Ultra-Low Density Polymer with Improved Sound Deadening Properties Made with Recycled Plastics
Publication Date: 2017-May-26
The IP.com Prior Art Database
As fuel economy standards are being increased on vehicles a higher focus is being paid to improving fuel economy of vehicles. Improved aerodynamics is a key to improving automobile fuel economy as is weight and affordability. Underbody shields are being added to many vehicles to reduce drag on vehicles traveling at higher speeds. At the same time quietness of vehicles is becoming more important to customers so reducing the amount of noise in the cabin of the vehicle is also becoming more important. Additionally we need to make sure the weight of the shields that are added is minimal. If the weight is too high it will negate the added fuel economy that the aerodynamic improvement of the added shields yields
Most OEMS use 20% by weight talc filled co-polymer polypropylene material. (Either recycled or virgin). Talc or glass are used to increase strength, heat deflection temperature and stiffness of the material. While co-polymer polypropylene has a density of about .91 kg/m
3 talc has a density of about 2.64
kg/m 3 raising the overall density of the compound to 1.06 kg/m
Our goal is to develop a polymer for use in extruded that has significantly lower density than current talc filled polypropylene.
The chart above shows unfilled polypropylene has lower density than most polymers and has relatively good strength
To produce the low density polymer compound we will introduce a combination of two fillers. The first material is a very low density material called cenosphere’s. A cenosphere is essentially a lightweight, inert, hollow sphere ceramic made largely of silica and alumina and filled with air or inert gas. Cenospheres were first used by the Romans as a low density filler that replaced sand in cement that was used to construct bridges and domed buildings like the Pantheon. The cenospheres used by the romans were found in volcanic ash. Today most cenospheres are, typically produced as a byproduct of coal combustion at electrical power plants and is found in the “Fly ash” of residue from the fired coal used by powered power plants. The process of burning coal in thermal power plants produces fly ash containing ceramic particles made largely of alumina and silica. They are produced at temperatures of 1,500 to 1,750 °C (2,730 to 3,180 °F) through complicated chemical and physical transformation. The ceramic particles in fly ash have three types of structures. The first type of particles are solid and are called precipitator. The second type of particles are hollow and are called cenospheres. The third type of particles are called plerospheres, which are hollow particles of large diameter filled with smaller size precipitator and cenospheres. There are many companies that commercially harvest cenospheres from fly ash by first floating on water where the low density cenospheres can be separated from heavier solid coal residue. The cenospheres are next centrifuged to further separate components and then filters are used to separate size The chemic...