Bonded caps from Specialty Silicone Products (SSP) are made of polypropylene (PP) plastic and bonded to platinum-cured silicone septa that’s easy-to-pierce.

Caps with Bonded PTFE Septa

To ensure analytical purity, SSP uses a proprietary bonding technology that maintains the septum’s analytical properties. In other words, our bonding process won’t add contaminants that can leach from the cap-and-septa assembly into your laboratory samples. 

Screw Cap Sizes for Bonded Septa Caps

SSP supplies bonded septa for analytical testing in the following polypropylene caps:

• 9mm screw caps
• 13-425 screw caps
• 24-400 screw caps
• 24-414 screw caps

Pre-Slit Products and Bonded Septa for Analytical Testing 

Our bonded caps can be manufactured with a single slit to allow for venting during the injection process. 

Caps with Bonded PTFE Septa

Caps with bonded PTFE (polytetrafluoroethylene) septa are specialized closures used for laboratory vials, typically in chromatography, analytical chemistry, and sample storage applications. PTFE is bonded to silicone for better resealability and chemical resistance. The PTFE septa are permanently attached (bonded) to the cap, preventing them from falling out or moving during use.

Bonded Septa for Analytical Testing

With our proprietary bonding technology, SSP can bond silicone/PTFE septa to PP screw caps for almost any application with gas chromatography (GC) or liquid chromatography (LC) and mass spectrometry (MS). 

Bonded Caps

All our bonded caps are made in the USA at our Ballston Spa, New York facility. These ribbed screw caps come in different colors and are supplied in bags of 100 or 1000. If you need a custom bonded septa cap, click here and let us know what you are looking for.