neck and neck of the shape i have created keeping it suspended inside the bottle.
after i have inserted it into the bottle i fill my hollow shape with sand (future tests will try using air like a balloon or other materials) then the shape inside the bottle is heavy, full and slightly heat proof.
then heat is added from outside and the plastic bottle should wrap around the shape. allow to cool down and pour all the sand back out and then pull the balloon/pocket (oven liner) out! i hope this makes sense any questions please ask!
this was a 5litre bottle made into something like a 2ltr bottle, this is a prototype but the concept is what i was trying to show
Once I saw on a tv show about agriculture here in Brazil
That a guy use pet bottles to make fence poles.
He use bamboo covered with cylinders of bottles and uses a heater to shrink the plastic.
great write up @tafnstuff. That plastic string has a surprising amount of pressure! Perhaps chloroform or acetone could also be used to bond and smooth PET forms.
Hi, i am also doing a lot of expiriments with PET. The biggest project is using those strings for building a bamboo bicycle. We built a very simple cutter and the last two weeks i spent in Uganda training locals to build an develope them further.
We were also working a lot with PET in the Injection mashine and it wasn’t even that bad. It did not turn out as well as other plastics but the first tests turned out better than we thouht.
