Hygral Expansion Research Articles

DCCA 처리와 산소 저온플라즈마 처리가 양모직물의 형태안정성과 태에 미치는 영향

Wool fabric was treated with oxygen low-temperature plasma (LTP) and dichloroisocyanuric acid. The effect of dimensional stability (relaxation shrinkage, hygral expansion, felting shrinkage), tensile strength and elongation, crease recovery, and hand of wool fabric between LTP, DCCA treated wool fabrics and control wool fabric were investigated. SEM photograph showed that a little micro crack was formed on the fiber surface by plasma treatment with hard condition and epicuticle scale was damaged by DCCA treatment. Felting shrinkage, tensile strength and total hand value were much different in each samples.

Influence of pH on hygral expansion, relaxation shrinkage and extensibility of wool fabric

The standard tests for relaxation shrinkage and hygral expansion of wool fabric take no account of pH. It is shown in this work that the pH of the solution in which wool fabric is relaxed as part of the procedure for measuring dimensional properties has a significant influence on the results. At around pH 4.8, which is close to the isoelectric point of wool, the hygral expansion reaches its greatest value and drops at both lower and higher pHs. A similar relationship between pH and extensibility of wool fabric was observed. Values of relaxation shrinkage were found to be dependant on pH. The reasons for the pH dependence of dimensional properties are discussed and these include changes in wool fiber swelling, yarn crimp and polymer relaxation phenomena with changes in pH.

The design of laminates with given thermal/hygral expansion coefficients: A general approach based upon the polar-genetic method

The problem of finding laminates having null thermal and hygral expansion or curvature coefficients is addressed in the paper, as well as the case of laminates having an isotropic response to thermal or moisture variations. The main feature of this research is the fact that the problem is treated and solved in the most general case: no simplifying hypotheses are made about the type of the stacking sequence, and the design procedure can also take into account elastic properties of the laminate, such as orthotropy, uncoupling and so on. The authors state the problem as a nonlinear programming problem, where a unique objective function includes all the requirements to be satisfied by the solutions. The nonlinear optimisation problem is stated and solved in the framework of the polar-genetic approach: the formulation is a function of the laminate polar parameters, while a genetic algorithm is used as numerical solving technique. A large number of numerical results are shown in the paper.

Preserving Wool Fabric Properties During Dyeing Using Some Maleic Acid Derivatives

The protective effects on wool dyeing of three compounds containing activated double bonds are studied and compared with some commercially available products. Wool fabric is dyed under different conditions with Kiton Fast Blue CR 200 in the presence of N-(trifluorophenyl) maleamic acid, N-(1-naphthyl) maleimide, N-(trifluorophenyl) male imide, Irgasol HTW NEW, and Miralan HTP. The consequences of the treatments are evaluated in terms of tensile strength, permanent set, and hygral expansion of the fabric samples. Optimal values of temperature, pH, and concentration of protective agent are determined for minimal changes in fabric physical properties during dyeing. The results show that two different chemical mechanisms can be used to explain changes to the physical properties that occur during the wool dyeing process.

Developments and trends in radiation curing

Six model dyes and two colourless compounds having different functionality were prepared, and their dyeing properties and the effect on inhibiting wool set and fabric hygral expansion were investigated. It was found that hetero-bifunctional reactive dyes are more efficiently able to bond to wool fibre regardless of dyebath pH than mono-functional (monochlorotriazine) reactive dyes. Also, dyeing wool fabrics with hetero-bifunctional dyes and colourless compounds containing vinylsulphone residues clearly decreased the hygral expansion and inhibited permanent set, when compared to dyeings produced with mono-functional reactive and non-reactive dyes. The improvements in the two physical properties were found to increase with increased reactive dye or reactive compound concentration. Dyes containing a β-sulphatoethylsulphone group diffused more evenly than dyes containing a preactivated vinylsulphone group. It was also shown that the number of sulphonate groups in a dye molecule affected migration properties.

The effect of various anti‐setting systems in wool dyeing. Part 1: Hydrogen peroxide based systems

Extensive setting of wool fabrics occurs during piece dyeing at the boil and gives rise to adverse changes in dimensional stability such as variable hygral expansion, loss in tensile strength and the appearance of unsightly marks such as ‘crow's‐feet’ on the fabric surface. Anti‐setting agents such as stabilised hydrogen peroxide systems have thus been marketed to control this problem. Much has been published regarding the anti‐setting and hygral expansion properties achievable but little information regarding the chemical effect of boiling wool with acidic solutions of hydrogen peroxide is available. Fourier transform infrared reflectance spectroscopy has thus been extensively used to quantify the chemical changes occurring on boiling wool in such aqueous solutions of hydrogen peroxide.

