Showing papers on "Natural fiber published in 1996"

Properties and modification methods for vegetable fibers for natural fiber composites

Abstract: SYNOPSIS Studies on structure and properties of natural vegetable fibers (NVF) show that composites made of NVF combine good mechanical properties with a low specific mass. The high level of moisture absorption by the fiber, its poor wettability, as well as the insufficient adhesion between untreated fibers and the polymer matrix lead to debonding with age. To build composites with high mechanical properties, therefore, a surface modification of the fibers is necessary. The existing physical and chemical NVF modification methods-e.g., plasma treatment or graft copolymerization-which are used for the development of NVF-polymer composite properties is discussed. It is shown that modified cellulose fiber-polymer interaction mechanisms are complex and specific to every definite system. By using an coupling agent, like silanes or stearin acid, the Young's modulus and the tensile strength increases, dependent on the resin, until 50%. Simultaneously, the moisture absorption of the composites decreases for about 60%. With other surface modifications, similar results are obtained. 0 1996 John Wiley & Sons, Inc

Tensile properties of short sisal fiber reinforced polystyrene composites

Abstract: The tensile properties of polystyrene reinforced with short sisal fiber and benzoylated sisal fiber were studied. The influence of fiber length, fiber content, fiber orientation, and ben-zoylation of the fiber on the tensile properties of the composite were evaluated. The ben-zoylation of the fiber improves the adhesion of the fiber to the polystyrene matrix. the benzoylated fiber was analyzed by IR spectroscopy. Experimental results indicate a better compatibility between benzoylated fiber and polystyrene. the benzoylation of the sisal fiber was found to enhance the tensile properties of the resulting composite. The tensile properties of unidirectionally aligned composites show a gradual increase with fiber content and a leveling off beyond 20% fiber loading. The properties were found to be almost independent of fiber length although the ultimate tensile strength shows marginal improvement at 10 mm fiber length. The thermal properties of the composites were analyzed by differential scanning calorimetry. Scanning electron microscopy was used to investigate the fiber surface, fiber pullout, and fiber–matrix interface. Theoretical models have been used to fit the experimental mechanical data. © 1996 John Wiley & Sons, Inc.

Influence of fiber surface treatment on the properties of sisal-polyester composites

Abstract: The effect of several chemical treatments, viz. organotitanate, zirconate, silane, and N-substituted methacrylamide, on the properties of sisal fibers used as reinforcement in unsaturated polyester resin (∼50 vol%) was investigated. An improvement in the properties was observed when sisal fibers were modified with surface treatments. Under humid conditions, a decrease of 30 to 44% in tensile and 50 to 70% in flexural strength has been noted. The strength retention of surface-treated composites (except silane) is high compared with untreated composites. It is observed that N-substituted methacrylamide-treated sisal composites exhibited better properties under dry as well as wet conditions. Fractographic evidence such as fiber breakage/splitting and matrix adherence on the pulled-out fiber surface explains such behavior.

Multi-layered panel having a core including natural fibers and method of producing the same

Abstract: A multi-layered laminated body may especially be used as an interior trim panel in a motor vehicle. The panel includes a substrate, a foam intermediate layer, and a decorative surface layer. The substrate preferably includes three layers, namely a core layer including a natural fiber filler material embedded in a thermoplastic matrix material, and two cover layers comprising natural fibers, glass fibers or polyester fibers in a thermoplastic matrix material. The thermoplastic matrix material is preferably polypropylene. All of the materials of the multi-layered panel are easily broken down or otherwise processed for reuse or recycling. The panels are preferably produced by hot laminating the individual layers of the substrate together and then laminating and molding the decorative surface layer onto the substrate.

