Leather Materials Research Articles

The Researchment of Knitted Antifouling Fabrics and the Splicing Design on Leather Garment

The garments splicing together the knitted and leather are main products in leather garment market in recent years. In view of the reflection of terminal market, the contradiction between washing and maintainance method of knitted and leather fabrics and undesirability of splicing design are the main factor that influence promotion of products. Through the antifouling treatment of the knitted fabrics, it make them have the function of waterproofness, oilproofness and antifouling;Splicing knitted fabrics on the parts that are easy to wearn out and easy to be restained, and other parts that impact comfort and produce esthetic fatigue on the leather garments, it meet the multivarient need of consumers’ comfort and fashion more. On this basis, Taking integrative consideration of combinative match，stitching technics splicing design, splicing reasonablity of fabrics and garments style, it initially form theoretical basis of splicing design of antifouling knitted fabric on leather garment.

Color Rabbit Hair Property and Market Foreground

based on investigation and sample testing, studied on fiber property of color rabbit hair. The color rabbit hair has good spinnability. Foreground of color rabbit hair was analyzed. Being comfortable, dressing property well and environment friendly, color rabbit hair products will play an important role in market. The suggestions were put out that new fashionable super products with color rabbit hair be produced and its added value increased. Color rabbit hair fur is also a good leather material. Offal hair of color rabbit may be used to new extending products. Color rabbit hair market possess good foreground. It should be developed constantly.

Leather material found on a 6th B.C. Chinese bronze sword: A technical study

During July to November, 2006, an important archaeological excavation was conducted in Yun country, Hubei province, southern China. Chinese archaeologists found some remnant of leather materials, covered with red pigments, on a 6th century B.C. Chinese bronze sword. To understand the technology/ies that may have been utilized for manufacturing the leathers, a combined of Raman spectroscopy, FT-IR and XRF was thus applied to the remnant of leather materials. Raman analyses showed that red pigment on the leather was cinnabar (HgS). FT-IR and XRF analyses indicated that the content of some elements, such as Ca (existing as CaCO 3) and Fe (existing as Fe 2O 3), were much higher than those in the surrounding grave soil. The results inferred an application of lime depilation and retting, and the Fe–Al compound salt as tanning agent. And it was furthermore implicated that the Fe–Al salt tanning technique had been developed in the middle and late Spring and Autumn Period of China.

The Characteristics of Qipao Design in Contemporary Fashion Design - Focused on Women's Collections from 2000 to 2009 -

Abstract The purpose of this study is to understand Qipao, that Chinese traditional women’s cloth, and analysis the aesthetic characteristics of that. Joining WTO in 2002 and 2008 Beijing Olympic made China get the attention by the world and get the opportunity that advent of China style. Chinese fashion cultural contents have abundant meanings in internal or external, therefore characteristics aesthetic of Chinese traditional fashion had much influence in world fashion design. Qipao that has influence in contemporary fashion design could be used special fashion design data for China market. A variety of literature and prior researches for Qipao’s history and transition process was studied. Internal and external documents, fashion magazines, internet information were investigated to study features of Qipao. Total 20 seasons fashion collections from 2000S/S to 2009F/W was examined, and selected 22 brands that showed Qipao style, after then extracted 418 photos among them. By the seasons, it showed 193 pieces in S/S and 225 pieces in F/W, and was put to practical use in F/W season than S/S. The results are as follows. The contemporary fashion collections shown in the Qipao style silhouette, detail, color, material, pattern and the results obtained by each, were in all respects diversity. In silhouette, including traditional tight silhouettes, 'H' silhouettes, boxy silhouette was such a variety. The five colors traditionally preferred color from the color was more of a tendency to be gorgeous. Modern reinterpretation of pattern designs by graphic pattern that has emerged. Also, shown in a contemporary fashion collection Qipao style leather material in application utilizing the glossy feel of a plastic material and has emerged feeling.Key words: Qipao(치파오), Chinese fashion(중국 패션), contemporary fashion design(현대 패션디자인).

