Septa are important components in laboratory environments, acting as seals in containers, vials, and equipment to protect samples from contamination and maintain sample integrity. Choosing the right septa material can significantly impact the success of an experiment or production process. Two critical factors to consider when selecting septa are their temperature tolerance and material hardness (durometer). To help users make informed decisions, the ILT Septa Temperature Guide and ILT Septa Material Durometer Guide provide detailed information about how different materials perform under specific conditions. This page offers a comprehensive overview of both guides, helping you select the best septa for your laboratory needs.
Office: 518-432-0617
Sales Hours
no sales hours
Address
45 Discovery Drive, Rensselaer, NY 12144
Fax: 518-432-9146
Sales Hours
no sales hours
Address
45 Discovery Drive, Rensselaer, NY 12144
English
Septa Temperature and Durometer Guide
ILT Septa Material Temperature Guide
| Material | Min. temp °C | Max. temp °C | Min. temp °F | Max. temp °F | |
|---|---|---|---|---|---|
| PTFE/Natural Red Rubber | -10 | 80 | -14 | 176 | |
| PTFE/Silicone Red Rubber | -40 | 120 | -22 | 248 | |
| PTFE/Silicone | -65 | 210 | -85 | 410 | |
| PTFE/Silicone/PTFE | -65 | 210 | -85 | 410 | |
| PTFE | -180 | 250 | -292 | 482 | |
| Butyl/ Chlorobutyl/ Bromobutyl | -20 | 130 | -4 | 266 | |
| "Pharmafix" Gray PTFE/Molded butyl | -20 | 130 | -4 | 266 | |
| PP/Silicone | -10 | 120 | -14 | 248 | |
| PFAS-Free Film/Silicone | -10 | 100 | -14 | 212 | |
Using the ILT Septa Temperature Guide
Selecting a septa material based on temperature resistance is crucial to ensuring it maintains its integrity during your analytical methods. Whether you’re working at room temperature or high-heat applications, like certain headspace applications, the right septa material can help protect your samples and ensure accurate results. This guide lists common materials such as PTFE, silicone, and butyl, each offering different temperature tolerances to accommodate specific applications.
PTFE/Silicone offers a broad temperature range, from -65°C to 210°C, making it ideal for general purpose use across a wide range of temperatures. For applications that demand extreme cold or heat, pure PTFE stands out with a temperature range of -180°C to 250°C. This makes it suitable for highly specialized fields such as cryogenics or high-temperature industrial processes. Materials like PTFE/butyl are chosen for their low permeability, as they have a moderate temperature range of -20°C to 130°C.
Key Features of Different Septa Materials
Each material used in septa manufacturing offers unique features tailored to specific needs. When choosing septa, it’s important to consider the following attributes:
- Resealability: Silicone and silicone/PTFE septa are known for their excellent resealability, making them ideal for applications such as autosampling that requires multiple injections from the same vial.
- Low bleed: In certain applications, particularly in gas chromatography, low bleed is an essential property. Septa with low bleed characteristics have reduced volatiles to prevent interference and improve results.
- Permeability: Some materials, such as PTFE/butyl, offer low permeability to make them suitable for applications where sample loss through gas leakage is a problem.
- Resistance to Coring: Septa that resist coring are critical in preventing contamination. Materials like PTFE backed liners help minimize the risk of coring, ensuring sample purity even after multiple penetrations.
- Chemical Resistance: Materials like PTFE provide strong chemical durability because of their inertness and compatibility with a wide variety of chemicals and solvents.
ILT Septa Material Durometer Guide
| Material | Shore A Durometer | Thickness (inches) |
|---|---|---|
| Silicone | 40-60 | 0.040” to 0.125” |
| Natural Rubber | 50 | 0.040” |
| Butyl | 50 | 0.050” to 0.090” |
Using the ILT Septa Material Durometer Guide
Beyond temperature resistance, another key property to consider when selecting septa is material hardness, which is measured by the durometer rating. Durometer ratings use the Shore A scale to gauge how soft or hard a material is. This particular guide lists ratings for common materials like silicone, natural rubber and butyl.
Silicone septa have a durometer rating of 40-60 Shore A, meaning they are relatively soft and pliable. This softness allows for excellent resealing properties, making silicone ideal for applications that involve repeated punctures, such as in autosamplers or syringe sampling. Softer materials also reduce the likelihood of coring, which occurs when a needle or sharp object removes part of the septa during puncture, potentially contaminating the sample.
The thickness of the septa also plays a role in its performance. Silicone septa, for instance, can range in thickness from 0.010″ to 0.125″ (3mm). Thicker septa are ideal for applications requiring multiple injections, as they offer greater durability and extend the lifespan of the seal.
Septa Material Chemical Compatibility
Ratings – Chemical Effect
- Poor = Post injection this septum will exhibit sample loss and deterioration
- Fair = Post injection this septum will maintain integrity for a limited period of time with some deterioration
- Good = Post injection this septum will maintain integrity for an extended period of time with minor deterioration
- Excellent = Post injection this septum will maintain integrity for high percentage of analytical sample analysis with absolute minimal deterioration
| Chemical | Rubber | Silicone | Butyl Rubber | Viton |
|---|---|---|---|---|
| Acids | Good | Excellent | Fair | Poor |
| Acids, diluted | Good | Good | Fair | Poor |
| Acetone | Good | Poor | Good | Poor |
| Alcohols | Fair | Good | Good | - |
| Benzene | Poor | Fair | Poor | Good |
| Chloroform | Poor | Good | Fair | Good |
| Dioxane | Fair | Good | Poor | Poor |
| Ethyl Acetate | Good | Excellent | Fair | Poor |
| Ethyl Alcohol | Excellent | Good | Fair | - |
| Halogenated Hydrocarbons | Poor | Excellent | Poor | - |
| Hexane | Poor | Good | Poor | - |
| Ketones | Excellent | Fair | Good | - |
| Methanol | Good | Excellent | Good | Poor |
| Pentane | Poor | Good | Poor | - |
| Sulphuric Acid | Fair | Good | Poor | Good |
| Surfactants | Excellent | Excellent | Fair | - |
| Toluene | Fair | Good | Poor | Excellent |
| Water | Excellent | Excellent | Good | Good |
Interested in our products? Contact us here to be connected to our sales team.