Crystalline structure of developing cotton fibers

Abstract: The crystalline structure of dried cotton fibers at varying development stages has been investigated using wide angle x-ray diffraction (WAXS) techniques. The cellulose I crystalline structure has been confirmed on dried SJ-2 Acala cotton fibers collected at varying developmental stages and at maturity. The cellulose I crystalline structure is clearly evident at the early developmental stage of 21 days postanthesis (dpa). The crystal system remains unchanged during the cotton fiber biosynthesis and at maturity. The degree of crystallinity and crystallite dimensions in the cotton fibers increase with cell development. The most significant increments are observed between 21 and 34 dpa (i.e., during the first half of the secondary wall thickening process). The unit cell sizes slightly decrease and thus the crystal density increases with fiber development. The alignment of the glucosidic rings in respect to the 002 planes improves with fiber cell development. © 1996 John Wiley & Sons, Inc.

Utilization of short oil palm empty fruit bunch fiber (opefb) as a reinforcement in phenol-formaldehyde resins: studies on mechanical properties

Abstract: The brittle thermosetting plastic, phenol-formaldehyde, was reinforced with oil palm empty fruit bunch fiber. Composites were prepared from resol type phenol-formaldehyde resin. Hand lay up technique followed by compression molding was used for composite preparation. Fiber lengths of 20, 30, 40 and 50 mm were used for composite fabrication. The effect of fiber length and fiber loading on the mechanical properties was studied. Tensile, flexural and impact properties of the composites were analyzed. The experimental results were compared with the theoretical predictions. Scanning electron micrographs of the fracture surfaces were taken to analyze the fiber-matrix adhesion, fiber pull-out and fiber surface topography. Finally, the properties of the composites were compared to those of other natural fiber filled PF composites.

Improvement of adhesion between polyethylene and regenerated cellulose fibers by surface fibrillation

Abstract: Regenerated cellulose fibers spun from straw pulp using the N-methylmorpholine N-oxide (NMMO) process were evaluated as a reinforcement for low-density polyethylene (LDPE). Surface fibrillation was carried out by a mechanical treatment to improve interfacial adhesion. Surface fibrillation resulted in a gradual change in surface topography, as detected by SEM. Long and numerous twisted fibrils were observed on the surface of the treated fibers. The fiber perimeters, determined by the Wilhelmy plate method, increased with an extended degree of fibrillation, while the strength of the fiber was not affected by the surface treatment. Model composites were prepared by embedding untreated and surface-fibrillated single fibers into an LDPE matrix, and the single fiber fragmentation (SEF) test was carried out to determine the critical fiber length. The interfacial shear strength (τ) was then calculated by applying a modified form of the Kelly-Tyson equation. It was found that the interfacial shear strength increased significantly as a result of surface fibrillation. The proposed mechanism for the improvement of interfacial adhesion is a mechanical anchoring between the matrix and the fiber.

The influence of classical and enzymatic treatment on the surface charge of cellulose fibres

Abstract: Natural cellulose fibres comprise several non-cellulose compounds and cationic trash which cause problems during different adsorption processes such as dying, printing, final fiber finishing and coating. Therefore the pre-treatment (classical NaOH or environmental friendly enzymatic treatment, demineralisation) is the most important step in cellulose textile prefinishing-cleaning. An appropriate way to describe the success of different processes in fiber pre-treatment which result in distinct surface charge is the determination of electrokinetic properties-zetapotential (ZP) of fibers and textile materials. The zetapotential was determined by streaming potential measurements as a function of the pH and the surfactant concentration in the liquid phase. Cellulose fibers in an aqueous medium are negatively charged due to their characteristic carbonyl and hydroxyl groups. The degradation and removal of specific hydrophobic non-cellulose compounds which cover the primary wall of the cellulose polymer change the surface charge. The ZP is mainly influenced by waxes, their removal decreases the negative ZP. This result is obtained by the classical chemical process as well as by an environmentally friendly enzymatic treatment. Our results indicate that the progress of textile treatment and purification is reflected by the zetapotential of the fabrics. This method enables the estimation of the process'es progress and the interaction between components of the liquid phase and the fibre surface.

Biodegradable and hydrolyzable sheet

Abstract: A biodegradable and hydrolyzable sheet which comprises at least one biodegradable synthetic fiber, at least one natural fiber and/or regenerated fiber, the fibers being bonded to one another with a binder which substantially loses its adhesive power in water. This sheet has a combination of a given tensile strength, a good softness, and a desired liquid absorption capability and, in addition, a desired biodegradability. Therefore, the sheet, when flushed away in a flush toilet, does not cause any significant increase in solid residues in a septic tank and sewage treatment equipment, rendering the sheet suitable particularly for wet wipes.

