Search results

1 – 10 of over 2000
Article
Publication date: 6 July 2015

Lijun Chen, Zhongbin Bao, Zhengrong Fu and Wen Li

The purpose of this research is to prepare a dispersion resin with good dispersity and a colour paste with good stability. At present, the colour paste is being prepared using the…

Abstract

Purpose

The purpose of this research is to prepare a dispersion resin with good dispersity and a colour paste with good stability. At present, the colour paste is being prepared using the pigment dispersion resin which has the group quaternary ammonium. The dispersion resin prepared has good dispersity of pigment and extender. However, the stability of storage and construction of the colour paste is relatively poor, which has a negative influence on the application of cathodic electrodeposited (CED) coatings. However, the detailed investigation on the dispersion resin and the stable colour paste has not been reported.

Design/methodology/approach

Three steps are adopted to prepare the dispersion resin, that is blocking toluene diisocyanate (TDI), quaternary ammoniation of blocked TDI and ring opening of epoxy resin. The resultant dispersion is used to prepare the colour paste. The factors, which have an influence on the dispersity of the dispersion resin and stability of the colour paste, are optimised.

Findings

The typical recipes of preparing the dispersion resin and the resultant colour paste are obtained. The dispersity of the dispersion resin and stability of the colour paste are good based on the typical recipe. In addition, the film of the CED coating is smooth, dense and hard when the colour paste is used in the CED coating.

Practical implications

The dispersion resin can be used to prepare a colour paste, which can be used in the CED coatings. In addition, it also can be applied as a binder of coatings and adhesions.

Originality/value

The factors, which have an influence on the dispersity of the dispersion resin and stability of the colour paste, are studied in detail. The typical recipes of preparing the dispersion resin and the resultant colour paste are obtained. Based on the typical recipe, the dispersity of the dispersion resin and stability of the colour paste are good.

Details

Pigment & Resin Technology, vol. 44 no. 4
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 26 July 2023

Hamdy Mohamed Mohamed and Wael Sabry Mohamed

The study aims to assess the efficiency of nanocomposite to improve the properties of gap-filling materials for pottery artifacts.

Abstract

Purpose

The study aims to assess the efficiency of nanocomposite to improve the properties of gap-filling materials for pottery artifacts.

Design/methodology/approach

Five different pastes were used in the laboratory studies. The pastes consist mainly of pottery powder (grog), dental plaster, microballoons and an adhesive of Primal AC33, nano-silica and nano kaolinite in various concentrations. The prepared samples were subjected to accelerated heat and light aging. Besides, some investigations were used to evaluate the efficacy of the additive nanomaterials, such as TEM, digital and scanning electron microscopy microscopes. Contact angle, color change, shrinkage degree, physical properties and compressive strength tests were also conducted.

Findings

The results indicated that using Nano-silica considerably improves the mechanical strength and decreases the shrinkage of gap-filling materials. According to the results, a mixture of grog, microballoons and Primal AC33/Nano-silica Nanocomposites is the optimal gap-filling paste for archaeological pottery. Moreover, this paste showed a higher contact angle (120°), lower color change (ΔE = 2.62), lower shrinkage (3.3%), lower water absorption (3.36%), lower porosity (5.05%) and higher compressive strength (5124 N/mm2).

Originality/value

This paper attains to develop an economic polymer-nanocomposite that can be used with gap-filling materials for pottery artifacts.

Details

Pigment & Resin Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 11 July 2016

Paula Correia, André Vítor, Marlene Tenreiro, Ana Cristina Correia, João Madanelo and Raquel Guiné

Thistle flower (Cynara cardunculus) aqueous extracts, as rich source of milk-clotting peptidases, have been widely used for cheeses marketed under the Registry of the Protected…

Abstract

Purpose

Thistle flower (Cynara cardunculus) aqueous extracts, as rich source of milk-clotting peptidases, have been widely used for cheeses marketed under the Registry of the Protected Designation of Origin, as it is the case of Serra da Estrela cheese, manufactured from raw ewes’ milk and without addition of any commercial starter culture. This paper aims at studying the influence of six different ecotypes of thistle flowers in cheese properties during the ripening and of final products.

