Plastic Bottle Blowing
July 10th, 2006
We’ve been experimenting with using glassblowing techniques on plastic bottles – without much success so far. Our intent is to invent a means of creating a “New World Bottle” (see previous post on Heineken’s World Bottle) from reused plastic water bottles, which are very abundant here in Lima, due to unsafe tap water, and which are not recycled here. These bottles, if remolded into blocks, and filled with sand, could be a DIY alternative to clay bricks, which cost between 10 and 40 cents each – for a total house price (10’ x 10’ x 8’ high) of $100-$400 for bricks alone. Granted, the margins we’re working in may not make it cheaper to use bottles, but we’d like to give it a try.
The benefit of this is that given the availability of plastic bottles, cheap labor, and sand (many of the slums around Lima are built on sand), people may be able to create the building materials for their own homes.
The problem so far is twofold: heating the bottles evenly is hard to achieve, even while spinning the bottles over a flame, as glassblowers do – and PET plastic shrinks when exposed to heat, so it’s very difficult to “inflate” the heated bottles once they’re soft. So far all we’ve made are the above “miniaturized” bottles. Next we’re going to try sealing the bottles before heating them, so they’ll remain the same volume. We are also trying to maintain better heating, so we may move to some kind of insulated box instead of just the kitchen burner. Maybe a basic brick oven? But costs then begin to rise.
I wonder what a house made of reformed, sand-filled plastic bottles would look like?
Related Posts: Lima Slums, Heineken Beer Bottle Bricks
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July 10th, 2006 at 10:20 am
I’m not sure I understand why you are using glassblowing techniques… from the picture of the worldbottle, my inclination would be to find something warm and try to press the sides to make them flat – 2 warm bricks? Maybe fill them part way with sand first too – warm sand?
The problem I can see with sealing them first is that they will expand when they are heated, and you may get the same kind of warping.
Final thought – what are the environmental effects of heating plastic – what is it off-gassing?
July 10th, 2006 at 12:27 pm
These bottles start as a tube of plastic that has the same diameter as the opening. They get the cap screw and lip first. Then they’re heated and placed into a mold and air is injected to push them out against the sides of the mold, giving them that shape. Perhaps you should use a similiar method to reshape them. You’d need to heat the bottle up before placing it inside the mold and use compressed air to force it into the brick shape.
July 10th, 2006 at 12:32 pm
Maybe instead of blowing the bottle you could try vucuforming the bottles? A perforated mold with a hand cranked vacuum pump (or bicycle or water powered) should do the trick. If the mold is heated perhaps the bottles would heat more evenly. Just a thought…
July 10th, 2006 at 1:02 pm
That was my inclination as well – the problem is that the temperature must be extremely even, while still very high. To use hot plates to flatten would require very even surface contact, which is impossible given the shape of the bottle.
Secondly, if we left the bottle sealed, the flattened sides would mean the lost volume would have to go somewhere, and might explode the bottle. We exploded one by putting water vapor in it (a “well that was predictable” moment). If we left the bottle open, the contracting sides would distort the bottle’s shape.
We’re going to be doing much more testing on this idea, and we’ll be sure to give the 2-brick method (we’ll name it the Devon method) a try. If you’re inclined to do some testing yourself, we’d be glad to publish your results!
As to the off-gassing, we’re aware of potential hazards, but are transitioning to outdoor experimentation and using respirators. The International Labour Association says: “The substance decomposes on heating producing toxic fumes and irritating fumes, causing fire and explosion hazard.” Which of course concerns us. Also, the Department of Energy says that “HDPE is partially crystalline. This raises the softening point so high that in the presence of air (oxygen)
it burns before it melts.” This may explain some of our difficulties, but we aren’t looking for complete liquid state, just a softening.
We promise to practice better safety as we proceed, and thanks for the suggestions!