Influence of swelling of noncrystalline regions in silk fibers on modification with methacrylamide

Abstract: The degrees of swelling of noncrystalline regions of domestic and tussah silk fibers were investigated by measuring the small-angle X-ray scattering intensity of the fibers in wet conditions and analyzing the scattering intensity based on a two-phase model, i.e., crystalline regions and water-swollen noncrystalline regions. The influence of the degree of swelling of noncrystalline regions on the graft treatment of these fibers with methacrylamide was investigated. The changes in the structure caused by the graft treatment were also analyzed using the wide-angle X-ray diffraction measurements. As compared with the tussah silk fibers, the domestic silk fibers showed a larger degree of swelling of the noncrystalline regions, and gained a larger amount of resin by the graft treatment. The crystallites with smaller sizes in the tussah silk fibers were destroyed preferentially by the graft treatment. For the domestic silk fibers, the crystallites were destroyed more seriously and rather homogeneously independent of the crystallite sizes. © 1996 John Wiley & Sons, Inc.

Ubiquitous fiber exposure in selected sampling sites in Europe

Abstract: Objectives This study evaluates personal exposure to respirable inorganic and organic fibers during normal human lifetimes and assesses the order of magnitude of the contribution of inorganic fibers other than asbestos to total fiber exposure from man-made and natural sources. Methods Four groups (suburban schoolchildren, rural retired persons, office workers, and taxi drivers), with five persons per group, were monitored over 24 h four times during one year. Personal sampling pumps collected airborne dust on gold-precoated Nuclepore filters. The fibers were analyzed for fiber sizes specified by the World Health Organization Results The geometric mean concentrations ranged from 9000 fibers·m-3 (office workers) to 20 000 fibers·m-3 (schoolchildren) for organic fibers, and from 600 fibers·m-3 (taxi drivers) to 4000 fibers·m-3 (schoolchildren) for gypsum fibers. For other inorganic fibers the concentrations were around 5000 fibers·m-3. The contribution of fibers with an elemental composition similar to that of man-made vitreous fibers (MMVF) was less than about one-quarter of the content of other inorganic fibers. The fiber size distributions were uniform across the groups, and the organic fibers were the longest and thinnest nonasbestos fibers. Conclusions Lifetime exposure to fibers can be ranked as organic fibers > other inorganic fibers > fibers with an elemental composition similar to MMVF > MMVF. Information on the biological effects of fibers is difficult to interpret for use in assessing the exposure risk for low levels of ubiquitous fibers, and there is a lack of knowledge on the effects of organic fibers.

Preparation and characterization of niobium oxide coated cellulose fiber

Abstract: The Nb 2 O 5 /cellulose composite was prepared by reacting α-cellulose with NbCl 5- n (OC 2 H 5 ) n , in nonaqueous solvent, under nitrogen atmosphere and submitting the obtained material to hydrolysis. An increase in the crystallinity degree is observed in the composite material because the precursor reagent reacts with the amorphous phase of the cellulose fibers. Loadings between 4.5 and 16.0% of the oxide were achieved and in every case the oxide particles uniformly cover the fiber surface. Lewis and Bronsted acid sites were determined by using pyridine as the basic molecular probe.

Metal coated melamine resin fiber and natural fiber mixture

Abstract: A fiber blend of (a) from 10 to 90 parts by weight of metal-coated melamine resin fibers or a blend of uncoated and metal-coated resin fibers and (b) from 90 to 10 parts by weight of natural fibers and wovens, nonwovens, yarns, tapes or moldings formed from the blend.

Chewing stick made from natural fibers

Abstract: A natural fiber chewing stick including a plurality of strips of treated natural fibers bonded together, said strips including flavor and other compositions added during processing. Typically, the individual strips used are of jute, but other natural fibers may be used.

