Synthetic Leather Research Articles

Getting rid of the unpleasant odor in new artificial leather using natural and synthetic fragrances

Usually, new artificial leather items are very smelly because they have been created using numerous chemicals. Their full smell remains until they become old enough. Removal of unpleasant chemical odor is important to preserve the safety and health at workplaces, to meet the demands of consumers and to develop marketing strategies. In this work, we focus on studying odor abatement using natural and synthetic fragrances. We have found that, in well-defined conditions, both types of fragrances efficiently hide the chemical odor. However, the use of the synthetic one combined with paraffin oil was more effective and cheaper.

Improving hygiene performance of microfiber synthetic leather base by mixing polyhydroxybutyrate nanofiber

Compared with natural leather, microfiber synthetic leather has many excellent properties such as chemical resistance and physical and mechanical properties. However, the preparation of high performance microfiber synthetic leather with excellent water vapor transmission rate, moisture absorption, and wearing comfort property still has a great challenge. The aim of this work was to improve moisture absorbent and transfer abilities by mixing polyhydroxybutyrate hydrophilic nanofibers in microfiber synthetic leather base. The effect of polyhydroxybutyrate nanofibers content on the structure and properties of microfiber synthetic leather base were investigated. The results indicated that polyhydroxybutyrate nanofibers with an average diameter of 0.40 μm were evenly distributed in all directions of microfiber synthetic leather base. As the nanofibers content increased from 0% to 20%, water contact angle decreased from 111.64° to 59.31°, resulting in 44% increase in water vapor transmission rate (from 3112.37 g/(m2 24 h) to 4350.53 g/(m2 24 h)) and 22.3% increase in moisture absorption (from 649.12% to 812.92%). Meanwhile, the addition of nanofibers made microfiber synthetic leather base dense, leading to 24.0% decrease in air permeability. In particular, the softness of microfiber synthetic leather base was increased by 42.18%. In addition, the tear strength was also significantly enhanced. Therefore, this study provided a viable method for preparing high performance microfiber synthetic leather base to use polyhydroxybutyrate nanofibers.

Study on Evaluating Fiber Orientation Distribution of Artificial Leather for Sports Equipment

Study on Evaluating Fiber Orientation Distribution of Artificial Leather for Sports Equipment

Stability, antibacterial ability, and inhibition of “zinc burning” of amitrole as thermal stabilizer for transparent poly(vinyl chloride)

Amitrole is reported as a novel kind of transparent poly(vinyl chloride) (PVC) thermal stabilizer that has both excellent inhibition of “zinc burning” thermal stability and antibacterial ability in this paper, which provide the possibility of applying the whole PVC industry into medical and food packaging, artificial leather, wire and cable, indoor decoration, and so on. From the results of Congo red test, discoloration test, and dynamic thermal stability test, we could clearly find out that amitrole could effectively replace the unstable chlorine atom and inhibit “zinc burning” of transparent PVC, while the long-term stability should be improved. Next, the stabilization mechanism of amitrole was also confirmed. The antibacterial activity of amitrole was measured by the bacteriostatic ring experiments. It was observed that the PVC films had good antibacterial properties after modified by amitrole. At last, optimal design of the amitrole/ZnSt2 (1:1)/ESBO formulation was studied, which have strong potential as thermal stabilizer to prepare super transparency and antibacterial PVC resin.

Screen printing of uv curable polyurethane acrylate binder prepared with different pigment concentrations on synthetic leather and gloss and hardness properties of printed films