July 10th, 2006 at 1:07 pm
Yes, we had thought of vacuum forming, but as aaron points out, they were originally created with pressure, not vacuum, which is easier to generate in any case. Apparently breath is not enough pressure to counteract the shrinking tendency (and in retrospect the possible fumes involved are too dangerous to continue with that method).
Our disinclination to use compressed air was based on our desire to have a system which could be implemented by people building their own houses, in slums. In many places outside Lima, where we are working, there is no electricity, and the most readily available form of heat/energy is fire. But perhaps this is something which could only be done on an industrial scale, with proper safety precautions, and the advantages of economy of scale.
Keep brainstorming, folks, this is great!
July 10th, 2006 at 1:40 pm
Ah, I was wrong. This bottle is PET or PETE, #1. A guide to plastic numbers (from CharityGuide.org, of all places):
1. PETE, polyethylene terephthalate: Soft drink, water, and juice bottles
2. HDPE, high density polyethylene: Milk jugs, trash bags, detergent bottles, some produce bags
3. Vinyl: Cooking oil bottles, meat packaging
4. LDPE, low density polyethylene: Grocery bags, bread bags, some produce bags
5. PP, polypropylene: Yogurt, sour cream, and margarine containers
6. Polystyrene: Hot beverage cups, some disposable plates, egg cartons, meat trays
7. Other
I’m thinking about simply approaching water bottling companies in Peru and seeing if they would be interested in producing a brick-bottle. The potential for fumes or other toxins seem too high for comfort in a non-controlled setting.
July 10th, 2006 at 3:48 pm
Why not just use the bottles as they are (filled with sand of course)? Perhaps use wooden posts at each side to stop the piles of bottles tumbling down? If you just stack the bottles in a pyramid shape you will find it is very stable – the problem is stacking them in a square…
July 10th, 2006 at 6:25 pm
What about using filled bottles neck side in to create circular buildings? Use 3 pieces of wood to frame a door and top with plywood or a tarp.
Maybe the chinks in the soda bottles could be filled with dirt cheap bulk epoxy; keeps the rain out and the bottles more securely together.
July 10th, 2006 at 8:59 pm
Submerging the bottle in hot water should provide rapid and uniform heat transmission. It may be possible to create a bladder in the desired shape of the brick which would be inserted into the bottle while deflated. A pump driven by a valve and lever could be designed to reliably inflate the bladder after years of use. In areas where fuel is an issue it should be possible to use solar energy to heat the water, leaving manpower as the only variable that would need to be renewed. The tank could also have a chimney to help move any escaped gas away from the operators.
All in all i think your idea is very interesting, I am curious to see what comes of it.
July 10th, 2006 at 9:20 pm
July 10th, 2006 at 9:32 pm
The hot water technique is one we tried early on – unfortunately the water did not reach a temperature high enough to soften the plastic significantly. The bottle shrank, but the plastic did not become malleable. I was thinking perhaps of a “water bottle toaster” which would use either a brick oven or electric heating elements to heat the bottle evenly from all sides. A brick oven is nice because the heat is high and quite even.
July 10th, 2006 at 10:29 pm
You may run into an issue with the oven concentrating any escapted gasses. Steam should be able to transfer sufficient heat & pressure to expand a bottle inside of a mold. It may even be possible to exploit the pre-existing threaded opening. With the bottle inside of a mold it should only be necessary to attach a fitting betwene the bottle and a sealed water resivour, the water resivour could be heated with an open flame untill sufficient heat and pressure is generated. With this method it should be possible to make multiple bricks at once. Unfortunately steam can be dangerous to work with so precautions would be needed to protect the operator.
July 11th, 2006 at 6:58 am
I was thinking about the problem of creating pressure, and I thought that if you had the bottle sealed with a cap with a pressure release valve you could use the pressure building up in the bottle when you heat it to expand it into a mold.