Sound absorbing material for engine cover

Abstract: PROBLEM TO BE SOLVED: To obtain large sound absorbing effect from a low frequency area to a high frequency area with a small volume by forming a sound absorbing material of fiber, and specifying the value of its thickness and surface density. SOLUTION: A sound absorbing material 2 for an engine cover is installed on the engine side wall surface of an engine proximity cover 1. The sound absorbing material 2 is formed of short fiber and/or long fiber with average diameter in a range of 10-60μm without distinction of material. The thickness of the sound absorbing material 2 is in a range of 5-50mm, and the surface density of the sound absorbing material is in a range of 100-5000g/m . The sound absorbing material 2 is formed of a fiber aggregate. Fiber forming the fiber aggregate can be natural fiber or synthetic fiber, but it is desirable to use synthetic fiber. As the synthetic fiber, it is desirable to use polyester group fiber or polypropylene fiber mixable with fiber different in a softening point.

Plate or molded product and its manufacture

Abstract: PROBLEM TO BE SOLVED: To realize a plate product equipped jointly with excellent moisture permeability and high strength by a method wherein the plate is composed of a fiber mat formed of mixed fiber of only palm fiber or that and another organic and/or inorganic fiber, and curable resin joining this resin together, and the fiber mat is laminated and formed by compression. SOLUTION: A fiber mat which is formed of mixed fiber of only palm fiber such as fiber bark, petiole base fiber, mesocarp fiber, etc., which are sampled from palm family plant such as coconut palm, oil palm, etc., or palm fiber and another organic and/or inorganic fiber, is provided. That and, when an occasion demands, a sheet shaped product composed of a thin piece of knitted texile, nonwoven fabric or banboo fabric, etc., which are composed of vegetable natural fiber arranged at least one face of and/or inside the fiber mat layer are arranged. Curable resin such as heat curable resin of phenolic resin or the like, reactive curing resin of silicone resin or the like, etc., is stuck thereto, a plurality of fiber mats and sheet shaped products are laminated, and formed by compression to obtain a plate product or molded product.

Effects of electron irradiation on physical properties of rubber/cellulose fibre composites

Abstract: Short term stress-strain properties were investigated for natural rubber reinforced with short cellulose fibres at various fibre loads. Stress-strain measurements were also performed on natural rubber composites containing cellulose fibres, electron irradiated in the presence of butadiene or N-hydroxymethylacrylamide, where the latter monomer produced the greatest improvement in stress-strain properties. Chemiluminescence analysis indicated the existence of a surface layer on the fibres after irradiation treatments, and water absorption measurements showed a decrease in water uptake for composites containing irradiated fibres. The results demonstrate the improvement of mechanical properties with a reduced sensitivity to moisture.

Laminated nonwoven fabric and its production

Abstract: PROBLEM TO BE SOLVED: To obtain a laminated nonwoven fabric comprising short fibers made of conjugate filament yarns of excellent cooling disposition, spinnability and drawability following their delivery from a spinneret, good in biodegracabiliy which is controllable, rich in both moisture and water absorbability, and having enough mechanical strength to stand its practical use. SOLUTION: First, a melt conjugate spinning is conducted to produce a sheath-core type conjugate fiber made up of core component consisting of a 1st biodegradable aliphatic polyester and sheath component consisting of a 2nd biodegradable aliphatic polyester lower in melting point than the 1st polyester. Subsequently, the conjugate fibers are drawn, the resultant oriented diligent yarns are then mechanically crimped and cut to a specified length into short fibers, which are then carded into a short fiber web, which is, in turn, laminated with a natural fiber web followed by subjecting both the webs to fluid jet treatment to effect three-dimensional interlacing of the constituent fibers into integration, thus affording the objective laminated nonwoven fabric. COPYRIGHT: (C)1997,JPO

Characteristics of concrete reinforced with San fibers

Abstract: This paper presents the results of an experimental investigation carried out to determine the physical and mechanical properties of natural San (Crotolaria Juncea) fiber, and its effect on compressive strength, splitting tensile strength and flexural strength (modulus of rupture) of concrete. San fiber is a natural fiber, which is widely available in many parts of India, and has good tensile strength. Concrete mixtures were prepared with three volume fractions of San fibers viz. 0.25%, 0.50%, 0.75%, and three fiber lengths viz. 20 mm, 25 mm, 30 mm. Experimental results of the mechanical properties of the San Fiber reinforced concrete have been compared with the theoretical model developed by Pakotiprapha et al. [10]. Comparison of the theoretical and experimental results shows good agreement.

