Carpet Yarns Research Articles

Vibration Reduction of the Nonlinearly Tufted Carpet Yarn by a Modified Sliding Mode Control Method

The yarn vibration causes the yarn tension value to fluctuate, causing a change in the amount of yarn feed, thus causing a deviation of the carpet pile height from the predetermined value. To solve this problem, the sliding mode control algorithm is used to design the sliding mode function and the sliding mode control law. And four variables in the yarn vibration system are controlled by the MATLAB software. For solving the chattering problem of the control law, the sliding mode control law is improved. The fuzzy sliding mode control algorithm based on the quasisliding mode is adopted. The results show that the sliding mode control algorithm is effective, but the sliding mode control force needs to be switched at high frequency and there is severe chattering. The fuzzy sliding mode control algorithm based on quasisliding mode is adopted to achieve better control effect with a smaller force. In addition, the control force does not have high‐frequency switching, and the change is relatively stable, which reduces the chattering phenomenon of sliding mode control.

Vibration characteristics of yarn in the tufted carpet machine

To control the yarn vibration in a reasonable range and to improve the quality of tufted carpet, it is very important to understand the vibration characteristics of yarn correctly. The transverse vibration equation of yarn is established using Newton’s second law in different paths, and then the yarn vibration characteristic curves in different regions are obtained. Firstly, the yarn path is divided and the optimal constitutive model of tufted carpet yarn is determined. Secondly, the transverse vibration is built by analyzing the force of yarn means. Then, the partial differential equation of yarn vibration is simplified as an ordinary differential equation by the Galerkin truncation method. The equation is solved numerically by using the Runge–Kutta method, obtaining the yarn amplitude in different regions. The vibration characteristics of the yarns after the jacquard parts are emphatically analyzed, and the effects of the speed, tension and damping coefficient on the vibration characteristics of yarns are also discussed. Finally, the results are verified by experiments.

Investigation of mordants for dyeing of yarns in ancient Persian carpets (15th–17th century) by IBA methods

This research work presents the application of proton induced X-ray emission (PIXE), to the study of carpet yarns collected from ancient Persian carpets belonging to Safavid period (1499–1722 CE). The elemental concentrations in the yarns of precious carpets were measured and compared with the corresponding data extracted from a set of prepared wool yarns dyed by the conventional mordant dyeing process. The results indicate the possibilities for identification of the applied dyes and mordant as well as inorganic impurities present in the carpet yarns. This could assist the art historians to understand the history of ancient carpets and variation of its constituent yarns through the ages. Based on the collected information, the museum restorers could be advised to adopt the appropriate mordant dyeing techniques for high quality restoration of these unique carpets.

Alternative plants to be used in natural dyeing on wool yarn fibers

ABSTRACTIn this study, 28 plants were collected from nature and the extracts were obtained with and without mordants from these plants. The wool yarns (3.5 N m natural wool carpet yarns obtained from the natural fibers 60 s, 23.3 µm, 10−4 cm) were colored by each of these extracts and the light and abrasion fastness of obtained colored substances of various colors were determined. While the plant showing the highest light fastness was walnut tree leaf (Juglans regia), the plant showing the highest abrasion fastness was determined as quince leaf (Cydonia oblonga). On the other hand, while the ferric sulfate as a mordant provided the highest light fastness, the highest abrasion fastness was obtained from the experimental group to which mordant was not applied.

An improved viscoelastic model for tufted carpet yarn

To overcome the problem that the existing mathematical model cannot characterize the viscoelastic properties of tufted carpet yarn completely and accurately, an improved viscoelastic model is built using the semi-empirical method. Using the test data of creep and stress relaxation, the parameters of the improved model are determined. Through the evaluation of fitting effect, the optimal mechanical model to characterize the viscoelastic properties of tufted carpet yarn is obtained. The results show that compared with the standard linear model, the improved model is more suitable to characterize viscoelastic mechanical properties of tufted carpet yarns, such as the creep and stress relaxation properties, which provides a solid theoretical foundation for analysis of vibration characteristics and dynamic tension control of tufted carpet yarn.

An improved method to analyze the tensile behavior of carpet yarn

Since the strain, friction, and vibration of carpet yarn have direct impact on the quality of tufted carpet, mechanical properties of yarn play an important role in carpet weaving. An improved method based on Boltzmann superposition principle for describing mechanical behavior of carpet yarn is presented in this paper, which greatly reduces the amount of calculation and further improves the fitting precision. To estimate the performance of the model, we carry out some experiments on carpet yarn specimens, and compared with a nonlinear viscoelastic model widely used in studying nonlinear material. The results showed that the improved method and the nonlinear viscoelastic model perfectly fit the stress relaxation experimental curves when the deformation of the specimens is small, however the improved method is more accurate than the nonlinear viscoelastic model based on single integral constructive equation when the models are used to predict the stress relaxation responses.

