Plastic lumber from trash

Hi,  thought I would share my plastic waste to plastic lumber and other items project.  

A few years ago I was really flat broke.  I tried making all sorts of things to earn and it was not working.  I came across the open source Precious Plastic project and started doing that.  

Started out in my garage with some hand power tools, and a stick welder.  The first machines were quite ugly.  But I did not charge that much for them either.  Then I started building more and more, getting better tools, and doing the stuff in the pics below.  

However now that the inflation monster has hit, machine sales have basically took a dump so I started making things with the machines I build.  

First of all this is not a solicitation to sell machines as I am living in SE Asia and have zero desire to export.  Second all of the machines and designs are open source on Youtube and at preciousplastic.com for you to download and make yourself.  

So with that out of the way, I present my plastic 2x4 lumber made from plastic trash.  

I am still working out the techneque a bit as some of the bubbles in the plastic is from moisture in the waste plastic, but otherwise if the trash is washed, and dried well, and shredded to small flakes, it will feed into the extrusion machine.  

Basically I get big sacks of plastic trash.  Cut the bottles open and give everything a good hosing off.  I use a small circular saw blade on a angle grinder, but a bandsaw would work better and a marge shredder to make big chunks would be even better.  (drains easier)

Once the plastic is clean-ish and at a reasonable size I put it in my plastic shredder/granulator me and a workaway guest designed.  I get it down to the sub 6mm flake in the picture.    I then put out in the sun to dry again.

Then I feed it into the plastic extrusion machine.  My newest machine can do abot 15 kilos per hour of plastic.  Which translates to 12 feet of 2x4 per hour.  For the mold I use ordinary hardware store steel tubing, with some flat bar tack welded to the outside to make it stronger.  I pump the steel tube full of the hot plastic.  Once it is full I drop the full steel tube into a barrel of water. (takes 2 person) and start filling another mold.  the plastic when it cools shrinks and the plastic board can be pulled out.  

Sometimes the molds will underfill and the surface finish is rough,  sometimes the mold over fills and the surface is smooth but it is very tight to remove from the mold, so there is a balance to be struck there.  

So far I have made about half a ton of these boards,  I have a order for 20 pieces of sand box for a gold course with them.  That will consume about a metric ton of plastic.  

I have also experimented with these as fence posts, and construction materials.  They work very nice, if a tiny bit flexible, but to date I have been unable to break one of these boards, even driving my truck over one.  

this plastic can be made into bricks, boards, all sorts of things.  Even furniture.

It is worked with ordinary wood working tools, and all the scraps can be re-used so very little goes to waste.  Even when I surface plane these smooth, the shavings are fed back into the system.

For our readers who want to learn more about this, here is a thread on Precious Plastics with some YouTube:

https://permies.com/t/58244/ungarbage/Precious-Plastic

Butte, thank you for sharing how you made their info work for you.

This is awesome, never heard of this before! Good work

Briella Ac wrote:This is awesome, never heard of this before! Good work

 thank you fro the kind words!

So to update, Last Friday I passed the 600 kilo mark for amount of plastic turned into 2x4 boards.  I have a limited power supply so I can only run one of the 3 plastic extrusion machnes at one time in the shop.  

I also have been working on getting some more plastic molding jobs.  Me and my helper made a thousand shampoo bar cases from discarded plastic washing machine cases, and discarded plastic food containers last month.  Now another eco company is asking for 12,000 shampoo bar cases so we have to come up with better molding.  

I found this awhile back on YouTube.  He had a near exact copy of a hand operated molding machine I designed almost 5 years ago.  It is too small for my uses, but then I found this new machine he designed:



I downloaded the blueprints, which were lacking in a formal layout, but there is enough measurement information to replicate the machine if you are on a budget, or like me living in SE Asia where shipping would be expensive.  Not to mention buying Chinese parts from the USA is kind of dumb.    I still have to import the Pneumatic cylinder, and valve, but the rest I can make locally.  

The Aluminum extrusion is very expensive, but 1 inch steel tubing and some epoxy paint would build the frame for less than 18USD in materials.  The metal plates he has, I could either sent out to laser cutting (and wait 2 weeks) or I could drill and cut in the shop to make in a few hours.  The rest of the bits turned on the lathe at the local automotive machine shop.

Anyways, check out his video.  As far as the DIY molders out there, It is pretty good.  It is not quite as powerful as my personal DIY hydraulic injection molder made from a log splitter, but it has the ability to keep a constant pressure on the mold.  Which is not easily done with the log splitter.  You need to keep pressure on the plastic going in so it does not shrink, much the same as home DIY aluminum casting.  

If anyone has questions on how to DIY their own machines, let me know.,

I like the concept. I have seen a number of companies start up on similar concepts.

One problem they ran into was that the plastic lumber would sag in summer temperatures (e.g., saggy picnic tables). It seems to need more structural support. Have you run into this problem?

