FA info icon.svg Angle down icon.svg Project data
Authors Jenna Bader
Jesse Brown
Isabel Contreras
Location Santo Domingo, Dominican Republic
Cost DOP 6,946.43
OKH Manifest Download

This page narrates a project implemented by Team Terrific between May and July of 2014 for the Practivistas Dominicana program in Santo Domingo, Dominican Republic. The project is to develop prototypes that can be utilized by community members in Arroyo Norte. The prototypes needed for this project are walls and tables for a new sustainable market, using mainly local resources from the waste stream.

Background[edit | edit source]

The newest project site for the Practivistas Dominicana program is in Arroyo Norte. Arroyo Norte is a community, which was built in close proximity to Duquesa, the dumpsite for Santo Domingo. The dumpsite is the largest in the country, and the community exemplifies Appropriate Technology by building homes, community centers, and markets out of the materials they have in abundance at the nearby dumpsite. They have asked for us to come in and use the waste materials to build prototypes with them for furniture and walls to construct a new supermercado in Arroyo Norte. This would be the first large market in the community. The market will be built in the near future, but for this project we will only be experimenting with materials to develop alternative designs for things necessary in a marketplace. The 25-room supermercado will need a funding source, which we hope our prototypes will help generate upon completion. Our role in this project is to develop aesthetically pleasing, structurally sound, and economically feasible prototypes for use in the supermercado.

Problem Statement[edit | edit source]

The objective of this project is to research and develop wall and table prototypes that can be reproduced and used in a sustainably constructed market in Arroyo Norte, Dominican Republic.

Criteria[edit | edit source]

The following table of criteria was developed in a community meeting and is used to evaluate alternative solutions.

Criteria Constraints Weights
Resistance Prototypes must successfully pass the spray test, scratch test, and tensile strength test. 10
Marketability The prototypes must have potential for reproduction at minimum, and potential for revenue production at best. 9
Aesthetics The prototypes must at least be visually acceptable to the community members involved, and at best look "clean". 9
Security The wall prototypes must look secure and be resistant to break-ins. 9
Educational Value The prototypes must display reused materials in some way. 9
Accessibility of Materials At least 90% of materials used in the prototypes must come from the Arroyo Norte waste station. 9
Mobility The furniture must be movable by 2 or less people. 8
Adaptability The prototypes shall be created with room adaptability in mind. 7
Cost The prototypes should minimize cost where possible. The walls shall not exceed $100 USD each, and the tables shall not exceed $50 USD each. 6

Literature Review[edit | edit source]

See our Literature Review for relevant research completed for this project.

Construction[edit | edit source]

Timeline[edit | edit source]

The table below outlines a timeline for Team Terrific to complete the prototypes by Thursday July 3, 2014.

Date Activity
Monday, June 16 Complete Budget/Finish negotiations with practivistas
Tuesday, June 17 Brainstorm Explosion/Plastic Bottle cap Mold Extravaganza
Wednesday, June 18 Complete plastic research/Brainstorm Explosion #2
Thursday, June 19 Work day - Melt massive amounts of HDPE Plastic #2/Finalize caps & bottles
Friday, June 20 Purchase plastic tools to mass produce plastic tiles
Saturday, June 21 Finish all plastic prototypes/Finish wood chips and resin
Sunday, June 22 BEACH DAY
Sunday, June 29 Build on and perfect prototypes/Beauty with Mama
Monday, June 30 Work on presentations
Thursday, July 3 Present Projects

Costs[edit | edit source]

The table below describes the cost to replicate our completed prototype projects. The cost table below does not include experimental materials and tools. Costs are listed in Dominican Pesos.

Quantity Material Source Project Cost ($) DOP Total ($) DOP
3 "Calentador"/Sterno cans La Sirena Plastic Wire 48.41 145.23
1 Quart Waterproof wood paint Centro Ferreteria J&R Cable spool table 750.00 750.00
1 Paintbrush (small) Centro Ferreteria J&R Cable spool table 250.00 250.00
5 Sandpaper (60 and 220 grit) JV Ferreteria Cerrajeria S.R.L. Cable spool table 37.17 185.87
2 Wood palettes Duquesa Earthship Bar 150.00 300.00
1 bin Plastic #2 HDPE Duquesa Plastic Prototypes 200.00 200.00
1 gallon Soy Cooking Oil La Cadena Plastic Prototypes 418.00 418.00
2 12" Clamp La Sirena Plastic Prototypes 392.00 784.00
1 Transportation of duquesa materials Duquesa Plastic Prototypes 500.00 500.00
2 Floral snippers Ferreteria U&P Plastic Prototypes 350.00 700.00
2 4" clamps Ferreteria U&P Plastic Prototypes 275.00 550.00
3 Scissors La Sirena Plastic Prototypes 100.00 300.00
1 Propane-powered grill Mexico/Duarte Blender Repair Shop Plastic Prototypes 1,800 1,800
1 Box cutter La Sirena Plastic Bottle Ripper 63.33 63.33
Total Cost $6,946.43

Completed Prototypes[edit | edit source]

This section illustrates a step-by-step tutorial on how to replicate the prototypes we created for the Arroyo Norte sustainable market.

