Caps for screw thread vials are available with either an open hole for autosampler use and standard addition or with a solid top for sample storage. Teflon and silicone rubber or ultra-pure silicone are used as raw materials to ensure that the septa are non-toxic; to ensure excellent functions, it is particularly suitable for gas chromatography, and to ensure that the septum does not fall into the sample vial during the injection process.
The adhesive-free bonding process is used to combine the polytetrafluoroethylene membrane and the silicon rubber or silicone bond together to maintain the excellent characteristics of the two materials. The polytetrafluoroethylene layer of the composite septum is in contact with the reagent. It is chemically inert and resistant to acid, alkali, temperature, and adhesion. It does not work with concentrated acid, concentrated alkali, or strong oxidants even at high temperatures. At the same time, the elasticity of silicone rubber or silicone layer can ensure sealing performance.
