Stoppers
Stoppers, also known as bungs, are used to give an airtight seal to laboratory flasks and test tubes by fitting tightly inside the neck of the container and preventing material from spilling. Stoppers can be made of glass, cork, rubber, or silicone. They are typically designed with a conical shape, but straight, flanged, and tapered options are also available.
Stoppers are the preferred choice for many applications requiring a tighter seal or a greater degree of chemical resistance. They also provide a good seal when a solution needs to be shaken or mixed without spilling. Stoppers are generally cylindrical in shape and have a tapered bottom end. They may be marked with a stopper number or size on the top and bottom diameters of the stopper. Sizing can vary among manufacturers.
Stoppers are available in a solid design or with holes known as positions placed in the top. Positions allow easy access to the material contained in the sealed vessel by pipettes, tubing, or other equipment without full removal of the stopper.
What Types of Stoppers Are Available?
• Turnover stoppers have external serrations to create an excellent internal seal combined with a flexible turnover sleeve that folds down over the container’s neck to create a double seal
• Serum bottle or vial stoppers have two or three legs with external serrations or straight sides and a flanged top to create an airtight seal
• Straight bromobutyl plug-type stoppers provide a maximum seal for vials and serum bottles with a straight-wall glass finish
• Ultra-pure, straight bromobutyl plug-type stoppers provide high chemical purity and low gas permeability. They offer excellent performance during freeze drying processes such as lyophilization, where stoppers must remain stable during transfer and sublimination phases
• Silicone recessed septa stoppers are non-toxic and have external serrations to create an effective internal seal
Eisco™ Solid ASTM Neoprene Stoppers
Pack of ten solid ASTM neoprene stoppers. Made from long lasting neoprene rubber. Oil resistant, use up to 250°F / 120°C. Suitable for use with petroleum products, minerals, oils, fats as well as most inorganic acids.
DWK Life Sciences Wheaton™ Stoppers for Serum Bottles and Vials: Sleeve Stopper
Provide airtight covers
Eisco™ 1 Hole ASTM Neoprene Stoppers
Pack of ten 1-hole ASTM neoprene stoppers. Made from long lasting neoprene rubber. Oil resistant, use up to 250°F / 120°C. Suitable for use with petroleum products, minerals, oils, fats as well as most inorganic acids.
Fisherbrand™ One-Hole Rubber Stoppers
One hole rubber stopper
Fisherbrand™ Twistit™ Rubber Stoppers
Stoppers made from soft, resilient, natural rubber with safe convenient countersunk holes, stoppers feature excellent aging characteristics with high resistance to deformation
Fisherbrand™ Solid Neoprene Rubber Stoppers
Recommended where rubber would be attacked or deteriorated
DWK Life Sciences Kimble™ Linear HDPE Stoppers
Closed bottom end fits the standard taper neck
DWK Life Sciences Wheaton™ Stoppers for Serum Bottles and Vials: Straight Plug Stopper
Provide airtight covers
Corning™ PYREX™ Hollow Glass Standard Taper Stoppers
Variety of sizes available
Corning™ PYREX™ Hollow Combination Standard Taper Joint and Reagent Bottle Stoppers
Choose from variety of sizes and taper types
DWK Life Sciences Wheaton™ Flange Style Rubber Stopper
For research and parenteral drug applications
DWK Life Sciences Wheaton™ Sleeve Style Stoppers for Vials without Crimp Closure
Provides injection site for multiple dose entry
Corning™ PYREX™ Polyethylene Standard Taper Stoppers
Improved design fully protects neck in event of accidental tipping