Filling Funnels
Funnelsare familiar items in the laboratory and wider workplace environment used to reduce risk of spillage or loss when filtering, filling, decanting or transferring liquids or powders from one vessel to another. Laboratory funnels are made from glass, plastic (typically HDPE funnels) or occasionally metal. Glass funnels are reusable, autoclavable and generally more heat-resistant, chemical-resistant and more durable than plastic funnels, although they may be prone to increased risk of breakage. Glass funnels can be either made from soda-lime glass for general purpose work, or from borosilicate glass for more exacting applications.
What different types of glass funnels are available?
- General purpose glass filling funnels for channeling, filling and decanting liquids
- Short stem funnels or powder funnels, used to prevent the stem from clogging when funneling fine powders
- Long stem analytical funnels, often used with filter papers
- Funnels with specially fluted interiors for rapid filtration
- Glass Büchner funnels, glass filtering funnels or vacuum filtration funnels, made with an integral sintered glass disc for filtering precipitates or particulates without the need for filter papers. The sintered discs come in a range of pore sizes, typically from 10 to 40μm
- Pear-shaped separatory funnels (separating or separation funnels) fitted with a stopper and a PTFE or glass stopcock, used in the chemistry laboratory for pouring off layered immiscible liquids
- Glass weighing funnels
Most types of glass funnel are manufactured in a range of sizes and dimensions, such as varying top diameters, stem lengths, stem diameters, bowl angles, bowl capacities and overall lengths.