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To explore the effect of acrylic acid polymerization and NaOH treatment of nylon‐6 on hemoglobin washability.

The nylon‐6 was chemically grafted with acrylic acid and treated with NaOH for the purpose to improve the washability of hemoglobin as a blood protein soil. The structural change before and after graft polymerization was analyzed by X‐ray photoelectron spectroscopy and scanning electron microscopy. The moisture regain, the contact angle, and the washability were each measured.

Graft polymerization and NaOH treatment of nylon‐6 changed the surface energy and structure of nylon‐6 causing the washability of hemoglobin to improve. Compared to ungrafted nylon‐6, the hydrophilic properties were increased remarkable by graft polymerization and NaOH treatment, which reulted in the improvement of washability.

Hemoglobin is one of the most difficult soils to remove from the fabric. The paper might be of interest to those who would consider purchasing fabrics that are good at both hydrophilic properties and washability.

The study on washability of hemoglobin as a blood protein soil for grafted fabric has not been reported so far. The results of this research may be used in a basic research for the development of new process which is capable of improving of hemoglobin washability.

Briefly reviews previous literature by the author before presenting an original 12 step system integration protocol designed to ensure the success of companies or countries in their efforts to develop and market new products. Looks at the issues from different strategic levels such as corporate, international, military and economic. Presents 31 case studies, including the success of Japan in microchips to the failure of Xerox to sell its invention of the Alto personal computer 3 years before Apple: from the success in DNA and Superconductor research to the success of Sunbeam in inventing and marketing food processors: and from the daring invention and production of atomic energy for survival to the successes of sewing machine inventor Howe in co‐operating on patents to compete in markets. Includes 306 questions and answers in order to qualify concepts introduced.

The purpose of the study was to find the best performance polymer material to be used in railway car bogies.

Wear tests and optical and scanning electron microscopy were used.

The friction coefficients of ultra-high-molecular-weight polyethylene (UHMWPE) and Nylon 6 polymers, as opposed to AISI 4140 steel, reduced with the increment of applied loads. With the increment of sliding speed, the friction coefficient increased in both UHMWPE and Nylon 6 polymers. The specific wear rate of the UHMWPE polymer was determined to be about 10-14 m2/N, whereas the rate of Nylon 6 was determined to be 10-13 m2/N.

The aim of the study was to find the best performance polymer material to be used in railway car bogies.

The friction and wear performance of UHMWPE and Nylon 6 engineering polymers were studied and compared to their AISI 4140 steel counterparts. It is an original work and it is not published in any media.

Nylon 6 filaments have weak light and heat resistance in terms of stability, which restrict its application in engineering field. The purpose of this paper is to prepare a new photo-stabilization functional nanocomposite inks by using graphene nanosheet as UV light-resisting functional materials incorporated with polyurethane.

Sunlight-resisting functional nylon filaments were produced by the continuous solution dip coating technology, through which the functional inks was coated on the surface of nylon 6 filament. The surface morphology of the coated filaments was characterized by scanning electron microscopy and the graphene/polyurethane nanocomposite inks as the coating agent was confirmed and well dispersed on the fiber’s surface.

Under UV exposure, the strength loss rate of the graphene-modified nylon filaments was less than 50 percent, while that of the control nylon filament was over 85 percent, which indicated that graphene remarkably enhanced the light-resistant property of nylon. Besides, graphene/polyurethane-coated Nylon 6 filaments exhibited reasonable electrical properties and the electrical conductivity could reach 10–4 S/cm.

Graphene inks was first proposed as the UV photo-stabilization in this paper.

The purpose of this paper is to analyze the effects of treatments using chitosan in different degree of deacetylations (DDs) on thermophysiological comfort properties of nylon 6,6/elastane pressure garments using a large skin model hot plate instrumentation to prevent infection and excess sweating during burn scar management for future designs.

Chitosans in different DD (DD 70, DD 81 and nylon 6,6/elastane fabrics in different structures, then the total DD 90) are treated with thermal resistance (R_ct) ((°ΔC)(m²)/W), total heat loss (Q_t or THL) (W/m²), apparent total evaporative resistance ( R e t A ), ((ΔkPa)(m²)/W), apparent intrinsic evaporative resistance ( R e f A ), ((ΔkPa)(m²)/W) and total insulation values (I_t) (clo) were analyzed using the large skin model hot plate instrumentation in comparison with untreated control samples. Antimicrobial activities, washing tests and moisture regain properties were also evaluated.

