Crimp closure, N 20, alu., center hole, Butyl dark gray/PTFE gray, 3.0 mm
*taxes and shipping not included
Delivery time approx. 5 working days
Quantity | Price/unit |
---|---|
To 9 | $71.50 |
From 10 | $60.90 |
From 50 | $54.90 |
These closures with molded Butyl/PTFE septa are only laminated with PTFE in the contact area with the sample. Thus the elastomeric Butyl can achieve on the vial's glass rims a very tight seal, while in comparison a completely PTFE covered septum would have a very slippery surface on the glass and could easily be twisted around.
Closure type | Crimp closure |
Nominal diameter | N 20 |
Assembling process | Assembled |
Cap material | Aluminum |
Cap color | Silver |
Cap hole | Yes |
Closure magnetic | No |
Septa material | Butyl/PTFE, Butyl/PTFE (Pharma-Fix) |
Colors of septa material | Dark gray/gray |
Septa thickness | 3.0 mm / 118,1 mil |
Septa hardness | 50° shore A |
Additional closure features | Molded septum, only centrically laminated with PTFE, typically called Pharma-Fix, excellent sealing, temp. resistant from -40 °C up to 120 °C |
Recommended application(s) | Headspace |
Autosampler compatibility | Agilent, PerkinElmer, Varian CP-9020/9025 / CP-9060 / Genesis |
Storage temperature | 15–25 °C / 59–77 °F |
Scope of delivery | 100x N 20 ready assembled crimp closures |
Gross weight (incl. packaging) | 176 g / 0.39 lbs |
Packaging dimensions | 220 x 150 x 15 mm / 8.66 x 5.91 x 0.59 Inch |
Hazardous material | No |
Extremely tight sealing and excellent analytical purity are of great importance, especially in the headspace area, since high temperatures are often used here causing high internal vial pressure. Since completely PTFE-coated liners have a very slippery surface on the glass rims, the sealing properties can be improved significantly by a PTFE lamination that is only applied centrically in the contact area with the sample.
With these so-called Pharma-Fix septa, the uncoated, elastomeric liner rim is on the vial’s glass crimp neck. As a molded septum, the side edges of these liners are designed lamellar so that they can be well compressed during the crimping process and be firmly pressed onto the glass rim. This creates a kind of suction between the elastomeric material and the edge of the glass, which creates an extremely good and firm seal.
Until now, such special liners were only available as a butyl / PTFE version, which, however, could only be used in a temperature range of -40 °C and 120 °C. Furthermore, butyl is more difficult to penetrate than the much softer silicone and its analytical purity is not as high.
MACHEREY-NAGEL offers two Butyl/PTFE versions in a center hole cap (70234, 70234.10) of which the latter one has a slightly better analytical purity.
Pharma-Fix closures with only centrical PTFE lamination
In addition our delivery program includes a center hole closure with a Silicone/PTFE Pharma-Fix liner (702340), which is characterized by high analytical purity and temperature resistance (-60 °C up to 200 °C) as well as good penetration and excellent sealing properties. The liner is made from the same, well-known blue transparent silicone compound we also use for our completely PTFE laminated closures.