Filter Cloth Technical indicators:
Filter paper technical indicators can be divided into two main areas, one filter paper filter characteristics, on the other hand is the physical characteristics. The filtration characteristics include air permeability, air resistance, maximum pore size, and average pore size. Physical properties include quantitative, thickness, stiffness, corrugated depth, bursting resistance, resin content and so on.
Quantitative: refers to the quality of the filter paper per square meter, in units of g / m².
Thickness: refers to the thickness of filter paper, excluding corrugated depth. Unit: mm.
Air resistance: resistance to air flow. With 100cm2 filter paper in a minute by 85 liters of air pressure drop to the value of that. The unit is mbar. Or the height of the water column (mm).
Corrugated Depth: The depth of the groove to be pressed to enhance the stiffness of the filter paper. The unit is: mm. In general, its value is 0.2mm.
Air permeability: The amount of air passing through the filter paper per unit time in a certain area, at a certain pressure (20 mm water column). The unit is: L / m2 · s.
Nominal filtration accuracy: refers to the filter paper on a size of the particle retention capacity, can be blocked or filtered out of 50% of the micro-sphere particle size prevail. Unit: μm.
Maximum pore size: The size of the void calculated from the pressure at which the first bubble was emitted on the filter paper. Unit: μm.
Average pore size: The pore size calculated using the "dense" bubbling pressure is called the average pore size. The unit is: μm.
Resin content: resin as a percentage of the weight of filter paper. Generally 10% to 30%
Stiffness: filter paper resistance to deformation. Unit: mg.
Breakdown: the maximum pressure per unit area of the filter paper. Unit: kPa.
Filter Cloth Instructions:
The use of filter paper in the experiment with the filter funnel and Buchner funnel and other instruments used together. Before use, the filter paper should be folded into a suitable shape. The common method is to fold the filter paper into a similar flower shape. The higher the degree of folding of the filter paper, the higher the surface area available, the better the filtration effect, but be careful not to over-collapse and cause the filter paper to break. The drainage of the glass rod on the multi-layer filter paper, forced evenly, to avoid damage to filter paper.
Filter Cloth Operation process
1. The filter paper folded, continuous twice, folded into a 90 ° center angle shape. funnel
2. The stack of filter paper, according to one side of the three, the other side of a layer open, into a funnel.
3. The funnel-shaped filter paper into the funnel, the filter edge is lower than the funnel side, pour some water into the funnel mouth, so that the wet filter paper and the funnel wall attached, and then the remaining water drained, stand.
4. Place the funnel loaded with the filter paper on the funnel of the filter, such as the ring on the iron platform, and place the beaker or tube in the funnel neck to keep the funnel neck tip against the wall of the receiving container.
5. To the funnel into the need to filter the liquid, the right hand holding Sheng Shi beaker, left holding a glass rod, the bottom of the glass rod close to the funnel three low side, so that the cup close to the glass rod, to be filtered out along the cup, Along the glass rod tilted trend, homeopathic flow into the funnel, the liquid flowing into the funnel, the liquid surface can not exceed the height of the filter in the funnel.
6. When the liquid through the filter paper, along the funnel neck down, to check whether the liquid along the cup wall downstream, note the bottom of the cup. Otherwise you should move the beaker or rotary funnel, so that the funnel tip and the beaker wall affixed, you can make the liquid along the bottom of the beaker slowly down.