Design/methodology/approach

Cheeses were produced with different thistle flower extracts and then the clotting time, weight and colour of cheeses, as well as texture properties and sensorial characteristics, were evaluated.

Findings

The clotting time varied from 47 to 66 min, and the weight loss along ripening varied between 32 and 40 per cent. There was some influence of thistle flower ecotype on the colour during ripening and in the final product. The results of texture analysis revealed significant differences between the thistle ecotypes: crust firmness varying from 2.4 to 5.6 N; inner firmness from 0.82 to 1.82 N; stickiness from −0.5 to −1.60 N; adhesiveness from −3.0 to −11.3 N.s; and Ecotype C was particularly distinguishable. Sensorial evaluation revealed differences among the cheeses, with Ecotype C receiving the highest score for global appreciation.

Originality/value

The usage of different extracts of thistle flower to produce Serra da Estrela cheese with different properties is a novelty, and it allows the possibility of manipulating this parameter in the future so as to produce cheeses with specific characteristics, addressed to different consumer targets.

Details

Nutrition & Food Science, vol. 46 no. 4
Type: Research Article
ISSN: 0034-6659

Keywords

Article
Publication date: 1 May 1995

A. Higazy, M.H. El‐Rafie, M.A. Ramadan and A. Hebeish

Poly (acrylic) starch composites were prepared by polymerizing acrylic acid, acrylamide alone or in admixtures with maize starch using KMnO4/citric acid as redox initiation. The…

Abstract

Poly (acrylic) starch composites were prepared by polymerizing acrylic acid, acrylamide alone or in admixtures with maize starch using KMnO4/citric acid as redox initiation. The cooked composite pastes were used as partial substituent of kerosene oil emulsion in the pigment printing pastes for cotton fabric. Printing was carried out under a variety of conditions including neutralization of the free carboxylic groups of the polyacrylic acid component in the composite or AA/Aam mixtures, composite concentration, and the type of pigment dyes. The effect of storage on the efficiency of the printing paste was also examined. The printed samples were assessed for colour strength (K/S) overall fastness properties. Results obtained indicate that:

Details

Pigment & Resin Technology, vol. 24 no. 5
Type: Research Article
ISSN: 0369-9420

Article
Publication date: 14 March 2016

Rabab Amin and Amal El-Ebissy

The purpose of this study was to prepare partially methylolated polyacrylamide-guar gum via graft copolymerization of acryalmide and guar gum using the potassium bromate/thiourea…

Abstract

Purpose

The purpose of this study was to prepare partially methylolated polyacrylamide-guar gum via graft copolymerization of acryalmide and guar gum using the potassium bromate/thiourea redox system.

Design/methodology/approach

Using HCHO (40 per cent), amide groups in the composite are converted to reactive composite. The reactive composites (N-methylolated [PAam-GG]) were used as pastes for printing cotton fabrics with pigment dye, under a variety of conditions. Variables studied include the amount of binder incorporated into the printing paste and different catalysts incorporated into the printing paste.

Originality/value

Characterization of printing samples under different conditions, including amount of the beneficial effects of varying conditions of printing on the color strength (K/S); the color parameters L, a, b, h and c; and the change in color difference (ΔE) were also investigated. The Fourier transforms infrared spectra of printed cotton fabrics has followed each condition of printing. The obtained results indicate that the improvement in the printing process may be due to change in molecular configuration as a result of the variation in chemical bond.

Details

Research Journal of Textile and Apparel, vol. 20 no. 1
Type: Research Article
ISSN: 1560-6074

Keywords

Article
Publication date: 11 June 2019

Raphael Kanyire Seidu

The purpose of this study is to identify the print effects produced on selected fabrics due to the adaptation of styrofoam, plastic net and wood as stamp blocks for printing.

Abstract

Purpose

The purpose of this study is to identify the print effects produced on selected fabrics due to the adaptation of styrofoam, plastic net and wood as stamp blocks for printing.

