Recycling waste plastics in developing countries: Use of low-density polyethylene water sachets to form plastic bonded sand blocks

Abstract

In many developing countries low-density polyethylene (LDPE) sheets, bags and water sachets are a major waste problem because local collection and recycling systems do not exist. As a result, LDPE has no value and is dumped causing aesthetic, environmental and public health issues. A relatively simple technology has been developed in the Cameroon that produces LDPE-bonded sand blocks and pavers. The application of this technology is an example of a community-driven waste management initiative that has potential to impact on the global plastics waste crisis because it can transform waste LDPE and other readily available types of plastics into a valuable local resource. In this research, waste LDPE water sachets have been melted and mixed with sand to form LDPEbonded sand blocks. The effect of sand particle size and sand to plastic ratio on density, the compressive strength and water adsorption are reported. Optimum samples have been further characterised for flexural strength and thermal conductivity. LDPE-bonded sand is a strong, tough material with compressive strengths up to ~27 MPa when produced under optimum processing conditions. The density and compressive strength increase as the particle size of the sand decreases. The potential for using this simple technology and the materials it produces to transform LDPE plastic waste management in developing countries is discussed.

Physical and Mechanical Properties of Recycled Pet Composites

“…As can be seen, ductility decreases with the addition of sand reaching lower values in the case of R-PET composites. The data exhibits visco-elastic behaviour for higher sand content, as was observed on LDPE/sand composites [8]. Sand changes plastic flow under load, clearly reducing its ductility.…”

“…These could be explained to the overpopulation of sand particles, which causes a weak interaction between sand and PET matrix and inefficiencies for stress transfer. The reduce in compressive strength has been seen on LDPE/sand composites for larger sand-size particles (> 1mm) [8]. Sand size has an influence on the mechanical properties of the composites due to an increase in porosity, reducing the encapsulating area by the binder.…”

“…On the other hand, there are some studies on polymer matrix and sand particles. Kumi-Larbi Jnr et al [8] use recycled LDPE water sachets to form sand blocks, and they found that the density and compressive strength of composites increases as the particle size of the sand decreases. Composite materials produced by PET wasted, and rigid sand has been studied concerning tensile properties.…”

Study on Blending of Wall Material of the Nonel Tube by CSW/PE-g-MAH

“…e detonation method of the nonel tube was observed under high-speed cameras [3,4], and the design and connection method of the blasting network was widely studied and applied [5][6][7][8]. e source material of ordinary plastic nonel tube is low-density polyethylene (LDPE), which has the characteristics of good toughness, easy processing, and wide application range [9][10][11][12][13]. With the development of the civil explosive industry, the use of the existing ordinary nonel tube is limited, and new requirements are imposed on the strength and heat resistance of the nonel tube.…”

Catalytic co‐pyrolysis of packaging plastic and wood waste to achieve H 2 rich syngas

“…It is also applied as a wrapping foil for packaging and for garbage bags. 7 Despite the high-energy content of plastics, 15 to 40 wt% of plastics waste is deposed into water bodies 8 and remarkable part (21-42 wt%) is placed in landfills. 9 Biomass (BM) and plastic wastes should be potential energy resources because they can be successfully and sustainably converted to (bio) fuel.…”