Cap Septa

Septa Chemistry & Construction

The septum is a high-performance PTFE/Silicone composite, designed to balance chemical resistance with mechanical resilience:

PTFE (Polytetrafluoroethylene) – Sample Contact Layer (Red)

• Chemically inert fluoropolymer
• Non-adsorptive surface
• Extremely low extractables and leachables
• Water absorption < 0.003%
• Excellent resistance to acids, bases, and organic solvents
• Operating temperature range: –200°C to +260°C

Silicone Elastomer – Support Layer (White)

• Platinum Cured
• High elasticity (Shore A 45° - 50°)
• Superior resealability after repeated needle penetrations

This Bi-layer laminated structure minimizes septa bleed, prevents analyte loss, and maintains sample purity—making it suitable for both trace-level and routine analyses.

The bonded septum ensures consistent positioning within the cap, eliminating septum movement and maintaining uniform sealing pressure.

Non-Slit– Technical Implications

• • Non-slit design requires direct needle penetration, providing:
• Strong initial sealing
• Reduced risk of vapor loss during storage
• Improved integrity for volatile samples before first injection

Septa Chemistry & Construction

PTFE (Polytetrafluoroethylene) – Sample Contact Layer (Red)

• Chemically inert fluoropolymer
• Non-adsorptive surface minimizes analyte loss
• Very low extractables and leachables
• Water absorption < 0.003%
• Excellent resistance to acids, bases, and organic solvents
• Maintains stability across a wide temperature range used in HPLC and GC

Silicone Elastomer – Support Layer (White)

• Platinum elasticity
• Ensures effective resealing after multiple autosampler injections
• Maintains septum integrity during repetitive needle cycles

The bonded septum ensures consistent positioning within the cap, eliminating septum movement and maintaining uniform sealing pressure.

Septa Chemistry & Construction

PTFE (Polytetrafluoroethylene) – Sample Contact Layer (Red)

• Chemically inert, non-reactive fluoropolymer
• Non-adsorptive surface minimizes analyte loss
• Very low extractables and leachables
• Water absorption < 0.003%
• Excellent resistance to acids, bases, and organic solvents
• Maintains stability across a wide temperature range used in HPLC and GC

Silicone Elastomer – Support Layer (White)

• Provides elasticity
• Ensures effective resealing after multiple autosampler injections
• Maintains septum integrity during repetitive needle cycles

The bonded septum ensures consistent positioning within the cap, eliminating septum movement and maintaining uniform sealing pressure.

Septa Chemistry & Construction

PTFE (Polytetrafluoroethylene) – Sample Contact Layer (Red)

• Chemically inert fluoropolymer with a low surface energy
• Non-adsorptive and resistant to interaction with analytes
• Extremely low extractables and leachables
• Water absorption < 0.003%
• Broad chemical compatibility with acids, bases, and organic solvents
• Operating temperature range: – ͂ 180 °C to + ͂ 220 °C

Silicone Elastomer – Support Layer (White)

• Provides elasticity
• Maintains septum integrity after repeated needle penetration
• Supports consistent sealing during autosampler operation

This bi-layer construction ensures stable sample containment while maintaining analytical purity.

Non-Slit– Technical Implications

• Non-slit design requires direct needle penetration, providing:
  • Strong initial sealing
  • Reduced risk of vapor loss during storage
  • Improved integrity for volatile samples before first injection

Septa Chemistry & Construction

PTFE (Polytetrafluoroethylene) – Sample Contact Layer (Red)

• Highly inert fluoropolymer with a fully fluorinated carbon backbone
• Non-polar, non-adsorptive surface minimizes analyte interaction
• Extremely low extractables and leachables
• Water absorption < 0.003%
• Excellent resistance to acids, bases, and organic solvents
• Thermal stability from – ͂ 180 °C to + ͂ 220 °C, suitable for HPLC and GC environments

Silicone Elastomer – Resealing Layer (White)

• Provides elasticity
• Enables consistent resealing after repeated autosampler injections
• Maintains septum integrity during routine analytical use

Snap caps provide a convenient sample containment system designed for non-volatile liquid samples. The snap-closure mechanism enables rapid without crimping or de-crimping tools, allowing efficient one-handed operation during sample preparation.

Why Snap Top Vials-Cap Septa are used against Screw Non-Bonded Cap septa?

Septa Chemistry & Construction

PTFE (Polytetrafluoroethylene) – Sample Contact Layer (Red)

• Chemically inert fluoropolymer with a low surface energy
• Non-adsorptive and resistant to interaction with analytes
• Extremely low extractables and leachables
• Water absorption < 0.003%
• Broad chemical compatibility with acids, bases, and organic solvents
• Operating temperature range: – ͂ 180 °C to + ͂ 220 °C

Silicone Elastomer – Support Layer (White)

• Provides elasticity
• Maintains septum integrity after repeated needle penetration
• Supports consistent sealing during autosampler operation

Technical Implications

• Minimizes analyte loss due to evaporation
• Reduces risk of oxidative degradation

Snap caps provide a convenient sample containment system designed for non-volatile liquid samples. The snap-closure mechanism enables rapid without crimping or de-crimping tools, allowing efficient one-handed operation during sample preparation.

