Introduction: Very Strong Shopping Bag Rope - No Tools Needed

Picture of Very Strong Shopping Bag Rope - No Tools Needed

I started thinking about rope recently after Mr. Balleng posted his rope making instructable.   I also remembered this old instructable in which they made a rope from shopping bags using a giant twisting device made out of bicycle parts.  Then I thought, why do you need to twist it?  I think twisting makes sense if you are using a very fibrous material so the fibers can kind of grab together and get intermeshed.  But plastic shopping bags aren't really fibrous, so maybe you don't need to bother with the twisting.

So I came up with this way to make a very strong rope.  The cool thing about it is you don't need *any* tools to make it.


Step 1: Materials

Picture of Materials

plastic grocery bags - lots of them.  You can get a lot by asking on freecycle.org.  I posted a message asking for them and got enough plastic bags to make 150 feet of rope!

Figure on approximately 2 bags per foot of rope

optional: scissors




Step 2: Flatten the Bags

Picture of Flatten the Bags

Straighten out the bag and flatten it out as indicated in the photos.




Step 3: Tear Through the Middle

Picture of Tear Through the Middle
As promised, no tools needed.....

You can use your fingers and tear them vertically from bottom to top very easily as demonstrated in the video.





Step 4: Optional Tool: Scissors

Picture of Optional Tool: Scissors

okay, if you have some scissors around, you can just cut them en masse

Step 5: Make Strands

Picture of Make Strands
Chain each half section of bag together with the next as shown in the photos.

Tear a tiny hole in the side near the bottom seam.
Thread the handle of another section through the hole you just made.
Thread the body of the other section through it's own handle you just passed through.
Pull it tight.

Repeat until you have about 5 or 6 half bags connected together into a strand about 6 feet long.

Make at least 2 of these strands to get started. It helps if they are contrasting colors, but not especially necessary.







Step 6: Start Braiding

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Take the two starter strands and wrap them around something solid.   I'm using a c-clamp clamped to the edge of a table.  You can use your feet though, to hold it still while you braid.

Offset their knots so that while you are braiding, the knots are not lining up together all at once (which would resulting in a much nappier rope).





Step 7: Braid

Picture of Braid
Much like bubble wrap - this is a kind of pleasant activity you can do while watching a movie or something.

You have four strands.  
The pattern is
   Right two strands:
       Right over left
   Left two strands:
       Right over left
   Middle two strands
       Left over right
Repeat


Step 8: Splice in New Strands

Picture of Splice in New Strands
As you are braiding and you start to run out of length on a strand, you can just extend it the same way you made the strings in step 3.

Try to keep your strand length to a maximum of 6 half bags or so.  Otherwise they start getting tangled and you spend a lot of time untangling the free ends.



Step 9: How Strong Is It?

Picture of How Strong Is It?

It is very very strong.  However I have yet to devise a test that will strain it to the point of breaking it.  

Will a single strand of it support my weight?   I *think* so, but I'm still working on a test for that that isn't too scary.
If I braided two or three strands of it together into a big fat rope would that hold my weight.  I'm certain it would.  You could probably tow a car with it.  
Would I stake my life on its strength?   Um... no.  
Would I use to to go mountain climbing.  No way.
Would I use it to save myself if I had nothing else to work with?  Absolutely.  Yes.  it is really strong.

I'm thinking of making something out it...  Still playing around with some ideas.



Step 10: Some Cautionary Statements

Picture of Some Cautionary Statements

Many people have pointed out in the comments that grocery bags will degrade in sunlight over time.    

I did think about that and pondered possible solutions - however all my ideas were expensive and laborious.  E.g., what if you painted the rope with some kind of outdoor plastic paint.   Or, what if I wrapped the rope in some other material that was not quickly degraded.   

So, take that under advisement.  This rope shouldn't be left out exposed to sunlight.  It should be put away somewhere shady after use.

Maybe I will do some experiments and report back on just how long the rope lasts under various conditions.  My todo list is already pretty booked though.  but maybe I'll get to it.

Also, please use common sense.  This was just sort of an experiment.  There are no guarantees as to how strong this rope really is and whether it should be relied upon for any serious lifting or dangerous applications.    Like a chain, a rope is only as strong as it's weakest section.