Dimensional and Surface Properties of Plasma and Silicone Treated Wool Fabric

To improve the dimensional properties of wool fabric, two kinds of silicone polymers are applied to plasma pretreated wool. With this treatment, hygral expansion increases slightly but still remains smaller than that of silicone treated wool without the plasma pretreatment. The wrinkle recovery angles of wool increase with the treatment, and the values of fabric treated with plasma and silicone polymers are higher than those with no plasma pretreatment. In addition, the harsher handle imparted by plasma modification is improved with silicone treatment. The results show that the plasma pretreatment modifies the cuticle surface of the wool fibers and increases the reactivity of the wool fabric toward silicone polymers. Therefore, the combination of plasma and silicone treatments can improve the dimensional stability, wrinkle resistance, and performance properties of the wool. Surface smoothness of the treated fabrics as measured with a new evaluation system shows good correspondence with results from a KES-FB4 surface tester.

Effects of Silicone Treatments on the Dimensional Properties of Wool Fabric

This study evaluates the effects of silicone softeners on the dimensional properties of wool fabric. Samples are treated with a simple pad-dry-cure process in an aqueous bath with aminofunctional and epoxyfunctional silicone softeners. The results indicate that dimensional stability and performance properties improve. The maximum effect is obtained with a 1:1 proportion of aminofunctional and epoxyfunctional silicone softeners, probably due to the synergistic effect of both softeners by the catalyzing reaction of the amine group. A hydrophilic epoxyfunctional silicone softener seems to increase fiber swelling and prevents the reduction of hygral expansion. As for the other properties, there are no significant variations when different kinds of epoxyfunctional silicone softeners are used. The most significant effect of the softeners is the surface coating, which reduces interfiber or interyarn friction.

Protective Effect of Maleic Acid Derivatives on the Properties of Wool Fabric Dyed at 120°C

Eleven maleic acid derivatives are synthesized and authenticated, then used as wool protective agents for dyeing wool at 120°C with Isolan Red S-RL. The protective effects are evaluated in terms of tensile properties (initial modulus, tensile strength, extension at break, and work to rupture) for both conditioned and wet-state fabrics, chemical damage is assessed in terms of alkali solubility, and hygral expansion is also measured. N-naphthyl and trifluorophenyl maleamic acid and N-benzyl and N-trifluorophenyl maleimides pro vide beneficial effects in terms of increased tensile strength, reduced hygral expansion, and minimal yellowing. However, N-benzyl and N-trifluorophenyl maleimides produce higher alkali solubilities. These results are in contrast to those for Irgasol HTW NEW treated wool, which has relatively low alkali solubility yet higher hygral expansion and poorer tensile properties.

Engineering the Extensibility and Dimensional Properties of Wool Fabric in Finishing

An empirical study to determine the quantitative relationships between changes in the dimensions of wool fabrics during finishing and the resultant changes in extensibility, relaxation shrinkage, and hygral expansion is reported. Sufficiently quantitative correlations can be obtained between relaxation shrinkage, extensibility, and dimensional change of wool fabrics to allow the finisher to ‘engineer’ these fabric properties in a simple temporary-setting operation. However, the response of fabric extensibility to dimensional change depends on yarn interaction within the fabric. A permanent-setting operation can be used to control hygral expansion by engineering the relaxed dimensions of the fabric. Unfortunately, unless the fabric has been permanently set in some earlier operation (e.g. piece-dyeing), the response of fabric to changes in the relaxed dimension is affected by the setting process.

The Relationship between Hygral Expansion and Measured Set of Piece-Dyed Worsted Fabrics

The influence of applied dye on the dimensional and setting properties of 100% wool fabrics is examined. The presence of dye molecules and hydrophobic groups reduces hygral expansion independent of measured fabric set. A mechanism is proposed to explain these observations.

The application of fabric objective measurement in shirt manufacture

Evaluates the mechanical properties of 60 different shirting materials: fabric extensibility, formability, shear rigidity, bending rigidity, relaxation shrinkage, and hygral expansion by the adoption of the fabric assurance by simple testing (FAST) system. Investigates manufacturing processes comprising spreading, cutting, sewing, handling, pressing and packaging and correlates the measured properties of the shirting fabric with their actual performance during making up. Claims this overall evaluation of respective fabric performance enables manufacturers to identify the range of mechanical properties ideal for high‐quality shirt production. Adds that specific manufacturing instructions can be prepared, based on the results of fabric property evaluation, for fabrics which tend to present difficulties in production. Points out that these can considerably expedite the manufacture of garments, avoiding the alternative – expensive “trial and error” – solution to problems.