Why Snap Top Vials-Cap Septa are used against Screw Non-Bonded Cap septa?

Septa Chemistry & Construction

PTFE (Polytetrafluoroethylene) – Sample Contact Layer (Red)

• Chemically inert fluoropolymer with a low surface energy
• Non-adsorptive and resistant to interaction with analytes
• Extremely low extractables and leachables
• Water absorption < 0.003%
• Broad chemical compatibility with acids, bases, and organic solvents
• Operating temperature range: – ͂ 180 °C to + ͂ 220 °C

Silicone Elastomer – Support Layer (White)

• Provides elasticity
• Maintains septum integrity after repeated needle penetration
• Supports consistent sealing during autosampler operation

Technical Implications

• This cap ensures quick, tool-free sealing with reliable retention on the vial.
• Maintained Seal Integrity After Puncture

These are engineered to provide secure sealing, chemical inertness, and thermal reliability for Gas Chromatography (GC) headspace analysis.

The high-strength aluminium crimp cap ensures a reliable closure by offering:

• Excellent mechanical rigidity for uniform crimping
• Formation of a gas-tight hermetic seal
• Minimal deformation under high-temperature conditions
• 3 mm Septum Thickness Benefits is to maintain high resistance to needle coring

In GC headspace workflows, where samples are often heated prior to injection, aluminium crimp caps help prevent vapor loss, pressure leakage, and oxygen ingress, ensuring accurate analysis of volatile and semi-volatile compounds.

PTFELayer (Sample Contact Layer)

• Fully fluorinated polymer with strong C–F bonds
• Chemically inert and non-adsorptive
• Extremely low extractables and leachables
• Excellent resistance to solvents, acids, and bases
• Water absorption < 0.003%
• Thermal stability from –220 °C to +250 °C

Silicone Elastomer Layer (Resealing Support)

• Provides elasticity
• Maintains sealing after multiple syringe injections
• Ensures consistent performance in routine and trace analysis

These are engineered to provide secure sealing, chemical inertness, and thermal reliability for Gas Chromatography (GC) headspace analysis.

The high-strength aluminium crimp cap ensures a reliable closure by offering:

• Excellent mechanical rigidity for uniform crimping
• Formation of a gas-tight hermetic seal
• Minimal deformation under high-temperature conditions
• 3 mm Septum Thickness Benefits is to maintain high resistance to needle coring

In GC headspace workflows, where samples are often heated prior to injection, aluminium crimp caps help prevent vapor loss, pressure leakage, and oxygen ingress, ensuring accurate analysis of volatile and semi-volatile compounds.

PTFE (Polytetrafluoroethylene) – Sample-Contact Layer (Beige)

• Fully fluorinated polymer with strong C–F bonds
• Chemically inert and non-adsorptive surface
• Extremely low extractables and leachables
• Excellent resistance to solvents, acids, and bases
• Water absorption < 0.003%
• Excellent resistance to aggressive solvents, acids, and bases
• Thermal stability from – ͂ 220 °C to + ͂ 250 °C, suitable for heated GC inlets and headspace conditions

Silicone Elastomer Layer (White)

• Provides controlled elasticity and puncture recovery
• Maintains seal integrity after repeated syringe penetrations
• Supports consistent injections in both routine and trace-level analysis

These caps engineered to deliver superior seal integrity, chemical inertness, and thermal reliability for demanding gas chromatography and headspace workflows.

Star Crimp Design – Mechanical & Sealing Advantage

Unlike conventional smooth crimp caps, the star crimp profile applies radially uniform pressure around the vial neck. This design:

• Improves hermetic sealing at high temperatures and pressures during GC analysis.
• Prevents vial breakage or bursting caused by vacuum or vapor pressure buildup.
• SC20 is used to safely release excess pressure with the help of cut design on the top of the aluminium cap allows controlled pressure release.
• Provides greater seal consistency across long analytical batches
• 3 mm Septum Thickness Benefits is to maintain high resistance to needle coring

The aluminium construction provides:

• High mechanical strength and dimensional stability
• Resistance to deformation during crimping and heating
• Reliable sealing during elevated-temperature GC injection and headspace incubation

PTFE (Polytetrafluoroethylene) – Sample-Contact Layer (Beige)

• Fully fluorinated polymer with strong C–F bonds
• Chemically inert and non-adsorptive surface
• Extremely low extractables and leachables
• Water absorption < 0.003%
• Excellent resistance to aggressive solvents, acids, and bases
• Thermal stability from – ͂ 220 °C to + ͂ 250 °C, suitable for heated GC inlets and headspace conditions

Silicone Elastomer – Resealing Layer (White)

• Provides controlled elasticity and puncture recovery
• Maintains seal integrity after repeated syringe penetrations
• Supports consistent injection reproducibility in both routine and trace-level analysis

The BSBAC20 is a 20 mm silver aluminium open-top crimp cap featuring a 6 mm central opening, engineered to deliver reliable sealing, controlled septum interaction, and thermal stability for gas chromatography, headspace, and related analytical techniques.