In this paper, UV curing technology and screen printing method were firstly together applied on synthetic leather, in order to determine the gloss and hardness values of screen printed UV curable polyurethane acrylate binder films prepared with different pigment concentrations. UV curable water-borne pigmented formulations were prepared with different pigment concentration (3%, 5% and 7%) and two types of photoinitiators (Omnirad® 500 and Omnirad® 819 DW). The curing process were conducted under different combinations of lamps (Ga, Hg, GaHg and GaGaHg) at three power levels. Pendulum hardness and gloss values of printed films were investigated. In gloss measurements, higher gloss values were obtained at the pigment concentration of 3% at all lamp combinations. Moreover, the highest gloss value (20.96) of the sample printed with 3% pigment concentration was obtained at GaHg lamp combination at 679 mJ/cm2 energy density. The higher hardness values were obtained at a pigment concentration of 3% at all lamp combinations. The highest hardness value (9.8) of the pigmented polymeric films with 3% pigment concentration was obtained at GaGaHg lamp combination at 966 and 1663 mJ/cm2 energy densities. The results show that high gloss and hardness values can be achieved at lower pigment concentration of 3%. Considering energy efficiency, curing under the GaHg lamp combination at an energy intensity of 679 mJ/cm2 can be recommended for synthetic leather samples, which are printed with low pigment concentration (3%).

The effect of ultraviolet‐curable water‐borne polyurethane acrylate binder concentration on the printing performance of synthetic leather

In this paper, synthetic leather samples were screen printed with pigmented pastes including two types of photoinitiators and three different concentrations of ultraviolet (UV)‐curable water‐borne polyurethane acrylate binder. The curing process was conducted under different combinations of lamps (gallium, mercury, gallium/mercury and gallium/gallium/mercury) at three power levels. Abrasion resistance, crock fastness, hardness and colour strength were investigated. Chemical changes in the clear and pigmented film structures because of UV curing were analysed by Fourier Transform‐infrared spectroscopy measurements. In hardness measurements, the highest hardness values were obtained with clear and pigmented formulations which have the highest solid content (57%). In colour measurements, higher K/S values were obtained in samples printed with the formulation having a binder concentration of 46%. Wet crock fastness values improved as the energy level increased during curing, and the highest values were obtained with a formulation which had a binder concentration of 57%. Greater amounts of binder in the formulations and increased amounts of energy applied to the surface during curing increased the hardness value of the prints, thus better abrasion resistance was obtained. Overall results suggested that the highest hardness, crock fastness and abrasion resistance values were obtained with the formulation with a binder concentration of 57%. However, for ease of application, printing efficiency and colour strength, the formulation with a binder concentration of 46% is recommended for printing, and curing under consecutive passes with gallium and mercury lamps at 120 W/cm is proposed in terms of energy efficiency and printing performance.

Thermal Analysis and Identification of Potential Fire-proof Energy Building Material Based on Artificial Leather

Artificial leather fire-proof materials have obtained a good market due to stable production quality and low production price. Three kinds of artificial leather materials (polyvinyl chloride artificial leather (PVC), polyurethane artificial leather (PU) and polyurethane/polyvinyl chloride artificial leather (PU/PVC)) have been investigated, and then seven analysis methods were introduced to identify the materials. Thermo-gravimetric analysis indicated the materials had fine thermal stability. Fire-proof testing revealed the artificial leather materials had good flame retardancy, which could improve the applicability of fire-proof building materials. Tearing examination results indicated that there was a clear distinction between PVC and PU. The PU displayed significant differences compared with PVC or PVC/PU through pH indicator to observe the color of the pyrolysis gas aqueous solution. The dissolution tests results showed that cyclohexanone, dichloromethane and dimethylformamide (DMF) were efficient solvents that could be used for identifying PVC, PU and PU/PVC. The ATR-FTIR, a way to provide the high discriminating ability for identifying artificial leathers, indicated that the artificial leathers had different infrared characteristic peaks. In addition, the main compositive materials of the artificial leathers could be inferred by the relative contents analysis of N and Cl in artificial leathers.

PERANAN CUMI-CUMI BAGI KESEHATAN

THE BENEFITS AND ROLE OF SQUID FOR HEALTH. Squids are rich in protein with a protein content 15-20%. Squids containing macro and micro minerals such as sodium, potassium, phosphorus, calcium, magnesium and selenium, besides that squid also comprise essential amino acids such as tryptophan, threonine, methionine, lysine, leucine, isoleucine, valine, phenylalanine, and non-essential amino acids such as glutamic acid, aspartic acid, tyrosine, cysteine, serine, proline, glycine, arginine and histidine. Squid ink contain alkaloids that potential as anti-inflammatory, antihypertensive, anti-diabetic, anti-microbial and anti-malaria agents. The benefit of Squids in the food industry are an enhancer of flavor and an artificial leather constituent in the biomedical field.

