Effects of BN on the Mechanical and Thermal Properties of PP/BN Composites

In order to explore the thermal conductivity of polypropylene(PP)/hexagonal boron nitride(BN) composites,PP composites filled with different proportions of BN were prepared through extrution compounding,injection moulding and compression moulding.The composites were filled with BN particles of 5 and 20 μm respectively,and their mass fractions in composites were considered.Percentage of BN was varied from 0 to 25wt% in steps of 5wt%.The effects of BN filler on mechanical properties of the composites were evaluated.The thermal behaviors were studied using DSC and TGA,and the thermal conductivity was also investigated by Laser Flash Device and the Model of 3D Heat Conduction respectively.The experimental results show that impact strength of PP/BN can be enhanced with the addition of BN,but that composites exhibit lower breaking elongation & tensile strength when compared to unfilled ones.It is found that mass fraction of BN influenced the final thermal stability and degree of crystallization of PP matrix,the degree of crystallization of PP with 15wt% of 20 μm BN can be improved by 25% than neat PP.Meanwhile,crystallization temperatures of PP composites are elevated by about 10 ℃.The thermal conductivity results demonstrate that the maximum value of the thermal conductivity is achieved from PP/BN with 20wt% of 20 μm BN,higher than that of pure PP by 95.65%,close to the simulation one.

Review of Fabric Defect Detection Based on Computer Vision

In textile inspection field,the fabric defect refers to the destruction of the texture structure on the fabric surface.The technology of computer vision makes it possible to detect defects automatically.Firstly,the overall structure of the fabric defect detection system is introduced and some mature detection systems are studied.Then the fabric detection methods are summarized,including structural methods,statistical methods,frequency domain methods,model methods and deep learning methods.In addition,the evaluation criteria of automatic detection algorithms are discussed and the characteristics of various algorithms are analyzed.Finally,the research status of this field is discussed,and the future development trend is predicted.

Oscillation Reduction of Breast for Cup-Pad Choice

Traditional studies of evaluating breast displacement included cup fabrics,shoulder straps,and under-bands restricted by own features of sports bras(SBs).The effects of pads on breast support during movement were investigated by conducting trials with the motion capture experiment.The three-dimensional breast displacements at five breast positions were collected and values in the vertical direction were evaluated.Results indicate that the effectiveness of the cup pad depends on the pad diameter and the thickness.SBs with larger pads and thicker pads made of soft polyurethane cause less overall breast displacement during vertical jumping compared to unpadded bras(p<0.05).The effectiveness of bra oscillation reduction was characterized by the total reduced percentage of the breast displacement.These findings enlarge scopes in terms of the current breast displacement analysis and understanding of selecting SBs associated with changes in the specifications of pads,thereby providing objective methods for bra cup evaluation and a design basis for breast protection.

Enzymatic Synthesis of Fatty Acid Methyl Esters from Crude Rice Bran Oil with Immobilized Candida sp. 99-125

The non-edible crude rice bran oil was extracted from white rice bran, and then was catalyzed by immobilized lipase for biodiesel production in this study. The effects of water content, oil/methanol molar ratio, temperature, enzyme amount, solvent,number of methanol added times and two-step methanolysis by using Candida sp. 99-125 as catalyst were investigated. The optimal conditions for processing 1 g rice bran oil were: 0.2 g immobilized lipase, 2 ml n-hexane as solvent, 20% water based on the rice bran oil mass, temperature of 40 °C and two-step addition of methanol. As a result, the fatty acid methyl esters yield was 87.4%. The immobilized lipase was proved to be stable when it was used repeatedly for 7 cycles.

Low temperature preparation of nano TiO_2 and its application as antibacterial agents

A low temperature preparation of nano TiO2 using sol-gel method was proposed. The antibacterial properties of the treatment solution and the treated cotton fabrics obtained via a dip-padding process were evaluated. XRD pattern shows that the nano TiO2 produced is an anatase phase. Aqueous nano-dispersion of the nano TiO2 exhibites positive results as an antibacterial finishing agent for cotton fabrics. The treatment solution possesses antibacterial rates of over 92% and 88.9% against Escherichia coli and Bacillus subtilis,respectively. The treated fabrics are slightly downgraded but still maintained over 89% and 83% of reduction towards the same bacteria. After washing for 50 times,the antibacterial performances of the treated fabric still remains at a relatively high level,indicating the durable characteristic of nano TiO2 treatment.

