The meat processing industry produces a huge quantity of by-products, approximately 150 million tonnes per year. The live weight of the animals is distinguished as edible, inedible, and discardable by-products, with the discardable parts equating to 66%, 52%, and 80% of the overall live weight of cattle, lamb, and pigs, respectively. Only a small percentage of those by-products are nowadays exploited for the production of high added value products such as animal feed, glue, fertilizers, etc., whereas the main management method is direct disposal to landfills. As such, the current disposal methodologies of these by-products are problematic, contributing to environmental contamination, soil degradation, air pollution, and possible health problems. Nevertheless, these by-products are rich in collagen, keratin, and minerals, being thus promising sources of high-value materials such as bioenergy, biochemical and other biomaterials that could be exploited in various industrial applications. In this paper, the possible utilization of slaughterhouse by-products for the production of various high added value materials is discussed. In this context, the various processes presented provide solutions to more sustainable management of the slaughterhouse industry, contributing to the reduction of environmental degradation via soil and water pollution, the avoidance of space depletion due to landfills, and the development of a green economy.

The use of biomass to produce bioenergy and biomaterials is considered a sustainable alternative to depleting fossil fuel resources. The world tanneries consume 8–9 MT of skin and hide every year producing 1.4 MT of solid waste. Most of the solid biomass generated from tanneries is disposed of as waste in the environment using either landfilling or thermal incineration. Disposal of this waste into the environment affects the ecosystem, causing bad odor (air pollution) and has an antagonistic impact on the environment. Due to this, European Union legislation bans the landfilling of biomass. This study aims to comprehensively review the possible valorization routes of leather processing industry biomass into high‐value biomaterials. Leather biomass (trimmings, shaving, splitting, and buffing dust) mainly contain 30%–35% collagen protein, which is produced by acid or alkali hydrolysis. The biopolymers obtained from leather industry biomass can be utilized in the production of several high‐value materials. In addition, leather processing industry biomass also contains fat, which can be converted into a bio‐surfactant, and other useful biomaterials. Keratin protein can also be extracted from the hair waste of hides and skins. The increased demand for biomaterials makes the using of leather industry biomass very attractive. From this study, it can be concluded that the conversions of leather processing industry waste to valuable biomaterial can protect the environment, generate additional income for leather industries, and pave way for sustainable and renewable biomaterials production.

The main aim of this study relies on analyzing multiple sizing machine setting on sized yarn pick-up and abrasion resistance using response surface methodology. To perform the experiment, three independent variables each at three levels (wet zone yarn tension (A) (340N, 380N, 420N), squeezing pressure (B) ((13N, 15N, 17N), and sizing machine speed (C) 30 m/min, 49 m/min and 68 m/min)) have been taken. Fifteen experimental runs have been performed using design expert 11 software (with Box-Behnken design). It has been observed from the Analysis of variance (NOVA) results of the experiment that wet zone yarn tension, squeezing pressure, and speed of the sizing machine have a significant effect on size pick-up% and abrasion resistance of the yarn. The interaction effect of BC with (p-value = .0053) and the interaction effect of AC with (p-value = .0143) have also a significant effect on abrasion resistance. Moreover, the interaction effects (AC and BC) have a significant effect on size pick-up. Regression analysis shows that wet-zone yarn tension and squeezing pressure have a negative relation with size pick-up and the speed of the machine has a positive relation. Whereas machine speed and wet-zone yarn tension have a negative relation with abrasion resistance and squeezing pressure has a positive relation.

Cattle hoofs are abundantly available by-product sources of organic material from the slaughterhouse. It can be successfully converted into keratin protein. Keratin extracted using alkali hydrolysis has a better conservancy of keratin structure. The purpose of this study is optimizing the extraction of keratin from cuttle hoof. Designing of the experiment, analysis of the results, and optimization of the process parameters have been conducted by central composite design (CCD). Three factors (temperature (A), time (B), and concentration of NaOH (C)) each at five levels have been used to extract the keratin protein from cattle hoof and two response variables (dissolution and purity ) have been considered in the study. The results obtained demonstrate that extraction temperature, alkali concentration, and time showed a significant effect on the purity and dissolution of keratin. The regression model shows that all factors have positive and significant relation with dissolution percentage whereas only temperature and concentration of NaOH have significant and negative relation with purity percentage. It is observed that the Biuret and Fourier-transform infrared spectroscopy (FTIR) tests showed better preservation of protein structure in extractive keratin. The FTIR spectra, indicates that amide I and amide II occur at a wave length of 1633 and 1542cm⁻¹ for raw cattle hoof and at wave length of 1650 and 1542cm⁻¹ for keratin protein, respectively. Thus, it can be concluded that the cattle hoof by-product could offer an alternative keratin source. Finally, the extraction process had an optimum value of 0.5M NaOH, 60 minutes reaction time, and 55°C temperature with 85 dissolution and 89.6 purity.

Weaving industries that use air jet loom are always emphasized to increase production and keep up the quality of woven fabric. But due to faulty mill practices or negligence, fabric mechanical properties of the fabric made on air jet loom are impaired. Improving the fabric quality can be achieved by improving work practices and optimization. The aim of this research is to optimize the air pressure and loom speed to produce a fabric with optimum mechanical properties and twist loss of weft yarn after weaving. To perform the experiment, three independent variables (loom speed, left-side relay nozzle pressure, and right-side relay nozzle pressure) was taken. With the combination of the three independent variables at five levels each, nineteen fabric samples were produced and each tensile and tear strength of the fabric in the weft direction were tested. Central composite design (CCD) was used to design the experiment, analyze the results of the experiment, and optimize the process. The results of the experiment show that variation in loom speed and air pressure affects twist of the weft yarn and mechanical properties of the fabric significantly and loom speed had a most significant effect on yarn twist loss, fabric tensile, and tear strength.