Another possibility is putting the bottle with a small amount of water inside in a microwave and cap it with a cap that has a pin hole in it to release excess pressure. The steam would provide pressure and heat, so if the bottle were inside a mold it might expand to the mold shape.
One more idea. A pump blows heated air into the bottle, which has a cap with a valve that allows the air to leak out of the bottle after it has circulated inside. When the bottle is well heated, the valve is closed and the the compressed heated air expands the bottle into the mold.
July 11th, 2006 at 8:21 am
Stack them with the long axis facing out as you would a cord of wood. You could possibly cap the bottles, heat them and force the necks back into the main cavity, or leave the necks out in alternating directions to help anchor a covering layer of mud, plaster, etc. Thicker walls, yes, but isn’t that a benefit for insulation purposes? I’m assuming, of course, that you had plans to cover the walls.
July 12th, 2006 at 12:15 am
There are plastic water bottles on the market that are approxiamately square already. Maybe you just need to show people the benefit of another source. For example, I have a 1 gallon Crystal Geyser bottle in front of me (no, I have no connection to CG). It’s slightly accordianated (to coin a term) with rounded corners, but is basically square. Other brands may be better.
The biggest problem is that the top of the bottle tapers to form the spout. One idea would be to simply cut that part off, fill it with sand, and put the cut-out bottom from another bottle over the top. You could probably get a seal, if needed, by just heating the plastic and melting it together along the seam. If that doesn’t work, just seal it with some mud, preferably rich in clay. Probably also use some mud to fill the little gaps and make a smooth surface. Does this sound like it might work? It sure seems to me a lot easier than trying to remold the bottles. Nice to have would be the ability to run verticle rods through them and into the ground or build a frame or some other technique to give more structural stability. Hate to have these things toppling on people in an earthquake.
July 12th, 2006 at 1:45 am
Another thought. I don’t know quite what’s available in the Lima shanty towns, but taking some quesses on what might not be too hard to get, here’s a thought.
Take a simple tube, such as the cardboard tube from a roll of TP or paper towels. To make a shorter tube, cut it down. To make a longer tube, unwind one and roll it a little smaller, so it fits inside the other one, and cover with tape or somethinng to seal. After you cut open the bottle, but before (or during) the filling with sand, put the tube in place, so that it runs from side to side of the bottle, preferably adhering it to the side with tape or, at a stretch, mud or clay. Fill the sand around it. When the sand brick is filled, you cut holes through the side, e.g. with an exacto khife, where the ends of the tube are. You now have a tube that you can puts poles or sticks through for greater stability. Another thought would be to run cords or ropes through the tubes of horizontally, vertically, and/or diagonally adjacent bricks and tie them together applying some tension. This might be the way to get more structural strength to the thing. A variation would be verticle tubes, for example, using paper towel rolls, with verticle poles run through them. Hopes this is a useful idea to you.
July 12th, 2006 at 1:55 am
I’m just thinking aloud here. I guess toilet paper rolls are not strong enough for the weight of the sand, although the vertical rolls might still work. If no stronger tubes are available (something like bamboo, perhaps?), it may be necessary to treat or reinforce the tubes. For the verticle tubes, I’d suggest something almost big enough to fill the hole, and pointed to stick into the ground a bit, preferable down to hard dirt, not sand. It may be a circular or polygonal shape will be more stable than square, and, if it falls, will be more inclined to fall out than in.
July 12th, 2006 at 6:02 am
I’ve seen ‘cordwood construction’ in several alternative house building books. It’s great when you don’t have straight logs. The Earthship books use a similar technique with aluminum cans and cobb chinking for interior walls. Use masking tape to connect two cans opening-to-opening for a nice, sealed ‘log’. If you laid plastic bottles neck-to-neck in a double thick wall the chinking would lock the bottles in place. This would be ideal for constructing fill walls in a post and beam structure of logs, salvaged lumber, etc. If the wall is just fill and not load bearing the bottles don’t need to be filled, allowing for natural lighting (if the caps are removed and the bottles are connected). You could adapt this method to lots of post consumer waste- anything of a uniform size from beverage containers to oil drums. On a side note- I have entertained the idea of splitting open green two litre bottles and using the resulting sheets to shingle a bamboo frame as a low tech recycled greenhouse.
