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Article
Publication date: 2 November 2015

Fawzia Fahim Abdel-Mohsen and Hassan Salah Aly Emira

– The purpose of this study was to prepare colour pigments for use as spectrally selective coatings for solar absorbers.

Abstract

Purpose

The purpose of this study was to prepare colour pigments for use as spectrally selective coatings for solar absorbers.

Design/methodology/approach

Nano-particles cobalt and nickel oxides were prepared by sol–gel techniques. These oxides were prepared with its molar ratios and annealed at 200, 400, 600 and 800°C. The structure of the pigments was characterized by infrared spectrometer, differential scanning calorimetry analysis, X-ray diffraction, transmission electron microscope and scanning electron microscope.

Findings

Encapsulated cobalt and nickel oxides were completely formed at 800 and 600°C, and its colour was black and dark green, respectively. The results confirmed that black and green pigments combined selectivity with colour. Optical properties such as absorption and reflection were affected by the firing temperatures on cobalt and nickel oxides–gel polymers. All synthesized pigments consisted of nano-particles.

Research limitations/implications

The prepared samples used in the present work were synthesized from cobalt chloride and nickel acetate. The salts were dispersed in polyacrylamide as a precursor.

Practical implications

The prepared metal oxides had good solar properties.

Originality/value

Colour becomes more important for thermal solar collectors, and it has attracted interest. This might be related to a generally growing attention towards architectural integration of solar energy systems into building. Architects would prefer different colours besides black, even if lower efficiency would have to be accepted.

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Article
Publication date: 13 January 2021

Amruta Joglekar-Athavale and Ganapti S. Shankarling

A mixed metal oxide-based spinel ceramic pigment has been successfully synthesized incorporating inorganic, high-temperature stable furnace cement as an inbuilt binder…

Abstract

Purpose

A mixed metal oxide-based spinel ceramic pigment has been successfully synthesized incorporating inorganic, high-temperature stable furnace cement as an inbuilt binder. Step by step synthesis was done for the spinel and cement mix formulations.

Design/methodology/approach

The pigment mix was synthesized by a solid-solid method where the inorganic binder was incorporated in the mix. The results suggested that CoCuMn-based spinel ceramic pigment with cement mix could be obtained at an annealing temperature of 1,100ºC for 1 h and the size, morphology and crystallinity of spinel mix were greatly influenced by the calcination temperature.

Findings

The pigment mix synthesized was applied as a coating to different substrates such as aluminum, glass and Mild steel. The results revealed that spectral selectivity of TSSS paint coatings based on the CoMnCu spinel ceramic mix was much better than that of solvent-based coatings for high-temperature applications. The presence of cement as an inorganic binder makes the functioning and application of paint easy as it becomes that of a waterborne type.

Originality/value

Ease of application, stability at high temperatures, best absorptivity at the solar selective spectrum and excellent adhesion properties for the selected surface are the key features of the designed pigment system. The applied pigment mix was studied as a coating to get the results for solar selective system.

Details

Pigment & Resin Technology, vol. 50 no. 3
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 23 July 2020

Henadeera Arachchige Ayomi Enoka Perera and Wilathgamuwage Don Gamini Lanarolle

Thermoplastic polymer fabrics are normally heat set to make them dimensionally stable. These fabrics in garment panel form may again be exposed to heat during the…

Abstract

Purpose

Thermoplastic polymer fabrics are normally heat set to make them dimensionally stable. These fabrics in garment panel form may again be exposed to heat during the processes such as bonding, sublimation printing and cause to change their dimensions. The purpose of this paper is to investigate the response of polyester yarns in knitted fabrics to heat setting and post-heat treatments.

Design/methodology/approach

In this study, the thermal shrinkage behaviour of heat set polyester knitted fabrics when subjected to post-heat treatment processes are analyzed using differential scanning calorimetry (DSC) and analysis of fabric shrinkage. DSC is a thermo-analytical technique that measures the difference in the amount of heat needed to increase the temperature of the sample and the reference. A heat flux versus temperature curve is one of the results of a DSC experiment. The polymer structure and morphology of polyester heat-treated and post-heat–treated fabrics were determined by examining the DSC thermograms.

Findings

Heat setting and post-heat setting causes the effective temperature of polyester to change. Effective temperature occurred around 160°C for fabrics heat set at low temperatures and increases as the heat setting temperature increases. Post-heat treatments cause to elevate the effective temperature. Shrinkage of fabrics below the effective temperature is not statistically significant while the shrinkage at higher temperatures is significant. Effective temperature is the main determinant of thermal shrinkage behaviour of polyester.

