What should I pay attention to during the use of the pass box?

There are the following precautions in the use of a pass box:
1. Operation specifications
Follow the correct order of opening doors
The interlocking device of the pass box is the key to preventing cross-contamination, and the principle that both sides of the door cannot be opened at the same time must be strictly observed. First, put the items into the side of the pass box, close the side door, and then open the other side door to take out the items. For example, in a clean room for drug production, if the doors on both sides of the pass box are opened at the same time, dust, microorganisms, and other pollutants in the low-cleanliness area will directly enter the high-cleanliness area and pollute the drug.
Control how items are placed.
When placing items, care should be taken to avoid obstructing the airflow passage inside the transfer window. For large or irregularly shaped items, a reasonable placement should be arranged. For example, when transferring a large circuit board in the electronics workshop, the circuit board should be placed flat in the transfer window to ensure that the airflow can flow smoothly through the surface, and play the role of purification and isolation. At the same time, do not place too many items in the transfer window, so as not to affect the air circulation and purification effect.
Attention transfer time
The time the item stays in the transfer window should be as short as possible, but it should also be ensured that there is enough time for purification (for the pass box with the purification function). In industries such as semiconductor manufacturing, where cleanliness is highly required, long residence times increase the risk of contamination of items. For example, when the silicon wafer waits to be transferred to the next process area in the pass box if it stays too long, it may adsorb particles in the air, affecting the chip quality.
Second, clean room process cooperation
Conforms to clean room workflow
The use of a pass box is closely integrated with the workflow of the entire clean room. Before entering the clean room, staff should be familiar with the routes and requirements for the transfer of goods between different areas. In the food processing clean workshop, when transferring ingredients from the raw material treatment area to the processing area, it must be operated through the corresponding pass box by the specified transmission route, otherwise, it may destroy the clean layout of the entire workshop.
Comply with different area cleanliness requirements.
When using pass boxes, staff in different clean areas should strictly follow the clean operation procedures of their respective areas. In biopharmaceutical sterile production areas, workers may need to perform additional cleaning steps such as hand disinfection before opening the delivery window to pick up items to prevent the introduction of external contaminants into the sterile area.
3. Special attention points for special types of transfer Windows
Laminar flow pass box
Pay attention to the direction and speed of the airflow: After opening the laminar flow pass box, wait for some time for the laminar flow to stabilize before placing the items, and the items should be placed along the direction of the laminar flow. At the same time, the wind speed of the laminar flow pass box has a specified range, for example, in the aseptic transfer of biopharmaceutical, the wind speed usually needs to be maintained at a certain level, too low to effectively remove the surface pollutants of the item, too high may cause the item to shift or even damage.
Prevent airflow interference: During use, avoid external factors that interfere with laminar airflow, such as not placing large ventilation devices near the pass box or blocking vents. In high-precision electronic chip manufacturing workshops, any interference with laminar flow may affect the cleanliness of the chip.
Air shower pass box
Ensure that the air shower is complete: After placing the item, ensure that the air shower process is complete. Shower time can be set according to the item and cleanliness requirements. In the precision optical instrument manufacturing workshop, for high-precision lens transfer, it may take a long air shower time to completely remove the tiny dust on the lens surface.
Pay attention to internal cleaning: the inside of the air shower transfer window will accumulate a lot of pollutants that are blown off during the air shower process, and it should be cleaned regularly, otherwise, it may pollute the transfer items again.
Vacuum pass box
Control the vacuum process: The process of vacuuming and restoring normal pressure is carried out in strict accordance with the operating procedures. For some pressure-sensitive items, such as fragile biological samples or special chemical materials, it is necessary to control the speed and degree of vacuuming to avoid damage to the items.
Check the sealing performance: After the transfer is completed, check the sealing performance of the vacuum pass box to ensure that there is no air leakage. Because leakage may cause outside air to enter, affecting the effect of the next delivery.