A reverse logistics inventory model for plastic bottles

Abstract

Purpose – The purpose of this paper is to present an original model for the production-recycling-reuse of plastic beverage bottles. Design/methodology/approach – It is assumed that discarded two-liter plastic polyethylene terephthalate (PET) bottles are collected from the market. The bottles are then sorted into non-contaminated and contaminated streams. The non-contaminated PET bottles are either remanufactured or used as regrind mixed with virgin PET to produce new bottles to satisfy varying demand. The contaminated bottles are either sold to industries using low-grade plastic or disposed of in a landfill. Numerical studies are used to illustrate the behaviour of the model, with an emphasis on exploring the reduction of total system cost and the amount of bottles going into a landfill. Findings – Numerical analyses conducted on the model found that the amount of bottles collected had the largest influence on the outcome of the total system unit time cost. Alternative materials to PET are surveyed and used to demonstrate a significant reduction in the cost of landfill disposal due to their more rapid degradation in the landfill. Research limitations/implications – Several areas for future work are highlighted. Potential modifications to the model could focus on accommodating bottles made of material other than plastic, incorporating the effects of learning on manual tasks, and on accommodating shortages or excess inventory. Originality/value – The model incorporates several unique aspects, including accounting for the cost of land use and associated environmental damage through the calculation of a present value that is charged to the manufacturer.