Modification of PA/PU superfine non-woven fiber for “breath” property using collagen and vegetable tannins

Unfigured sea-island superfine fiber PA/PU non-woven (USFSLB) is used to mimic leather’s microstructure as the base of artificial leather. USFSLB has many characteristics and advantages resembling those of natural leather. However, compared with natural leather, the wearing comfort of artificial leather is inferior due to its poor moisture adsorption and permeability. In this work, a “two-step” method of chemical treatment is proposed, in which collagen/chromium-vegetable tannin (C-CrT) is immobilized on nylon fiber of USFSLB to improve its moisture adsorption and permeability (“breath” property). The two-step surface modification involved sulfuric acid hydrolysis and modifying the C-CrT on nylon fiber. Compared with the pristine USFSLB, the tensile strength, the elongation at break, the anti-static performance, the thickness, and the uniformity of C-CrT-treated USFSLB were improved at different levels. Importantly, the C-CrT-treated USFSLB showed excellent moisture adsorption and permeability, especially the liquid wicking rate (LWR) improved by 344%. The self-assembly mechanism of collagen/chromium-vegetable tannin (C-CrT) modified on nylon fibers was analyzed and discussed.

Preparation of high-performance microfiber synthetic leather base using thermoplastic polyurethane/sulfonated polysulfone electrospun nanofibers

Compared to natural leather, microfiber synthetic leather has many excellent qualities, such as chemical resistance and physical and mechanical properties. However, preparation of microfiber synthetic leather with a high water vapor transmission rate (WVT), moisture absorption and wearing comfort property is still a challenge. In this study, we prepared thermoplastic polyurethane (TPU)/sulfonated polysulfone (SPSf) electrospun nanofibers and applied them to a microfiber synthetic leather base (MSLB). The effects of TPU/SPSf nanofiber content on the structure and properties of the MSLB were investigated. The results indicated that the TPU/SPSf nanofibers with an average diameter of 0.12 µm were well distributed at all directions in the MSLB. Differential scanning calorimetry analysis showed four T g peaks, further demonstrating the existence of TPU/SPSf nanofibers. With the increase of TPU/SPSf nanofiber content from 0 to 30 wt%, the contact angles decreased gradually from 111.64° to 67.07°, leading to 55.19% improvement in the WVT value (from 2868.96 to 4452.24 g/(m2•24 h)) and 26.25% improvement in the moisture absorption (from 628.70% to 793.75% mm/s). Simultaneously, when the nanofiber content was 30 wt%, the nanofibers tended to bundle and 6.79% decrement of air permeability was observed. Specifically, the softness of the MSLB was improved by 88.55%. Moreover, the thermal stability and the tear strength were also obviously enhanced. Consequently, this research provided a feasible and promising way to prepare a high-performance MSLB using TPU/SPSf nanofibers.

Preparation and Properties of DMF-Based Polyurethanes for Wet-Type Polyurethane Artificial Leather

DMF-based polyurethanes for wet-type polyurethane artificial leather were prepared using 4,4′-diphenylmethane diisocyanate (MDI) as diisocyanate, 1,4-butanediol (BD)/1,6-hexanediol (HD) as chain extender, and four different macroglycols (MW: 2000): poly(butylene/3-methyl-pentylene adipate) glycol based on 1,4-butanediol/3-methyl-1,5-pentanediol (MPD), poly(butylene adipate) glycol based on BD, polycarbonate glycol based on HD/MPD, and polycarbonate glycol based on HD. The properties of the as-polymerized polyurethane solutions and their films and the size/uniformity of cells of the foam layer of the resulting artificial leather were investigated. The viscosities of as-polymerized polyurethane solutions were significantly high in the range of 7500–15,000 cps, indicating that the molecular weight of the obtained polyurethanes is high. The tensile strengths of polyurethane films based on carbonate-polyol and BD chain extender were found to be higher than those of polyurethane films based on ester-polyol and HD chain extender. The elongation at the break of polyurethane films with the MPD component were higher than that of polyurethane films without the MPD component. The artificial leather containing MPD had smaller cells than the artificial leather without MPD and had higher uniformity. From these results, DMF-based polyurethanes prepared by using MPD components containing polyols are found to be most suitable for wet-type artificial leather.

