Intelligence control of on-line dynamic gray cloth inspecting machine system module design. I. Tension controller design

Tension is very closely related with fabric inspection quality, as not well controlled tension of gray cloth will lead to stretch, relax or fold of gray cloth, so that no sharpest image can be taken. Now that gray cloth tension and convey speed are related with taking sharp image, so this study attempts to design a gray cloth tension control module, develop the intelligent online dynamic gray cloth defect automatic detection system. Gray cloth tension control module makes direct regulation of structural tension of feed and wind rolls and conveys speed control module by load cell coupled with A/D, D/A signal conversion and two sets of inverters. This study utilized fuzzy control theory to design controller so as to keep surface tension consistency of gray cloth, improve recognition rate of gray cloth defect, so that the system can have high action efficiency. In previous fuzzy controller designs, membership functions were often designed by means of trial-and-error method, which usually cost much time. This study used Taguchi method to make membership function programming, and made main effect analysis to choose a group of optimal membership function combination. Through systematized, efficient experimental design, tension controller designed in this study could stabilize gray cloth tension very soon, and acquire sharp gray cloth image.     

Dynamic modeling and control of a padder roller system

This is the first time in the literature dealing with the dynamic modeling and control of a rotating padder roller system. It is intended to design a control system with effective scheme and robustness to stabilize all vibration modes of a rotating padder roller system by using one set of sensor and actuator. The controller design depends on the specific pole-zero patterns. In practice, the pole-zero patterns remain the same, no matter how the physical system parameters are different. By properly placing the actuator and sensor, a realizable controller and sensor is designed to stabilize all the vibration modes and make the closed loop system absolutely stable. This will suppress the vibration without suffering from spillover and can eliminate an infinite number of vibration modes. The performance of this controller has been successfully implemented by computer simulation.     

Analysis and construction of a quality prediction system for needle-punched non-woven fabrics

In this study, polyester and polypropylene staple fibers were selected as the raw material, and then processed through roller-carder, cross-lapper and needle-punching machine to produce needle-punched non-woven fabrics. First, the experiment was planned using the Taguchi method to select processing parameters that affect the quality of the needle-punched non-woven fabric to act as the control factors for this experiment. The quality characteristics were the longitudinal and transverse tensile strength of the non-woven fabric as well as longitudinal and transverse tear strength. The L₁₈ (2¹×3⁷) orthogonal array was selected for the experiment as it offered an improvement on the traditional method that wastes a lot of time, effort and cost. By using the analysis of variance (ANOVA) technique at the same time, the effect of significant factors on the production process of needle-punched non-woven fabrics could be determined. Finally, the processing parameters were set as the input parameters of a back-propagation neural network (BPNN). The BPNN consists of an input layer, a hidden layer and an output layer where the longitudinal/transverse tensile and tear strength of the non-woven fabric were set as the output parameters. This was used to construct a quality prediction system for needle-punched non-woven fabrics. The experimental results indicated that the prediction system implemented in this study provided accurate predictions.     

Dynamic modeling and control of pressure dyeing machine’s running roller system

Key factor determining production quality is the deformation control between running rollers of pressure dyeing machine during the operation. Currently the industrial communities try to alleviate the defects by taking experiments. This study aims to approve theoretical practicality of providing controller and its parameters suitable to abolish vibration displacement in operating pressure dyeing machine in order to improve pressure dyeing quality and lengthen machine’s life. Firstly, the dynamic equation of the pressure dyeing machine’s running roller is derived and its corresponding open-loop transfer function is obtained from modal summation method. Then, the root locus method is used to design a controller which is realizable in the industrial communities. Simulation indicates that the designed controller not only can eliminate vibration response generated during pressure dyeing process and reducing greatly the previous process defects by making the two running rollers smoothly contact with each other. The solution is a high efficient way to ameliorate pressure dyeing process with low cost and easy access.     

Ultra-porous flexible PET/Aerogel blanket for sound absorption and thermal insulation

Ultra porous and flexible PET/Aerogel blankets were prepared at ambient pressure, and their acoustic and thermal insulation properties were characterized. Two methods were selected for the preparation of PET/Aerogel blanket. Method I was a direct gelation of silica on PET. PET non-woven fabric was dipped and swelled in TEOS/ethanol mixture, and pH of reaction media was controlled to 2.5 using HCl to promote hydrolysis. After acid hydrolysis, pH was controlled to 7,8,9, and 10 with NH₄OH for the condensation. Method II was by the dipping of PET non-woven fabric in the dispersion of Silica hydrogel. The gelation process was same with Method I. However, PET fabric was not dipped in reaction media. After the hydrogel was dispersed and aged in EtOH for 24 hrs, then, PET non-woven fabric was dipped in the dispersion of hydrogel/EtOH for 24 hrs. The surface modification was carried out in TMCS/n-hexane solution, then the blanket was washed with nhexane and dried at room temperature to prevent the shrinkage. The silica areogels synthesized in optimum conditions exhibit porous network structure. Silica aerogel of highly homogeneous and smallest spherical particle clusters with pores was prepared by gelation process at pH 7. When direct gelation of silica was performed in PET nonwoven matrix (Method I), silica aerogel clusters were formed efficiently surrounding PET fibers forming network structure. The existence of a great amount of silica aerogel of more homogeneous and smaller size in the cell wall material has positive effect on the sound absorption and thermal insulation.     

