Filter paper is used for filtering liquids in chemical and other scientific and automotive procedures. In chemistry, it is made of cellulose and is treated with hydrochloric and hydrofluoric acid, and it is particularly useful due to the fact that it burns out almost completely without leaving behind much ash, less than 0.0001 gram to be exact. In other applications, such as automotive procedures, filter paper can be made of other fiber materials, such as cotton.
There are different kinds of cellulose filter paper that each carry different qualitative and quantitative properties. Black band filter paper allows 100 mL of fluid to flow through it in about 20 to 30 seconds. It is designed for filtering thicker gelatinous solutions. White band filter paper allows 100 mL of fluid to flow through it in about 40 to 60 seconds. It is designed for filtering coarse crystalline solutions. Blue band filter paper allows 100 mL to flow through it in about 200 to 400 seconds. It is designed for filtering fine crystalline solutions.
When selecting the proper filter paper for a particular purpose, whether it be for a chemistry laboratory or an automotive task, things to consider are the filter paper's effective area, fiber diameter and tensile strength. Some automotive filter papers are designed for oils, while others are meant to be used to filter air.