Comments

SwordSlash300 (author)2013-12-19

That is awesome! Now i can use all my grocery bags and I want to try and test its strength! Awesome idea! :)

Basement_Craftsman (author)2013-12-18

I did this in a grocery store, when I was bored out of my mind. You sure brought it to a higher level. Nice 'ible

Captain443 (author)2013-12-12

WTG --- Get Job.... For your weight testing I might suggest taking a 3 ft piece of threaded rod bending it over to from an eye on one end and then get a nut, a washer, and a piece of some material (Block of wood) big enough to hold everyday weights on the threaded rod... Then hang the rope from whatever you want, attach the eye hook and build up the weight's until it breaks.... Just a thought ... Good Luck....

foobear (author)Captain4432013-12-13

Thank you for the positive feedback! And yes, I do need to get a job - heehee

Captain443 (author)foobear2013-12-14

LOL...I am sorry I dont know where the word "GET" came from...
It was supposed to be "Great"....
Like in WTG --- Great Job....

Again I thought it was a Job Well Done and I am sorry for the type-o

Good Luck I hope the weight testting works out for you....

bob3030 (author)2013-12-01

I've always liked recycle/reuse projects. Thanks for posting.

foobear (author)bob30302013-12-08

thank you for the positive feedback

gerflash (author)2013-12-01

Wow! Good idea! Now I know what to do with that 5 year collection of poly bags that I just couldn't throw out! And yes, got to watch out for excess exposure to sunlite.

foobear (author)gerflash2013-12-08

glad to help

kyluddy (author)2013-12-07

This is a great idea! You did a great job and it's a perfect idea! Its a great way to recycle and it's just plain awesome. Really good job.

foobear (author)kyluddy2013-12-08

Thank you. Your comment is 100% positive and I really appreciate that.

nuwisha made it! (author)2016-06-07

looped, braided and coiled

foobear (author)nuwisha2016-06-10

very cool!

murat.tamgili (author)2016-05-16

great idea recycle has no limits however thoughts on durability it s still really useful idea thanks for ible

KendraH10 (author)2016-03-20

This was pretty simple :)

joceyrichard (author)2016-03-15

the standard plastic bag can hold up to 17 pounds. So the robe is pretty strong! I am using my rope to make a hammock. I just made a swing out of it and it works just fine. But I made sure to put it in the shade.

foobear (author)joceyrichard2016-03-16

That's cool. I didn't know that about the 17 pounds strength. Please post a photo of your finished hammock when you finish it!

joceyrichard (author)2016-03-15

the standard plastic bag can hold up to 17 pounds. So the robe is pretty strong! I am using my rope to make a hammock. I just made a swing out of it and it works just fine. But I made sure to put it in the shade.

joceyrichard (author)2016-03-15

the standard plastic bag can hold up to 17 pounds. So the robe is pretty strong! I am using my rope to make a hammock. I just made a swing out of it and it works just fine. But I made sure to put it in the shade.

leon0862 (author)2015-09-05

Awesome work. Had a tiny bit trouble following the braiding steps (Mental/Visually) but I completely understand it. As for the whole "don't leave in the SUN" problem, out of most I have to say it would make great rope for water. Since Natural/Classic rope made of technically dead plants from their fiber, this is at least a cheaper and recyclable improv-ment.

leon0862 (author)leon08622015-09-05

As for test wise: Try it on other set of test first before you put your own self at risk.

Challenge not just a few but every condition you can. I.E.: Weather, Temp, Moisture, Reliability, Chemical Reactions (In case of some Chems. that can/will dissolve it), Stress, and Durability,(I know some of you will say aren't the two the same but I mean by strength on how well it can just be pull straight out, and How well it will handle Gimmicks like multiple pulleys and puling over corners.)

leon0862 (author)leon08622015-09-05

P.S. Safety First. ^ ^

"Smarter must be better than dead Donkey."

gserrano701 (author)2015-03-10

Great idea. I've done rope using stretched stripes of plastic, I opted for stretching because by doing it the molecule chains in the plastic straighten out and asume a parallel configuration along the axis of the strain. In my tests a strip of plastic increases in length between 5 and 7 times, depending on the type/quality of the plastic. The gain in stregth is enormous.

CharlesChristopher (author)2014-03-07

I like it.

Woodlandboy46 (author)2014-01-26

hello i Think is an amazing idea, i got exited and jumped the gun and didn't finish reading the instructable and started doing a three strand braid do you think it will be a problem

foobear (author)Woodlandboy462014-01-27

that's cool that you were excited! I'm sure a three strand braid will be very strong as well

devinnov28 (author)2014-01-26

i will try this now!