Glass Bottle Wall[edit | edit source]

Materials needed:

  • 100 Jumbo Presidente bottles
  • earthen mortar: clay, sand, water
  • shovel
  • bucket
  • level
  • rebar
  • eco-blocks
  • gravel
  • plastering trowel
  • earthen plaster: cal putty, sawdust, sifter/ sifted sand, water
Collect glass bottles

Collect similarly sized glass bottles. We used a combination of large Presidente bottles and medium-sized Brugal bottles.

Dig foundation

Dig a 6 inch trench about the same width as two blocks, and the same length as the wall frame. Fill the trench with a few inches of gravel.

Add blocks

Place blocks on top of gravel, and level. Then, hammer a couple pieces of 10 foot rebar, two feet deep into the ground for structural support. Note: We used eco-blocks, developed by the Las Malvinas Practivistas 2014 team.

Mix earthen mortar

Mix earthen mortar. Recipe: 1 part sand, 1 part clay, add water until a non-runny mortar-consistency is reached. Note: The ground in Arroyo Norte has high clay content, so we used the local clay from around our project site.

Completed foundation

Complete the foundation by using earthen mortar mixture

Build the wall

Lay earthen mortar, and add rows of large Presidente bottles. Each bottle was laid facing the opposite direction as the one next to it. As you move up the wall, take the time to pack the earth tightly around each bottle. Use a piece of wood on each side to check that each row is level before adding the next row of bottles.

Day 1

Bottle wall construction day 1. Let the wall rest overnight before adding any more height.

Day 2

Bottle wall construction day 2. We left more space around the bottles on this section of wall so we can plaster around the exposed bottles, which will allow natural light to shine through.

Completed prototype

Plaster over the wall with earthen plaster. To make earthen plaster, soak cal (lime) in a barrel of water for 24 hours (Note: cal soaked water is nutrient-rich and can be poured into soil, but make sure to wash cal off your hands within 1 hour, or it will irritate your skin). Then, pour out the water (into your plants), and add equal parts of lime putty and sifted sand to a large bucket, plus 2 handfuls of sawdust. Mix and apply to wall surface with a trowel. Once dry, the plaster and any remaining cracks can be sandpapered smooth to assist in weatherproofing the wall.

Plastic #2 Tiles: Melting In a Sandwich Press[edit | edit source]

These tiles were melted using a sandwich grill to melt HDPE Plastic #2, which was taken from the waste stream in Arroyo Norte.

Upcycled materials

Gather materials from the trash

Cleaning HDPE (Photo by Jenna Bader)

Thoroughly clean the HDPE plastic with a brillo pad, or to be really appropriate, you can use any abrasive material laying around like grass, plastic bags, etc. The point here is to have no dirt, residue, or discolor on the plastic because it will not be aesthetically pleasing after it melts.

Meat grinder experiment (Photo by Jenna Bader)

Cut the plastic: We experimented cutting plastic with a meat grinder to make even smaller pieces of plastic. Results: The final product was not worth the additional work of grinding plastic with the meat grinder. You need a very sturdy meat grinder to grind the plastic, which ours was not. Also, it could potentially work more efficiently if you connected the crank apparatus to a DC motor and a car battery.

Community help cutting plastic

Cut the plastic: The most efficient way for cutting plastic was by hand with the help of many community volunteers and various types of scissors and pruning shears.

Sandwich grill (Photo by Jenna Bader)

Melt the plastic: We experimented with melting plastic in a standard sized sandwich maker like this. First, we placed wax paper on the sandwich grill, placed plastic confetti on the paper, and placed a second piece of wax paper on top of the plastic confetti. Close sandwich grill and heat it up to 350 degrees F to melt the plastic. Results: The tiles were successful, but fairly thin. Also, wax paper melted to the plastic. Parchment paper is ideal for this method, and can be found at La Sirena (Jose Contreras) in Santo Domingo, Dominican Republic.

Propane sandwich grill

Melt the plastic: We purchased a propane powered large grill with a flat surface to melt larger pieces of tile in the same way as Step 5. Results: At the lowest setting, which is around 325 degrees F, we successfully melted 1/4" thick tiles of plastic without melting the wax paper.