Laminated nonwoven structure and its production

Abstract: PURPOSE: To obtain a laminated nonwoven structure bearing a combination of water- absorbing ability with hydrophilicity, excellent in tensile strength, interlaminar debonding resistance, dimensional stability and flexibility, by unifying a polyester melt-blown ultrafine fiber nonwoven fabric and a natural fiber nonwoven fabric through dotted fused regions. CONSTITUTION: A blend of 70-95wt.% of polyethylene terephthalate 1.20-1.32 in relative viscosity and 30-5wt.% of a crystalline polypropylene is subjected to melt spinning at the melt flow ratio of the polypropylene to the polyester of 4-20, and the resultant delivered fibers are drafted by a high-pressure air jet at a temperature higher than the melt temperature and cooled, and then accumulated on a moving collection surface, thus producing a nonwoven fabric comprising sheath-core type ultrafine fibers )].

Flexural strengths of performance-designed wood fiber composites

Abstract: Wood fiber-based composites are historically, and today, cost-driven commodity materials. This is partially a result of the low cost of wood (two to five cents per pound) and the traditional way of using wood products. Certain wood fibers have been shown to have specific tensile strengths comparable to certain nonwood engineered materials. Combining the positive attributes of wood fibers, modern thermosetting resins, and other polymeric systems with concerted research efforts may provide ample opportunities for manufacturing wood fiber and wood fiber-nonwoodfiber hybrid composites for performance-designed and -driven, and cost sensitive applications. This study examines specific static flexural properties and costs of aspen wood fiber composites and compares them with glass fiber reinforced polymer matrix composites. Also presented are the characteristics of polyisocyanate thermoset resins and their potential for bonding wood fibers with nonwood materials in manufacturing hybrid composites.

Metal ion-containing organic fiber improved in durability and its production

Abstract: PURPOSE: To obtain a fiber having deodorizing and antibacterial potencies and adequate washing durability by adding a metal ion elimination-preventing agent to an organic fiber having metal-containing carboxyl groups. CONSTITUTION: This production of a metal ion-containing organic fiber improved in durability is to graft polymerize methacrylic acid on an organic fiber such as a natural fiber e.g. cotton or wool, a synthetic fiber e.g. nylon or polyester, etc., for example, cotton yarns, treat the product with sodium hydroxide to change COOH into COONa, substitute Na with a metal ion such as copper, zinc, iron, nickel, cobalt or silver to obtain the cotton yarns having metal- containing carboxyl groups, then add a metal ion elimination-preventing agent comprising at least one compound selected from a group consisting of benzotriazole-based compounds, imine ring-containing compounds, triazine thiol compounds or silane coupling agents containing amino groups, mercapto groups or tertiary ammonium salts, e.g. 2,2-bishydroxymethylbutanol tris2[3(1- aziridinyl)]propionate.

Biodegradable raising seedling pot

Abstract: PROBLEM TO BE SOLVED: To provide a biodegradable raising seedling pot, obtained by adding biodegradable resin as a binder to nonwoven fabric formed of biodegradable fiber and pressing and forming it in a pot shape, which need not be disposed of after being used, superior in shape retention, flexibility, and design, and useful for a garden plant, a flower, etc. SOLUTION: The biodegradable resin such as starch, carboxymethyl celluose, sodium alginate, casein or an ethylene vinyl acetate denatured starch polymer is added as a binder to the nonwoven fabric which consists of biodegradable fiber such a s natural fiber, regenerated fiber, aliphatic polyester short fiber or their mixture having 30-60g/m 2 Metsuke unit weight (1 Metuke: 4.3560g/m 2 ). COPYRIGHT: (C)1997,JPO

