Material tests with Systec autoclaves
Systec autoclaves for a wide range of applications
In addition to standard sterilization applications, Systec laboratory autoclaves are used in a wide range of other applications. Beyond the common procedures of the European pharmacopoeia, e.g. the Glass Test (for determining the hydrolytic resistance of pharmaceutical glass ware) and the Rubber Closure Test, these applications include a variety of special applications, such as material tests and the simulation of environmental conditions. In more detail, these special applications include processes for the simulation of ageing phenomena and moisture resistance. Examples given are the Pressure Cooker Test according to DIN EN 60749-33 and the HAST Test (highly accelerated stress test) according to DIN EN 60068-2-66.
The Glass Test is a test method that examines the hydrolytic resistance of the inner surface of glass containers and eventually classifies them. This is done by determining the amount of sodium and other alkaline earth metals or oxides of alkaline earth that are released from the filled glassware by hydrolysis during treatment with moist heat. The analysis is performed either by titration or by spectrophotometry of the liquid inside the glassware, while the upstream sterilisation process of the two analytical methods is the same. In the autoclave, a special ramp program is used to run various temperature ranges at specific time intervals, whilst the narrow limits of the pharmacopoeia must be complied with.
Similar to the aforementioned Glass Test, the Rubber Closure Test is used to examine the chemical resistance of the tested material. In this test, rubber stoppers and caps of pharmaceutical vessels are first placed in suitable glass flasks. In the following, the glass flasks are filled with a prescribed amount of deionised water and are subjected to the sterilization process inside the autoclave. As with the Glass Test, narrow process limits are prescribed by the European pharmacopoeia for the compliance of the respective process steps. Particularly high demands are made on the cooling options of the autoclave because it must cool the samples from 121°C to 25°C within 30 minutes. Finally, the water is analysed using various methods, and the examined rubber stoppers or caps are categorised.
Pressure Cooker Test: In this process, semiconductor components are tested for moisture resistance using saturated steam in a pressurised atmosphere. This destructive method is used to simulate a highly accelerated test load. Pressure, humidity and temperature in the autoclave are applied in such a way that failures inside the component housing are being revealed in an accelerated manner. The test is also used by some of our customers to simulate the ageing of magnets. In accordance with DIN EN 60749-33, the test load in the autoclave is normally carried out over 96 h at hot pressure storage at 100% rel. humidity at 121 ± 2°C and 202 kPa.