Of course that dosn't apply to ground contact applications, where the plastic lumber is evenly supported.

Douglas Alpenstock wrote:I like the concept. I have seen a number of companies start up on similar concepts.

One problem they ran into was that the plastic lumber would sag in summer temperatures (e.g., saggy picnic tables). It seems to need more structural support. Have you run into this problem?

Of course that dosn't apply to ground contact applications, where the plastic lumber is evenly supported.

I have not seen that with HDPE,  but my guess is that it was recycled milk jugs which is LDPE.  The two plastics can mix, but LDPE has a much lower melt point.    HDPE like mine will not start to soften until well above 150 degrees.  

I came across a similarly designed injection molding machine a few weeks back. I love the idea of recycling being done locally instead of the current situation that has numerous inefficiencies. I figure having more ideas for different methods will help motivate more people in this space.

Daniel Schmidt wrote:I came across a similarly designed injection molding machine a few weeks back. I love the idea of recycling being done locally instead of the current situation that has numerous inefficiencies. I figure having more ideas for different methods will help motivate more people in this space.

I am familliar with the Action Box molder, but I personally prefer the other design from a production standpoint.  The way it is designed, it is very hard to put a mold in a clamp, and remove the mold.  One needs to have access from more than 2 sides to set up the spacers, stop blocks that make it a repeatable process.  by that I mean you need to have a way to put the mold in the machine, clamp it, fill it, and repeat over and over, exactly in the same position for the mold opening to mate with the machine perfectly every time.  Also double pneumatic cylinders may be a bit of overkill vs a single sc100 cylinder

Reminds me of the Trex decking materials.

I would like to build a machine that turns plastic waste into small chips. I could then sit at my local transfer station and pick the garbage to chip it. While the extrusion machine is above my ability to build at present, I'd love to resell these chips for such construction. If nothing else, it would save a lot of money for my town by seriously compacting the trash they have to deal with. Are there any better designs out there? How closely should the various plastics be sorted or commingled?

Cécile Stelzer Johnson wrote:I would like to build a machine that turns plastic waste into small chips. I could then sit at my local transfer station and pick the garbage to chip it. While the extrusion machine is above my ability to build at present, I'd love to resell these chips for such construction. If nothing else, it would save a lot of money for my town by seriously compacting the trash they have to deal with. Are there any better designs out there? How closely should the various plastics be sorted or commingled?

Most of the shredder designs I've seen use lots of lazer or plasma cut blades, which makes them a little hard for the average person to construct.

For a fun example of the design, British maker Colin Furze took the concept to its ridiculous (of course) extreme.


Anyway, the design I personally want to try instead is to attach a homemade hopper to a power hand plane. I even bought a cheap import plane to do this... then I wound up using it as a plane. :)  Go figure. :)
https://www.instructables.com/Low-Cost-Plastic-Shredder/

I do build plastic shredders which is my main income source.  Not a easy thing to build.  I started out making the Precious Plastic v3 design.  Sold a lot of them.  I have a fair amount of metal fabricaiton experience and a metal fab shop, so getting the laser cut parts and building it was pretty easy for me.  

Shredding plastic, you really do not have much way around the expense part.  It simply is not very easy to build a low cost plastic shredder, and I have devoted several years of my life thinking about it full time.  

At this point, I do not even bother making cheap machines because they break and people complain.  

Smallest decent plastic shredder you are looking at at least 2000 USD.  You can 'shred' cheaper but either you get a machine that breaks fast, or a tiny output, or a plastic flake that is useless for molding.

So far in the last month I have processed well over a ton of lumber, plus the extra time spent shredding and processing PP and HDPE plastics.  

I ended up needing more plastic that I could buy locally, so I had to buy a ton of recycled plastic HDPE pellets from a shop across town.  It was double the cost per kilo vs raw trash plastic, but I did not need to hire a guy to spend days cutting it down, shredding, and washing it.  

At present making plastic lumber for store fixtures at the local mall, and a big batch of molded plastic containers.  

The new injection molder is almost done.  Only the lathe turned parts awaiting delivery from the machine shop.  Big delay with the pneumatic cylinders coming from China.

Will post a new thread on that, once the whole process is sorted out.  That project uses scrap plastic appliances, shredded dishes, and plastic crates as the feed stock.

K Eilander wrote:

Cécile Stelzer Johnson wrote:I would like to build a machine that turns plastic waste into small chips. I could then sit at my local transfer station and pick the garbage to chip it. While the extrusion machine is above my ability to build at present, I'd love to resell these chips for such construction. If nothing else, it would save a lot of money for my town by seriously compacting the trash they have to deal with. Are there any better designs out there? How closely should the various plastics be sorted or commingled?