Instability of Flexible Strip Hanging Over Edge of Flat Frictional Surface

The conditions for an overhanging flexible strip to slide off a flat surface are investigated. This problem may be applicable to pieces of paper, fabric, leather, and other flexible materials, including plastic and metallic strips used herein for experimental comparisons. The critical overhang length depends on (a) the length, weight per unit length, and bending stiffness of the strip, (b) the coefficients of friction (CoFs) between the strip and both the surface and its edge, and (c) the inclination of the surface. The strip is modeled as an inextensible elastica. A shooting method is applied to solve the nonlinear equations that are based on equilibrium, geometry, and Coulomb friction. Three types of equilibrium shape are obtained. In the most common type, one end of the strip overhangs the edge and the other end contains a segment that is in contact with the surface. In another type, contact only occurs at the nonoverhanging end and at the edge. The third type involves the strip balancing on the edge of the surface. The ratio of the critical overhang length to the total strip length is plotted as a function of the surface CoF, edge CoF, and weight parameter for a horizontal surface. In most cases, this ratio increases as the CoFs and the strip’s bending stiffness increase, and decreases as the strip’s weight per unit length increases. The rotation of the strip at the edge tends to increase as the strip’s weight per unit length, the strip’s length, and the surface CoF increase, and to decrease as the strip’s bending stiffness increases. Inclined surfaces are also considered, and the critical overhang length decreases as the surface slopes more downward toward the edge. The theoretical results are compared with experimental data, and the agreement is good.

Enzymatic hydrolysis of Alaska pollack (Theragra chalcogramma) skin and antioxidant activity of the resulting hydrolysate

Fish skin, a by-product of the food industry, contains a large amount of collagen. However, only a small proportion of fish skin is used in the production of leather materials and animal feedstuffs, most of it being discarded. The aims of this study were to prepare peptides from Alaska pollack (Theragra chalcogramma) skin by enzymatic hydrolysis and to evaluate the antioxidant activity of the resulting hydrolysate. Protamex was the most efficient enzyme for preparing antioxidant peptides from Alaska pollack skin. The optimal hydrolysis conditions were as follows: hydrolysis time 8 h; enzyme/substrate ratio 2:1000; skin/water ratio 1:6; temperature 55 degrees C; pH 6.0. Under these conditions the highest yield of peptides was 83.44%, with 85.95% of the hydrolysate being mainly composed of oligopeptides with molecular weights ranging from 180 to 1000 Da. The hydrolysate showed 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity, with an IC(50) value of 2.5 mg mL(-1), and its reducing power was 0.14 at 1 mg mL(-1), 53.8% of that of reduced glutathione at the same concentration. This study demonstrated that the hydrolysate of Alaska pollack skin was mainly composed of oligopeptides with two to eight amino acid residues and possessed antioxidant activity.

Research of furniture that uses leather material

Research of furniture that uses leather material

Basic forensic identification of artificial leather for hit-and-run cases

Single fibers retrieved from a victim's garments and adhered to the suspect's automobile have frequently been used to prove the relationship between victim and suspect's automobile. Identification method for single fiber discrimination has already been conducted. But, a case was encountered requiring discrimination of artificial leather fragments retrieved from the victim's bag and fused fibers from the bumper of the suspect's automobile. In this report, basic studies were conducted on identification of artificial leathers and single fibers from leather materials. Fiber morphology was observed using scanning electron microscopy (SEM), color of these leather sheets was evaluated by microspectrophotometry (MSP), the leather components were measured by infrared micro spectrometry (micro-FT-IR) and the inorganic contents were ascertained by micro-X-ray fluorescence spectrometry (micro-XRF). These two methods contribute to other analytical methods too, in the case of utilized single fiber analytical methods. The combination of these techniques showed high potential of discrimination ability in forensic examinations of these artificial leather samples. In regard with smooth surface artificial leather sheet samples, a total of 182 sheets were obtained, including 177 colored sheets directly from 10 of 24 manufacturers in Japan, and five of them were purchased at retail circulation products. Nine samples of suede-like artificial leather were obtained, 6 of them were supplied from 2 manufacturers and 3 sheets were purchased as retailing product. Single fibers from the smooth surface artificial leather sheets showed characteristic for surface markings, and XRF could effectively discriminate between these sheets. The combination of results of micro-FT-IR, color evaluation by MSP and the contained inorganic elements by XRF enabled to discriminate about 92% of 15,576 pairs comparison. Five smooth surface samples form retailing products were discriminated by their chemical composition into four categories, and in addition color information to this result, they were clearly distinguished. Suede-like artificial leather sheets showed characteristic extra-fine fibers on their surface by the observation of SEM imaging, providing high discriminating ability, in regard with suede-like artificial leather sheets were divided into three categories by micro-FT-IR, and the combination of these results and color evaluation information, it was possible to discriminate all the nine suede-like artificial leather sheets examined.

Research on the possibility of ignition of materials by electrostatic discharge in pure oxygen environment at different pressures

In spacecraft environments, spacesuits materials such as textiles, leather, or other materials are used in a pure oxygen environment. The materials are in serious risk of being ignited by electrostatic discharge (ESD) and may cause fire and even disasters or death of astronauts. In this paper, a well sealed chamber was first developed for ignition test. Then, ignition tests of four textiles and leather materials were carried out under oxygen pressures of 42 kPa, 101 kPa and 142 kPa using different ESD models. It is concluded that the materials are more easily ignited at higher oxygen pressure.