Pretreatment of natural fiber

Abstract: PURPOSE: To perform bleaching capable of imparting improved cloth feeling and dyeability, and good in homogeneity by treating a natural fiber with a treating solution containing a bleaching agent, a bleach stabilizer and a specific anionic wetting agent or dispersant. CONSTITUTION: A natural fiber originating from a plant or animal such as cotton, linen, wool or silk, or a blended product of a natural fiber with a synthetic fiber such as a polyamide, polyester or acrylic, preferably cotton, linen or a blended product of these natural fibers with the above synthetic fibers is treated with a treating solution containing a bleaching agent such as hypochlorite or hydrogen peroxide, a bleach stabilizer such as tripolyphosphate and an anionic wetting agent or dispersant with or free from a nonionic component in which 5-100 equivalent percents of the counteractions is lithium ion, and 95-0 equivalent percent is one or more kinds out of Na , K , NH4 , Ca and Mg .

Production of film using natural fiber as raw material

Abstract: PURPOSE: To produce a film composed of opened material of natural fibers having a tensile strength equail to or larger than a synthetic resin film without using an organic solvent. CONSTITUTION: Natural fibers are opened by adding water and a suspension of the opened natural fibers having diameters of 0.01-2μm are obtained. A concentration of the suspension is adjusted to 0.1-10wt.% and cast on a flat surface, water is removed by vaporization and dried to obtain a film. The natural fibers are at least one kind of natural fibers selected from cellulose-based, chitinchitosan-based, collagen-based, fibroin-based and fibrous inorganic materials. Thickness of the film is adjusted to 0.1-500×m. The suspension obtained by adding water to the natural fibers and opening is coated between plural films, the films are laminated and the resultant laminated material is compressed to remove water.

Agent for treating leather, fur and natural fiber and fiber product mainly composed of natural fiber and treatment using the same

Abstract: PURPOSE: To obtain a treating agent for leather, fur, natural fibers and natural fiber products, improves their washing resistance, dimensional stability, flexibility, tensile strength, touch or fabric hand, compressing a specific composition. CONSTITUTION: This treating agent comprises (A) a polyoxyalkylene polyol having 2-6 functional groups (preferably having 600-5,000 molecular weight and 3 functional groups), (B) a water-soluble polyurethane and/or a water- dispersible polyurethane, (C) an aromatic (poly)isocyanate and/or an aliphatic (poly)isocyanate and (D) a surfactant (preferably a nonionic surfactant as an ethylene oxide adduct to an alkylphenol. The component B is preferably a non-reactive water-soluble polyurethane obtained by reaction of a polyethylene glycol with tolylene diisocyanate. Preferably, the amounts of component A of 25-70wt.%, component B of 15-60wt.%, component C, of 0.3-3%, and component D of 0.8-15wt.% are blended together.

Elastic Properties of Polymer Systems Reinforced with Short Organic Fibers.

Abstract: This paper addresses the experimental and theoretical investigations of mechanical properties of polymer resins reinforced with natural fibers These materials have potentially a wide area of applications and relatively low cost because they are made of inexpensive resins and fibers obtained from plants available in the Mexican desert We present the results of experimental investigations of elastic properties and strength of composites based on three types of polymer resins reinforced with natural fibers of Palma Zamandoca Theoretical analysis of effective elastic and strength properties of short-fiber matrix composites is given based on the advanced self-consistent scheme permitting to account for interactions between fibers The method utilizes the idea of introducing the effective strain field which affects every inclusions in the composite In distinction to the traditional forms of the effective (ie, self-consistent) field method we assume that the effective field is not constant and the same for all fibers but rather depends on the orientation of each of them This allows to take into account the characteristics of the spatial distributions of fibers in the volume of composite The scheme utilizes the asymptotic solution of elastic problem for rigid cylindrical bar The results of theoretical analysis are compared with extensive experimental data on composites with natural fibers manufactured and tested by the authors as well as with the data for composites with inorganic fibers (eg, glass and carbon fibers) available in literature