A study on the design improvement of protective footwear for firefighters

In this study, protective footwear for firefighters in Korea was evaluated. Based on the results of wearing evaluation, three types of new designs of firefighting protective footwear were developed: prototypes I, I and II. The prototypes with improved designs were evaluated by wear trails and design preference. Surveys on wearing and design preference of firefighting protective footwear, led to suggestions for designs elements of protective footwear. Firstly, the combination of laces and buckle was suggested for the closure. Secondly, the footwear material suggested was artificial leather with excellent waterproof and ventilation standards. In addition, retro-reflective and fluorescent materials and various colors were suggested for visibility. Thirdly, appearance designs were suggested in three categories: figure, line, and arrangement. Based on the design suggestions, prototypes with improved designs were made. An evaluation was conducted wearing the prototypes with improved designs. All prototypes were found to satisfy more than half of the design and wearing evaluation categories.

Preparation and Properties of Split Microfiber Synthetic Leather

A split microfiber synthetic leather using split microfiber nonwoven as the base and waterborne polyurethane (WPU) coating as the polymer coating was prepared by a dry transfer-coating method. First, the nylon/polyester (N/P) split microfiber nonwoven was manufactured, and the structure and properties were investigated. FESEM analysis indicated fiber diameter size was between 2.2~5.5 μm, and performance attaributes met the demands of textiles-nonwovens for synthetic leather. Then the effect of coating-forming temperature, foaming agent concentration and foaming ratio on the structure and performance of WPU coatings were systematically studied. Finally, the structure and properties of the split microfiber synthetic leather were analyzed. The results showed that the split microfiber synthetic leather arranged in a three-layer configuration, and its air permeability, tensile strength, elongation at break, tear strength, peeling strength and creasy recovery angle were better than knitted synthetic leather and real leather.

Evaluation of the Chemical Composition of Synthetic Leather Using Spectroscopy Techniques.

Synthetic leather samples from Brazil and Paraguay were evaluated in this study using three spectroscopy techniques: inductively coupled plasma optical emission spectrometry (ICP-OES), laser-induced breakdown spectroscopy (LIBS), and wavelength dispersive X-ray fluorescence (WDXRF). The obtained information from each technique was separately inspected with principal component analysis (PCA). The concentrations of the elements determined in the synthetic leathers using ICP-OES decreased in the following order: Ca > Cr > Mg > Ba > Pb > Al > Fe > Zn > Sb > Ni with a concentration range below the limit of quantification (<LOQ, case of Ni) to 112 233 mg kg-1 (case of Ca). Additionally, Cu, As, Sr, Ti, Cd, Mn, Co, and Ni were present in only few samples in a concentration range from <LOQ to 163 mg kg-1. Principal component analysis was the tool used to evaluate the samples from their chemical content obtained quantitatively using ICP-OES and qualitatively using LIBS or WDXRF spectra. The results showed that the association of PCA with spectroscopic techniques was satisfactory for data inspection of synthetic leathers according to the chemical composition. Laser-induced breakdown spectroscopy and WDXRF were able to identify the presence of toxic elements like Cr (LIBS and WDXRF) and Pb (WDXRF).