Study on the Camouflage-Protective and Dyeing Properties of Natural Dye Indigo

There are two major camouflage protections in modern military tactics:UV-protection and near infrared camouflage.However,not all natural and composite dyestuffs provide the mentioned properties.In this study,the cotton fabric was dyed with natural indigo and the natural indigo dyeing process was optimized.Green leaves were chosen as the simulating object,and the camouflage properties of the dyed cotton fabric were evaluated.It was observed that the dyed cotton fabric had good UV-protection and near-infrared camouflage properties.The UV-protection effect was strongly dependent on the absorption characteristics of natural indigo for UV radiation.The near infrared camouflage effect was mainly dependent on the reflection spectrum characteristics of natural indigo in the near infrared waveband.

Optimization of the Production Process of Flash-Spinning UHMWPE Superfine Fiber by Response Surface Methodology

In this paper, statistical optimization method was used to optimize the flash-spinning process conditions. Ultra-high molecular weight polyethylene （UHMWPE） superfine fiber was fabricated by flash-spinning method using UHMWPE as the fiberforming polymer, 1, 2-dichloroethane as the main solvent. The important parameters of the flash-spinning were filtered by Plackett-Burman experimental design based on the single factor experiments. After determining the best regions of the fiber properties, the optimum level of the important parameters were determined by Box-Behnken design. The results of the design showed that the important parameters influencing on the properties of the flash.spinning fiber were spinning temperature, spinning pressure, and spinning solution concentration. The optimum technical parameters were： spinning temperature 186. 4 ~C, spinning pressure 6. 16 MPa, spinning solution concentration 3.06 %. The highest combination property of the flash-spinning fiber was 86.39 under this condition.

Preparation of Composite Phase Change Material Based on Sol-Gel Method and Its Temperature-Adjustable Textile

In this study,the sol-gel method was introduced to prepare the composite phase change material (CPCM). The CPCM was added to fabric with coating techniques and the thermal activity of modified fabric was studied. In addition,the thermal property and the microstructure of CPCM were also discussed in detail by means of polarization microscope and differential scanning calorimeter,respectively. According to the analysis of main influencial factors of the property of CPCM,the optimal preparing technique was determined. It was proved that CPCM could exhibit a good thermal property while phase transformation process took place,and a better appearance of the fabric modified with CPCM could be obtained due to the fact that in a warm circumstance,the liquid-state phase change material could be firmly enwrapped and embedded in the three-dimensional network all the time during the phase transformation. Besides,the fabric treated with CPCM had a high phase-transition enthalpy and an appropriate phase-transition temperature. As a result,a desirable temperature-adjustable function appeared.

Fabrication and characterization of novel foaming polyurethane hollow fiber membrane

Foam-like materials had attracted great interest as promising absorbent. In this study, thermoplastic polyurethane(TPU) block sponge was synthesized. Polyester(PET) braid tubular reinforced polyurethane(PU) spongy hollow fiber membrane was prepared by a concentric circular spinning method. The method was woven from an outer coated water-blown PU separation layer and inner PET braid tubular. We have developed a simple and useful preparation technique for the PU spongy hollow fiber membrane. For the first time, the PU spongy hollow fiber membrane was prepared using a coating and controlled foaming technique. The influence of toluene isocyanate index on the physical properties, morphology, and structure of flexible PU sponge was discussed in terms of water contact angle(CA), pure water flux(PWF), Fourier Transform Infrared Analysis(FTIR),pressure-responsive property, and pull-out strength. The morphologies of the membranes were investigated by scanning electron microscopy. We have characterized the foams from an intuitive point of view and demonstrated that the dimensional morphology of the membrane was closely related to isocyanate index. The result showed that the surface cell size of the PU sponge hollow fiber membrane gradually decreased with an increase of the isocyanate index. Due to the elasticity of PU at room temperature, the pressure responsive characteristic of the membrane was prepared. When isocyanate index was 1.05, the interface bonding strength of PU spongy hollow fiber membranes reached as high as 0.37 MPa, porosity and PWF were 71.5% and 415.5 L·m^-2·h^-1,respectively.

3D Modeling and Simulation of Fancy Fabrics in Weft Knitting

Weft knitted fancy fabrics are widely used in knitted garment design. Due to the complexity of the structures, their modeling and simulation needs to be solved in three-dimensional (3D) CAD developments. In this paper, 3D loop geometrical models of weft knitted fancy structures, including tuck stitch, jacquard stitch, transfer stitch and fleecy stitch, were developed based on an improved model of plain loop, and their central axes as some 3D space curves were achieved by using Non-Uniform Rational B-Splines (NURBS). The 3D visual simulation programme was written in C++ programming language using OpenGL, which was a function library of 3D graphics. Some examples of weft knitted fancy fabrics were generated and practical application of 3D simulation was discussed.

Assessing Gray Scale Grades for Color Change of Dyed Fabrics via Image Processing Technology

Gray scale grades for color change of dyed fabrics are assessed via image processing technology.Digital images of groups of specimens are obtained,cropped,and saved as JPEG format.Relationships between gray scale grades for color change and the corresponding color differences calculated via image processing technology are investigated,compared with those obtained from high accurate computer color matching system.Results show that the new method is acceptable with an accuracy of 92.0% when the grading errors are of not more than one grade.

