Funnels are meant to physically separate liquids from solids. Ceramic or Porcelain Funnels made from specialty heavy ceramic porcelain and glaze with special chem resistant glaze at temperatures around 1000C. Ceramic funnels are the best for major filtration needs where manual labor is used. Funnels operate under gravity or vacuum. Vacuum filtration usually must faster.  There are several types of funnels used for different applications. It is important to use correct funnel. You can consult with us if unsure.