Research on the absorbing properties of some new types to composite materials

The paper aims to introduce innovative systems to absorb and attenuate noise from industry or urban and
extra-urban environment, efficient and sustainable, based on composite materials made by recycling solid wastes. The composite materials are obtained by including some materials considered wastes – pellets from plastic bottles, sawdust, ash from thermal plant and sterile municipal waste - in a polymer type organic matrix. Thus are obtained new organic materials which embed non-biodegradable waste, which can affect seriously the environment. The sound absorption capacity of these new composites varies depending on the proportion and nature of the waste used. The absorption coefficient which determines the phonic absorbing capacity of all new obtained materials is calculated for each sample. Samples are made of resin and
reinforcement material in different proportions, which are tested to determine the absorption coefficient against frequency, using a device called KUNDT TUBE. Both for material preparation and sampling tests the in force standards are respected.