A model of seam pucker and its applications Part I: theoretical

Abstract

This article considers a simple model of the lock stitch (301) seam, and uses it to derive a measure of the severity of puckering in the seam. The numerical value of the measure depends on the bending properties of the fabrics and thread in the seam, together with the tensions in the threads. How the latter may be estimated is discussed.     

Investigation of Seam Pucker in Lightweight Synthetic Fabrics as an Aesthetic Property Part I: A Cognitive Model for the Measurement of Seam Pucker

Seam pucker is an area which is now receiving particular attention especially with the development of microfibre fabrics which are inherently prone to deformations during garment manufacture. Although fabric properties can be related to seam pucker, the aesthetic judgement is still left to subjective assessment which is based upon ranking the stitched fabric samples by judges having compared them with photographic ‘standards’. The shortcomings of this procedure are obvious; judges do not always agree, they need to be trained, the procedure is time consuming and non standardised. This paper reports upon the development of a new measuring procedure which is based on the use of a computer and a camera, ie computer ‘vision’. This procedure is objective and is focused on the aesthetic property of the seam assembly, by ‘modelling’ the cognitive process involved in seam pucker assessment The results are organised in two parts: Part I reports on the development of a cognitive ‘model’ for the measurement of seam pucker and Part II on the model implementation using the computer ‘vision’ system.     

动态投入产出模型及其应用

研究了一类考虑到科技进步的投入产出模型及其在制定国民经济发展规则中的应用。     

The Objective Assessment of Fabric Pilling. Part II: Experimental Work

The paper presents the results of pilling assessments of fifty knitted fabrics by the application of the laser triangulation technique. It also compares the results with the corresponding values given by a panel of judges.     

Thermal Properties of Amylose and Its Derivatives. Part II

The effect of nature of substituent groups on the stability and mode of decomposition of amylose derivatives has been studied. Kinetics of decomposition of amylose phenyl acetate, amylose tosylate and amylose phthalate have been investigated using the thermogravimetry (TG) and differential thermal analysis (DTA) in nitrogen atmosphere. TG data are analyzed using the methods of Chatterjee, and Anderson and Freeman while DTA data are analysed using the method of Reich. TG thermograms of all the amylose derivatives studied show the characteristic sigmoidal curves and the evaluation of kinetic parameters from them indicates that the major decomposition reaction follows almost first order kinetics. The nature of substituent groups in amylose derivatives plays an important role on the stability and following order of stability has been noted: amylose palmitate > amylose acetate > amylose propionate > amylose phenylacetate > amylose benzoate > amylose > NaCMA > amylose succinate > amylose phthalate > amylose tosylate.     

The Automatic Control of Card-web Linear Density. Part II: Experimental Verification of Short-term Control

A controller based on the use of error signals, taken from measurement of web density on both the doffer and cylinder of a cotton card, to control the speed of the doffer was assessed for its ability to control the short-, medium-, and long-term irregularity of the web linear density at output from the card. It is shown that, on a modern high speed card, the system can control the irregularity down to 25-cm wavelengths.     

Dry Peeling of Tomato by Infrared Radiative Heating: Part II. Model Validation and Sensitivity Analysis

In an accompanying study, a predictive mathematical model was developed to simulate heat transfer in a tomato undergoing double sided infrared (IR) heating in a dry-peeling process. The aims of the present study were to validate the developed model using experimental data and to investigate different engineering parameters that most strongly influence the rate and uniformity of IR heating. The mode was verified by comparison of the predicted temperature profiles with experimental data for tomatoes with three dimensions. Uniformity of temperature distribution at tomato surface was quantified by surface-averaged temperatures and a derived temperature uniformity index. The predicted temperatures agreed well with experimental data (r ²?>?0.9). Simulation results illustrated that IR heating induced a dramatic temperature increase on the tomato surface, which extended to 0.6 mm beneath (>90 °C) during a 60-s heating period, whereas interior temperature at the tomato center remained low (<30 °C). Sensitivity analysis suggested that strategies to enhance IR heating rate and uniformity can be implemented through varying emissive power, adjusting the distance between emitters, and presorting tomatoes according to size. The validated model provides an effective design tool for better understanding the complex IR radiation heating in developing the innovative IR dry-peeling process.     

