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
Ace Glass, Inc. #22 PTFE Stopper with Polypropylene Extraction
#22 standard taper PTFE stopper with polypropylene extraction nut for easy removal from outer joints.
Chemglass Life Sciences Septum Stopper, Sleeve Type, for 8mm OD Standard Wall or 9mm OD Medium Wall, Red
Septum Stopper, Sleeve Type, for 8mm OD Standard Wall or 9mm OD Medium Wall, Red. Sleeve type stoppers with a hollow plugs and sleeve extensions that folds down over the neck of a vessel, tubing, etc. The diaphragm can be punctured with a syringe needle, re-sealing after the needle is withdrawn.
Research Products International Corp Laboratory Grade Rubber Stopper, Black SBR Rubber, Size #13, 68 x 58 x 25mm, 4 per Package
Laboratory Grade Rubber Stoppers offered in a wide range of common sizes for most laboratory applications. Available standard black SBR rubber. Solid rubber stoppers are molded in the USA according to standard industry size specification. Packaged in approximately one pound packages.
Enterprise Technology Solutions Ettore Products Blades,f/Window Squeegee,Replacement,Rubber,20",144/CT,Black
First-rate rubber blades provide impressive squeegee results for professionals and DIY homeowners alike. Easily clean your windows leaving behind no water streaks. Extensive quality control for each blade ensures consistent, high-caliber performance. 20" rubber replacement blades perfectly fit your favorite Ettore Squeegee head for continued use. Replace rubber blades regularly for best window-cleaning results.
SCIMAC Safety Lab Stopper, Extraction Nut, Standard Taper, Hollow, PTFE, Joint: 19/38, Hollow
Safety Lab Stopper, Extraction Nut, Standard Taper, Hollow, PTFE, Joint: 19/38, Hollow, Height: 55mm. Full Length; Safety Lab Solid PTFE| Black Extraction Nut | Easy Removal from glass Joints | Boiling & Distilling Flasks |Autoclave Safe at 250˚F | Complies to ASTM E675
Chemglass Life Sciences Stopper, # 27, Polyethylene
Stopper, # 27, Polyethylene. These blue and white stoppers are made with closed bottoms, of linear high-density polyethylene to conform to stopper dimensions. The three unit rings on the base provide an efficient seal. The improved design fully protects the neck in the event of accidental tipping. These stoppers may be used in place of the conventional flask stoppers.