Experimental Outcomes[edit | edit source]

The following documents explain experimental outcomes of our experiences melting HDPE plastic using an electric and a propane-powered sandwich press.

Electric Sandwich Grill

The following experiments document our experiences melting small pieces of HDPE #2 plastic into tiles using an electric sandwich grill and wax paper.

Image Experiment Description
Melted HDPE experiment #1 Experiment #1 We placed plastic in wax paper, put it in the sandwich grill, then turned the grill onto high heat. It took 15 minutes for the temperature to melt the plastic. This experiment was conducted in a home in Arroyo Norte using electricity that might not have the same voltage as the electricity outlets in the city. The wax paper stuck to the plastic material after it was completely cooled, which led us to believe that we used a poor quality paper, or the wrong type of baking paper.
Melted HDPE experiment #2 Experiment #2 This experiment was conducted in the city with consistent electricity, on the same sandwich grill, and the same wax paper. The difference with this was that we got the sandwich grill up to temperature before placing the plastic inside. We also started at a medium temperature and increased it when we noticed that nothing had melted after 10 minutes. This sample of melted plastic was placed under 6 thin terra cotta tiles to cool with not much pressure, which caused many wrinkles in the final product due to plastic shrinkage upon cooling.
Melted HDPE experiment #3 Experiment #3 This experiment was conducted in Arroyo Norte in the same sandwich grill and wax paper. This plastic was placed in the sandwich grill after it was already brought up to heat from a previous experiment. We started it on medium, and after 5 minutes, raised the grill to high temperature. It melted in 5 additional minutes, then we took the paper and plastic out of the grill with gloves. To cool, we placed the melted plastic between two sturdy pieces of wood, which were clamped together using 2 clamps holding over 5 psi of pressure. This is the most successful experiment by far. After it was fully cooled, we cut it into a tile shape using a hand saw.
Reuse scraps Re-use HDPE Scraps Use pruning shears to cut the unused melted plastic material. This plastic can be re-melted over and over again using the same process.

Propane Grill

The following experiments were performed using a large 12" x 12" flat paneled sandwich grill powered by propane.

Image Experiment Description
Large grill experiment #1 Experiment #1 We turned the grill onto the lowest heat possible, it took 10 minutes for the grill to reach 325 degrees F. Once the temperature was achieved, we placed plastic confetti in wax paper, put it in the sandwich grill, and covered it with the same piece of wax paper like a quesadilla. This experiment was conducted in Arroyo Norte, outdoors.
Experiment #1 results Experiment #1 Results Successful! The wax paper stuck to the plastic material after it was completely cooled, but can be scraped off the cooled piece. This paper is not ideal, but it works for now. The tile looks smooth, and is about 1/4" thick.
Large grill experiment #2 Experiment #2 We started with the grill preheated to 325 degrees F, and used banana leaf instead of wax paper. The banana leaf was cut into large squares, and used just as the wax paper in previous experiments. Once melted into a tacky substance, it was removed from the grill and placed in a wooden press to cool.
Banana leaf experiment results Experiment #2 Results The banana leaf successfully held the plastic together without leaking onto the grill, which was successful. However, due to the moisture content of the banana leaf, the final product of plastic tile has visible bubbles below the surface, which aesthetically is not what we want.

Plastic #2 Molds: Melting in cooking oil[edit | edit source]

CAUTION: Melted plastic is extremely hot, and takes hours to cool. Wear safety gloves and wooden tools when working with melted plastic and eye protection around hot cooking oil.

Cut #2 Plastic

Cut #2 plastic into 1"x1" pieces

Make a mold

Make a wooden mold with a flat bottom, 4 sides, and a lid that can drop inside the mold. Line the mold with parchment paper (not necessary, as the oil keeps the plastic and wood from sticking)

Put plastic into oil

Put oil in a tall cooking pot, turn stovetop on to High heat. Once the oil reaches 350 degrees F, add plastic and stir together.

Wooden mold

Once the plastic is melted to a sticky and tacky consistency, scoop it out into the wooden mold with a slotted spoon. Let the oil drip back into the pot for a few seconds for each scoop.

Press plastic

Press the plastic into the wooden mold, filling all edges and corners.

Let it cool

Put the lid on the wooden mold and clamp it shut. (Or use a plastic pressing machine AKA Jesse Brown, as pictured)

Plastic brick

Let the plastic cool for 4 hours, then remove from clamps and mold. If all goes well, you should have a beautiful plastic brick. Note: Some edges may need to be cut with a saw to make clean lines. This is a result of too little pressure applied to the plastic during the cooling period.

