Sound-absorbing green composites based on cellulose ultra-short/ultra-fine fibers

Abstract

In this paper studies on sound absorption of the thermoplastic composites on the basis of waste natural fibers are presented. Cotton fibers and cellulose ultra-short and ultra-fine fibers obtained from flax fibers following enzymatic and additional mechanical treatment were used as the components of polylactide composites, and their influence on sound absorption behavior was investigated. The composites were obtained from a pressing process of fibrous multilayer structures. The sound absorption properties of three types of composites were compared: composites reinforced by cotton fibers, composites reinforced by cellulose ultra-short and ultra-fine fibers, and composites reinforced by cotton fibers and cellulose ultra-short and ultra-fine fibers. The role of cellulose ultra-short and ultra-fine fibers in changing the sound absorption properties of composites was determined. It has previously been shown that using natural fibers with a thermoplastic polymer results in increased sound absorption. The best improvement of sound absorption can be obtained by combining cotton fibers and cellulose ultra-short and ultra-fine fibers, especially nanofibers, as a reinforcement.

Investigation Of Sound Absorption Properties Of Bark Cloth Nonwoven Fabric And Composites

“…Non-woven felts have been investigated as sound absorption materials by various researchers [25][26][27]. Therefore, in this study, an exploratory investigation of the sound absorption properties of the non-woven fabric from the inner bark of mutuba trees (Ficus natalensis) is characterised.…”

“…It is observed that the performance of the fabrics at 6400 Hz was overall best having a sound absorption coefficient of 0.92 compared to the average of 0.7 obtained from the Ficus bark cloth species. Krucinska et al [27] showed that cotton/PLA composites of 5.8 mm thickness with microfibres had a sound absorption coefficient of 0.93 at 6400 Hz. The bark cloth fabrics showed an irregular dependence of sound absorption coefficient of like other non-wovens over a wide range of frequency, this behaviour was also confirmed elsewhere [26].…”

Bio-Based Composites for Sound Absorption

“…Natural fibre-reinforced composites are used not only for construction but also for new uses, e.g., attenuation of sounds. Soundabsorbing composites can show a high degree of sound absorption, especially at high frequencies [14][15][16][17][18][19].…”

“…Sound waves cause vibration of the fibres in the material and as a result of friction the created energy is converted into heat. A larger fibre surface promotes greater energy loss of the sound wave [16].…”

Sound Absorbing Insulating Composites Based on Polyurethane Foam and Waste Materials

“…Research confirms the possibility to use different types of fibers, natural or synthetic, in making composite materials with acoustic properties. Thus, researchers have used different waste with fibrous characteristics to obtain sound absorbing materials: cellulose fibers [4,5], cotton [6], bamboo fibers [7], hemp fibers [8], jute fibers [9], banana fibers, non-woven short polypropylene fibers [10], coconut fibers [11,12], textile fibers [13], agricultural waste [14], tanned leather [15] and waste glass fibre [16,17].…”