Mechanical properties and crystallization behavior of polypropylene non-woven fabrics reinforced with POSS and SiO2 nanoparticles

PP/POSS and PP/SiO₂ composite non-woven fabrics filled with polyhedral oligomeric silsesquioxanes (POSS) and SiO₂ respectively using a convenient blending method were prepared through melt-blown process with corona charging. The morphology of the composite fibers and the distribution of POSS and SiO₂ nanoparticles in PP matrix were investigated by field-emission scanning electron microscope (FSEM) and transmission electron microscope (TEM), respectively. POSS and SiO₂ can act as nucleating agent and accelerate the crystallization process during nonisothermal cooling. The shear storage modulus G??, loss modulus G??, and complex viscosity ??* of non-woven fabric reduce when 1 wt % POSS was added and increase for PP5/POSS composite non-woven fabric compared with pure PP non-woven fabrics. However, all G??, G?? and ??* of PP/SiO₂ non-woven fabric decrease with increasing SiO₂ content owing to plasticization by SiO₂. Both stress and elongation at break of the PP/POSS melt-blown non-woven fabrics are improved compared with PP non-woven fabrics, however decrease when SiO₂ was added, as compared to the neat PP non-woven fabric. The onset temperature of decomposition for both the PP/POSS and PP/SiO₂ composite non-woven fabrics is higher (5?C10 °C) than pure PP and char content is increased with increasing POSS and SiO₂.     

基于模糊算法的茶叶理条机温度控制设计

为了防止茶叶在理条过程中出现色泽变黄、变暗或产生焦味的现象,需要有效地控制理条过程中的温度,提高茶叶的加工质量。将模糊算法与理条过程的温度控制结合,运用Matlab对设计进行仿真及进行理条实验,表明主副加热部件模糊温度控制精度高,超调量小,碎茶率为6%（传统方式碎茶率为11.8%,单一加热部件模糊控制碎茶率为8.3%）,理条温度为90℃,评审分数为932.5分,优于传统理条方式与单一加热部件模糊控制理条方式,该研究为提高茶叶理条质量提供了参考。     

Carriage speed control of a cross-lapper system for nonwoven web quality

In a cross-lapper system, the carriage unit is used to make uniform web in appropriate width and thickness. Traditionally, this is a stable, sluggish system with large attenuation of the input in the steady state. In this paper, the modeling, stability, order reduction, dynamic analysis and controller design of a cross-lapper system for good nonwoven web quality will be presented to deal with this issue. A realizable controller is designed which can not only make the closed-loop system efficient for good tracking property but also can achieve the meaningful design objectives. The performance can be effectively shown from the computer simulation.     

Numerical Simulation of Tensile Behavior of 3D Orthogonal Woven Composites

In this paper, the composite reinforced with three dimensional orthogonal woven fabric/epoxy resin was fabricated with vacuum assisted resin transfer model. The tensile behavior in 0° and 90° directions were experimentally executed. The tensile behavior of 3D orthogonal woven composite was numerical simulated based on the unit cell model and compared with the experimental result, the influence of crack damage and stress on fiber, resin and fiber/resin interface was analyzed. The maximum differences between experimental and simulated results are 3.23 % and 7.94 %. The verified model can be used to simulate the other static and dynamic mechanical properties and analyze the influence of the behavior of component material on the mechanical material properties of 3DOWC.     

Self-organizing map network for automatically recognizing color texture fabric nature

The method of recognizing color texture brought forth in the present study is to employ unsupervised learning network to automatically recognize the fabric type and the main texture types. Firstly, the color scanner is adopted to extract fabric image which is afterwards saved as the digital image. Secondly,CIE-Lab color model is taken to obtain the feature value and wavelet transform is utilized to display the texture of the fabric image. Thirdly, co-occurrence matrix is employed to figure out the feature values of the texture structure such as angular second moment, entropy, homogeneity, contrast. Finally, self-organizing map (SOM) network is used as the classifier. The experiment result shows that the study can automatically and accurately classify the fabric types (including shuttle-woven fabric, jersey fabric and non-woven fabric) and main texture type of the fabric (such as plain weave, twill weave, satin weave, single jersey, double jersey and non-woven fabric).     

