Valorisation of chicken feathers: Characterisation of thermal,mechanical and electrical properties

Increasing consumption of chicken results in generation of large amounts of wastes that need to be disposed of properly. Chicken feathers constitute about 5–10% of the weight of the chicken and thus they comprise a significant portion of the poultry wastes. Disposal of waste chicken feathers is problematic in that they do not readily degrade after landfilling, there is increasing shortage of landfill space, and they are contaminated with microbial biomass that makes them hazardous waste. Feathers contain ~91% keratin protein and thus, potentially, feathers can be beneficiated into high-value compounds or products comprised of keratin proteins or keratin fibres. Thus, valorisation of feathers could be a viable option for sustainable disposal of the waste. Characterisation of physicochemical properties of the chicken feather is an essential step to identifying possible avenues for valorisation of this waste biomass. While chemical, physical and morphological properties of chicken feathers and related potential valorisation routes have described by the authors, identification of their mechanical, thermal and electrical properties have not been reported and this information is necessary to have a complete and comprehensive characterisation of waste chicken feathers. Hence, in this research, the mechanical, thermal and electrical properties of feathers were determined and evaluated to ascertain suitability of the feathers for production of high-value materials. The feathers and fractions thereof were characterised by TGA/DSC, Instron (material and structural testing), Dynamic Mechanical Analyser, and a two-probe measurement of resistivity instrument. Under heated conditions, the TGA of chicken feathers confirmed the occurrence of three zones of weight loss. The TGA/DSC results revealed a glass transition temperature around 67 °C and a melting temperature ~230 °C in the crystalline phase. The tenacity of chicken feather barbs at maximum load was ~16.93 cN/tex. The results from electrical properties indicated that chicken feather fractions have low conductivity. Overall, the results indicate that chicken feathers have potential to be used in a variety of applications such as electrical insulator materials, yarn production for use in textiles, nonwoven fabric production, filler for winter clothing, geotextile and construction materials.     

Valorisation of chicken feather barbs: Utilisation in yarn production and technical textile applications

Waste chicken feathers represent 5–10% of the total weight of mature chickens. Thus, they are produced in large quantities as a by-product of poultry meat processing industries. Currently, disposal of waste chicken feathers is problematic and the methodologies used are not environmentally sustainable. Consequently, technologies for beneficiation of the feathers are needed in order to overcome these problems. Considering that chicken feathers are similar to natural fibres (wool and silk) used in textile applications, it is plausible that protein in feathers can be exploited and used likewise. This paper reports on the physiochemical properties of proteinaceous fibre obtained from chicken feather barbs with the objective of assessing their potential for use in yarn production and technical textile applications. It is demonstrated that chicken feather barbs exhibit the following properties: hollow honeycomb structure, low density, high slenderness ratio, high flexibility, spinnable length, fineness, and high flexibility. These are unique properties that are not found in any other natural or synthetic fibres – the implication being that chicken feathers can be used in diverse manufacturing applications such as production of composites, yarns, technical textiles, nonwovens, and pulp and paper. However, this paper focuses on textile applications and illustrates how the physicochemical properties of fibres from feathers can be useful and applicable for textile applications. Beneficiation of waste chicken feathers in this manner will result in use of environmentally sustainable methods for disposal of the waste.     

Valorisation of waste chicken feathers: Optimisation of decontamination and pre-treatment with bleaching agents using response surface methodology

Environmental concerns, rapid oil consumption, the high price of oil, and limited oil reserves are driving research into cheap, biodegradable, sustainable, renewable, and abundantly available green materials. Waste chicken feathers are abundant and cheap by-products from poultry processing plants and their beneficiation offers possible solutions to these issues. Raw chicken feathers are wastes that are mixed with offal fat, debris, blood, preen oil and other wastes from the poultry process. Consequently, feathers are hazardous wastes that are contaminated with bacteria, which makes them odoriferous and unfit for valorisation as is. These contaminants must be removed before possible valorisation otherwise the feathers will not fit for purpose. The effects of oxidative (hydrogen peroxide and sodium hypochlorite) and reductive (Sodium dithionite) compounds as decontamination agents were studied on chicken feathers to assess their decontamination and pre-treatment efficiency and their effects on physicochemical and mechanical properties of the feathers. Statistically designed experiments were used to optimise the decontamination process using response surface methodology with a Box-Behnken experimental design. Regression equations were obtained to analyse microbial count and the optimum process parameters were identified. Under optimised conditions, the treated chicken feathers were characterised and their properties compared with those of unwashed chicken feathers. From the results, it was deduced that the inorganic bleaching treatments were effective removing the microbial impurities from the feathers and their use resulted in enhanced physicochemical properties of the chicken feathers. The untreated chicken feathers had the highest microbial counts (1.48E+ 07 ± 6.72E05 Cfu/g) whereas decontaminated samples showed a reduction in thousand-fold. The impurity removal after washing was about 8–18%.