Determination of extractable chromium from leather

People are exposed to chromium ions from leather materials due to everyday contact with different textile objects. The problem is that Cr(VI) is extremely toxic and may cause contact allergic dermatitis on the skin and may also be a trigger for many diseases. Huge amounts of chromium ions are released by waste waters to rivers after chromium-tanning processes in the leather industry; the presence of chromium is not only a problem for human health, but also for the environment. For this reason it is extremely important to monitor the presence of chromium as Cr(VI) and as total chromium. This study aims to present an appropriate analytical method for monitoring Cr(VI) and the total chromium present on leather materials. Applying this method to chromium-tanned leather samples, it was observed that the amounts of total chromium as well as of Cr(VI) are higher than prescribed and recommended by different regulations. Chromium(VI) exceeded the limit of 3 mg/kg in the majority of tested materials, while the total chromium exceeded the limit of 50 mg/kg in all tested samples. For this reason, it is recommended to avoid direct and prolonged contact of those materials with the skin.

Experimental study of the behaviour of leather under vacuum conditions

A characterization of the device-pumping behaviour of our vacuum reactor for plasma treatment of materials at low pressure is presented. The analysis of the pumpdown curves measured both in the viscous and in the molecular regimes was made to study the outgassing flowrates of several leather materials. Estimates of the relevant flowrates in different pressure ranges and measurements of the flow composition have been obtained. Such data can be interpreted in the framework of simplified desorption models and could be used in order to design the pumping system needed for vacuum treatment of such materials. We have also measured other related quantities such as the moisture uptake and the weight loss.

Prediction of depth removal in leather surface grit blasting using neural networks and Box-Behnken design of experiments

In this work, leather material is for the first time prepared by grit blasting process in order to improve peel strength when bonding. Peel tests show that it is the surface depth of removal rather than surface roughness that dominates the bonding performance. Therefore, measurement of surface removal is critical for surface preparation of using a grit blasting process. Indirect measurement of preparation performance is essential due to the hazardous conditions for conventional sensing equipment in the blasting chamber. A neural network modelling approach is proposed for the prediction of surface removal of leather materials, and the neural network model also characterizes the process, which is very useful for machine design and optimum control. The data used for the training of the artificial neural network is collected through screening experiments, which was efficiently planned using the Box-Behnken design method.

Adhesives in the leather industry - perspectives for changing needs

Adhesion is a surface physico-chemical phenomenon. The nature of the adhesive joint and its mechanical properties depend strongly on the nature of the substrate and the interaction of adhesive with the substrate. The adhesives are used in a wide array of applications ranging from packaging to aircraft and spacecraft. Leather is a unique biomaterial. It has a three-dimensional fibrillar textured surface. The use of adhesives in the leather industry has been mostly confined to the production of footwear and, to some extent, in leather goods and garments. Leather articles and footwear are made using synthetic dissimilar materials, where the adhesion between the leather and other materials such as cotton fiber, nylon, polyester, and other synthetics is important. The use of adhesives in such instances requires a careful selection and application of adhesives depending on the end-use of the leather product. The present overview discusses, at length, the various aspects of usage of adhesives in the leather industry, keeping in view the perspectives for the changing needs that are emerging in the third millennium. The description of adhesives widely in use and the improvements required to meet the environmental aspects and on-line production are discussed in terms of their formulations, physical properties, cure, and substrate preparations.

Automated defect inspection and classification of leather fabric

This paper describes an automated vision system for detecting and classifying surface defects on leather fabric. In the defect inspection process, visual defects are located and reported through a two-step segmentation procedure based on thresholding and morphological processing. In the defect classification process, the system utilizes both geometric and statistical features as its feature sets; that is, a new normalized compactness measure, and first- and second-order statistical features. In an effort to maximize the classification efficiency, a three-stage sequential decision-tree classifier is adopted for the classification of five types of defects: lines, holes, stains, wears, and knots. If line defects are identified as a result of classification, they are checked by a line combination algorithm to determine if they are parts of larger line defects and, in such a case, are reported as combined line defects. Satisfactory results were achieved in the classification test with an overall accuracy of 91.25%

A neural network approach for defect identification and classification on leather fabric

In this paper, an automated vision system is presented to detect and classify surface defects on leather fabric. Visual defects in a gray-level image are located through thresholding and morphological processing, and their geometric information is immediately reported. Three input feature sets are proposed and tested to find the best set to characterize five types of defects: lines, holes, stains, wears, and knots. Two multilayered perceptron models with one and two hidden layers are tested for the classification of defects. If multiple line defects are identified on a given image as a result of classification, a line combination test is conducted to check if they are parts of larger line defects. Experimental results on 140 defect samples show that two-layered perceptrons are better than three-layered perceptrons for this problem. The classification results of this neural network approach are compared with those of a decision tree approach. The comparison shows that the neural network classifier provides better classification accuracy despite longer training times.