基于DMC-PID串级控制的茶叶远红外烘干机设计与试验

根据茶叶物料烘焙时具有迟滞、大惯性和非线性的特点,采用传统PID控制时温度控制精度不高,超调量较大,鲁棒性差。设计了一种基于动态矩阵控制的茶叶烘干机,烘干机采用多层隧道式,上加热方式,加热元件为电加热远红外辐射板,运用DMC-PID串级温度控制系统,前级的DMC算法提高温度控制系统的动态响应能力与鲁棒性;后级PID算法提高系统的抗干扰性能。对样机进行绿茶烘焙试验,试验表明,采用PID温度控制系统时烘干机超调量为10.5%,而采用DMC–PID串级温度控制其超调量为5.9%。DMC-PID可显著提高茶叶烘干机的温度控制精度及成茶品质。     

Optimisation of spinning parameters for processing of 100% sunnhemp fibers

This study was an attempt to spin 100% sunnhemp fibers, grown in Akola district of Maharashtra, India, on Jute spinning system. The sunnhemp fibers were first sprayed with oil and then softened. These fibers were then processed through various machine sequence by varying the number of carding and drawing machines. The yarn was spun in each case and tested for Count Strength Product and Evenness. This yarn was then used as a weft yarn to weave a 3/1-drill fabric with a cotton warp and tested for tensile strength. It was concluded that the set III with three carding and three drawing sequence gave an even yarn. The optimum twist per inch in the yarn was found to be 6.0.     

A study on coarse Hanji yarn manufacturing and properties of the Hanji fabric

Hanji (Korean traditional paper) yarn displays excellent humidity control, air permeability, and absorbency as well as pleasantness to the touch due to its structural characteristics, and thus, it has been developed as a new eco-friendly fibrous materials. In this study, Hanji, having a basis weight of 8 and 10 g/m², was prepared using mulberry fibers. The prepared Hanji was cut into Hanji tape of 5–10 mm in width using a rotary slitter and then the tape was twisted to manufacture Hanji yarn. To ensure a uniform twist of Hanji yarn and a smooth twisting process, a water supply system was designed to provide water directly at the twisting zone. At a fixed spindle speed, the feeding speed of the delivery roller was varied to provide different twist numbers for the Hanji yarn. The Hanji yarn manufactured with water treatment has higher tensile properties and a softer touch than the Hanji yarn prepared without water treatment. The Hanji yarns have count numbers of 7–11 Ne and tensile strengths of 1.0–1.2 gf/d. Moreover, the fabric from Hanji yarn shows an excellent color fastness of 4.0 grade, staining of 4–5 to washing, and 4–5 grade to dry cleaning.     

Application of one-quarter fractional and full factorial design to study set mark phenomenon of multifilament polyester fabrics

Set marks are fabric defects in weft direction which are caused by an interruption of the weaving process. In this study, based on one-quarter fractional factorial design, among eight parameters of weaving machine, i.e. horizontal and vertical position of back rest roller, horizontal position of warp stop motion, shed crossing degree, shed crossing point position, warp tension, stoppage position of machine, and stoppage time, four most effective parameters was determined. These parameters were stoppage position of machine, vertical position of back rest roller, shed crossing point, and horizontal position of warp stop motion. Then using full factorial design effectiveness of these parameters was evaluated statistically at 99 % confidence level and effect of them on set mark studied in detail. Statistical evaluations showed that the stoppage position of machine was the most effective parameters on intensity of set mark of multifilament polyester fabric. A specific image capturing device for using on weaving machine based on CCD camera was designed. Image processing technique was used to measure the pickspacing in stop zone objectively. Five picks before and five picks after stoppage was considered as stop zone and the standard deviation of pickspacing was used as a criterion which interpret this defect. Dynamic loading of warp yarns were execute to evaluate the relaxation behavior of polyester multifilament warp yarns.     

A new approach to evaluate the effect of body motion on heat transfer of thermal protective clothing during flash fire exposure

The effect of dynamic change of air gap between protective clothing and skin caused by continuous human body motion on thermal protective performance of protective fabric cannot be simulated in current bench-top test. In this study, a newly modified TPP test apparatus with a dynamic air gap manufacturing system was applied to investigate the effect of body motion on heat transfer of fabrics exposed to flash fires. Three different velocities of body motion were simulated respectively. The results indicated that the dynamic air gap with variation range of 0–25 mm significantly improved thermal protection of fabric comparing with no air gap, but approximated to static air gap of 6.4 mm width for different heat transfer modes. It was manifested that thermal protection had no linear relationship with the air gap width variation frequency due to convection heat in microclimate, and the TPP values was shown as 0.5 rps < 0.25 rps, 0.5 rps < 1 rps and uncertain for 0.25 rps with 1 rps. The amplitude of simulate epidermis surface temperature fluctuation had a negative correlation with air gap variation frequency. Most of the temperature curves rose smoothly along with periodical variation, only the temperature fluctuation of 0.25 rps could be observed in a variation cycle.     