July 12th, 2006 at 12:21 pm
This is such a great discussion folks! Has anyone else tried prototyping any of this? I’d love to post photos.
August 8th, 2006 at 10:21 pm
How is this project going? I{m in Salvador, Brazil and interested in similar issues!
Did you happen to read the recent series in the LA Times called Altered Oceans? Really makes the case for coming up with alt uses for the waste plastics we have now . . .
I also read online that the EU has supported research in Niger or Kenya on making bricks out of plastic carrier bags and garbage bags with a cement mold to patch roadways – fill in potholes, etc. Maybe an app for Peru?
In terms of bottles, is there a way that you could use their same method – using a cement mold – to create bricks from bottles? I
Good luck and stay in touch!
Mark
August 8th, 2006 at 10:42 pm
I just found this site with specs for building a plastic baler for $50-$150, using items that you should probably be able to get in Peru.
http://www.bae.ncsu.edu/topic/vermicomposting/pubs/ag473-12.html
With the plastic in bales, you might be able to adapt a strawbale approach to home construction to fit your needs-
similar to what Penn State has experiemented with in partnership with Native American communities in the U. S.
http://www.engr.psu.edu/greenbuild/projects/completed/completed.asp?p=2.2
How serious are you guys about utilizing waste plastic to address housing needs in Peru? Elsewhere? I could put you in touch with the folks running the AIHI initiative mentioned above, and I would be interested in helping with your work – learning more about the construction technique of it in the process (I study community and regional planning at UT of Austins School of Architecture, but am interested in self-help and hands on construction work).
If the plastic itself can{t be used as a building material, perhaps just having the plastics in bales would be useful . . . dunno – hope you will stay in touch!
August 9th, 2006 at 4:35 am
Be carefull with the temperature. Too hot and the plastic crystallises and becomes brittle. PET will not last outside unless it is painted as it is not very UV resistant.
The temperature of the plastic sould be between the glass transition temperature 70 celcius and its melting temperature 255 celcius. 149 celcius is ideal.
The mold should be above 25 celcius – ideally 40 to 60 celcius.
I suggest that you place the bottle in the brick shaped mould, then pour hot sand into the bottle, possibly using a metal funnel, and push it down/in with a stick. The sand should push and stretch the bottle to the mold shape.
Using sand as a mold plug, the sand temperature should be between 120 and 155 celcius. Possibly hotter to allow for cooling.
Let me know if it works
August 9th, 2006 at 10:24 am
all in favor of the ideal—-but remember that construction waste is another
massive contributor to landfills. brick is expensive because it’s fantastically durable…and even at the end of the life of the original structure can often be
reclaimed for new projects, or worst case, ground back into clay and sand. a
house of plastic bottle bricks might actually insulate very well if filled with sand; but structurally i’m doubtful, and the remaining material—
PET and sand crushed together—may be just more landfill at the end.October 3rd, 2006 at 2:32 pm
[...] Previous Posts: Plastic Bottle Blowing, Plastic Bag Wallet [...]
October 18th, 2006 at 10:48 am
Lots of dairies use silage bags. It’s #4 LDPE plastic. I was wondering if i could use their waste plastic to make plastic fence posts. First clean it and shred it to smaller pieces, then melt it to a liquid and pour it into a mold to make a solid fence post. Doable?
October 21st, 2006 at 6:53 am
Hi. Am looking at all the plastic Beverage containers in Mexico. Beaches littered. Can I shred and press into a brick mold? What heat do I need in my mold to sear the brick and make it solid? I have a hydraulic setup with a simple bottle jack as a ram. Good pressure, simply need heat?