It is found that chitosan DDs have a significant effect on thermophysiological comfort properties of nylon 6,6 fabrics. A small but statistically significant decrease was observed in thermal resistance (R_ct) (Tog) and isolation (I_t) (clo) properties for higher chitosan DDs and for higher chitosan concentrations for all fabric samples after each treatment. Antimicrobial activity showed a small but statistically significant decrease for all samples with the increase of DD and fabrics treated with lower DD 70 of chitosan showed better antimicrobial activity for all samples. Additionally, fabrics treated with higher DD’s exhibited higher moisture regain.

Treatments with chitosan in different DD and in different concentrations impact the heat and moisture transfer properties of nylon 6,6 fabrics significantly. It is a reference to evaluate the thermophysiological comfort properties of pressure garments for future designs using dry and sweating skin tests while imparting antimicrobial activity with chitosans in different DDs.

To synthesize some new heterocyclic disperse azo dyes and their utilization in textile printing.

To prepare 1‐cayno‐1‐substituted aryl azo‐2‐methyl benzothiazole by the reaction of 2‐aminothiophenol with malononitrile and the end product coupled with different diazonium salts. The prepared dyestuffs are established using element analysis, IR measurements, ¹H‐NMR and Mass spectra. Printing pastes containing the prepared dyestuffs and a thickener were used for printing polyester and/or nylon 6 using either transfer printing or traditional printing.

New selected arylazo cyanomethyl benzothiazole dyes were obtained from the reaction of diazotized aniline derivatives with 2‐cyanomethyl benzothiazole as a coupling component. The suitability of the prepared dyestuffs for either heat transfer printing or traditional printing on polyester and nylon 6 fabrics has been investigated. The prints obtained from dyes containing non polar groups which have sublimation properties possess high colour strength as well as good overall fastness properties if compared to those obtained using dyes containing polar groups.

The new heterocyclic disperse azo dyes were prepared from 2‐cyanomethylbenzothiazole and were utilized in preparing pastes for textile printing to print polyester and nylon 6 fabrics. In addition, the variation in substituents on the synthesized dyes could also be studied.

The method of synthesis of the new dyestuffs provides a simple and practical solution to prepare some new heterocyclic disperse azo dyes with low molecular weight, suitable for sublimation in heat transfer printing methods.

The methods for synthesis of the new heterocyclic disperse azo dyes are simple. These dyestuffs could be used in textile printing of polyester and nylon 6 on an industrial scale.

The purpose of this paper is to reinforce the selective laser sintering (SLS) parts of nylon‐12 using organically modified montmorillonite (OMMT).

A dissolution‐precipitation process is developed to prepare an OMMT/nylon‐12 composite powder (3 wt% OMMT). X‐ray diffraction (XRD) was used to characterize nanostructure features. The dispersion of OMMT in the nylon‐12 matrix was observed by scanning electron microscope (SEM). The effect of OMMT on the thermal properties of nylon‐12 was studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The mechanical properties of the SLS parts made from the composite powder and neat nylon‐12 powder were measured and compared.

The X‐ray diffraction and SEM results indicate that the OMMT is intercalated by nylon‐12 molecular chains and uniformly dispersed in the nylon‐12 matrix during the dissolution‐precipitation process, and thus the OMMT/nylon‐12 intercalated nanocomposites are formed. The DSC and TGA results show that the OMMT can increase the melting enthalpy, relative crystalline content, crystallization temperature and thermal stability of nylon‐12. The tensile strength, tensile modulus, flexural strength, flexural modulus and impact strength of the SLS specimens made from the composite powder are 23.2, 31.7, 18.7, 32.4 and 8.4 percent higher than those of neat nylon‐12 SLS specimens, respectively, while the elongation at break decreases by 17.5 percent.

The conclusion of forming intercalated nanocomposites was drawn from the XRD results in the present work. Further work should be done to observe the nanostructures of the materials by transmission electron microscope.

