Xuemei Ding

Low carbon supply chain with energy consumption constraints: case studies from China’s textile industry and simple analytical model

Purpose This paper aims to discuss the low carbon supply chain practices in China’s textile industry. To curb greenhouse gas emissions, the Chinese government has launched restrict regulatory system and imposed the energy consumption constraint in the textile industry to guarantee the achievability of low carbon economy. The authors aim to examine how the energy consumption constraint affects the optimal decisions of the supply chain members and address the supply chain coordination issue. Design/methodology/approach The authors conduct two case studies from Chinese textile companies and examine the impact of energy consumption constraints on their production and operations management. Based on the real industrial practices, the authors then develop a simple analytical model for a low carbon supply chain in which it consists of one single retailer and one single manufacturer, and the manufacturer determines the choice of clean technology for energy efficiency improvement and emission reduction. Findings From the case studies, the authors find that the textile companies develop clean technologies to reduce carbon emission in production process under the energy consumption enforcement. In this analytical model, the authors derive the optimal decisions of the supply chain members and reveal that supply chain coordination can be achieved if the manufacturer properly sets the reservation wholesale price (WS) despite the production capacity can fulfill partial market demand under a WS (or cost sharing) contract. The authors also find that the cost-sharing contract may induce the manufacturer to increase the investment of clean technology and reduce the optimal WS. Originality/value This paper discusses low carbon supply chain practices in China’s textile industry and contributes toward green supply chain development. Managerial implications are identified, which are beneficial to the entire textile industry in the developing countries.

A mathematical model for simulating heat and moisture transfer within porous cotton fabric drying inside the domestic air-vented drum dryer

Abstract A mathematical model was developed to describe the processes of coupled heat and mass and momentum transfer occurring in convective drying of 100% porous cotton fabric. In this model, the variation in both air and fabric properties were expressed as a function of temperature and moisture content. The resulting systems of transient non-linear partial differential equations in the space-time domain together with the set of initial values and boundary conditions were numerically solved by utilizing the finite difference method. A series of laboratory drying experiments were performed using a computer-controlled dehydration system, which was developed to obtain data of drying kinetics under varying operating conditions for the validation of the predicted results from the proposed model. The experimental results has shown a very good agreement with the predictions of the model, which indicates that the proposed numerical model can be used with confidence as a tool in optimizing the design and operation of the fabric drying system. A parametric study was performed using the modeling tool has demonstrated the impact of key operational parameters on the drying kinetics, which has significant meaning on improving fabric’s appearance smoothness and decreasing the damage. It is expected that the model can be applied for other fiber products and processes involving similar phenomena.

Enhancing the energy efficiency of domestic dryer by drying process optimization

ABSTRACT The domestic tumble dryers are becoming indispensable household appliances and responsible for up to 10% of the total residential energy use in developed countries. However, their energy efficiency is low. In this paper, the development of a multi-sensor computer-controlled prototype platform for fabric drying is described for improving the efficiency of dryers. The prototype platform enables the real-time control and recording of key drying parameters including heater power, air flow velocity, rotating speed of drying drum, and drying cycle time. These parameters are automatically adjusted according to the exhaust air humidity instead of the temperature which is used traditionally. Additionally, a new drying model of dividing the drying process into four stages based on the humidity of the exhaust air has been investigated to further increase the energy saving. The performance of this staged drying model is experimentally evaluated in respect to energy consumption, drying time, and the smoothness of fabric after drying. The results clearly indicate that the staged controlling of heating power input not only decreases energy consumption by 21.5%, but also improves the fabric smoothness by 0.9 grade compared to using a single heating power input for the whole drying process. The research outcome can enable the design and production of new dryers that are more energy efficient and lead to dried clothes that require less ironing, which in turn further reduces energy consumption.

The relationships between washing parameters, fabric movement and wrinkling in a top-loading washer

Easy care for clothing is increasingly important, but the major problem is still the severe wrinkles formed on garments after machine washing. In this research, orthogonal tests and the analysis of variance (ANOVA) at a 95% confidence level were used to determine the critical parameters that affect fabric smoothness. We developed a video capturing and processing system for dynamic measurements of fabric in a top-loading washer to find the relationship between fabric movement and wrinkling performance during laundering. The ANOVA results showed that the smoothness of woven cotton fabrics was mainly affected by the washing load and the drum rotating speed, with p values of 0.000 and 0.036, respectively. Additionally, a relation models for fabric movements suggested by a curvilinear regression analysis indicated that the main causes of fabric wrinkling during top-loading washing were liquor ratio and the centrifugal force imposed on the fabric. The smoothness grade increased with the decrease of washing load and drum rotating speed, since these settings led to lower liquor ratio with a constant water volume and less stress on the fabric. The results of this study provide valuable information for the optimization of washing programs for fabric smoothness.

Research on physical properties change and damage behavior of cotton fabrics dried in drum-dryer

Abstract In order to investigate the impact of the repeated drying in dryer on physical properties of cotton fabric, smoothness appearance (SA), dimensional shrinkage, bending stiffness, Scanning electron microscopy (SEM), thermo-gravimetric analyzer (TGA) and x-ray diffraction (XRD) were employed. Results showed that smoothness appearance grade of cotton fabrics significantly depended on drying cycles during first 15 drying cycles. The dimensional shrinkage of cotton fabric was slight and had no relationship with drying cycles, and the shrinkage in the warp direction (1.29-1.71%) is higher than that of weft direction (0.002-0.045%). The bending stiffness was enhanced by drum-drying based on the bending stiffness data. And found that drying had little effect on thermal stability and crystallinity of cotton fibers. This indicated that drying only affected the appearance physical properties of cotton fabric such as appearance smoothness, dimensional stability, did not change composition and molecular structure. And from multiple levels including fabric-level, yarn-level and fiber-level, explained reasons of fabric properties change (namely, damage behavior). Moreover, this finding is not only helpful to understand of damage mechanisms of cotton fabrics drying in dryer, but also provided reference for dryer manufacturers to accurately specify the types of clothing that can be dried by using a dryer.