Some Textile Applications of Finite-element Analysis Part II: Finite Elements for Yarn Mechanics

The concepts of modal decomposition developed in an earlier paper are used to produce a three-dimensional element for aligned fibre assemblies. The element degrees of freedom are introduced and the chosen mode shapes of the element demonstrated. The finite element is tested by using simple material-property assumptions, and the element is verified against a theoretical model of the twisting of a single fibre about a solid core. The element is then verified qualitatively by modelling realistic yarn situations, and the resultant deformation plots are presented.     

Virtual try-on technologies in the clothing industry. Part 1: investigation of distance ease between body and garment

The aim of the first part of the research was to investigate distance ease distribution between straight shape virtual dress and 3D body in respect to fabrics mechanical (tensile, bending, shear) properties using virtual try-on software Modaris 3D Fit (CAD Lectra). The second part would be intended for the basic construction adjustment according to the mechanical properties of textile materials. The objects of the investigations were 100% cotton and cotton-blended plain weave fabrics. Mechanical properties were defined by KES-F (Kawabata). Virtual mannequin was covered with straight virtual dress. Distance ease distribution as well as the values of simulated 3D garment at bust girth ES_{3D_bust} (cm) were investigated. It was defined that distance ease in 3D garment was lower than ease allowance used for 2D basic construction. The strongest effect upon the distance ease between body and garment had tensile strain of fabrics in weft direction.     

The Mechanism for the Synthesis of Starch and Its Relationship to Flagellin and to the Newly Proposed Structural Model for DNA. Part II.

All of the components and enzymes required for the synthesis of starch by the glycogen precursor method have now been shown to exist. In this mechanism, the genetic inducer sucrose stimulates the production of phosphorylase and the Q-enzyme. These and other enzymes in turn convert sucrose to glycogen. The external branches of the glycogen are then removed by the debranching enzyme isoamylase. The removed branches act as substrates, necessary co-enzymes, suppliers of adenosine diphosphate glucose (ADPG), and possibly genetic inducers for the production and enzymatic activity of glucosyltransferase. They are converted into ADPG by the D-enzyme plus other enzymes and then into amylose. Consequently, the percentage of amylose is directly proportional to the degree of debranching of amylopectin, which in turn is determined by how long amylopectin can be retained in the plastid solution before precipitating with isoamylase or other enzymes to form starch. The ability of the above specialized mechanisms to occur in the same solution is thus a result of selective complexing of enzymes to different polysaccharides and the production of different genetic inducers. Thus the interaction of different inducers with DNA repressors determines the time-sequence for the production of specific enzymes. The thermal stability of thermophile flagellins and the inability of 6 M guanidinium chloride (GCl) to dissociate mesophile flagellin dimers (M_w = 40,000) or thermophile flagellin trimers (M_w 54,000) supports the conclusion that protein-amylopectin complexes exist and cannot be readily dissociated. Because hydroxyls are involved in these flagellin aggregates, then the hydroxyls of much larger amylopectin molecules should also be able to form similar stable bonds with proteins. It is proposed that mutations can be caused by either elimination of active genes by feed-back mechanisms (permanent repressors) or by chemicals and radiation. New genetic strains of grains produced by radiation for resistance to pests can thus only lead to disaster. Improvement of the soil is the only means for the production of lasting resistant strains.     

Durability of Handmade Wool Carpets: A Review

This paper presents various aspects related to the durability characteristics of handmade carpets. Various kinds of materials and knots used in handmade carpet have been explained at the beginning. Then the mechanism of carpet durability has been explained with respect to mechanical and appearance aspects. The various techniques for measuring the mechanical and appearance related durability characteristics have also been presented in this article. Finally, the influence of wool fibre, yarn, and carpet structural parameters on the durability has been explained. The shortcomings in terms of durability, characterization of carpets, and scope of further research have been presented at the end of the review.     

Synthesis and Applications of Reactive Carbohydrates Part II: Graft Polymerization of Starch and Hydrolyzed Starches with Acrylamide

Starch and different hydrolyzed starch samples were subjected to two independent reactions, namely, grafting with acrylamide using K₂S₂O₈ as initiator and oxidation with K₂S₂O₈ under the grafting condition but in absence of the monomer. Copper number and carboxylic group measurements showed that both grafting and oxidation decrease outstandingly the copper number of the hydrolyzed samples and diminish completely the copper number of the original starch sample. On the contrary, grafting and oxidation cause significant enhancement in the carboxylic content, indicating partial conversion of the aldehydic to carboxylic groups under the oxidative action of K₂S₂O₈; but it is certain that higher amounts of carboxylic groups are created in absence than in presence of acrylamide. Polymerization studies showed that the hydrolyzed starch samples are much more susceptible than the original starch sample toward grafting with acrylamide only during the initial stages of the reaction. Preliminary experiments describing introduction of methylol groups into the molecular structure of grafted sample and application of the methylolated product to cotton fabric were also reported.     

