Features & Benefits

Molded Thermogreen LB-2 GC Septa

Molded Thermogreen LB-2 GC septa are manufactured from high quality, low bleed material using the same exclusive rubber formulation as the popular Thermogreen LB-2 septa. Therefore, they exhibit the same traits. Conditioned and ready to use, they offer extremely low bleed over a wide range of inlet temperatures (100 °C to 350 °C). The difference is that molded septa, unlike traditional die cut septa, offer easier installation and also provide a better seal inside the injection port. The reason for this can be seen in Figure 1. With a die cutting process, cupped and/or distorted septa can result when the cutting surface becomes dull. With a liquid injection molding process, every septum conforms to the same mold shape with crisp, clean sides. Additionally, the liquid injection molding procedure used to manufacture our molded Thermogreen LB-2 septa results in septa with ultra low bleed. The complete list of features/benefits of molded Thermogreen LB-2 septa include:

• Rubber formulation exclusive to Supelco
• Strict tolerances (diameter, thickness) due to the constant dimensions of the mold itself, resulting in easier installation and better sealing
• Ultra low bleed over a wide range of inlet temperatures (100 °C to 350 °C)
• No foreign substances or powders (which could contaminate the inlet) are used during manufacturing
• Fully tested for bleed and contamination
• Already conditioned, ready to use
• Ideal for use with low bleed GC-MS columns
• Version without injection hole designed for customers who do not use autosamplers

Figure 1. Comparison of Molded and Die Cut Septa

Molded    septum	Die cut septum

Molded Thermogreen LB-2 GC Septa With Injection Hole

A liquid injection molding process allows injection holes to be incorporated into the septa. An injection hole allows needle penetration through the same location, time after time. This helps reduce septum coring, and prevents septum fragments from entering the injection port. The high puncture tolerance makes these septa ideal for autosamplers as well as users of solid phase microextraction (SPME). Figure 2 shows examples of our molded septa with and without injection holes. Molded Thermogreen LB-2 septa, with injection hole, have the same features/benefits as the version without an injection hole. In addition they offer:

• A dimpled center that guides the needle through the septa, resulting in minimal coring
• Easier needle penetration and high puncture tolerance (ideal for autosamplers)
• Strict tolerances of injection hole (centering, size, and depth) resulting in long life
• Version with injection hole designed for customers who use autosamplers and/or SPME

Figure 2. Molded Thermogreen LB-2 GC Septa, Without and With Injection Hole