Light_Lab (author)2013-12-02

As many people have mentioned all plastics are degraded eventually by sunlight and/or oxygen. The degradation is usually limited by UV absorbers and antioxidants in plastics used outdoors. Plastic bags are expected to breakdown quickly in the environment so little or no protection is added. In fact we have in Australia some starch based bags that break down very quickly. Depending how you use the ropes and where you leave them tied in the environment it might not be a bad thing.
As this site has a global audience I should mention that the polymers used to make plastic bags varies considerably throughout the world and in different applications. HDPE, LLDPE, LDPE, starch etc etc each plastic has a different modulus (stretchiness). The plastic in the picture appears to be HDPE so it is quite rigid.
The reason the bags used tear easily in one direction indicates that the blow up ratio wasn't balanced when the bags were made. It is a manufacturing defect that might not be consistent with different bags.

foobear (author)Light_Lab2013-12-08

Thanks for this information I found that I was able to do the bag tearing trick with several different varieties of bags from different stores. So maybe it's a defect, but it is a common one.

Light_Lab (author)foobear2014-01-04

It is a common defect, even our older polymer banknotes here in Australia can develop linear splits in use. It is more difficult to perfectly balance the blow up ratio in rigid plastics. Ultimately the desire to maximize production wins out and the film ends up orientated in the machine (take off) direction. Therefore I would expect that the easiest way to tear is mostly from top to bottom (or bottom to top) but not across the bag.

Ezava2 (author)2013-12-27

melt rubber on it caution it will smell

spark master (author)2013-12-01

This very nice, but remember these bags do degrade in sunlight. can take years or months, don't depend on your life with one. A Hammock can fail and smack you head first on hard earth!

just a thought

foobear (author)spark master2013-12-08

sobering advice taken thanks

spark master (author)foobear2013-12-09

Your welcome! I just happen to notice the bags did that. Relatively fast depending on quality of plastic, type of plastic, color, biodegradability as per manufacturer.

They will degrade indoors as well, just much slower. The theory is in a land fill they break down, sad part is they really need sunlight to do it fast enough to be useful in a landfill.

HibbityDibbity (author)2013-12-01

To test if it will hold your weight, you can tie a loop in one end and tie a length to a rafter/tree branch/etc. so that the loop only hangs 6" or so off the ground, then stand in the loop. I suspect it would hold your weight with no problem, as the tensile strength of those bags is pretty impressive, though I agree that I certainly wouldn't use it in a situation where life and limb were at stake. I also would not use it outside for a long time, as UV light would degrade the material. could be really great for a lot of applications around the house though! Excellent re-use of materials, and very creative!

foobear (author)HibbityDibbity2013-12-08

this is a good suggestion thank you

HibbityDibbity (author)foobear2013-12-09

It is a hard-learned suggestion. A couple good buttock bruises will make a fellow devise some solid risk-management skills.

danceworkshop_3 (author)2013-11-30

This is cool

foobear (author)danceworkshop_32013-12-08

cool

kalpeshswani (author)2013-12-01

Hi Nice work !!
One Error , quote in your bio is by Mahatma Gandhi (not ghandi)
"Whatever you do will be insignificant, but it is very important that you do it." - Gandhi

foobear (author)kalpeshswani2013-12-08

thanks for noticing

Kevanf1 (author)2013-12-01

Try Freegle.org in the UK to get hold of loads of plastic bags. Freecycle is dead in the water over here but networks like Freegle and Freeworld-Recycling have filled the void and gone even better.

Excellent 'ible', well done. You could also use this rope as a bird scarer in a garden. Just snip some bit off the sides so that they flat around in the breeze and string it around your plants that you don't want the birds getting at...

foobear (author)Kevanf12013-12-08

good suggestions, thank you

Gadisha (author)2013-12-01

Cool idea, thanks for posting this! :)

foobear (author)Gadisha2013-12-08

yw thx

grapenut (author)2013-12-01

I always love a simple ible. The video clip was quick and effective. Had I been left to interpret the still photo I would have been lost...

foobear (author)grapenut2013-12-08

glad the video was clear!

assemblyrequired (author)2013-11-27

Very impressive... Does it stretch much? Also, for testing, you could tie some milk gallon jugs and slowly pour in water till it breaks. Just a thought for you!

foobear (author)assemblyrequired2013-11-27

It does stretch to a point, but once stretched it tends to stay stretched out. That's an interesting idea. I'm thinking a 5 gallon bucket, attach the rope the handle, hang it high from a tree, add water till it fills up, see how long it can stay there. Good suggestion, I think I will try it.

ctdahle (author)foobear2013-12-01

Neat idea. I started braiding a rope this morning and the kids took over.

Not sure about your testing scheme...5 gallons of water is only about 43 pounds. I think we'll just tie the "rope" to the cross bar on the swing set and use it to suspend a plywood disc about a foot from the ground. I'll sit on the disc and then the kids will pile on too and if it breaks, we will all fall in the sand and have a good laugh.

Be aware that plastic grocery bags photo-degrade pretty quickly, so if you use them to weave the rigging of your desert island escape raft, be sure to collect spare bags for repairs!

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