Most of the shredder designs I've seen use lots of lazer or plasma cut blades, which makes them a little hard for the average person to construct.

Sorry to break it to you, but there is no 'low' cost way to make plastic flake.  Best I was able to do is 150 bucks in laser cut parts and a 300 dollar hoist motor + machining, bearings, chain flex coupler, a length of 1 inch tubing, hex bar, and sheet metal hopper.    Which after all that I sell locally in the Philippines for 890usd.  No I will not ship overseas, not here to sell product.  

If you looking at setting up at the transfer station, you gonna need some horsepower and equipment.  think complexity and expense of a small rock crushing plant.  They will literally provide you with a mountain of plastic, and you will need to process it in truckloads at a time.  The little precious plastic machine I described above will get you a couple pounds for your molder, but that is it.  20 min before you need to let the motor rest or it will over heat.  

My big shredders start at 5hp and go up to 18hp.  Even there you will be hard pressed to process truckloads.  It took 2 days for my guys to process 800 kilos of preshredded PP food containers with a 5hp machine.  

But no fear, I started in a 1 car garage with some hand tools, and knowledge of where to get stuff made.   I got 5 people in the shop as of this month.  I literally had bout 100 bucks to start out with.  I just started building machines for others, and earned enough to build some for myself.   If I can do it on a third world tropical island, you can too.

My little hand wood planer was not up to the task, so I outsourced a batch to a wood working shop and it was bout 2 bucks a board to run thru a commercial planer.  I do not have enough budget yet to buy one of those.

Here is the results.

90% HDPE recycled pellets and 10% shredded PP used microwave food containers.  the PP plastic thins out the HDPE as I am using a blow mold grade that is quite thick and gummy.

So it has been awhile since I last posted.  Made a lot of lumber since.  Getting a lot better at it.  This week I finally set up a proper production line with work stations.   It has the extrusion line that fills the molds, a cooling tank to cool the full  molds, then the cooled lumber is punched out of the mold with a hammer and rod.  There is a special rack to hold the mold in place for that.  Then the lumber is taken to the trimming station where the ends are trimmed up to length.  The trimming station is not quite where I want it to be, it needs an adjustable stopper added so I get the perfect 2, 4 or 6 foot board cut.  Then the still slightly soft warm board is set in the storage rack, fully supported and held so it does not warp as it cools overnight.  After that it is strapping the bundles together and ready for the customer.  

We have made a LOT of planters and sand boxes.  Current production is fencing materials.  

Those boards look fantastic. I see a lot of recycled plastic 'timber' being used here in the UK - for board walks, benches, planters, signs and bollards. It's expensive to buy and not widely available. I believe, for instance, that the National Park in Pembrokeshire source their recycled plastic from Hereford, a 5 hour round trip. I imagine that they would be cheaper and used more often if there were more producers like yourself

I spotted a few plastic benches and tables "in the wild" at the weekend as we stopped for a cup of coffee. I thought I'd snap a couple of pictures to share them, as I mentioned them in my last reply.

Well a lot has happened in a year.

I have built a bunch of factories allover the Philippines.

Building a bigger 10hp extrusion machine that pumps out 40kilos of plastic per hour and runs on 220v at 63 amps single phase.  So far 3 are in operation, a fourth is in the shop with some wiring and its ready.  

Also working on recycling the low value plastics like films, bags, sachets etc.  The kind of stuff that no one else will take.

Moved into a new shop space.  about 3x bigger than before with room for big trucks to come in.  

Up to 6 employees now.  

Plastic recycling is getting to be a livliehood.

It haas been awhile since I posted.

Updates:

Making plastic fence posts.  2 inch and 3 inch diameter from waste bubble wrap plastic.

Companies are giving me tons of the plastic every month.

Downside is now I am lagging behind in shredding and processing it to feed in the machine.

Plastic agglomeration aka making the light weight film plastic into more dense granules that feed into the machine has become a challenge.  

I need a conveyor belt in the worst way to bag the stuff up.

building more extrusion machines this month and some plastic agglomeration experiments.  

I bought a feed pellet mill for the plastic.  it is not working so great on plastic to pelletize it.  It works some days, some days no.

I built a 10hp extrusion machine for the shop.  If I feed it plastic pellet made from recycled plastic, I can get about a half metric ton per shift with 2 men working.  it will use about 110kwh for the shift.    Local power rates come out to 23 usd for the power for a day of processing.  or roughly 2 cents usd per pound to melt it and pump it in the mold.  

Shredded plastic it just depends on the plastic type, how well it feeds in the extrusion machine.  I ran shredded shampoo bottles all day and it was the same as the pellets.  I also have run shredded foil snack food packaging and it ran half that per hour and the food residue cooked off in the plastic.  It still make a okay fence post but it did not smell nice and was a little bit sticky.   the smell and stickiness went away after a couple weeks of being outdoors.