The proposed plastic molding stations convert commingled plastic wastes into plastic lumbers through the two-stage extrusion-injection process. The residents will exchange their plastic wastes for everyday products provided by the station owner. The owners will use the produced plastic lumber to make furniture and sell for profit. This solution is economically beneficial to the local residents and it solves the plastic waste problem in the two communities.
Proposed Solution: Plastic Extrusion-Injection Molding Stations The proposed plastic molding stations convert commingled plastic wastes into plastic lumbers through the two-stage extrusion-injection process. The commingled plastic wastes are mainly soft plastics in the form of laminated sachets, packets and bags which are not usually accepted in junk shops. They are also composed of a variety of chemicals, including polyethylene, polypropylene, polystyrene and so on, making them difficult to be processed by conventional recycling technologies. Thus, the extrusion-injection method is chosen because it readily homogenizes the mixture of chemicals into the plastic lumber. The plastic lumber is a new material with many desirable properties, such as waterproofness and durability, which makes it a suitable material for furniture and outdoor applications like pavers or fences. Solution Description and Deliverance The molding stations will be owned by local residents and run as a cooperative enterprise. The residents will be encouraged to bring their plastic wastes to the molding station in exchange for everyday goods, for example, 20 used sachets for 1 sachet of shampoo, or 10 plastic bags for 1 sachet of salt. These provisions will be purchased by the station owners, or ideally be provided by the producers of such packaged products as compensation for the pollution they created and a demonstration of their participation in solving this problem, which can be advertised in other countries. The owners of the stations will process the plastic wastes into all kinds of products that can be sold for a profit, or they can make contract with the local government to produce street furniture and pavers. In general, this model involves people from the bottom of the pyramid in two ways: as suppliers they sell their plastic wastes and receive daily necessities, and as customers they gain access to affordable and high quality plastic furniture. Economic Impact For the residents in the two communities, the daily waste generation is estimated to be 0.2 kilograms per capita, with approximately 15% being plastic wastes. For a family of five, this corresponds to 150 grams of plastic wastes per day, 4.5 kilograms per month. Assuming 50% of the plastic wastes are hard plastics that can be readily recycled, this leaves 2.2 kilograms of soft plastics that can be exchanged for approximately 60 sachets of products, corresponding to a total value of 150 Php in the case of Dove shampoo. Therefore, for a family with an income of 5000 Php per month, this project will result in an increase equivalent to 3% of their monthly income. For the station owners, one plastic chair can be made out of the 2.2 kilograms of soft plastic wastes provided by one family, and the estimated selling price is 300 Php. Thus, for a service group of 1000 families, 150,000 Php of gross profit is generated if the owners are paying for all the compensational goods delivered. The margin of profit grows if the owner receives support from the aforementioned production companies, and better products such as tables and benches can also be produced and sold for a higher price to middle class customers. Environmental Impact As estimated above, the proposed molding stations will be capable of treating the plastic wastes in the two communities, which accounts for about 15% of all the wastes generated. For a total population of 15,000 residents, it is estimated that 13,500 kilograms of plastics will be prevented from improper disposal per month with this solution. Although the proposed solution only deals with plastic wastes in the current stage, it is anticipated that people could form a habit of waste management by constantly bringing their wastes to the designated locations. The molding stations can be placed near the main road with a special garbage disposal room attached, to encourage people to bring the plastic-free wastes to be collected by the government workers daily. In this way, the total amount of improperly disposed wastes can be reduced and the local environmental condition can be improved. The extrusion-injection process requires the plastic wastes to be washed and shredded. Due to the commingled nature of plastic wastes, a variety of contaminants could end up in the wastewater, including food ingredients, washing detergents, shampoo and so on. Thus the wastewater has to be discharged through the sewer system and must not be directly discharged into the environment. Otherwise, this could result in negative environmental impacts such as water pollution and eutrophication. Social Impact By reducing the amount of improperly disposed wastes, the rate of reproduction of disease-carrying bacteria and pestilence can be reduced and the health condition of the local residents can be improved. As a result, the burden of the healthcare system can be lessened and the resources can be distributed to other areas where needed. Moreover, with improved living conditions, people’s productivity is also expected to increase, leading to an increase in income generation and a further raise in living standards. The furniture made from plastic lumbers also have positive effects on people’s lives. Their affordability makes them more acceptable by the locals, and their waterproofness and durability enable them to last longer than wood or bamboo furniture in such an environment where floods are frequent. The plastic lumbers can also be shaped into bricks and be used to build dams, reducing the property damages and economic losses caused by floods. In summary, this project provides immense economical, environmental and social benefits to the local communities, while it can also produce enough revenue for it to be sustainable, therefore, the overall evaluation of this project suggests that it is feasible and beneficial.