Compression molded composites from discarded nylon 6/nylon 6,6 carpets for sustainable industries

Discarded carpets with high amount of petroleum-based fibers are usually disposed in landfills, leading to waste of high value petro-polymers and environmental pollution. A novel method to reuse nylon carpet targeting environmental protection and material saving was developed. Recent studies showed that melt blended nylon carpet composites by screw extruder had low mechanical properties and disqualified carpet composites in transportation and construction industries. In this research, compression molded composites from discarded nylon 6/nylon 6,6 carpets had good sound absorption, mechanical properties and water stability. As compared with jute/PP composites, the compression molded composites from nylon 6/nylon 6,6 carpets had up to 40%, 59%, 124% and 32%, higher sound absorption, flexural strength, elastic modulus and impact resistance, respectively. Unshredded nylon 6,6 carpet yarns and styrene-butadiene-rubber/calcium-carbonate binders in carpets reinforced nylon 6 and polypropylene, and thus made the composites strong. Styrene-butadiene-rubber particles and multiple interfaces in the multi-component composites endowed compression molded nylon 6/nylon 6,6 carpet composites with good sound absorption. Developing compression molded carpet composites with good mechanical properties and sound absorption provides a new method of reusing carpets.

TRADITION OF VEGETABLE DYEING IN FETHIYE AND CURRENT STATUS

Natural and vegetable dyeing which has a long tradition in Turkish culture was unable to compete with artificial dyes in time and has come to the point of being almost non-existent in many important weaving center. Fethiye has a distinct place in Anatolian weaving culture with a unique woven carpets and flat woven tradition. Vegetable dyeing is still trying to continue with the traditional recipes in the Fethiye region. In this study, it is aimed to explain traditional dyeing methods with endemic plants used in dyeing of carpets and flat weaving yarns’ of Fethiye region. In the area, plants such as walnut leaves and bark, elm bark, thyme, euphorbia, acorns, quince leaves, and also artificial dyestuffs are often used in dyeing of knot yarns of carpet. Widely practiced methods in dyeing as follows: firstly wool carpet yarns dyes with vegetable dyestuffs and then the dyeing process continues with the addition of artificial dyes to colored water. Dyeing of yarns of flat weavings are used some plants such as walnut shells and leaves (Juglans regia L.), vine leaves (Vitis vinifera L.), quince leaves (Cydonia vulgaris Pers.) euphorbia (Euphorbia sp.), onion skins (Allium cepa L.), poplar bark (Populus alba L.), elm bark (Ulmus laevis), thyme (Thymus), fumarium (Fumaria officinalis L.), acorn (Quercus aegilops L.), almond leaf (Amygdalus orientalis Miller), and barberry root (Berberis vulgaris L.). Alum and citrus fruit are frequently used mordants in the region and they are located in many dyeing recipe as natural mordants. Citrus fruits, alum and the salt and sometimes colored water obtained with walnut shell are used as mordants. Preparing to dye of yarns with some of these mordants by pre-processing is called acimiklama. Blue, green, red, yellow and shades of these colors are generally dyed in the region. Recipes concerning these colors were presented in detailed. Keyword: Fethiye, carpet, rug, flat weaving, dyestuff, vegetable dyeing

Study of engineered carpet yarns structure; Part B: By cross-sectional microtomy

This paper describes the measurement of packing density and radial packing density of newly developed three-layered, wool structure yarn for pile carpets. Three different varieties of Indian wool, in terms of fibre diameter, medullation and bending rigidity, were strategically positioned in the (ring spun) yarn cross-section. The measurements of all the researched yarns have shown that radial packing density is neither uniform across the yarn cross-section nor maximum at yarn core. The maximum packing density of these yarns occurs at some different distances from the yarn axis and it sharply decreases from that point towards yarn surface. In general, all the yarns are seen to have slight hollowness near their axis. The possible mechanism of the fibre density distribution in the yarn cross-section is also discussed.