Production and performance analysis of an antibacterial foot sweat pad

An antibacterial foot sweat pad was designed and produced by using materials of standard disposable absorbent hygienic products. Topsheet layer of the pad was modified by two volatile oils; cinnamaldehyde and geraniol and a standard zinc-based synthetic antibacterial agent. Physical properties of the sweat pad was arranged according to the sweat disposal amount and dimensions of a foot. Besides antibacterial performance of the topsheet layer of the pad, surface characteristics (friction test), bending rigidity of the modified topsheet layer, liquid absorption and transfer characteristics of the pad were also investigated. Subjective forearm test was conducted to determine effects of antibacterial coating materials on coolness and dampness to touch sensations created by the pads in dry and wet forms. According to the results, cinnamaldehyde created maximum antibacterial activity, which is better than the commonly used synthetic agent, on topsheet layer of the pads and geraniol had an acceptable performance. But cinnamaldehyde treated topsheet fabric became stiffer, rougher and its liquid absorption characteristics deteriorated significantly. Zinc-based synthetic antibacterial agent created higher coolness and dampness sensations during skin contact according to forearm test results.     

Enhanced visualization of simulated woven fabrics

The woven fabric graphics designed with available computer aided design (CAD) systems using different colored warp and weft yarns look quite different from the appearance of their actual fabrics. To enhance the visual effects of designed woven fabric graphics, this paper reports a modified CAD woven fabric system, which allows users to design a fabric using parameters including fabric weaves, yarn number, yarn material, fabric count, crimp shape of interwoven yarns, and illumination. This enhanced system can design both yarns and fabrics, and consider the transitional color effect around interweaving points of warp and weft yarns. Its simulation image quality of woven fabrics has been greatly improved, and several textile mills and universities are currently using this woven fabric design system.     

Dimensional and physical properties of plain knitted fabrics made from 50/50 bamboo/cotton blended yarns

In this study, the dimensional and some physical properties of plain knitted fabrics made from 50/50 bamboo/cotton blended yarns are investigated. In order to see the differences and similarities, the results are then compared with those for similar fabrics knitted from 50/50 conventional viscose/cotton and 50/50 modal/cotton blended yarns. Each fabric type was produced with three different stitch lengths. After all fabrics were dyed under identical dyeing conditions, they were subjected to dry and full relaxation treatments. For dimensional properties of fabrics, course, wale and stitch densities were measured. Then, by calculating statistically best-fit lines passing both through the experimental points and the origin, dimensional constants i.e. k values were predicted in terms of the fiber types. The result show that each fabric type knitted from bamboo/cotton, viscose/cotton and modal/cotton blended yarns behaves in a similar manner. However, in both dry and fully relaxed states, the modal/cotton knitted fabrics tend to have slightly higher k values than the bamboo/cotton and viscose/cotton knitted fabrics. For physical properties, fabric weight per unit area, thickness, bursting strength, air permeability and pilling were evaluated. The results show that the weight, thickness and air permeability values are independent of the fiber type. Plain knitted fabrics from modal/cotton blended yarns have the highest bursting strength values. Plain knitted fabrics from bamboo/cotton blended yarns tend to pill less.     

Quality control of card web uniformity for a vertical-type cross-lapper machine. I. Dynamic system modeling and industrial controller design

This series of paper addressed the quality control of a vertical-type cross-lapper machine, which is used to produce uniform layers of fibers with suitable widths and thicknesses. The nonlinear model of the system was derived, and the corresponding state space representation was obtained. The linearized model based on the equilibrium position of the nonlinear model was generated, and the associated control property was analyzed. The high order linearized model would be reduced to a verified lower order model for control system design. The designed traditional and modern controller could make the crosslapper machine for good card web quality control.     

Characterizations of stick-slip stage of yarn pull-out in dry and softening treated polyester plain woven fabric

The aim of this study was to understand the stick-slip properties of polyester plain woven fabric. For this reason, pull-out test was conducted on dry and softening treated polyester woven fabrics. It was found that stick-slip force and accumulative retraction force depend on the number of pulled ends in the fabric, fabric sample dimensions and softening treatments. Stick-slip forces of polyester fabric in the multiple yarn pull-out test were higher than those of the single yarn pull-out test. Stick-slip force in single and multiple yarn pull-out tests in the dry polyester plain fabric were generally higher than those of the softening treated polyester plain fabric. On the other hand, the amount of stick-slip force was related to the number of interlacement points in the fabric whereas the amount of accumulative retraction force was related to fabric structural response.