plastic block press

Plastic block press showing all parts and measurements.
plastic block under compression
Final plastic block under 3,400 pounds per front wheel weight. The block compressed about three quarters of an inch with the weight on it.  The block returned to its original shape when the weight was removed.

Turn low value plastic trash into valuable building blocks with a $300 homemade press.

December 15, 2010, was a big day for Harvey Lacey, the maker of a hand-operated press that turns plastic trash into building blocks. That was the day Harvey made his first plastic block. His website at chronicles his efforts to make a block press and plastic building blocks.

Harvey says, “I see a solution to two problems facing us today. Plastic pollution is a worldwide issue. Another worldwide issue is affordable shelter. This block addresses both of those issues. It takes trash plastic and makes it into an affordable alternative building material.”

Harvey goes on to explain, “One of the things I’m trying to do with the block press is make it like someone would under more difficult circumstances. So I’m using common tools, no fancy machine shop lathes, sheet metal shop presses, etc. I’m also trying to use scrap stuff found around the shop. So far the only thing I’ve purchased for the block press is the three foot by one inch ACME thread rod and nut, $69.00 with shipping.”

Basic facts: The inside width of the press is eight inches, which is also the standard width for a building block made of concrete. Final block size is 8”x8”x16”. Four 12 gauge galvanized wires hold the plastic block together. A simple tool is used to cinch and twist the wire tight while still in the press. Each block weighs six to ten pounds depending on how much plastic and pressure is added. They are difficult to compress or distort. Horizontal wire around each block facilitates attaching plaster mesh. Tied together with wire, and braced with masonry reinforcement and rebar the plastic blocks create a very strong wall ready for plaster inside and out.

Half blocks are used at corners and at window and door openings. Cutting full blocks without losing the integrity of the block is not possible, so half blocks are a necessity. These are made by inserting a half block plug in front of the ram and then applying the same method and pressure as full blocks.

1/10/2011 6:46:29 PM

Jan, applying sufficient heat to fuse the plastics greatly complicates construction of the press. It would take a lot of energy. Plus, this process is already patented by ByFusion Technology, as explained in the article.

harvey lacey
1/9/2011 1:26:49 PM

Jan, I just did a look up on durability of galanized steel inside of walls. 22 gauge has life expectancy of over six hundred years. The wire I'm using is 12 gauge. That's almost twice as thick. The wire isn't just to hold the shape of the block. It is also there to replace mortar. Without the wire for tying the blocks together and to the reinforcing steel you would need a special mortar with additives to bond plastic to sand and cement. The plastic and wire construction provides a strong and flexible wall. This is an important consideration in most of the places where seismic activity is the reason for the crisis. Another thing to consider about this wall construction is it is the way we built things before we developed mortar and methods to shape stone or create bricks. We tied things together because it is simple and it works.

jan steinman
1/8/2011 12:31:33 PM

I'm a bit concerned about the wires used. They are a non-recycled item that must be purchased, and it seems that they have a shorter life than the blocks themselves, which could mean that the highly-compressed blocks could rapidly expand upon wire failure. What about heating the entire press, causing the plastic to fuse to itself while compressed? The heat could be supplied by a solar concentrator or wood.

1/7/2011 6:22:39 PM

Yeah, I really think this has a lot of potential. I'd love to see people pick up on the idea and run with it.

stan quick
1/7/2011 1:20:49 PM

I live in a city that does not recycle most plastics. I live sustainably and am about to retire. This idea is just what I am looking for to reduce garbage even further. If we can develop low cost water filters and low cost solar systems for developing countries, why not low cost building materials. The up-side potential is limitless!

rita h johnson
1/7/2011 8:31:02 AM

very interesting article, sounds plausible, thank the author for being willing to share this with the public, I printed out the article and will attempt it. will let you know how it all comes out. we have an abundance of plastic trash as we have 3 children and 3 adults living together, we go through 2 gallons of milk every day.

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