Preparation and Characterization of Temperature-Sensitive Hydrogels Composites by Coating Method

In this study,the hydrogels composites with coatings based on a temperature-sensitive linear copolymer of N-tert-butylacrylamide(NTBA)and acrylamide(AAm)on cotton fabrics have been developed.The cotton fabrics were coated using aqueous solution of the linear copolymer,1,2,3,4-butanetertracarboxylic acid(BTCA)as a cross-linker and sodium hypophosphite(SHP)as a catalyst,followed by drying and curing.The effects of cross-linking reaction conditions in coating process on water-impermeable ability of coated cotton fabrics were investigated in detail.The results indicate that the coated fabrics have temperature sensitivity.The coatings of poly(NTBA-co-AAm)hydrogels were bonded on the surface of the cotton fabrics,as verified by SEM and optical microscopy,which gave the water-impermeable ability to the hydrogels composites.Moreover,the hydrogels formed in the coating process also identified that - COOH of BTCA reacted with -NH2 in the linear polymer and formed three-dimensional network hydrogels.FTIR and XPS were used to characterize the cross-linking reaction of - COOH of BTCA and - OH of cellulose.

Degradation of Azo Dyes by Photocatalysis of Fe(Ⅲ)-oxalate Complexes/H_2O_2 in Aqueous Non-ionic Surfactant Triton X-100 Solution

Two azo dyes,C.I.Reactive Red 195(RR195)and C.I.Acid Black 234(AB234)were degraded by photocatalysis of Fe(Ⅲ)-oxalate complexes/H2O2 in aqueous non-ionic surfactant,Triton X-100(TX-100)solution.Some factors affecting the dye degradation such as TX-100 concentration,irradiation intensity,and sodium chloride were investigated.The interaction and competition between dye and TX-100 during the degradation were also examined using spectrophotometry and maximum bubble pressure method,respectively.The results indicated that TX-100 showed a significant reduction effect on degradation of two azo dyes,but which was largely confined to TX-100 concentration below the Critical Micellar Concentration(CMC).And the reduction was considerably decreased above the CMC,especially in the case of AB234.Moreover,the reducing effect of TX-100 on dye degradation almost did not vary with irradiation intensity.And the impact of sodium chloride on dye degradation was limited by the addition of TX-100.

Relationships between Different Preparations of Cotton Hollow Yarn and Water Soluble PVA Extraction

In this paper cotton hollow yarns were obtained from the core spun yams which were produced on a little modified conventional experiment ring frame with water soluble staple PVA yam as the core. For comparison, yams with same linear densities, same twists of the sheath, different linear densities, different twist directions of the core were prepared. The results show that the tensile strengths of the hollow yarns decrease first, then increase and decrease again, at last the tensile strength trends to reach a steady state with the soluble PVA core extraction proceeding. And when the sheath linear densities of the core spun yams are constant, their twist and twist direction are same as that of the core it will be easier to remove the core of the yam with a higher core size. When the linear densities of the sheath and the core are all constant, the twists of them are same, it will be easier to remove the core of the yam with a different twist direction of core to the sheath.

Modulation of the plasma uniformity by coil and dielectric window structures in an inductively coupled plasma

The effects of coil and dielectric window structures on the plasma distribution are examined in a cylindrically symmetric planar inductively coupled plasma(ICP).A two-dimensional(2 D)fluid model is employed to investigate the design issues of ICP source for etching.When the gradient coil structure is applied at 400 W and 20 mTorr,the ionization rate caused by the power deposition decreases at the reactor center as compared to that in a reactor with a planar coil above the planar dielectric window,and a rather uniform plasma is obtained.However,for the vertical coil geometry,all the coils move to the position of the outermost coil,and the peaks of the power deposition and ionization rate appear at the radial edge of the substrate.In this case,the plasma density is characterized by an edge-high profile.Further,it is observed that the plasma uniformity is improved by increasing the source power under a gas pressure of 20 mTorr and becomes better when the gas pressure increases to 30 mTorr with the source power being fixed at400 W in the gradient coil configuration,but the uniformity of plasma worsens with the rising source power or pressure due to the strong localization in the vertical coil geometry.Moreover,when the discharge is sustained in a reactor with a stepped dielectric window at r=0.135 m,the best plasma uniformity is obtained at 400 W and 20 m Torr because the ionization rate is enhanced at the outermost coil,and the dielectric window at r=0.135 m blocks the diffusion of plasma towards the axis.In addition,higher source power and lower gas pressure produce more uniform plasma for the designs with a stepped window near the symmetry axis.When the dielectric window is stepped at r=0.135 m,the non-uniformity of plasma initially decreases and then increases with the increase in source power or gas pressure.When the dielectric window is stepped at the radial edge of the chamber,the plasma uniformity is improved by increasing the source power and gas pressure due to the enhanced ionization at the larger radius caused by the severe localization.