Alcoxymethyl Ethers of Glucose and Its Oligomers Part II. Composition and Structure of Alcoxymethyl Glucose Ethers

Dodecoxymethyl glucose ethers were separated by TLC and column chromatography and the main components were identified. The fraction of monododecoxymethyl glucose ethers was separated into positional isomers. The reactivity of hydroxyl groups of glucose in the reaction with dodecoxymethyl chloride was investigated.     

A Review of Hydrophobic Nanocellulose and Its Applications

Nanocellulose is of great interest in various areas nowadays as a natural nanostructured biomaterial. However, in many applications, the high hydrophilicity due to a large number of hydroxyl groups is not desired. The hydrophobic modification of nanocellulose can thus increase its application. This work reviewed recent developments of methods for nanocellulose hydrophobic modification, through physical adsorption and chemical grafting. The applications of hydrophobic nanocellulose were also reviewed.     

A Study of the United Kingdom Textile Cycle. Part II: Modelling the Cycle

Some evidence is presented which suggests that the relationship between time series representing activities in different parts of the textile industry and in the economy is not deterministic. Box/Jenkins Modelling of nineteen different series shows remarkable similarities between the models. A general model is suggested, which could be used to generate demand input for a capacity-planning simulation model.     

Compression of gellan gels. Part II: Effect of sugars

The effect of sucrose, glucose, fructose and their mixtures on the gelation of 0.5 wt% low acyl gellan in the presence of potassium chloride (100 mM) was investigated by large deformation compression experiments. The sugar concentration varied from 0 to 15 wt% whereas all their combinations at a final concentration of 15 wt% were also studied. Stress at failure and strain at failure along with Young's modulus were calculated from each compression curve. Samples prior to compression were refrigerated at 5 °C for 1, 2 and 24 h. Glucose showed no contribution to the gellan network strength but decreased the firmness of the gels. On the other hand, fructose and sucrose enhanced the strength of the network, with sucrose being slightly more effective, but had no effect on firmness. This behaviour depended solely on the presence of each sugar and not in their concentration. The elasticity of the gels was not significantly altered by the addition of sugars or their mixtures. Strength and firmness shared similar profiles when mixtures of sugars were used to promote gelation. Sugars, when in mixtures, showed no synergistic interactions whereas their type seems to affect the properties of the resulting gels.     

A basis for estimation of consumption: literature values for selected food volatiles. Part II

In this paper we present a compilation of quantitative literature data on volatile compounds in 15 food items including some brandies, meats, oils as well as vegetables, vinegar and potatoes. Levels of the volatile compounds identified (approximately 900) in this group of food items are generally in the ppm range. Carboxylic acids were present in much higher levels in plum brandy, vinegar, lamb and mutton (heated), whereas alcohols, esters and carbonyls aldehydes are particularly abundant in brandy.     

Gas concentration in the interstitial atmosphere of a wheat silo-bag. Part II: Model sensitivity and effect of grain storage conditions

A lumped capacitance model was applied to simulate the change in gas concentration in a wheat silo-bag. The sensitivity of the solution to a given model respiration rate and permeability (degree of gas-tightness of the silo-bag) was examined. Results showed that gas concentration is more sensitive to changes in respiration rate than to permeability of the plastic film. Considerable changes occur in gas concentration in a damaged silo-bag. The definition of an effective permeability to account for gas transfer through holes and plastic film allowed the examination of the effect of different holes configurations (number and size of perforations) on the evolution of gas concentration.The influence of grain storage conditions on the evolution of gas concentration was investigated. The model was run for initial grain temperatures of 20, 25, 30 and 40C and MC in the range (12–16% w.b) and climatic conditions of the South East of Buenos Aires province, Argentina.When dry grain (12–13% w.b) is stored, O₂ level remained above 12% and CO₂ level below 7%. For wet grain (15–16% w.b), CO₂ level was in the range 14–16% after six month storage. The simulations showed that for wet grain anaerobic conditions may be achieved within two weeks to three months of storage, depending on the grain initial temperature. Estimated mean DML for all the storage conditions remained always below 0.04%, the critical limit for safe storage of wheat that will be used for seeds.