High-purity aluminium cap provides:

• High mechanical strength for consistent crimp formation
• Dimensional stability during elevated-temperature operation
• Resistance to deformation during crimping and thermal cycling

Aluminium crimp caps are preferred in GC and headspace analysis due to their ability to maintain a hermetic, gas-tight seal, preventing analyte loss and atmospheric ingress during sample equilibration and injection.

Open-Top (Inner Hole) -

The 6 mm central opening allows:

• Direct and controlled interaction between the syringe needle and the septum
• Reduced needle deflection during puncture
• Lower risk of septum coring and particulate generation
• More consistent penetration force during repeated injections

This design improves injection reproducibility and extends septum life, particularly in high-throughput or repetitive injection workflows.

The smooth inner cap profile ensures:

• Uniform radial compression of the septum
• Even distribution of crimp force around the vial neck
• Tight, leak-proof sealing when paired with compatible 20 mm septa

This sealing consistency is critical for maintaining internal vial pressure and preserving volatile components during headspace and GC analysis

Commonly used in:

• Provides controlled elasticity and puncture recovery
• Maintains seal integrity after repeated syringe penetrations
• Supports consistent injection reproducibility in both routine and trace-level analysis

The BSBASC20 is a 20 mm silver aluminium seal crimp cap, designed as a non-pierce mechanical closure for crimp-neck vials in chromatographic and laboratory workflows where needle access is not required.

Manufactured from chemically inert aluminium, the cap offers:

• High mechanical strength and dimensional stability
• Excellent resistance to corrosion and oxidation
• Thermal stability under elevated temperatures

Aluminium’s low chemical reactivity ensures minimal interaction with solvents or analytes, reducing the risk of contamination, adsorption, or background interference.

Crimp Seal Function – Mechanical Integrity

The crimping process forms a uniform metal seal around the vial neck, providing:

• Secure containment of vial contents
• High resistance to internal pressure changes
• Protection against atmospheric ingress

This makes the cap suitable for headspace equilibration, thermal conditioning, transport, and storage of samples where piercing or injection is not required.

Application

• Headspace preparation (pre-analysis sealing)
• Thermal treatment or equilibration steps
• Sample storage and stability holding

These caps engineered to provide secure sealing, chemical inertness, and thermal reliability for gas chromatography and headspace analysis.

• 3 mm Septum Thickness Benefits is to maintain high resistance to needle coring

Manufactured from high-strength aluminium, the cap offers:

• Uniform and reproducible crimp formation
• A hermetic, gas-tight seal around the vial neck
• Resistance to deformation under elevated GC and headspace temperatures

Aluminium’s low chemical reactivity ensures minimal interaction with solvents or analytes, reducing the risk of contamination, adsorption, or background interference.

PTFE (Polytetrafluoroethylene) – Sample-Contact Layer (Red)

• Fully fluorinated polymer with strong C–F bonds
• Chemically inert and non-adsorptive
• Extremely low extractables and leachables
• Water absorption < 0.003 %
• Excellent resistance to acids, bases, and organic solvents
• • Thermal stability from – ͂ 220 °C to + ͂ 250 °C, suitable for heated GC inlets

Silicone Elastomer – Resealing Layer (White)

• Provides elasticity and puncture recovery
• Maintains seal integrity after repeated syringe penetrations
• Supports reproducible injections in routine and trace-level analysis

Red silicone offers a balanced hardness profile commonly used for standard GC septa.

Septa Chemistry & Construction

PTFE (Polytetrafluoroethylene) – Sample Contact Layer (Red)

• Chemically inert fluoropolymer with a low surface energy
• Non-adsorptive and resistant to interaction with analytes
• Extremely low extractables and leachables
• Water absorption < 0.003%
• Broad chemical compatibility with acids, bases, and organic solvents
• Operating temperature range: – 180 °C to +220 °C

Silicone Elastomer – Support Layer (White)

• Provides elasticity
• Maintains septum integrity after repeated needle penetration
• Supports consistent sealing during autosampler operation

This bi-layer construction ensures stable sample containment while maintaining analytical purity.

Non-Slit – Technical Implications

• Non-slit design requires direct needle penetration
• Strong initial sealing
• Reduced risk of vapor loss during storage
• Improved integrity for volatile samples before first injection

Septa Chemistry & Construction

PTFE (Polytetrafluoroethylene) – Sample Contact Layer (Red)

• Highly inert fluoropolymer with a fully fluorinated carbon backbone
• Non-polar, non-adsorptive surface minimizes analyte interaction
• Extremely low extractables and leachables
• Water absorption < 0.003%
• Excellent resistance to acids, bases, and organic solvents
• Thermal stability from –180 °C to +220 °C, suitable for HPLC and GC environments

Silicone Elastomer – Resealing Layer (White)

• Provides elasticity
• Enables consistent resealing after repeated autosampler injections
• Maintains septum integrity during routine analytical use