Cut #2 Plastic

Cut #2 plastic into 1"x1" pieces

Make a mold

Make a wooden mold with a flat bottom, 4 tall sides, and a lid that can drop inside the mold. This mold was built tall to minimize the amount of surface area receiving pressure, thus reducing the necessary psi.

Put plastic into oil

Put oil in a tall cooking pot, turn stovetop on to High heat. Once the oil reaches 350 degrees F, add plastic and stir together.

Wooden mold

Once the plastic is melted to a sticky and tacky consistency, scoop it out into the wooden mold with a slotted spoon. Let the oil drip back into the pot for a few seconds for each scoop.

Press plastic

Press the plastic into the wooden mold, filling all edges and corners.

Clamp the mold

Put the lid on the wooden mold and clamp it shut.

Plastic block

Let the plastic cool for 4 hours, then remove from clamps and mold. If all goes well, you should have a beautiful plastic brick. Note: Some edges may need to be cut with a saw to make clean lines. This is a result of too little pressure applied to the plastic during the cooling period.

Earthship Bar[edit | edit source]

Earthship Bar Prototype Description
Earthship Pony Wall with Bar Top, Adobe Illustrator Design by Jesse Brown This bar was created using old tires found in Arroyo Norte, filled with clay and dirt on site, and supported with rebar. The tires are bonded with moist earth (mostly clay), which is packed in and around the tires. Rebar was used to provide further structural integrity. Once the filled tires are leveled and the earth dried they will be covered in a plaster mixture of lime, sawdust, and a concrete mixture containing extra fine sand.

The bar top design was made into a poured slab of gesso and cement. The bar top was co-built with members of the community who are skilled in using these materials and methods. We built a mold for the bar top using scrap pallet wood and scrap billboard material. The gesso mixture was poured over scrap pieces of metal wire and layers of plant fibers, which add strength to the bar top. About 1 hour later when the bar top dried, the mold was pulled apart, leaving a clean and sturdy bar top behind.

Materials needed:

  • shovel
  • used tires
  • metal malette
  • salvaged rebar/ pvc pipe
  • earth (can be any mixture of dirt, sand, clay, etc.)
  • level
  • earthen plaster: lime, cement, sifter/ sifted sand, water, sawdust
  • plastering trowel
  • palette wood
  • table top: gesso, portland cement, water, cabulla fiber, scrap rebar/metal sticks, scrap billboard material
Earthship base

Dig a trench to secure the first row of tires

Level tires

Use a level on each tire as you build the earthship wall, ensuring structural integrity.

Fill tires with earth

Two pieces of scrap rebar and one piece of scrap PVC pipe were hammered into the ground, and each tire was lifted over at least one piece of rebar to hold it in place.

Tire wall in progress

Fill tires with clay and earth mixture, packing the tire as full as possible with a metal malette.

Plaster earthsip

Plaster the tires with sawdust plaster. Ingredients: 22 gallons of sawdust, 2 gallons of lime, 16 and 1/2 gallons of sifted sand, 1 bag of cement, and roughly 20-22 gallons of water. This produces roughly 40 gallons of plaster. (This plaster was created by the Las Malvinas ecoladrillo schoolroom Practivistas team.)

Wooden frame

Make a frame out of scrap wood. We used the billboard material so that the gesso would not fall through when we poured it in. To make bar top mixture: add equal parts of portland cement and white gesso powders to a bucket of water. Pile powder onto the water until you see a little island form on top...mix together with hands and once it reaches a thicker texture, quickly pour into the mold, a layer at a time.


Add scrap metal wire to act as rebar. Add cabulla as additional rebar strength. Cabulla is a plant found in Arroyo Norte, which strings out into long fibers. We did one layer of cabulla, a layer of gesso, and then another layer of cabulla.

Bar top mold

Remove nails and wood from the wooden mold frame with a hammer. Level the top with a flat-edged metal yard stick/level, scraping while it's still workable (feels solid, but still wet) and use a knife to clean-up the edges while it's still workable. And voila, Earthship Bartop!

Plastic Bottle Ripper[edit | edit source]

Plastic Bottle Ripper Description
Plastic Bottle Ripper, Adobe Illustrator Design by Jenna Bader The Plastic Bottle Ripper turns large plastic bottles into long spools of plastic string of uniform width. The design utilizes a 90 degree aluminum angle iron, a razor blade, and a few nuts bolts and washers. To create this Plastic Bottle Ripper, take your angle iron, and cut 3 holes into it at various lengths to create various widths of plastic string. Next, drill 2 holes into the angle iron where the bolts will be attached. Then, place the razor blade near the holes and add the nuts, washers, and bolts to secure the blade (sharp side facing the corner of the angle iron). Lastly, secure the angle iron vertically, put a 2 liter bottle on the long bolt, feed a small piece of soda bottle through the hole, and pull the string.

