纺织产品的闭环回收系统的研究模型(项目)

NTC Project S09-NS04 1

National Textile Center Annual Report: November 2010 National Textile Center: Annual Report Logistics of Closed Loop Textile Recycling Project No. S09-NS04 Competency: Management Systems

Project Team: Jeffrey A. Joines, Leader, NC State University, JeffJoines@ncsu.edu Kristin Thoney, NC State University, Kristin_thoney@ncsu.edu Russell King, NC State University, king@ncsu.edu Gilbert O’Neal, NC State University and ITT, wgoneal@itt.edu

Students: Iurii Sas, Ph.D. Student, NC State University James Lavin, Ph.D. Student, NC State University Tyron Keys , M.S. Student, NC State University James Spratley, M.S. Student, NC State University Ryan Woolard, M.S. Student, NC State University Scott Ryan, Undergraduate Student, NC State University

Industry Partners: VF Corporation and the ITT Research Consortium (www.itt.edu), Wake County; Cause

for Paws; DR3; Original Mattress Factory; New Life Plastic Recycling

Goal Statement The goal of this project will be to determine how to design robust closed loop recycling systems for different sectors of the textile complex, addressing similarities and differences in methods of collection, distribution networks, and manufacturing management strategies. The outcome will be a set of new optimization models that can be used to design the closed loop system as well as forecast estimation models of returned products. From these models, companies will be able to determine the efficiencies and cost effectiveness of their proposed closed loop recycling systems. Specific targets of the current project are the following:

 Develop a series of models for the reverse logistics problem that will focus on a variety of textile product categories (carpets, apparel, upholstery, industrial fabrics, etc.);  Develop a methodology for determining forecast estimates of the reverse material demand stream (i.e., recycled products);  Develop a methodology and framework for gathering and using all the information to solve these models;  Create econometrical cost models to compare effectiveness of recycled material to virgin polymer/material; and  Validate the methodology by developing a simulation of the closed loop network designed.

Abstract Designing and optimizing the supply chain has become a priority as well as a necessity for the survival of the US textile complex. However, the focus has been primarily on forward supply chain operations, and there has been very little consideration of utilizing recovered products or recycled raw materials and the reverse supply chain. As such, many of the current networks and/or products are currently not suitable for closed loop recycling. Closed loop recycling is becoming increasingly important due to consumers’ heightened environmental consciousness, governmental legislation, and raw material costs owing to fluctuations in oil prices. In 2008, the United States generated 250 million tons of municipal solid waste. Of this total disposal, 12.4 million tons were discarded textile NTC Project S09-NS04 2

National Textile Center Annual Report: November 2010 wastes. Only 1.9 million tons, or 15.3%, were recovered for recycling, energy generation, or composting (U.S. EPA website). Because of the large amount of textiles consumed on a yearly basis, developing closed loop recycling systems has the potential to have a significant positive environmental impact, and, if efficient, a positive impact on revenues of textile companies as well. Developing an efficient closed loop recycling system for textile materials involves both creating processes to transform the used material into a desirable output and then setting up and operating appropriate manufacturing and logistics distribution structures for the arising flows of recovered products. This project will investigate and focus on the latter.

Introduction Existing research in closed loop recycling of textile products has been focused primarily on carpets. Jane Ammons, Matthew Realff, and their colleagues at the Georgia Institute of Technology have formed a Reverse Production Systems Research Group which focuses on closed loop recycling. They have published papers primarily related to developing reverse production systems for the carpet (Realff et al., 2000; Realff et al. 2004) and electronics (Hong et al. 2006) industries. Much of the focus is on developing a robust design involving formulating and developing heuristics to solve mathematical programming models. In addition, Biehl et al. (2007) developed a simple simulation model to assess carpet reverse logistics system performance for a small number of collection sites. There is also much general closed loop recycling literature, including many papers from researchers associated with the RevLog (Reverse Logistics) research network in Europe (Dekker et al. 2004). In addition, there is also a wide body of literature on the closely related problem of remanufacturing. One of our former graduate students, Sebnem Ahiska, worked on a remanufacturing problem where she has applied Markov decision processes to determine optimal inventory decisions and has characterized the resulting policies (Ahiska 2008, Ahiska and King, 2009a, 2009b, 2009c). Another of our graduate students, Institute of Textile Technology Fellow Ryan Woolard, investigated facility location decisions and costs associated with closed loop recycling for textile products, developing a framework in which carpet is the primary case study (Woolard, 2009). Much of the existing literature on closed loop recycling either addresses other industries or assumes the collection sites are already in place. Estimating the amount of return product (demand) has not been well studied.