I wanted to have a go at making rope from plastic bags, a project I had seen online from a few sources, like MAKE magazine which I had a subscription to for some time (thanks Wombles) and Instructables, both excellent sites for finding crafts to engage in, especially to check out a range of ways to do similar things. There are certainly projects that would suit a range of needs, check them both out.
I started collecting plastic shopping bags when we went shopping, bags I would have ordinarily recycled either when we did our fortnightly recycling bin, or back to the supermarket to the dedicated bag-recycling point. I also had a friend bring a butt-load of them as well.The primary construction of a strand of bags rope is to cut the bag from the bottom of the handle loops, on both sides, down to the bottom sealed hem. this gives you a double loop of plastic fabric, that is very sturdy in the up-down axis.
It's possible to then loop one bag into another with the working bag looping through the exposed loop of the standing bag, and then through itself, and when the knot is sured up, a very solid join is made.
Repeating this process, with a fresh bag being looped into the end of the standing end, the chain is continued for as long as you want. I wanted to braid my strands, so I created three fifty-bag chains, and lined them up. This was a mistake.
I found that having the full lengths meant that when I was braiding the lengths were constantly getting tangled with each other.
My solution was to bundle up the three lengths into some of the heavier bags I had left over. These gave me a far more manageable bundle to braid with, but were still bulky.
A far better idea would have been to make short lengths of 6-7 bags long and added more as the braid progressed.
One trick is to ensure that the three chains are off-set such that the knots don't bunch up in the braid, and this gives the rope something that ALL "primitive" non-monofilament ropes benefit from. Weakness in individual strands are overcome by the braiding (or twisting in twisted ropes) and whilst there may be individual components of the cords that have damage, or weak points, the overall effect balance that out, and supports itself.
One thing I found during the braiding process, I encountered many of the sides of the cut edges hanging outside the braid, and these tags of plastic can be woven back into the rope fairly easily. Where I could, I knotted them and ensured they would not spring loose. I could have twisted the chains in order to capture the tags, but that would have increased the effort needed to make the rope considerably. All in all, once I had my three strands of chained bag-loops, the weaving process took around an hour, and was a reasonably simple process. Keeping a uniform braid is the key aspect for this, and those first few meters were the hardest to keep even, mostly because of the super-long chains I started with.
Making the chains was another time consuming but simple process, light work made quick by my Big Wet cyberpunk pals one evening as we watched John Wick (epic, awesome movie!) one evening. Ensuring the side-seam cut was correctly made, and didn't cut too far to either side, leading to failure of the loop, was one problem, and lead to some wastage. Generally, the plastic gags were remarkably robust, and the chains themselves were quite sturdy, especially if given a slight twist to gather them up.
Once braided, the resulting rope was really quite sturdy. I was able to loop it over a post and pull on both ends with all my strengths without any problem, and lean back with all my weight on it. I had hoped to get some better way to test it, but I'd say that for a static load, they are quite stable. I suspect they could be used for any number of lashing, binding or dragging tasks, but I wouldn't want to use them for any life-sustaining tasks unless there were no alternative.
So, from approximately 150 bags, I made a 10m length of braided, 3-strand chain rope, purely from salvaged shopping bags. None too shabby.