Design/methodology/approach

The art-based experimental research approach was used to produce and identify the art (prints) produced by stamp blocks on different fabrics using water-soluble print paste.

Findings

They stamp block surfaces used in the block printing process produced interesting effects or prints that are uniquely associated with each other. Fabrics such as silver and satin produced shinny print effects coupled with a tough hand or feel as compared to a paperish hand produced on the surfaces of cotton-polyester blend and linen fabrics. The addition of white glue to the paste produced a smooth and embossed-like print effect on fabrics like mercerised cotton and linen. Further results were captured to indicate the hand of these fabrics after printing due to the change in viscosity of the print paste.

Originality/value

The use of calabash and wood surfaces as stamp blocks used in Ghana and the rest of the world is common for printing patterns on fabrics. This study essentially reveals the possibility of using different surfaces for stamp blocks which produce aesthetically pleasing print effects. This when adopted by craftsmen and students would widen the teaching and creative scope in block printing and further produce viable prints for the market using available materials in the environment. These activities would promote and maintain the philosophy of block printing even in the era of advance printing technologies.

Details

Research Journal of Textile and Apparel, vol. 23 no. 2
Type: Research Article
ISSN: 1560-6074

Keywords

Article
Publication date: 17 September 2020

Opeolu M. Ogundele, Sefia T. Muazu, Ajibola B. Oyedeji, Eugénie Kayitesi, Patrick B. Njobeh and Samson A. Oyeyinka

Cassava is a starchy crop with several industrial applications, but it deteriorates very fast after harvest. Refrigeration has been used to extend the storage life of the root and…

Abstract

Purpose

Cassava is a starchy crop with several industrial applications, but it deteriorates very fast after harvest. Refrigeration has been used to extend the storage life of the root and the starch isolated from the stored roots characterized. Hence, the purpose of this research is to investigate the chemical, functional, pasting and sensory properties of custard prepared from starch isolated from refrigerated cassava root.

Design/methodology/approach

Freshly harvest cassava root were cleaned and stored in a refrigerator operating at 4 °C for a period of one, two and three weeks. Starch was extracted from the fresh and stored roots using established method and custard prepared from each of the starch sample. The custard sample was analysed for amylose content, functional, pasting and sensory properties.

Findings

Amylose content in the pastes varied significantly from 18.45 to 25.45%. Refrigeration showed a significant impact on the swelling power of the custard, which could be linked to variation in amylose content. Colour and textural properties of the custard were similar across the samples suggesting a minimal impact of refrigeration on the isolated starch. Refrigerated cassava roots can produce acceptable custard with minimal changes in sensory properties if the storage period is closely monitored.

Originality/value

In a previous study, the authors have shown that starch and cooked paste may be made from stored cassava roots without substantial changes in the quality of these products. This study further confirms the possibility of using starch from the stored roots in food applications such as in custard formulation. No report has documented the properties of custard from starch obtained from refrigerated cassava root.

Details

British Food Journal, vol. 123 no. 2
Type: Research Article
ISSN: 0007-070X

Keywords

Article
Publication date: 1 January 1973

Hoechst Cassella Dyestuffs Ltd

The method described is adopted in Farbwerke Hoechst AG for testing the colouring properties of organic pigments. The method closely follows the instructions for determining the…

Abstract

The method described is adopted in Farbwerke Hoechst AG for testing the colouring properties of organic pigments. The method closely follows the instructions for determining the relative tinctorial strength of coloured pigments according to DIN 53 204. It has been found to be necessary to make minor modifications in testing organic pigments. A pigment grinder of a specific type is used for the dispersion process. Depending on the dispersibility of the pigment, a known, readily reproducible degree of pigment dispersion is attained, which is comparable to that of a production batch after one to two passages on a triple‐roll mill. Somewhat different results may be obtained if different dispersing equipment is used.

Details

Pigment & Resin Technology, vol. 2 no. 1
Type: Research Article
ISSN: 0369-9420

Article
Publication date: 26 August 2014

Tao Zhang, Kairui Zhang, Tao Li, Chaoxia Wang and Fan Yang

– The purpose of this paper is to prepare waterborne UV-curable pigment pastes for cotton fabric printing.