New approaches to engineer the yarn structure; Part A: For better carpet performance

Invariably different fibres are mixed homogeneously at yarn stage to obtain the desired carpet characteristics such as resiliency, lustre, reduced shedding and cost reduction. In order to fully exploit the individual fibre characteristics, i.e. fibre diameter, medullation and bending rigidity, an attempt has been made to engineer the carpet yarns to strategically position different characteristics of fibre across the yarn cross-section. Accordingly three layered engineered yarns of 4 Nm linear density of different fibre components as in control yarns, i.e. Malpura Magra and Chokla wools to 1:4:5 in inner, middle and outermost layer, respectively, were produced by using modified SIRO spinning method on worsted spinning system. The recovery property of yarns was found to be better for all engineered yarns as compared to control yarns. Carpet made from considered yarns were subjected to compression, dynamic loading and abrasion for assessing their performance. Higher bending rigidity and recovery properties of control and engineered yarns have improved the carpet performance. Carpet resiliency was found to be better for carpet made from engineered yarns. The engineered yarn carpets give lower abrasion loss and carpet thickness loss under dynamic loading. Among all the control and engineered yarns, carpets made from two layered roving to obtain three-layered yarn have yielded best results.

Genuine information sources in colouring woollen carpet yarn with vegetable dyes and archiving

Genuine information sources in colouring woollen carpet yarn with vegetable dyes and archiving

Elastic Rod Based Carpet Loop Pile Trajectory Simulation

The 3D simulation of tufted carpet pile loops need to calculate the direction loop pile. By simplifying the tufted carpet yarn into elongated elastic rod, without considering the extrusion between loops piles, applying pressure at both ends of loop pile. By analyzing the elastic rod stress deformation and using Matlab simulate to determine the yarn centerline direction with the flexible line. The simulation results show that the obtained yarn centerline path is consistent with the trend of actual loop pile.

Analytical approach of creep behavior of carpet yarn

Based on mechanical models, the creep behavior of carpet yarns after dynamic loading was investigated. For prediction the creep elongation, the frequently used mechanical models reported in the literature were analyzed. The mechanical models which were used in this article were: standard linear model, four-element model, two-component Kelvin's model, and Eyring's model. The obtained creep formulas were fitted to experimental creep data, and the parameters of the model can be obtained using the Marquardt algorithm for nonlinear regression. When comparing the experimental creep curve with the fitted curve from the mechanical model, it is clear that the four-element model explain the experimental creep curve better. During tufting machine stops, the carpet yarns were undergone constant load. The confirmed viscoelastic model will be used to calculate total creep elongation during carpet machine stoppage. Thus, the start-up marks which occurred at carpet machine restarts can be exactly eliminated by adjusting the feeding length according to the creep elongation. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Analytical approach of mechanical behavior of carpet yarn by mechanical models

The viscoelastic models for describing mechanical behavior of polypropylene carpet yarn are presented in this paper. Since carpet yarn is subjected to tensile and frictional forces during tufting, the mechanical properties are important material features especially in vibration analysis. In this paper, the standard linear model and the standard nonlinear model are developed to simulate the polypropylene yarn tensile, stress relaxation and creep behaviors. The obtained formulas are fitted with experimental data and the ideal model parameters are determined by applying least squares. The results showed that the standard linear model fits well the tensile, relaxation and creep experimental curves, and will be employed to analyze the vibration characteristics of yarn during the tufting.

Study on the Intelligent Creel of Advanced Carpet Loom

The detailed design and development of the intelligent creel mechanical structure and control system is based on the research and analysis of specific operation and practical functions, which realizes its functions of intelligent analysis, right amount of supply and prompt storing. As the transmission of the carpet yarns from the storage unit to the loom, the intelligent creel is able to automatically make analysis of the usage amount of different yarns according to different orders, makes more reasonable supplies to the loom and prepares yarns before used up, which makes best use of the yarn and increases the production efficiency. Meanwhile, a lot of time and labor of replacing yarns is saved.

Viscoelastic Modeling of Yarn for Tufting Carpet

The viscoelastic properties of polypropylene yarn, used to analyze the stress-strain behavior are characterized in this study. Since the yarn is subjected to dynamic tension and friction during the tufting process, the various mechanical properties are important parameters. In this article, the normal linear solid model and the nonlinear model consisting of spring and dashpot were presented to model the tensile and stress-relaxation response of polypropylene carpet yarn. Then, the experimental data were fitted with the two models to obtain the parameters by applying least square fitting. The result suggests that the standard linear model provided the best fit for the experimental data of the tensile and stress-strain behavior of yarn. The material model can be employed into analysis of vibration characteristic of yarn in tufting carpet process.

Results of a Plant–wide Assessment at an Integrated Carpet Yarn Plant

The Georgia Tech Energy and Environmental Management Center (EEMC) and Shaw Industries partnered to conduct a plant-wide energy assessment at a South Carolina carpet yarn plant. The study was jointly funded by Shaw and the US Department of Energy. The plant manufacturing process begins with the conversion of caprolactum monomer into nylon, and concludes with the twisting of nylon filaments into yarn and heat setting. The energy assessment addressed every phase of the production process. Energy saving improvements for boilers, air compressors, HVAC, yarn extruders, and twisters were discovered. In addition, opportunities to improve general energy management practice at the facility were found. The final energy assessment report contained 18 recommendations with an estimated energy savings of $925,853, or 13.8 percent of the plant's annual energy cost.