FAST – Fabric Assurance by Simple Testing

Describes the FAST system, developed by CSIRO for quality control and assurance of fabrics. FAST, or Fabric Assurance by Simple Testing, consists of a series of instruments and test methods which are inexpensive, robust and simple to use. It measures properties which are closely related to the ease of garment making‐up and the durability of worsted finishing. FAST‐1 gives a direct reading of fabric thickness over a range of loads with micrometre resolution. FAST‐2 measures the fabric bending length and its bending rigidity. FAST‐3 measures fabric extensibility at low loads as well as its shear rigidity. FAST‐4 is a quick test for measuring fabric dimensional stability, including both the relaxation shrinkage and the hygral expansion.

The effect of corona treatments on the hygral expansion of wool worsted fabrics

The effect of dry corona and aqueous treatments on the hygral expansion of wool gabardine has been investigated. Increasing the severity of the corona treatment produced a concomitant reduction in the hygral expansion of the fabric. X‐ray photoelectron spectroscopy has been used to study the chemical modification of the wool fibre surface.

Effects of Dyeing and Finishing on Hygral Expansion and Other Crimp-Dependent Physical Properties of Wool Fabrics

Low stress tensile properties as measured by KESF instruments—hygral expansion, relaxation shrinkage, and the crimp of the yarns in a fabric—were determined for a pure wool fabric after each of a number of dyeing and finishing processes. The dyeing recipes and dyes cover the range for wool in industry. Dye-fiber interactions were evaluated by comparing the properties of dyed fabrics with those of blank dyed controls. Dyeing and finishing alter many mechanical and physical properties of a fabric by changing the crimp of its yams, due to stress relaxation of interyarn forces in the unfinished fabrics during processing. The degree to which the initial interyarn stresses are relaxed is also an important parameter. Acid and chrome dyes did not affect the resulting fabric properties, but reactive dyes often had a dramatic effect on changes that took place during piece dyeing. Reactive dye-fiber interactions altered fabric crimp as a result of dyeing. In turn, crimp differences affected the resulting crimp-dependent fabric properties—hygral expansion and low-stress tensile properties. The effect was resistant to decatizing. This result has beneficial implications for controlling hygral expansion.

The effect of dyeing on the hygral expansion of worsted fabrics. Part 3ndashreactive dyeing

The influence of different types of reactive dye on fabric set and hygral expansion is detailed. Lanasol (α‐bromoacrylamide) reactive dyes were found to inhibit the development of set during dyeing, resulting in lower dimensional instability. The low hygral expansion is attributable to set inhibition by the fibre reactive group and to water exclusion by the presence of dye molecules. An alkaline aftertreatment is shown to result in increased fabric set and dimensional instability.

The effect of dyeing on the hygral expansion of worsted fabrics. Part 2‐the influence of metal cations

Wool gabardine fabric has been dyed in the presence of several different metal cations. Their influence on setting behaviour and subsequent dimensional properties is detailed. The use of extremely low levels of copper(II) sulphate as a novel dyebath antisetting treatment for wool is also demonstrated.

Hysteresis Effects Associated with the Adsorption and Desorption of Water by Woven Wool Fabrics

Changes have been examined in the lengths of four woven wool fabrics on adsorption and desorption of water. The lengths are greater on desorption than on adsorption, a trend that is opposite that previously reported for length differences at a given regain. The magnitudes of the length differences (at constant regain or relative humidity) are determined primarily by the levels of fabric hygral expansion. After extending the conditioning time from 24 hours to up to 14 days at a particular relative humidity, length and regain differences decreased, but the relationships between length and regain for both adsorption and desorption were unaffected. At a given relative humidity following desorption, lengths and regains were greater as the relative humidity from which desorption occurred was increased.

The effect of dyeing on the hygral expansion of worsted fabrics — Part 1

The influence of dyebath pH, dyeing time, levelling agents, dyestuff and anti‐setting agent on hygral expansion has been investigated. The incorporation of an anti‐setting agent in the dyebath minimised increases in hygral expansion resulting from the dyeing process.

Novel Dyebath Treatments for the Prevention of Increased Hygral Expansion Occurring in Piece Dyed Worsted Fabrics

Novel treatments for the reduction of dyebath induced hygral expansion are described. Their application in Neolan P dyebaths offers the potential for reduced dimensional instability with a limited impact on the final fabric colour.