Maintenance[edit | edit source]

Schedule[edit | edit source]

Instructions[edit | edit source]

Conclusion[edit | edit source]

Testing Results[edit | edit source]

Glass Bottle Wall

  • When the earthen mortar mixture is cracking, add more sand. When the earthen mortar is crumbling, add more clay.
  • The earthen mortar mixture should be on the dryer side when applying.

Melting HDPE Plastic #2 in Electric sandwich grill

  • Successfully melted thin plastic pancakes
  • Plastic pancakes need to be folded while hot and repressed to create clean edges, or have edges cut off after cooled.
  • Cook time: ~10 minutes

Melting HDPE #2 Plastic in Large Propane-powered sandwich grill

  • Successfully melted thicker, larger plastic pancakes
  • Plastic pancakes need additional work to create clean edges
  • Cook time: ~15 minutes

Melting HDPE #2 Plastic in Parchment Paper VS Banana Leaf

  • Parchment paper: Best material for melting plastic in sandwich grills because it does not stick, burn, or leave any impurities behind in the end result.
  • Banana Leaf: Successfully melted large plastic pancakes with banana leaf. However, the banana leaf stuck to some parts of the plastic surface (~10%), which takes additional work to remove once cooled.
  • Wax paper: Successfully melted one 1 out of 10 attempted thin plastic tiles with wax paper, but it melts, burns, and sticks to the plastic tiles most of the time. We were able to make it work at a very consistent temperature in the electric sandwich grill, but it's not ideal.

Melting HDPE #2 Plastic in Soy Oil on the Stovetop

  • Melting in oil kept a consistent temperature, but left the pressed block very oily after it was cooled.
  • Plastic pieces that were cut small heated to temperature quicker than re-used previously melted blocks of plastic.
  • Cooking time: 15 minutes once oil is up to temperature
  • This method seems to have the most potential for reproduction of melted plastic materials because it is efficient, quick, and easy.
  • In Arroyo Norte: It would be possible to cook plastic with a propane-powered stove, but I would not suggest this method over an open-fire because it's important to keep a consistent temperature.

Molding HDPE #2 Plastic Bricks

  • Successfully molded 2 solid bricks of plastic using a small wooden mold with a removable top, and clamps to keep pressure on the plastic while it cooled.
  • Pressure was not enough with 2 clamps, so it had some bumpy edges. More pressure on the cooling brick would make cleaner-looking bricks that don't need to be cut smooth once cooled.

Molding HDPE #2 Plastic Blocks

  • Successfully molded 3 large blocks of plastic using a large wooden mold with a removable top.
  • The removable top fell into the mold, allowing any amount of plastic to be pressured evenly inside it
  • This method can be very efficient for making plastic tiles, all you have to do is get the cooled block on a band saw and cut 20 tiles out of one block of plastic.
  • This method has a lot of potential for the next steps of developing furniture for the Arroyo Norte marketplace.

Discussion[edit | edit source]

Lessons Learned[edit | edit source]

Next Steps[edit | edit source]

Glass Bottle Wall

  • Plaster over the earthen mortar once the wall is completely dry.
  • Mosquito-proof the completed wall. For example: Fill bottles with water and wine corks to seal the moisture and to illuminate the space more.

HDPE Plastic Prototypes

  • Energy analysis of melting plastic in oil on the stovetop vs. propane sandwich press vs. electric sandwich press
  • Find the most efficient way for community members in Arroyo Norte to melt large amounts of plastic safely (temperature cannot exceed 350 degrees F)
  • Make a tall mold out of wood or metal to make table legs out of HDPE molded plastic. Mold must withstand the pressure placed on the cooling plastic.
  • Experiment with the pressure used on plastic while it's cooling: does the small surface area really decrease the need for higher pressure (psi) if it's as tall as a table leg?
  • Find a way to use reclaimed/repurposed materials from the waste stream for the molds

Troubleshooting[edit | edit source]

Team[edit | edit source]

Team Terrific

Brought to you by Team Terrific, Practivistas 2014

References[edit | edit source]

See Literature Review

Peer reviewed journal article[edit | edit source]

This work became a peer reviewed journal article:

  • Title: An Analysis of Recycling High Density Polyethylene with Limited Resources
  • Authors: Isabel Noemi Contreras, Jenna Bader, Patricia DuRant, Lonny Grafman
  • DOI:
  • Published: Oct 29, 2018
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