Toward green manufacturing evaluation of light-emitting diodes (LED) production – A case study in China

Abstract

Manufacturing of chips and their associated products is a complex and multi-step process where evaluation on the materials and environmental efficiencies is difficult, and a typical life cycle assessment cannot fulfil the role. In this research, a multiple evaluation scheme in view of green manufacturing is developed by combining critical evaluation, mass flow analysis and environmental impact assessment, in order to define the green degree for chips and lamps production of light-emitting diodes (LED). Mass and energy flow are identified with a subsequent critical evaluation for the whole process to determine the importance of 160 kinds of substances, energies, waters, pollutants, and procedures. In 96 kinds of substances, the organics and metal contained substances have higher criticality and accounting for 33.49% and 56.54%, respectively. To understand the effects of critical pollutants, a comprehensive environmental assessment factor (CEA) is then implemented, and waste water in chip preparation section has larger CEA value. As a result, ten green manufacturing level is defined through a grading decision function, and LED filament lamp reaches a higher manufacturing level than surface-mounted device (SMD) based LED lamp. By defining three scenarios, the manufacturing level of largest environmental effect scenarios is 7, reflecting the CEA of the pollutants is the most critical parameter. With this evaluation system, the green manufacturing level of one manufacturing section or different manufacturing processes can be evaluated, which can guide the identification and classification of LED lamps and other products.