Ideas?
December 19th, 2006 at 5:29 pm
Another consideration is using the bottles for some other purpose. The WHO has recomended filling them with water and placing them on corrigated roofing to allow the UV light and heat to sterilize the water. If you suceed and these become a valuable building recourse you may inadvertantly remove them as a source of clean drinking water.
January 9th, 2007 at 2:32 pm
HI,
I was mulling this very problem over this morning, before doing any further research. My husband started googling as I was talking about some of my ideas, and came up with this great site that uses PET bottles as they are, connecting them with twine, filling them with sand, and adding concrete. They’re building houses and cisterns in Honduras this way, and they’re teaching kids to do it at school: http://www.eco-tecnologia.com/
June 29th, 2007 at 2:00 am
ask some cola comapny to help or the company which sells water in thes bottles can help i once saw n t.v that they just use a warm plastic ballon to make these bootles by blowing them into a mould
i hope this will help
August 7th, 2007 at 5:41 am
Interesting…
I too have been working on implementing a housing solution with 2L pop bottles. In Canada, they’re also round, but I recently moved to Japan and they have mostly rectangular ones like Martin said in #15. Even more conveniently, these ones actually have a notch around them at roughly half way up.
My plan so far has been to use fishing line to tie the bottles together, weaving them at the notch, and using the clove hitch knot around the bottle mouths, producing a structurally cohesive block. (the bottles should be upside down, providing dispersed structural support for the floor)
The plan I was thinking to use though involved making the bottles provide displacement for offshore living (where the price of land is free)
I’ve been a bit of a coward when it comes to implementation. If people are interested in this sort of thing, lend some encouragement and I’ll get something done.
Right now I have roughly 70 bottles sitting outside on the porch because I collected them thinking to figure out how to put them together… then I thought of fishing line.
September 3rd, 2007 at 10:11 pm
I think it is very dangerous to blow PET bottles over fire. Think about the toxic fumes you will inhaled working on this project.
Physics professor Newton Lima’s ecological brick invention used the bottle whole so no baling machine will be required. First he sealed the bottle with air before inserting it into the centre of a much larger rectangular wooden mold. The mold is then filled with quartz sand and cement and once hardened, the “PET brick” is removed and ready for use.
The benefit of building homes with his “PET bricks” in hotter climate is that it will keep your home cooler as the air pumped into the bottle acts as an effective insulator.
You can view picture of this brick and other type of bricks created with food (primarily candy) wrappers, peanut shells and wood shavings at the following link:
http://www.temasactuales.com/temasblog/?p=90
September 25th, 2007 at 11:11 am
Dummies… PETE plastic will degrade under UV exposure and crack… then all your left with is a great big sand box, congratulations.
November 4th, 2007 at 4:58 pm
What about creating the square mould,heating the bottle in extremely hot water, then inflating the bottle INSIDE the square mould? a variation on the injection moulding principle? Just a thought.
November 28th, 2007 at 7:06 pm
Nice!
December 10th, 2007 at 7:54 pm
Hmm, What if..
1. Instead of filling with sand, fill with water, or water with some additive that will over time solidify.
2. Instead of reshaping the bottles (time and labor intensive), use them as is, but filled as above to avoid collapse.
3. Design, and have made one or more different “male to male” adapters, which would link 2 or more bottles together as mentioned in a previous post for cans & masking tape.
Thus, a box of purchased, or donated adapters, scrounged bottles, water, and something to solidify the contents and you’re off to the races.
I’m sure you’ve also seen the houses made from tires, filled with dirt and “stucco’d”, of course that’s typically only good for dry climates.
December 12th, 2007 at 11:15 pm
Has anyone seen this? My suggestion: contact this guy and ask him how he did it… http://www.ananova.com/news/story/sm_2517250.html.
December 12th, 2007 at 11:16 pm
Here’s story, just in case link doesn’t load (as it didn’t when I tried it just now).