Originality/value

The study reveals the significance of the effective temperature of polyester on heat treatments and post-heat treatments. The study revealed that heat-setting temperature is a primary determinant of the thermal stability of polyester fabric that are subjected to heat treatments.

Details

Research Journal of Textile and Apparel, vol. 24 no. 4
Type: Research Article
ISSN: 1560-6074

Keywords

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Article
Publication date: 17 May 2013

Mazeyar Parvinzadeh Gashti, Rambod Rashidian, Arash Almasian and Ali Badakhshan Zohouri

In recent years, the textile industry has been required to develop new methods and technologies through introduction of some new materials in various processes rather than…

Abstract

Purpose

In recent years, the textile industry has been required to develop new methods and technologies through introduction of some new materials in various processes rather than employing the same conventional chemicals. The aim of this research was to investigate the changes induced on the cotton fibre by the nanoclay treatment using a pre‐treatment method.

Design/methodology/approach

The fibres were dyed with basic and direct dyes after the nanoclay pre‐treatment. Technical measurements were studied including Fourier‐transform infrared spectroscopy (FTIR), UV‐visible spectrophotometer, differential scanning calorimetry (DSC), thermal degradation analysis (TGA), scanning electron microscopy (SEM), moisture regain measurement (MRM), tensile strength test (TST), reflectance spectroscopy (RS) and fastnesses evaluation.

Findings

The intensity of the major peaks in FTIR spectra of the nanoclay treated sample is in favour of the chemical changes of the cellulose functional groups. Basic dyes showed a higher dyeability on the clay pre‐treated samples compared to raw materials. The results of the colour measurements showed that the more concentration of the clay mineral was used, the darker the colour of the dyed sample was. Some interesting results were obtained in the research.

Research limitations/implications

The nanoclay and a dispersing agent used in the present context were used as received. Besides, the type of the dispersing agent is important for preparation of a colloidal dispersion of nanoclay.

Practical implications

The method developed in this research provides a simple and practical solution for improving the dyeability of cotton with direct and basic dyes.

Originality/value

The method for enhancing the dyeability of cotton is novel and can be used in cotton processing with new properties.

Details

Pigment & Resin Technology, vol. 42 no. 3
Type: Research Article
ISSN: 0369-9420

Keywords

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Article
Publication date: 14 June 2018

Katrin Wudy, Maximilian Drexler, Lydia Lanzl and Dietmar Drummer

The thermal history during laser exposure determines part properties in selective laser sintering (SLS). The purpose of this study is to introduce a new measurement…

Abstract

Purpose

The thermal history during laser exposure determines part properties in selective laser sintering (SLS). The purpose of this study is to introduce a new measurement technique based on a CO2 laser unit combined with a high-speed DCS. A first comparison of the thermal history during laser exposure measured with Laser-high-speed-(HS)-differential scanning calorimetry-(DSC) and in SLS process is shown.

Design/methodology/approach

This Laser-HS-DSC allows an imitation of the SLS-process in a very small scale, as the sample is directly heated by a CO2 laser. For this study, the laser power and the impact time is varied for determining temperature and achieved heating rates. Consequently, the temperature levels measured by the Laser-HS-DSC are compared with measurements in SLS-process.

Findings

The influence of laser power and impact time on resulting maximum temperatures und heating rates during laser exposure are investigated. With increasing laser power and impact time the maximum temperature rises up to approximately 450°C without material degradation. The heating rate increases up to an impact time of 3 ms and stays almost equal for higher durations.

Research limitations/implications

The Laser-HS-DSC experiments are based on few particles limiting a complete comparison with SLS process. In SLS, one volume element is exposed several times. In this study the PA12 material was exposed only once.

Originality/value

For the first time, laser sintering experiments can be transferred to a laboratory scale to analyze the influence of laser exposure on resulting temperature field during laser exposure without superimposing effects.

Details

Rapid Prototyping Journal, vol. 24 no. 5
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 28 June 2013

Fawzia Fahim Abdel‐Mohsen and Hassan Salah Aly Emira

This work aimed to prepare black transition metal oxide pigments to be used as solar absorbers in the solar selective and other industrial paints.

Abstract

Purpose

This work aimed to prepare black transition metal oxide pigments to be used as solar absorbers in the solar selective and other industrial paints.