Characteristics of Electrical Heating Elements Coated with Graphene Nanocomposite on Polyester Fabric: Effect of Different Graphene Contents and Annealing Temperatures

This paper reports the fabrication of electrical heating elements based on the graphene/waterborne polyurethane (WPU) composite coated on polyester fabric with toughness like that of artificial leather. Samples were prepared with 0, 4, 8, and 16 wt% of graphene by using the knife edge method, and then, the samples were annealed from 100 oC to 160 °C. The graphene content had a large effect on the electrical and electrical heating properties. The surface resistivity was decreased by approximately 6 orders of magnitude with an increase from 0 wt% to 16 wt% graphene/WPU composite fabric. The electric heating properties were also improved, as indicated by the percolation threshold. Samples with various graphene contents were annealed, and it was found that the electrical and electrical heating properties were improved, and the most enhanced properties were obtained when the samples were annealed at 120 °C. The initial modulus and tensile strength were increased in comparison with those of 0 wt% and 16 wt% graphene/WPU composite coated on fabrics, but the elongation at break value was slightly decreased with an increasing graphene content. When the samples were annealed, initial modulus and tensile strength of samples were improved at 120 °C and 140 °C, and they were slightly decreased at 160 °C. However, the elongation at break showed an opposite tendency to the tensile strength. With the increase in content of graphene and annealing at 120 °C and 140 °C, the samples were more stiff and tough, and at 160 °C, the samples were softer. Therefore, graphene/WPU composite coated on polyester fabric by use of the annealing process may have applications in electrical heating elements due to its excellent heating performance and toughness like that of artificial leather.

The effect of moisture on friction coefficient of fabrics used on taekwondo personal protective equipment

The purpose of this study was to investigate the friction characteristics of different fabrics used in personal protective equipment worn during competition and matches. During vigorous taekwondo activity, sweat, movement, and body collisions may cause personal protective equipment to slide from its original position and accordingly fail to protect the athletes effectively. Therefore, a thorough study investigating the friction characteristics among different fabrics used in personal protective equipment and its effect on the skin is needed. This study is intended to be helpful for the athletes in the selection of appropriate personal protective equipment fabrics. Universal Nano + Micro + Macro Materials Tester was used in friction tests between six different personal protective equipment fabrics and the dorsum forearm skin to obtain the coefficients of kinetic friction and static friction. The results indicated that PVC faux leather showed better anti-skid performance under dry conditions. Under wet conditions, however, the friction coefficient of PVC faux leather decreased significantly due to lubrication, and thus lowered the anti-skid performance. In addition, the friction coefficient of fabrics with better water absorption or drainage capacity showed greater adhesion with the increasing of skin hydration. In particular, 100% polyester weft-knitted fabric showed better anti-skid performance under wet conditions. The result of this study provides a good reference in the selection and design of Taekwondo personal protective equipment for athletes, coaches, and manufacturers.

Soft and Flexible Bilayer Thermoplastic Polyurethane Foam for Development of Bioinspired Artificial Skin.

Inspired by the epidermis-dermis composition of human skin, here we have simply developed a lightweight, robust, flexible, and biocompatible single-electrode triboelectric nanogenerator (S-TENG)-based prototype of bilayer artificial skin, by attaching one induction electrode with unfoamed skin layer of microcellular thermoplastic polyurethane (TPU) foam, which shows high-performance object manipulation [by responding differently toward different objects, viz., aluminum foil, balloon, cotton glove, human finger, glass, rubber glove, artificial leather, polyimide, poly(tetrafluoroethylene) (PTFE), paper, and wood], due to electrification and electrostatic induction during contact with the objects having different chemical functionalities. Comparative foaming behavior of ecofriendly supercritical fluids, viz., CO2 over N2 under variable temperatures (e.g., 130 and 150 °C) and constant pressure (15 MPa), have been examined here to pursue the soft and flexible triboelectric TPU foam. The foam derived by CO2 foaming at 150 °C has been prioritized for development of S-TENG. Foam derived by CO2 foaming at 130 °C did not respond as well due to the smaller cell size, higher hardness, and thicker skin. Inflexible N2-derived foam was not considered for S-TENG fabrication. Object manipulation performance has been visualized by principal component analysis (PCA), which shows good discrimination among responses to different objects.