Plastic bottle house
A Serbian maths professor has celebrated his retirement by moving into a house he built himself entirely out of plastic bottles.
It took five years and 13,500 bottles for Tomislav Radovanovic, from the central town of Kragujevac, to build the 60sq metre house.
He told the national news agency Tanjug that he hopes to enter the Guinness Book of Records and has already sent them an application.
Only the foundation of the property is concrete, and all other parts of the house are made of plastic bottles that he had been collecting for years.
Even the kitchen furniture and windows are made of plastic bottles.
Radovanovic said his former students had helped him build the property by collecting the bottles he needed.
January 3rd, 2008 at 3:24 pm
Hey,
I was searching for info about what hdpe ofgasses, and found that “department of energy” website. I think the advice they have about not burning the plastic is spot on, but they’re wrong about hdpe as far as I can tell. It’s a polymer, not a crystalline structure, and it’s used in rapid prototyping without the need for any ventilation: http://www.candyfab.org/article.php/printingplastic
-Adina
January 3rd, 2008 at 4:07 pm
Apparently I’m wrong, and it is crystalline. That was me being silly and not checking before posting.
However, I’m pretty confident that the candyfab folks know what they’re talking about when they say that one can melt HDPE to make objects without huge worries about off gassing.
January 13th, 2008 at 11:55 pm
Interesting…
January 28th, 2008 at 8:10 am
Couple of comments to chip back in:
PET degrading in UV: You could paint the bottles, or use mud to stucco them, which should protect them from the sun.
wolter: Shredding plastic shortens the polymer chains and results in weaker plastic. But look at this post: http://www.vestaldesign.com/blog/2006/03/plastic-bag-wallet.html for a way to use plastic bags to make sturdy canvas-like materials. You could conceivably make “sandbags” out of them… they’d pack flat too, for easy transportation…
Adina (#38-9): I’m glad to hear it… I still have doubts; don’t most plastics generate dioxin when burned? I was aware of this but got excited and just started working… now I look at the above picture and imagine all the terrible chemicals entering my lungs… ugh. Well, all in the name of discovery!
In any case, folks, do check out some of our other design for the developing world (D4DW) work here.
April 22nd, 2008 at 9:45 am
I have a few thoughts: the bottle structure probably has more integrity as a circle, untampered with. heating the bottles may release toxic gasses as well as weakening them. If they remain exposed to air, I think they will eventually degrade to the point where they may crack. How about using them as-is, something like an earthship made of tires? This would require other materials, like cement or adobe and perhaps some rebar, but it would greatly reduce the amount of purchased materials needed.
April 22nd, 2008 at 12:48 pm
http://www.globalgiving.com/pfil/1830/finished%20cistern.jpg —a picture of a water cistern
May 18th, 2008 at 7:44 pm
thats an awesome way to make a bad ass bong. sick, making one nowssss!!!!11
May 20th, 2008 at 7:20 am
If you have access to any concrete you can make it go a very long way by filling the bottles with sand (or just using empty tin cans), putting them in the bottom of a square cardboard milk container and then pouring in the concrete. One guy used this and creek stone filler from the nearby Miami river to make Loveland Castle near Cincinnati, Ohio. http://www.cincinnatiusa.com/Attractions/detail.asp?AttractionID=130
Using empty bottles and cans in the blocks in the upper walls lightened them.
If not, the square milk container should still make a good mold. I’d still rather the bottles held the backfill for some other structural material… I just don’t trust rubbers and plastics over time.
July 2nd, 2008 at 8:32 pm
I am looking up everything I can find on bottle houses both Plastic and glass. Can’t find any suggestions for building methods and techniques.Like stacking etc. or how to do corners or join walls. Should I just rely on my early days of playing with Licoln logs. Any links or “How To” input would be appreciated.
September 8th, 2008 at 9:03 am
or just put it in the dishwasher on heated dry