Capsule Filter Sterilization method and precautions

2023-02-28 Admin The shell of the Capsule Filter is made of polypropylene (PP), which can not be sterilized online due to the limitation of pressure and heat resistance. High-pressure steam sterilization is the most commonly used sterilization method, so how to ensure a good and effective sterilization process? Next, we will describe the operation steps and precautions of high-pressure steam sterilization of bag filter for your reference.

High-pressure steam sterilization refers to the method of using saturated steam with pressure greater than normal pressure to kill microorganisms in a closed high-pressure steam sterilization kettle. High temperature and high pressure sterilization can not only kill ordinary bacteria, fungi and other microorganisms, but also kill spores and spores. It is the most reliable and widely used physical sterilization method. It is mainly used for sterilization of high-temperature resistant articles, such as culture media, metal instruments, glass, enamel, dressing, rubber and some drugs. There are many types and styles of high-pressure steam sterilizers, such as: ① The down-exhaust pressure steam sterilizer is a widely used sterilization equipment. The pressure rises to 103.4 kPa (1.05 kg/cm2), the temperature reaches 121.3 ° C, and it can be maintained for 15~30 minutes to achieve the sterilization purpose. ② Pulse vacuum pressure steam sterilizer has become the most advanced sterilization equipment. Requirements for sterilization conditions: the steam pressure is 205.8kPa (2.1kg/cm2), the temperature is above 132 ℃ and maintained for 10 minutes, and all microorganisms including spores and spores with strong resistance can be killed.

Dry or wet bag filters can be sterilized by this method, and the sterilization conditions should be the same as those of the filter sterilization validation. In order to ensure the integrity and sterility of the filter after sterilization, the sterilization process must adopt correct operation methods. Next, we will describe the operation steps and precautions of high-pressure steam sterilization of bag filter for your reference.

1、 Preparation before sterilization

A. Exhaust/drain valve and inlet and outlet: during the whole sterilization process, the bag filter valve and inlet and outlet must be kept fully open and unblocked to ensure good air circulation, steam infiltration and condensate discharge.

B. Sterility protection of the filter: in order to maintain the sterile state of the bag filter after sterilization, all openings of the filter must be wrapped with appropriate sterile materials. Select a porous and breathable high-pressure sterilization bag, put the whole filter in the sterilization bag for sealing, or use sterile non-woven cloth to wrap all openings of the filter. The package should not be too tight to ensure good air circulation and steam penetration during sterilization. If the air flow and steam penetration are not smooth during the sterilization process, the filter may be deformed due to excessive pressure difference during the heating or cooling stage of the sterilization kettle, or the sterilization effect may be affected.

C. Filter hose: select the hose with the largest inner diameter, and keep the hose open and unblocked. The hose connecting the filter should not be bent, folded or U-shaped. If the inlet and outlet of the filter are connected with hoses, it is forbidden to connect the two hoses to form a loop. The end of the hose can be wrapped with sterile non-woven fabric for sterile protection.

D. Clamp: currently, the commonly used TC clamp materials are plastic and stainless steel. It is recommended to use two-piece plastic clamp or three-piece stainless steel clamp for connection, which can not only ensure uniform stress, but also avoid the deformation of accessories caused by too tight clamp.

E. Stainless steel fittings: if the filter is connected with stainless steel fittings, do not make the filter, especially the exhaust/drain valve, bear the weight of these fittings. The high temperature conditions of sterilization will reduce the rigidity of the filter. When the filter bears the weight of unsupported stainless steel fittings, it may cause deformation and damage to the filter. Please provide independent support for these stainless steel accessories to eliminate the impact of their weight on the bag filter.

2、 Filter placement during sterilization

A. Direction of filter: in order to achieve better sterilization effect, the bag filter must be placed vertically and in the normal operation direction (liquid flow direction), with the filter outlet downward. Compared with horizontal or inverted placement, keeping the filter vertical and placed in the normal operation direction is more conducive to the discharge of condensate and heat transfer.

B. Filter placement: the filter can be installed on the process tank and put into the sterilization kettle for sterilization, or can be sterilized separately. If the process tank is connected, it is recommended not to connect additional hardware upstream of the filter to avoid deformation of the filter. If placed separately, please follow the above recommendations of "preparation before sterilization" and put it into the sterilization kettle for sterilization. The filter should always be vertical and the outlet should be downward during sterilization.

C. Sterilization cycle: too large pressure difference is easy to cause damage to the filter. It is recommended to select a reasonable and slow pulsating vacuum cycle procedure and refer to the supplier's recommended sterilization parameters.