Hawach Qualitative Filter Paper Introduction
Hawach qualitative filter paper is generally gravity-filtered, and solid-liquid separation is carried out using filter paper to retain solid phase particles. The filter paper is usually used in a single layer or a plurality of layers. Filter paper has natural mechanical strength and certain toughness. If you need to speed up the filtration speed, you can fold the filter paper multiple times. For example, stacking two layers of filter paper into a fan shape or a tie pattern can significantly increase the filtration speed. When filtering the air pump, 2-3 layers of filter paper can be stacked in the funnel according to the pumping force, or a dense filter cloth should be placed first, and the filter paper is filtered on the top. Highly corrosive concentrated nitric acid and concentrated sulfuric acid solution should not be filtered by ordinary filter paper. Qualitative filter paper is also commonly used to clean the test bench and various equipment tools in the cleaning and wiping laboratory.
Qualitative filter paper is divided into fast, medium speed and slow speed. Fast moisture breakage ≥120, separation performance of iron hydroxide, high loading, suitable for filtration of coarse particles, medium and gelatinous precipitates. The medium-speed moisture breakage is ≥140, the separation performance is lead sulfate, medium separation performance, medium filtration speed, liquid filtration covering most laboratory applications, and medium-speed filter paper is often used in industrial filtration. The slow moisture-resistant breaking degree is ≥180, and the separation performance is barium sulfate (heat). The retention ability is strong, the adsorption effect is obvious, and the particles can be intercepted to a large extent, which takes a long time. Hawach’s qualitative filter papers BIO-4 and BIO-113 are fast filter papers; BIO-1, BIO-2 and BIO-91 are medium speed filter papers; BIO-5 and BIO-6 are slow filter papers.