Electrostatic Application of Carpet Yarn Spin Finishes as a Strategy for Reducing Environmental Water Pollution: Theoretical Basis

High-speed processing of yarns into carpet and textile consumer products generally requires application of friction-reducing coatings onto the fibers. Such coatings, often totaling up to 1 1/2 - 2 wt% as applied both by the original fiber manufacturer and additionally by the final product manufacturer, facilitate trouble-free movement of the fibers across surfaces and through guides associated with weaving and other manufacturing operations. These yarn spin finishes unfortunately present significant air- and water-pollution concerns in the final stages of production. Their volatilization during heat-setting of yarns generates appreciable emission of VOC air pollutants in both the ambient and the workplace atmospheres. Their removal by product-washing operations results in spin finishes typically contributing up to 60-70% of the COD pollution load of wastewater effluents from carpet manufacturing plants. Due primarily to lack of uniformity of the fiber coating achieved by conventional application methods, excess spin finish is routinely dispensed at the time of spinning polymeric fibers to ensure satisfactory performance. Furthermore, it is topically applied to the peripheral surface of the coalesced fiber bundle and not more effectively onto the individual filaments, which comprise the bundle as they issue from the spinnerets; typically 60-120 such filaments are brought together to comprise one fiber threadline. This paper reports the theoretical basis of an electrostatics-based process and engineering prototype for the precharging of high-speed dielectric-filament arrays, the electrohydrodynamic spray application of charged spin finish thereon, and the net charge balance/neutralization of such coated fibers. Prototype evaluations on-line at a full-scale 15 m/s polymeric-fiber production unit will subsequently be presented.

Factory‐scale proving trials using combined mixtures of three by‐product wastes (including incinerated sewage sludge ash) in clay building bricks

AbstractThis paper reports the results of a series of factory trials which has been recently completed involving Staffordshire University, a major United Kingdom water company and a commercial brick manufacturer, which demonstrate the practical possibilities of incorporating three by‐product wastes, waterworks sludge, incinerated sewage sludge ash and carpet yarn, into the commercial brick‐manufacturing process as a sustainable alternative to their current disposal route of landfill. An initial laboratory development programme primarily involving waterworks sludge or water treatment residue (WTR) confirmed the technical feasibility of its use in brick‐making as an alternative disposal route. However, owing to the very high water content of this waste when freshly produced, ranging between 85 and 70% depending on individual sources, its introduction into the commercial brick‐making processes was identified as likely to present practical difficulties. Consequently, to overcome this problem the reported work describes a successful way in which the handling of WTR was improved by pre‐mixing it with the two other by‐products that jointly possess water‐absorbing properties and the ability of improving the unfired strength of the experimental products. This investigation then progressed from the laboratory to full‐scale brickworks trials encompassing the manufacture of >300 000 experimental bricks. This work programme also included emission monitoring during the firing process, together with full physical testing of the experimental products for direct comparison with the standard commercial products manufactured at the collaborating brick factory.© 2002 Society of Chemical Industry

Measuring Nylon Carpet Yarn Heat History by Remote NIR Spectroscopy. Part II: Applying Remote Fiber Optic NIR Techniques to the Manufacturing Environment

Part I of this series demonstrated the Near-IR (NIR) method of determining the heat-set temperature (HST) of carpet yarn on bobbins in the laboratory, using a remote fiber optic probe. Part II describes an at-line NIR technique to determine the HST of carpet yarn bobbins at three manufacturing sites. At-line NIR measurement of HST is expanded to evaluate the influence of machinery and yarn processing factors, environmental factors, and quality differences. Optimized Suessen and Superba HST at-line NIR calibrations are developed in the laboratory and successfully transferred and verified on the manufacturing floor. Very good agreement is obtained between the stated HSTS and NIR-determined HSTS for samples with a wide range of HSTS and routine production samples, which exhibit quality differences in manufacturing. The major influence on NIR-determined HST results is the temperature and %RH in the manufacturing area; the NIR calibration can be readily adjusted with a control bobbin to offset these environmental effects without loss of method accuracy. An analytical methodology is presented for developing and transfering (verifying and validating) NIR measurements from a laboratory to an at-line analysis in the manufacturing area. Operational concerns and other procedural details include sample matrix effects, data treatment, temperature and environmental impacts, instrument parameters, and details of the experimental process.