A Structure-properties Study of MDI-based Hydrophilic Polyether-polyester Polyurethane

A series of segmented polyether-polyester polyurethane with amorphous hydrophilic soft segment domains were prepared from 4,4'- diphenylmethane diisocyanate (MDI), polybutylene adipate (Glycol) 2000 (PBA2000), and polyethylene glycol 1000 (PEG1000), with 1,4-butanediol (BDO) as the chain extender. Furthermore, several representative properties of the polyurethanes, such as moisture permeability, water resistance, hydrophilic property, and phase inversion temperature, were investigated. The studies show that the structure and concentration of soft segment have a remarkable effect on the main application properties of polyurethane. On the contrary, the functional properties of the polyurethane are almost not affected by its hard segment.

Atmospheric-pressure Air Plasma Treatment of Polyester Fabrics for Inkjet Printing with Pigment Inks

Without any preprocessing,polyester fabric has lower ability to hold on water and inks due to the smooth morphology of polyester fibers. Therefore, patterns directly printed with pigment inks have poor color yields and bleed easily. Pretreatments of polyester fabric were carried out with atmospheric air plasma under different experimental conditions. After plasma treatment the samples were printed with magenta pigment ink. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analyses indicated that the enhanced color performance was mainly contributed by not only the etching effect but also oxygen-containing polar groups induced onto fiber surfaces through plasma treatment. Thereby the surface modification of polyester fabrics using atmospheric-pressure air plasma offers a potential way to fabric pretreatment for pigment inkjet printing with the advantages of environmental friendly and energy saving over traditional pretreatment methods.

The Application of Fractal to Design Knitted Sweaters

Pattern design is very important for knitting industry. Fractal theory is adopted to create image automatically, which is applied to design knitted sweaters. Based on Mandelbrot set(M-set), image could be generated automatically by visual basic (VB) program. Plenty of wonderful patterns are created by the following methods: selecting any parts of the image and magnifying, extending generalized M-set, editing the selected images with photoshop. The edited pattern is used to set on any parts of clothes to show fashion effect. Actual knitted structure is simulated by knitting CAD software. The results show that the fractal theory has greater potential applications in knitted pattern design, and it deserves further research.

Synthesis and Characterizations of 1,4-butanediol( BDO )-Regulated Poly( ε-caprolactone)(PCL) Waterborne Polyurethane with Controlled Biodegradability for Medical Applications

Waterborne polyurethane （ WBPU ） with controlled biodegradability and biocompatibility was synthesized by using poly （ε-caprolactone） （ PCL ） as the polyglycol, isophorone diisocyanate （IPDI） as the isocyanate, 2 acid （DMPA） as the chain extender and 1, 4-butanediol （BDO） as the hard-segment regulating agent. We found that BDO content significantly influenced mechanical properties, degradable performances and cyto-biocompatibility of PCL-WBPUs. Increasing the BDO content in PCL-WBPU enhanced its tensile strength and decreases strain. Enzymolysis and hydrolysis properties were also regulated by BDO content, but with different meechanisms. Cyto- biocompatibility was evaluated with ATDC5 cells. The results show that the biodegradability of PCL-WBPU is significantly determined by BDO content, which exerts a serious influence on its polymer structure, leading to resultant degradable properties.

Preparation of Polyimide Fiber/Thermoplastic Resin Composites with Improved Mechanical Properties

As a high-performance material for preparing composite materials, polyimide fibers suffer from many potential drawbacks, including poor bonding with other substrates, which results in composite materials with poor mechanical properties. Therefore, this study proposed a simple and rapid technique for obtaining loose, porous polyimide fiber papers by implementing a wet method using equal amounts of polyimide fiber and polyimide fiber paper as reinforcements, respectively. The polyimide resin-based composite materials were prepared by hand lay-up and hot pressing. The results showed that the paper-based reinforcement exhibited high porosity and the fibers were arranged with a uniform pore size distribution. The tensile properties, bending performance, and interlaminar shear performance of the paper-based composite improved by 130%, 108%, and 34.5%, respectively, compared to those of the fiberbased counterpart. The factors affecting the mechanical properties of the composites were analyzed based on the fiber length, fiber beating or lack thereof, and the basis weight of the paper. The increased uniformity of the polyimide fiber paper changed the ordering of the fibers and resolved drawbacks such as difficult dispersion, uneven pore size distribution, and poor mechanical properties related to single fibers in the resin-based composite material.