Filter papers was produced in factrories using rags for first time 150 years ago. Today, it becomes possible to produce special filter papers for any kind of filter. Paper-based permeable materials can obtain from pine trees and their leafs. Main filter material is paper for filtration of liquids and gases. Filter paper is consist from cotton, polyester, silk which is inhomogeneous fibers. These fibers have diameter between 5-50 microns. Compared with other materials, filter paper has many advantages.
There two main filtration system. They are surface filtration and depth filtration. Good a for filtration, filter paper has sieving, sedimentation, diffusion and shock mechanism for particle suspencion. Filter papers must have following characteristic depending on its climatic conditions, operating conditions, engine or machines technical specifivations.
Paper strenght: It is defined as the mass per unit area of the paper. Generally define as gram for per square meter.
Burst Strenght: Putted filter paper onto as circular burst with rubber diaphragm. At the bursting moments value gives papers burst or split strenght. This value known as newtons per square meter.
Streching: Filter paper with certain lenght and width, is pulled with two jaw mechanism with certain speed and it cuts so reached to tensile value of the paper.
Air permeability: Air passing amount of unit time(second) and unit area under certain pressure difference. For flow, Flow unit is spent in a cubic centimeter per second
Pore Size: It gives the largest particle diameter which can pass in filter paper.