Feature-based 3D reconstruction of fabric by binocular stereo-vision

Generally, image-based evaluation on the performance of textile appearance such as smoothness and pilling was interfered by fabric pattern, color, and illumination. In this paper, a new method was used to reconstruct a 3D surface of fabric based on image’s features which could eliminate the influence of surface texture. Concretely, two parallel-placed digital cameras were calibrated based on planar pattern and the captured binocular images were rectified through epipolar line. The feature points of binocular images were extracted by the Scale-Invariant Feature Transform which could detect and describe local features of images was insensitive to transformations and colors. Based on the similarity in descriptor and a geometric constraint, pairs of sparse matched points were detected and were regarded as the source points of diffusion regions. Remaining points of the overlapped areas were then matched based on normalized cross correlation in “best-first” principle. The outputs of the system included a surface disparity map and the space coordinate of fabric. The experimental results showed that the high-fidelity 3D fabric surface reconstructed by the new method was insusceptible to fabric structures, colors, fiber contents, etc., providing available solution for the further inspection on the performance of textile appearance.

RFID-Embedded Smart Washing Machine Systems in the Big Data Era: Value Creation in Fashion Supply Chain

Both RFID and intelligent decision support system have been widely integrated into manufacturing and retailing. In this paper, the RFID-embedded smart washing machine (RFID+SWM) is proposed and its intelligent decision support system prototype is described. It is discussed that how this application and system create values to the fashion industry through data analysis. The data from RFID+SWM is recorded, stored, and analyzed for decision making. For example, the fashion color trend is analyzed by using consumer washing data from the RFID+SWM. The proposed intelligent decision support system is identified to monitor customers’ apparel wearing behavior at the usage stage and to provide various values to change product development, production planning, and retailing management in the fashion business. The new era’s fashion business becomes smarter with intelligence, interconnection, and visibility. The proposed technology and developed prototype system help optimize business process in the fashion supply chain.

Steam impinging and heat and water spreading in fabrics

This study is about the heat and mass transport phenomena in a system with steam jet flow to eliminate/alleviate cloth wrinkles. We first adopted a theoretical approach to derive the mean capillary radii so that a fabric can be characterized as an assembly of capillary tubes with varying diameters. We then analyzed the processes as a heat transfer via the fibers and water via the pores in fabrics of different anisotropies. During water movement, the water weight actually intensifies the inherent anisotropy of the fabric in the water flow pattern. For heat transfer, the water weight becomes irrelevant and both convection and radiation are shown to be too trivial to include. Corresponding experiments are also conducted, using infrared and visible light cameras to record the heat and water flow processes, respectively. The results are compared with the theoretical predictions and the discrepancies are explored and explained.

Optimization and performance evaluation of silk fabrics dried in the domestic dryer

Abstract To determine the optimal drying procedure for large load and non-ironing procedure for small load when silk fabrics were drying-cared in daily usage; change in appearance, mechanical properties and microstructure of silk fabrics before and after drying with various drying parameters (heater power, air velocity and drum-rotating speed) were investigated. Results revealed that the performance of silk fabric after drying is more sensitive to air velocity (humidity of drying-air) rather than heater power (temperature). Heater power of 3000W, air velocity of 8.5m/s and drum rotating speed of 45-50rpm (No.2) was proved to be optimal for drying silk fabrics due to its ideal smoothness appearance, dimensional stability and drying efficiency. When consumers dry a small amount of clothes, a drying procedure of heater power of 3000W, air velocity of 8.5m/s and drum-rotating speed of 0rpm (No.6) is more reasonable procedure because it reduces or eliminates ironing. And indicating drying in dryer can be an effective alternative to indoor-drying or sunlight-drying if suitable procedure being set. This finding provided reference for manufacturers to design and improve of dryers, especially for drying procedures optimization of delicate textiles, and consumers a feasible care method without reducing the quality of fabric.

Wrinkling mechanism of woven cotton fabrics during domestic tumble drying

ABSTRACT Cotton wrinkling after home laundry has become an unfavorable phenomenon for consumers for a long time. Research has indicated that the wrinkles during tumble drying result from complicated changes of fabric physical properties as well as drying parameters such as temperature of drying air and drying duration. However, most of the research that has been done in this field has showed certain limitations, such as not simulating the real drying process or not understanding the cotton wrinkling mechanism accurately. This research, through an experimental design of 21 cotton fabrics in tumble drying, has explained the wrinkling behavior of woven cotton fabric in different drying stages and has investigated the wrinkling forming stage during tumble drying. Results showed that fabric characterization (such as thickness, density, and weight) does not significantly influence the smoothness appearance of the cotton fabrics in the tumble dryer. Moreover, heater power in the falling-rate period (heater power 2) and relative humidity dividing point between falling-rate period and unheated air blowing stage (air RH dividing point 2) were the most important factors that influenced the smoothness appearance of cotton fabrics. Therefore, it is indicated that wrinkles are formed in the latter part of the drying cycle. The results can provide a reference for dryer design and drying performance optimization.