Pass-through Box

Pass-through boxes are a kind of auxiliary equipment of the clean room, which is mainly used for the transfer of small items between the clean area and the clean area, and between the clean area and the non-clean area, so as to reduce the number of opening times and the pollution.

Materials and components：

Pass-through boxes production commonly used plates are cold rolled steel plate (A3 plate) and stainless steel (SUS201, SUS304, SUS316, etc.). Their difference is: A3 steel plate processing performance is good, but easy to rust, hardness is not strong. Heat treatment is needed for hardness. SUS (steel use stainless) series stainless steel toughness is great, but the mechanical processing is difficult. The corrosion resistance of SUS201, SUS304 and SUS316 is enhanced successively.

The pass-through box consists of a left box, a right box (interlocking device is installed in the box), an upper box, a lower box, an inner wall, a UV sterilizing lamp and a double door structure. Other optional accessories are buzzer, intercom, differential pressure meter, etc.

Installation:

It is necessary to select a convenient position on the wall first, and then open the hole, the hole should be about 10mm larger than the outside diameter of the pass box. After opening the hole, put the box into the wall, which is generally installed in the middle of the wall. After the balance is fixed, the gap between the box and the wall is decorated with rounded corners or other decorative strips, and then sealed with glue.

Classification:

* Based on the interlocking ways, pass-through box can be divided into electronic pass-through box and mechanical interlocking pass-through box.

1. electronic pass-through box

The internal of the electronic interlock pass-through box adopts integrated circuit, electromagnetic lock, control panel, indicator light and so on to realize interlock. When one door is opened, the open indicator light of the other door is not bright, which tells that the door cannot be opened. At the same time, the electromagnetic lock action realizes interlock. When the door is closed, the electromagnetic lock on the other door starts to work and light, indicating that the other door can be opened.

2. mechanical interlocking pass-through box

The interior of the box uses a mechanical form to realize the interlock. When one door is opened, another door cannot be opened, and another door can be opened after the other door is closed.

* Based on the working principle, pass-through box can be divided into air shower pass-through box, laminar flow pass-through box and ordinary pass-through box.

1. air shower pass-through box

Air shower pass-through box prevent dust and microorganisms from sticking to the box by setting high-pressure air nozzles around the box to blow high-speed air toward its surface. This method can effectively keep the cleanliness of the cabinet, but also can prevent cross-contamination between the clean room and the outside, but requires a lot of energy consumption. The highest degree of cleanliness can reach ISO6.

2. laminar flow pass-through box

The laminar pass box is mainly used for the transfer of goods between clean area and clean area or between clean area and unclean area (mainly used in biopharmaceutical industry). Its principle is to eliminate the dust brought into the pass box during the placing of products after opening the door by laminar self-purification. The filters of laminar flow box usually use high efficiency filters, which can effectively filter out particles larger than 0.3 micron, while also filtering out microorganisms such as bacteria and viruses in the air. To ensure continuous filtering effect, the filter needs to be replaced regularly. Its wind speed is generally 0.3-0.8 m/s. Through the form of laminar flow filtration, an ISO5 purification environment is formed inside the box, so that there will be less pollution after opening the door in the clean area. In the process of laminar self-cleaning, the door lock of the transfer box is often controlled by the timing relay. If the self-cleaning time is not reached, the door cannot be opened. The laminar pass box should reach the lowest level of ISO6, and the highest level of ISO5 or even ISO4.

3. ordinary pass-through box

Ordinary pass box is a simple cabinet without any special device. It is not effective in preventing cross-contamination between clean rooms and outside, nor can it keep the cleanliness of pass boxes, so it is rarely used in the occasions where high cleanliness is required.