Design/methodology/approach

Mixed metal oxide CoCuMnOx spinel pigments were synthesised via the sol‐gel route. These oxides, namely (I‐Co0.50Cu0.25Mn0.25)Ox, (II‐Co0.25Cu0.50Mn0.25)Ox and (III‐Co0.25Cu0.25Mn0.50)Ox, were prepared with different molar ratios and annealed at 600, 800 and 900°C, respectively. The prepared oxides were characterised by infrared spectrometer (IS), differential scanning calorimetry analysis (DSC), X‐ray diffraction (XRD) and transmission electron microscope (TEM).

Findings

The prepared pigments have a spinel structure with the composition CoCuMnOx. All synthesised pigments consisted of nano particles ranged from 10 to 80 nm. The optical properties showed high absorption and moderately low reflectance in the solar wavelength range.

Research limitations/implications

The prepared samples, used in the present work, were synthesized from cobalt sulphate, copper chloride and manganese chloride. The salts were dispersed in polyacrylamide as a precursor.

Practical implications

The prepared samples were thermally stable and had good optical properties. They could be used as absorber materials in the painting of solar collectors.

Originality/value

These thermally stable mixed metal oxides could be used in the painting of solar collectors. The three mixed metal oxides could be used as absorber materials for heating solar collectors due to their high absorption and moderately low reflectance in the solar wavelength range.

Details

Pigment & Resin Technology, vol. 42 no. 4
Type: Research Article
ISSN: 0369-9420

Keywords

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Article
Publication date: 28 June 2013

Mohammad Fahim Ansari, Gautam Sarkhel, Dipendra Nath Goswami and Bangali Baboo

The purpose of this paper is to see the effect in the properties of shellac on blending with rosin (another natural resin) and study their changes during storage.

Abstract

Purpose

The purpose of this paper is to see the effect in the properties of shellac on blending with rosin (another natural resin) and study their changes during storage.

Design/methodology/approach

Blending of rosin was done at seedlac (semi‐pure lac) stage. Shellac was then prepared by bhatta (Indian country) process, in the form of button lac. Physico‐chemical properties of the blends were studied at regular time intervals following standard procedures.

Findings

Improvement in the physicochemical properties of shellac was noticed by blending with rosin to a great extent; less degradation in the properties of blends was observed with storage compared to those of parent shellac.

Research limitations/implications

Because rosin possesses very high fluidity and life under heat, exact value of flow and life under heat of rosin and its blends with shellac having high rosin content could not be determined.

Practical implications

The results give an idea to entrepreneurs, processors and industrialists of how much rosin is to be blended with shellac to bring improvements in its fluidity and life under heat for commercial exploitation, especially for inferior quality of shellac.

Originality/value

Systematic study has been done for the first time, as no quantitative data was available on the changes in the different properties of shellac which take place on blending with rosin.

Details

Pigment & Resin Technology, vol. 42 no. 4
Type: Research Article
ISSN: 0369-9420

Keywords

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Article
Publication date: 17 August 2018

Yasser Assem, Heba A. Mohamed, Rana Said and Ahmed El-Masry

The purpose of this paper is to prepare amphiphilic block copolymers polyethylene adipate-block-polyethylene glycol (PEA-b-PEG)s and study their performance as…

Abstract

Purpose

The purpose of this paper is to prepare amphiphilic block copolymers polyethylene adipate-block-polyethylene glycol (PEA-b-PEG)s and study their performance as plasticizers in rotogravure ink formulations.

Design/methodology/approach

Series of amphiphilic block copolymers (PEA-b-PEG1), (PEA-b-PEG2), (PEA-b-PEG3), (PEA-b-PEG4) and (PEA-b-PEG5) were prepared by the reaction of adipic acid, ethylene glycol and polyethylene glycol of different molecular weights (300, 1,000, 2,000, 10,000 and 20,000 g/mol), respectively. Full characterization of the prepared copolymers was achieved using Fourier Transfer Infrared Spectroscopy (FTIR), 1H NMR, thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The performance of the prepared copolymers as plasticizers for neat nitrocellulose resin were studied in different formulations, namely, R1, R2, R3, R4 and R5 containing copolymers (PEA-b-PEG1), (PEA-b-PEG2), (PEA-b-PEG3), (PEA-b-PEG4) and (PEA-b-PEG5), respectively. In addition to formula R0 that contains acetyl tributyl citrate (ATBC) as a commercial plasticizer. The mechanical properties, thermal analysis (DSC, TGA) and optical properties of the prepared formulations films were investigated. Theses amphiphilic block copolymers were then applied as plasticizers in different rotogravure ink formulations (F1, F2, F3, F4 and F5) and compared with commercial rotogravure ink formula (F0). The color measurements and optical properties of all formulations were achieved.

