Noise pollution is one of the harmful physical sources in the textile industry, which is among those industries that are faced with noise exposure problems. The results of environmental sound measurements at modern textile mills have shown that the sound pressure level varied from 95 to 130 dB, where the highest sound pressure level was at weaving machines. Textile insulation materials can be fitted in order to decrease sound pollution at a low cost. The objective of this work is to design a sound absorber that can be fixed to the body of the machines, at the point of the noise generation, to reduce noise pollution. Poly(lactic acid) (PLA), which is an environmentally friendly material, was used to produce different samples of meltblown nonwoven absorbers to be used for damping the noise of textile machinery. PLA meltblown nonwoven fabric with the areal density of 16.7 g/m2, average fiber diameter of 1.1 µm, mean pore diameter of 9.8 µm and thickness of 0.27 mm exhibited significant sound absorption. The sample with the smallest average fiber diameter among those investigated had the highest damping effect: 23.95, 41.29 and 29.32 dBA at frequencies of 400, 1000 and 1500 Hz, respectively. Our goal is to have a practical tool that accurately evaluates the absorber sound damping under the actual running conditions of the textile machinery. The design of the absorber from one layer of the PLA meltblown nonwoven over a rigid polyurethane foam sheet had an excellent sound absorption property.

An analysis of fiber mechanics during cutting is conducted using a rotating cutting set up. It was found that high cutting speeds, low cutting angles, and high cutting normal forces lead to low values of cutting force. In this study, a set of high performance organic and inorganic fiber types are tested throughout different conditions of cut testing. Inorganic fibers gave the lowest specific cutting force. Values of cutting stresses on the edge of the blade were proved to be a function of fibers’ Young’s moduli. Higher Young’s moduli give lower cutting stresses on the blade edge while cutting fibers. Organic fibers were found to have a higher cutting resistance than carbon and glass fibers. A significant indirect correlation was found between the shear stress of the fibers and the fiber Young’s modulus. The value of the cutting force is significantly affected by both normal force and cutting velocity. The analysis of fiber mechanics during cutting is conducted using a rotating cutting set-up. It was found that high cutting speeds, low cutting angles, and high cutting normal forces lead to low values of cutting force. In this study, a set of high performance organic and inorganic fiber types are tested throughout different conditions of cut testing. Inorganic fibers gave the lowest specific cutting force. Values of cutting stresses on the edge of the blade were proved to be a function of fibers Young’s modulus. Higher Young’s modulus gives lower cutting stresses on the blade edge while cutting fibers. Organic fibers were found to have a higher cutting resistance than carbon and glass fibers. A significant indirect correlation was found between the shear stress of the fibers and the fibers Young’s modulus. The value of the cutting force is significantly affected by the normal force, cutting angle, and cutting velocity.

The object of this paper is to investigate the acoustic insulation properties of needle-punched nonwovens produced from recycled polyester waste blended with virgin polyester serving as supportive material. The research work also studies the effect of different processing parameters of needle punching nonwoven machines through the investigation of different needle speeds, lattice speeds, and penetration depths. Throughout the research work, several needles punched nonwoven fabrics were produced under different conditions as follows: Three needle speeds were applied: 280, 245, and 227 rpm. Three lattice speeds were applied: 0.72, 1.47, and 2.35 m/min. Three depths of penetration for the needles were applied: 26, 10, and 5 mm. Finally, different blends of waste/virgin polyester fibers were produced and tested: 40/60%, 20/80%, and 100% virgin polyester. The four parameters investigated had a statistically significant effect on the sound transmission losses obtained. It was proved that as the frequency increases, the needle speed gains importance while the needle penetration depth loses importance. The results of testing the different samples indicated that the highest sound transmission loss is attained using non-woven fabrics produced from virgin polyester fibers and prepared at high stitch density.