Collecting and taking advantage of the lunch boxes, plastic cups that are discharged into the environment, a group of 3rd year chemical engineering students, Polytechnic University (National University of Ho Chi Minh City) seek to make plastic trashes into lightweight, soundproof and recyclable bricks.

Student Lac Dan Hy, group leader said, this type of brick can be used as paving, wall panels against heat. The plastic composition also helps to avoid water repellency and is lighter than traditional bricks. Once the product degrades, it is completely recyclable.

For the manufacture of lightweight bricks, there are three main steps. First, plastic cup boxes are cut and crushed in the form of particles of 0.5 mm size to achieve a certain fineness. Then mix the cement and water together with the resin and the binder. The mixture is poured into molds and dried or dried within 24 hours.

Although the production process can be easily done, the most important step is to find the correct ratio of resin and cement when mixed into the mixture. According to Dan Hy, to make a product that can be used, the group has to test more than 30 times in many months because if the ratio is not correct, the brick will not be hard enough, fragile.

The group conducted many tests on bending, compression and abrasion resistance of products. Through many times of implementation, the team found the optimal formula to manufacture. A finished brick can be made from 500g of plastic, accounting for about 50% of the volume of bricks, 50% of cement and 10% of the sludge volume.

Depending on the application, bricks are shaped differently, the proportion of resin mixed in bricks also changes accordingly. Compared to conventional brick products, bricks have the advantage of being light and durable. Brick products meet the standards of M50 concrete of Vietnam with 90% insulation, not igniting in normal conditions and soundproofing about 60-70%.