A dissolution‐precipitation process was used to prepare OMMT/nylon‐12 composite powders for SLS process. During the preparation process the OMMT could be intercalated by nylon‐12 molecular chains and uniformly dispersed in the nylon‐12 matrix, thus forming the OMMT/nylon‐12 intercalated nanocomposites. Therefore, the mechanical and thermal properties of nylon‐12 SLS parts were enhanced.

Process parameters in Fused Filament Fabrication (FFF) can affect mechanical and surface properties of printed parts. Numerous studies have reported parametric studies of various materials using full factorial and Taguchi design of experiments (DoEs). However, a comparison between the two are not well-established in literature. The purpose of this study is to compare full factorial and Taguchi DoEs to determine the effects of FFF process parameters on mechanical and surface properties of Nylon 6/66 copolymer. In addition, perform in-depth failure mechanism analysis to understand why the process parameters affect the responses.

A full factorial DoE was used to determine the effects of FFF process parameters, such as infill density, infill pattern, layer height and raster angle on responses, such as compressive strength, impact strength, surface roughness and manufacturing time of Nylon 6/66. Micro-computed tomography was used to analyse the impact test samples before and after impact and scanning electron microscope was used to understand the failure mechanism of infill and top layers. Differential scanning calorimetry (DSC) scans of infill and top layers were then taken to determine if a variation in crystallinity existed in different regions of the build.

Analysis of variance and main effects plots reveal that infill density has the greatest effect on mechanical and surface properties while manufacturing time is most affected by layer height for the polymer used. A 20% reduction in infill increased impact strength by 19% on average, X-ray images of some of the samples before and after impact tests are presented to understand the reason behind the difference. Moreover, DSC revealed a difference in the degree of crystallinity between the infill and top layers for 80% infill density samples. In addition, Taguchi DoE is realized to be a more efficient technique to determine optimum process parameters for responses that vary linearly as it reduces experimental effort significantly while providing mostly accurate results.

To the author’s knowledge, no published paper has reported a comparison between predictive DoE method with full factorial DoE to verify their accuracy in determining the effects of FFF process parameters on properties of printed parts. Also, a theory was developed based on DSC results that as the infill is printed faster, it cools slowly compared to the top layers, and hence the infill is in a less crystalline state when compared to the top layers. This increased the ductility of the infill (of 80% infill samples) and thus improved impact absorption.

The aim of this research is to develop, demonstrate and characterize techniques for fabricating such scaffolds by combining solid freeform fabrication and computational design methods. When fully developed, such techniques are expected to enable the fabrication of tissue engineering scaffolds endowed with functionally graded material composition and porosity exhibiting sharp or smooth gradients. Results of bio‐compatibility and in vivo implantation are presented.

The purpose of this paper is to evaluate the energy consumed to fabricate nylon parts using selective laser sintering (SLS) and to compare it with the energy consumed for injection molding (IM) the same parts.

Estimates of energy consumption include the energy consumed for nylon material refinement, adjusted for SLS and IM process yields. Estimates also include the energy consumed by the SLS and IM equipment for part fabrication and the energy consumed to machine the injection mold and refine the metal feedstock required to fabricate it. A representative part is used to size the injection mold and to quantify throughput for the SLS machine per build.

Although SLS uses significantly more energy than IM during part fabrication, this energy consumption is partially offset by the energy consumption associated with production of the injection mold. As a result, the energy consumed per part for IM decreases with the number of parts fabricated while the energy consumed per part for SLS remains relatively constant as long as builds are packed efficiently. The crossover production volume, at which IM and SLS consume equivalent amounts of energy per part, ranges from 50 to 300 representative parts, depending on the choice of mold plate material.

The research is limited to material refinement and part fabrication and does not consider other aspects of the life cycle, such as waste disposal, distributed 2 manufacturing, transportation, recycling or use. Also, the crossover volumes are specific to the representative part and are expected to vary with part geometry.

The results of this comparative study of SLS and IM energy consumption indicate that manufacturers can save energy using SLS for parts with small production volumes. The comparatively large amounts of nylon material waste and energy consumption during fabrication make it inefficient, from an energy perspective, to use SLS for higher production volumes. The crossover production volume depends on the geometry of the part and the choice of material for the mold.