18mm Screw Thread Headspace Caps with Septa
    • 18mm screw caps with septa
    • 18mm screw cap size
    • ptfe butyl septa
    • 18mm precision screw caps
    • 18mm screw caps package
    • 18mm screw metal caps package
    18mm screw caps with septa

    18mm Screw Thread Headspace Caps with Septa

    Suitable for: 18mm Screw Headspace Vials
    Caps Material: Magnetic Metal
    Septa Material: PTFE / Silicone
    Septa Size: 17.5*1.5mm
    Cap Features: 8mm Centre Hole
    Color: Metal Silver
    product description


    18mm magnetic precision screw metal cap, silicone/PTFE septa, PTFE/butyl septa


    Metal caps offer the widest range of temperature tolerances and are very resistant to fracture from impact. Metal caps are great for gas chromatography  applications. A metal closure is manufactured from either steel (coated with anti-corrosive coating of either chromeplate or tinplate) or aluminum.


    PTFE/Silicone Septa:

    High quality, pure silicone is laminated to PTFE to give a pure, highly inert septum with excellent resealing characteristics even after repeated punctures.

    PTFE/Silicone septa are the preferred product for use in most HPLC and GC applications where resealability and high purity are critical. Works well for applications where ease of needle penetration is important.

    Septa-silica gel has strong repetitive sealability, and it can maintain good close performance after multiple injections; PTFE is a material with better chemical conditions at present, and it can withstand strong acids and alkalis. The two materials After compounding, the bottle can be used for various laboratory purposes such as sealed sampling, chemical storage and so on. 

    Gray PTFE/ Butyl Septa:

    The Gray Butyl septum with PTFE barrier is an economical solution for low temperature (100°C), low-pressure applications. This septum is restricted for use with many solvents, and is not compatible with alkanes, benzene, chlorinated solvents or cyclohexane. Gray butyl offers good sealing characteristics for fixed gases and low molecular weight compounds.

    Butyl rubber/PTFE septa are used with ketones and acids, and where silicone-containing septa do not perform well. Both types of silicone and butyl rubber septa have a PTFE barrier layer which faces the sample, which reduces the contact between the sample and the silicone and butyl rubber.

    The butyl septa on the PTFE surface can be used in the headspace sample bottle to evaluate the injection activity and the penetration efficiency of methyl bromide on the activated carbon. The septum can be used to seal the vial during liquid sample collection for unmodified benzene analysis using HPLC method.

    18mm Screw Headspace Cap Detials

    Part No.



    Blue PTFE/White Silicone Septa, Φ17.5*1.5mm


    Red PTFE/White Silicone Septa, Φ17.5*1.3mm


    White PTFE/Blue Transparent Silicone Septa, Φ17.5*1.3mm For SPME


    Gray PTFE/Red Butyl Septa, Φ17.5*1.6mm


    18mm Magnetic Precision Screw Metal Cap, 8mm Centre Hole


    Blue PTFE/White Silicone Septa, 18mm Magnetic Precision Screw Metal Cap, 8mm Centre Hole


    Red PTFE/White Silicone Septa, 18mm Magnetic Precision Screw Metal Cap, 8mm Centre Hole


    White PTFE/Blue Transparent Silicone Septa, 18mm Magnetic Precision Screw Metal Cap, 8mm Centre Hole


    Gray PTFE/Red Butyl Septa, 18mm Magnetic Precision Screw Metal Cap, 8mm Centre Hole

    Company Introduction

    1. Founded in 2007, Zhejiang Aijiren, Inc. specialized in chromatography consumables, such as autosampler vial for HPLC, headspace vial, GC vials, micro inserts, septa and caps, syringe filter, etc, covers more than 10000 square meters, and has clean workshop more than 2000 square meters. 100, 000 class cleaning room;  

    2. 15 years export experience, exprot to more than 70 countries, 2000+ customs around the world; 

    3. More than 10 years experience for automatic analytica technique

    4. Aijiren has own R&D Center and Quality Controll Center to keep products in high quality.

    5. All materials are produced at 100,000 grade clean room.
    6. Passed ISO9001:2015  quality management system certification, RoHS compliance can also be provided.

    How to confirm product quality before placing orders?
    After production, all articles are delivered to QC center, only qualified products can be release to the next procedure.
    Meanwhile, you are welcome to ask for samples for testing.
    How to star order or make payment?
    Proforma Invoice will be sent first after confirmation or order together with our bank infomations.
    Pay by T/T, Westren Union or Alipay.
    What is the charge standard about the Samples?
    1) For our first cooperation, free samples will be provide buyer afford the shipping cost.
    2) For our old customers, we will send free samples, even though new design samples, when have stocks.
    3) Samples delivery date is 24 to 48 hours, if have stocks. Customer design is about 3-7 days.
    Can you provide OEM service?
    Yes, we had already do OEM service for more than 4 world famous Brand in chromatography area.
    What is the MOQ?
    For vials, caps and syringe filters MOQ is 1pack(100pcs), for hand crimper/decrimper MOQ is 1pack(1pc).
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