Texture in Penderecki’s Sonoristic Style

In his so-called “sonoristic” period of the early 1960s—represented by pieces such as Threnody, Fluorescences, Polymorphia, and others—Penderecki employed a compositional system whose axiomatic concept was not a single sound, but the sound matter in its totality. Distinct states of this sound matter were governed by two relatively independent systems: (1) a basic system which ruled the texture of sound masses and (2) a timbre system governing their sound color. Categories of the basic system are a few binary oppositions concerning pitch, time, and loudness: spatial mobility vs. immobility, temporal mobility vs. immobility, spatial continuity vs. discontinuity, temporal continuity vs. discontinuity, high vs. low register, loud vs. soft dynamics. These categories account for the morphology of the basic system because a combination of terms chosen from individual categories generates an inventory of units in Penderecki’s sonoristic style. The same set of categories also determines syntax, as the temporal order of units in the course of musical narration is ruled by the internal logic of individual binary oppositions. Categories of the timbre system are in turn metal, wood, and leather—materials of which the sound sources of traditional musical instruments are most often made—forming a ternary opposition. The timbre system underlies the wealth of new musical tools as well as eccentric playing techniques on traditional instruments called for by the composer.

Persistent contact dermatitis

A 46-year-old man presented with a 6- to 7-year history of an eczemataus eruption on the dorsal aspect of the feet (figure 1). The patient had been wearing leather oxford shoes to work for 18 years. He had used several corticosteroid creams on the feet, but improvement was limited.A potassium hydroxide (KOH) test was negative for fungal infection. Two-day patch tests using a screening tray of 24 common allergens as well as small samples from four pairs of the patient's shoes were also negative. Further treatment with topical and systemic corticosteroids and antibiotics provided only short-term relief.One year following the initial visit, 4-day patch tests using a vehicle tray, the patient's medications, and samples from his work shoes revealed strong positive reactions to amcinonide cream and the shoes. The ingredients list of the amcinonide cream was obtained from the manufacturer, and subsequent patch tests revealed positive reactions to both the active ingredient (amcinonide) and the emulsifying wax (figure 2). The rash cleared when the amcinonide cream was discontinued and replaced with a corticosteroid from another class.We concluded that a reaction to the leather material in the patient's work shoe was complicated by a reaction to amcinonide cream. We believe that both the active ingredient and the emulsifying wax were relevant factors in the persistence of allergic dermatitis.

Polypropylene glycol/polymeric-MDI urethanes for bonding leather footwear materials

Adhesive compositions based on polymeric-MDI and mixtures of polypropylene glycols and cured using the polymeric-MDI for bonding leather footwear material are reported. As a result of the polyfunctional nature of the polymeric-MDI, these compositions have only a limited shelf-life. Nevertheless, our studies show that satisfactory bond strengths are achievable for immediate bonding. Our investigation further indicates that the peel strength increases with decreasing molecular weight of glycols in the mixture and attains a maximum for compositions containing monomeric propylene glycol.

Textile Applications for EB/UV Curing

The important fundamental features of both the electron beam and ultraviolet radiation processors are reviewed, highlighting the major advantages of each for the textile industry. The curing of flock adhesives and the graft modification of fibers and filaments for bulk and surface property enhancement are described as typical of the high speed performance available with modern electron beam equipment. Applications of ultraviolet curing to bonding enhancement on textiles and to surface coating such as leather and man-made fabrics, are reviewed. At the present time, the adoption of this non-polluting technology is particularly active in the printing industry as tougher pollution control legislation takes effect. Some data on its healthy growth rates worldwide are reviewed, and its importance for energy intensive industries, such as textile finishing, is discussed.

The metallic soaps of naphthenic acids — Part 1

Substantial quantities of naphthenic acid are used in the form of metallic salts (metallic soaps) e.g. as driers in paints, as pigment grinding and dispersing aids, as preservatives and mildewproofing agents for textiles, paper, film, and leather and cellulose materials i.e. additive, catalysts etc. These soaps are usually plastic substances, except calcium, which resembles a hard fibrous material.