Why do companies use filter presses rather than funnels and paper? There are two main reasons. Firstly, the volumes used are generally very much larger than ever used in the classroom. It would be impractical to build a big enough filter funnel. Using the press is also more efficient. The increased pressure in the press means that the solution is filtered a lot more quickly. A filter funnel relies on the pull of gravity to draw the liquid through the filter. This very quickly slows to a drip as the solid begins to build up on the filter paper.