To meet the corresponding cleanliness level in a clean room in addition to the design, purification, air conditioning and other equipment, the use of clean room doors with good air tightness is also a key point. So, what kind of clean door can have better air tightness? What are the details that can guarantee the air-tightness of the door for a longer validity period?
Where does air tightness come from? To check whether the doors and windows have good air tightness, we can just look at where the door leaks. The joint must be the easiest to pass through air, so we mainly pay attention to the following five points:
Combination between door frame and door leaf: Check whether there is sealant strip at the joint between the door leaf and the door frame.
Combination of door leaf and ground
Compared to the combination of door leaf and door frame, it is much more difficult to ensure the air tightness between the door leaf and the ground. Currently, the mainstream solution for airtight doors is to increase the air tightness by adding automatically drop-down seal. Only by selecting a lifting broom strip at the bottom of the door leaf can the air tightness of the clean room door be ensured. The automatic strip is actually a sealant strip with a built-in structure. There are sensitive sensing devices on both sides of the sweeping strip, which can quickly identify the opening and closing status of the door body. Once the door body begins to close, the lifting broom bar will pop out smoothly, and the sealant bar firmly adheres to the ground, effectively preventing the inward and outward flow of air at the bottom of the door leaf. The sealant strip needs to be stuck in a slot, and the entire process of ejecting the sweeping strip is smooth. The corresponding structure and elastic material are qualified to ensure durability.
(3) Material for sealant strip
EPDM adhesive tape is different from ordinary adhesive tape. Clean room doors use high-density and highly elastic adhesive tape, usually EPDM adhesive tape. Silicone adhesive tape is also used in the pursuit of high-quality effects. This kind of adhesive strip has great elasticity and high anti-aging degree. It has good shrinkage and rebound effect when the door is opened and closed. Especially when the door is closed, the adhesive strip can rebound quickly after being squeezed, fill the gap between the door leaf and the door frame, and greatly reduce the probability of air circulation. EPDM adhesive strips are often used on broken bridge windows and car doors with high noise insulation requirements. The typical effective service life can be up to 15 years. For purification doors that use inferior quality sealant strips, air tightness may only be guaranteed 2 or 3 years after the door is installed, and the sealant strips can easily lose their air tightness due to aging.
5) The air-tightness of installing clean room doors is also closely related to the installation process. Before installing an airtight door, it is important to ensure that the sandwich panel wall is vertical and that the door body and wall are at the same horizontal line during installation, making the entire door structure flat and reasonable, ensuring that the gaps around the door leaf are controlled within a reasonable range, and maximizing the sealing effect of the adhesive strip.