Findings

It was found that the performance of the prepared copolymers as plasticizers in different formulations based on nitro cellulose resin gives better gloss, adhesion for R1 compared with the other samples and color strength for F1 compared with F0. Finally, all the samples gave excellent plasticizing effect.

Research limitations/implications

The authors believe that type of these materials open the way for a new class of plasticizers that upon application or even degradation gives small ecofriendly molecules (adipic acid and or ethylene glycol moieties) taking into consideration the simplicity of the rout of the synthesis process.

Practical implications

The prepared ecofriendly (PEA-b-PEG)s could be successfully used as plasticizers instead of commercial plasticizer ATBC.

Originality/value

The research provides that the prepared (PEA-b-PEG)s with different molecular weights can act as plasticizers in rotogravure ink formulations, and their performance was acceptable and available.

Details

Pigment & Resin Technology, vol. 47 no. 5
Type: Research Article
ISSN: 0369-9420

Keywords

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Article
Publication date: 4 January 2013

Mazeyar Parvinzadeh Gashti, Mohammad Yousefpour Navid and Mohammad Hossein Rahimi

Silicone softeners are widely used in the textile industry to improve the performance of textile products. The thermal characteristics and flammability of polyester…

Abstract

Purpose

Silicone softeners are widely used in the textile industry to improve the performance of textile products. The thermal characteristics and flammability of polyester fabrics can be influenced by these compounds, which need to be considered, as important issues of human safety. The purpose of this paper is to investigate the changes induced on the polyester fibre by silicone softener treatment using a pad/dry/cure method.

Design/methodology/approach

The fibres were first treated with nano‐ and microemulsion silicone softeners. The influence of the silicone emulsion type on thermal properties and flammability of the resultant samples were investigated by various analytical techniques, namely, the differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), dynamical mechanical thermal analysis (DMTA) and horizontal flammability test (HFT).

Findings

Results showed that the silicone softeners increase the thermal degradation and flammability of the polyethylene terephthalate (PET) substrate.

Originality/value

The paper's study of thermal and flammability of the silicone‐treated sample is novel and can be used to optimize the properties of silicone polymers during production and consumption.

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Article
Publication date: 18 April 2016

Jian Zhou, Qiuyu Zhang, Hepeng Zhang, Jiaojun Tan, Shaojie Chen, Qing Liu, Mingliang Ma and Tiejun Xin

The purpose of this paper is to evaluate the properties of several thiol-acrylate photosensitive systems and compare with corresponding acrylate free-radical systems. The…

Abstract

Purpose

The purpose of this paper is to evaluate the properties of several thiol-acrylate photosensitive systems and compare with corresponding acrylate free-radical systems. The potential stereolithography applications of thiol–ene photosensitive systems are also discussed.

Design/methodology/approach

In the both thiol–ene and acrylate free-radical photosensitive systems, various key performances were characterized. The function group conversions were characterized by real-time Fourier transform infrared spectroscopy. The tension strength was determined according to the standard ASTM D638-2003, the flexible strength was determined according to ASTM D790-07 and the hardness was measured according to ASTM D2240-05. The volume shrinkage was measured by dilatometer method. The glass transition temperature was analyzed by differential scanning calorimeter.

Findings

As adding mercapto propionates into acrylate system, the inhibition of polymerization by oxygen was controlled and the flexible performance was improved. In addition, the photosensitive resin showed better tension strength, higher elongation at break and lower volume shrinkage. Among the four mercapto propionates, rigid TEMPIC showed most obvious affect, followed hexa-functional DPMP, tetra-functional PETMP and tri-functional TMMP.

Originality/value

Although the thiol–ene photosensitive resin has unmatched advantages in performance, there are no reports on the thiol–ene photosensitive resin in the stereolithography application. In this study, thiol–ene photopolymerization material was first tentatively implemented in stereolithography area. Several critical performance parameters were compared between thiol–ene and acrylate free-radical photosensitive systems.

Details

Rapid Prototyping Journal, vol. 22 no. 3
Type: Research Article
ISSN: 1355-2546

Keywords

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