Abstract

Purpose

The purpose of this paper is to prepare waterborne UV-curable pigment pastes for cotton fabric printing.

Design/methodology/approach

O/W (oligomer-in-water) emulsions of polyurethane acrylate (PUA) oligomer in sodium dodecyl benzene sulphonate (SDBS) aqueous solution were prepared by ultrasonic emulsification method.

Findings

The present work studies various factors affecting the stability and droplet size of the O/W emulsion stabilised by SDBS. The optimal emulsifier concentration was 2.5 per cent, under which condition the stability of the emulsion increased as the emulsifier content increased, with a subsequent decrease in the droplet size of the emulsion, while above which emulsion agglomeration occurred. Increasing the power and duration of ultrasonic dispersion resulted in increased emulsion stability and decreased droplet size, while increases in the oligomer content reduced the emulsion stability. Darocure 1173 mixed with PUA and then emulsified in the SDBS aqueous solution guaranteed uniform dispersion of the photoinitiator, resulting in faster curing speed.

Originality/value

This paper presents a new method for making waterborne externally emulsified oligomers for UV curing, and finds that it is easy to convert the existing oligomers into waterborne equivalents by this method. Cotton fabrics printed with the oligomer emulsion based pastes were found to have good colour strength and crockfastness.

Details

Pigment & Resin Technology, vol. 43 no. 5
Type: Research Article
ISSN: 0369-9420

Keywords

Case study
Publication date: 12 January 2022

Jaco Maritz and Mark Peters

The teaching objectives of the case are as follows: to develop an understanding of the scope and complexity of strategy and marketing; to examine what is meant by purpose…

Abstract

Learning outcomes

The teaching objectives of the case are as follows: to develop an understanding of the scope and complexity of strategy and marketing; to examine what is meant by purpose, direction, objectives and consider how these might be set and used; to help students think and act in a strategic way; to give faculty the opportunity to illustrate the strategist’s and marketer’s toolbox, namely, tools and frameworks, such as Porters 5 Forces – The attractiveness of the industry, Porter’s Generic Marketing Strategies, strengths, weaknesses, opportunities, threats analysis, the 4P’s – with a focus on product and distribution. The case is intended for use in MBA and Executive education courses in strategy, marketing and leadership. The case offers relevant experiences and instructive lessons in formulating and implementing business strategies. The case highlights the importance of contextual leadership intelligence and competence in enabling entrepreneurial business activities.

Case overview/synopsis

Tomato Jos (Nigeria) is a large tomato processing business in Kaduna, Nigeria. Nigeria is the second-largest producer of tomatoes in Africa, with Egypt as the largest. The country ranks 14th overall as a world producer. In Africa, and specifically Nigeria, there is a strong push to support small-scale farmers as a source of employment creation, as well as meeting the needs of food security. The CEO, Mira Mehata, is an ex-pat graduate from the USA with strong Agri sector experience. The business has received extensive support from the Kaduna Government as the business has secondary objectives to assist small-scale farmers in the region. Farmers need consistent off takers and reasonable set prices to see a return on their investment and Tomato Jos plays that role of being the middle-man. This results in less wasted produce – the bane of farmers globally. The price for fresh tomatoes is about three times that of processed tomatoes IE in paste or sauce – so that is an added challenge for farmers to see the value in processed tomatoes. The business currently has a 2% Market Share in Nigeria with a target of 10% over the next five years. The business so far has invested three billion Naira and plans a further five billion Naira over the next few years. The business is seen as a high-profile success story with a supportive eco-system with a push from both the Nigerian Government and some major private sector players example Dangote.

Complexity academic level

The case is intended for use in MBA and Executive education courses in Strategy, Marketing and Leadership.

Supplementary materials

Teaching notes are available for educators only.

Subject code

CCS 11: Strategy.

Details

Emerald Emerging Markets Case Studies, vol. 12 no. 1
Type: Case Study
ISSN: 2045-0621

Keywords

1 – 10 of over 2000