Egyptian Folkloric Trims in designing and producing Costumes of the Contemporary Women

In the early fifties there were many voices demanding attention to our folklore and studying it in a serious scientific way. A score of studies have been conducted in this regard. In addition a number of researchers were interested in folklore that received care and encouragement. This interest was a natural response to the study of folklore according to its presence at the social and national levels. Accordingly, studies were interested in folklore including all its folkloric arts, where there were many methods of reading the folkloric art from the creative point of view in the various arts. The art of fashion industry had a big share of the folkloric art. From this point of view, the two researchers used the trims of the Egyptian folklore in the design and production of Poncho for women, which is predominantly characterized with the Egyptian heritage in a contemporary way of nowadays fashion, and the use of raw materials (basic - assisting) and one of the methods of folkloric fashion trims, that is the method of "addition". The problem of the research is the possibility of using the trims, materials and methods of the Egyptian folklore to design and produce costumes for contemporary women and to consult the views of specialists and consumers regarding these designs. The objective of the research was to identify the decorative values and symbolic indications of the symbols, materials and methods used in the Egyptian folklore and attempt to employ them in the development of a collection of executed contemporary designs of women's fashion. The research followed the descriptive approach with analysis and application to answer the research questions and hypotheses. It was possible to employ the trims of the Egyptian folkloric heritage in designing and producing (10) executed designs inspired by some symbols of the Egyptian folk heritage (Hijab” Triangle”,- square - rectangle – diamond - hand palm - eye - zigzag line - the bride - the shape of the burqa) , and used raw materials such as (flax, chalky, mauri, artificial leather, chamois, automated embroidered

English

This article focuses on heat radiation intensity optimization on the surface of a shell metal mould. Such moulds are used in the automotive industry in the artificial leather production (the artificial leather is used, e.g., on car dashboards). The mould is heated by infrared heaters. After the required temperature is attained, the inner mould surface is sprinkled with special PVC powder. The powder melts and after cooling down it forms the artificial leather. A homogeneous temperature field of the mould is a necessary prerequisite for obtaining a uniform colour shade and material structure of the artificial leather. The article includes a description of a mathematical model that allows to calculate the heat radiation intensity on the outer mould surface for each fixed positioning of the infrared heaters. Next, we use this mathematical model to optimize the locations of the heaters to provide approximately the same heat radiation intensity on the whole outer mould surface during the heating process. The heat radiation intensity optimization is a complex task, because the cost function may have many local minima. Therefore, using gradient methods to solve this problem is not suitable. A differential evolution algorithm is applied during the optimization process. Asymptotic convergence of the algorithm is shown. The article contains a practical example including graphical outputs. The calculations were performed by means of Matlab code written by the authors.

Preparation and Characterization of Self-Colored Waterborne Polyurethane and Its Application in Eco-Friendly Manufacturing of Microfiber Synthetic Leather Base.

A novel self-colored waterborne polyurethane (SCPU) was synthesized and used in the preparation of a microfiber synthetic leather (MS-Leather) base in order to reduce the pollution caused by N,N-dimethylformamide (DMF) and dyes. The SCPU was prepared using the reaction of a reactive brilliant red K-2G with a waterborne polyurethane which was then extended via a first generation of hyperbranched poly(amine-ester). With the introduction of the dye, new absorption peaks at 1118 cm−1 [S=O], 1413 cm−1 [N=N], and 1635 cm−1 [C=N] appeared in the Fourier transform infrared (FTIR) spectrum of SCPU, and SCPU mean particle size increased to 162 nm. The X-ray diffraction (XRD) peak intensity of SCPU at 19.27° was 1310 cts. The thermal stability of SCPU at 200–280 °C was inferior to that of the control sample; however, it improved at temperatures above 360 °C. Finally, a free-dyeing MS-Leather base prepared by using SCPU without DMF was manufactured. It was found that the dyes were distributed mainly in the polyurethane matrix rather than in the microfibers. Moreover, the color changes of the base before and after being washed in both a water and a soap solution were 0.93 and 4.21, respectively. This indicated that the base’s washing color fastness to water was better than to a soap solution.