1. Introduction to Pass Box Concept

The pass box, as an auxiliary device in clean rooms, is mainly used for the transfer of small items between clean and non-clean areas to reduce the number of times the clean room door is opened and minimize contamination in the clean area. Pass boxes are widely used in industries such as microtechnology, biological laboratories, pharmaceutical factories, hospitals, food processing, LCD, electronics, and any other place requiring air purification. Pass boxes are made of stainless steel plates, smooth and flat. The double doors are interlocked to prevent cross-contamination, equipped with electronic or mechanical interlocking devices, and UV germicidal lamps.

2. Classification of Pass Boxes

Pass boxes are divided into three categories: 1. Electronic interlock pass box 2. Mechanical interlock pass box 3. Self-cleaning pass box. Pass boxes can be categorized as laminar flow pass boxes, regular pass boxes, and according to the actual requirements, various models of pass boxes can be produced. Pass boxes can be classified based on whether they have purification functions: regular pass boxes and laminar flow pass boxes.

Similarities and differences between regular pass boxes and laminar flow pass boxes:

A. Pass boxes and laminar flow pass boxes are mainly used for the transfer of small items between clean areas, clean areas, and non-clean areas to reduce the number of times the clean room door is opened and minimize cross-contamination between clean areas.

B. Pass boxes and laminar flow pass boxes can be classified based on different interlocking methods: electronic interlock pass boxes and mechanical interlock pass boxes. Pass box doors are interlocked, meaning only one door can be opened at a time.

C. Pass boxes and laminar flow pass boxes can be classified based on the material of the box: stainless steel pass boxes, external steel plate internal stainless steel pass boxes, etc. Commonly used materials for pass box production include cold-rolled steel plate (A3 plate) and stainless steel plate (SUS201, SUS304, SUS316, etc.) with a thickness of 0.8-1.5mm.

D. Laminar flow pass boxes have four air shower nozzles at the top, a fan, and a pre-high-efficiency filter inside the box, while regular pass boxes do not have this self-cleaning function configuration.

Optional accessories: intercom, germicidal lamp, and other related functional accessories.

Pass through box standard operating procedure

1. Purpose: To standardize the operation of the pass box  and ensure its normal use.

2. Scope: Applicable to the use of clean room pass boxs sop file

3. Responsibilities: Operators, workshop directors, and engineering equipment departments are responsible for the implementation of this procedure.

4. Contents:

4.1 Inspection and preparation work before starting the equipment

4.1.1 Check if the Pass-Through Chambers is intact;

4.1.2 Check if the pass box is within the cleaned range;

4.1.3 Check if the doors on both sides of the pass box  are tightly closed;

4.1.4 Turn on the power and check for any abnormalities in the ultraviolet lamp.

4.2 Operation

4.2.1 Turn on the main switch

4.2.2 Open one side of the door, place the cleaned items into the pass box , and close the door tightly.

4.2.3 Turn on the ultraviolet lamp switch (if available, this is an optional item). Objects entering the clean area from the non-clean area must be exposed to the ultraviolet lamp in the pass box  for no less than 30 minutes before entering; objects exiting from a higher clean level area do not require ultraviolet disinfection.

4.2.4 Notify the operator on the other side to open the pass box  door and retrieve the items.

4.2.5 Turn off the main power switch, open the window door, retrieve the items, close the window door, and record the ultraviolet lamp exposure time.

4.2.6 Clean the Pass-Through Chambers

4.3 Cleaning the pass box

4.3.1 Clean according to the "pass through box Cleaning and Disinfection Standard Operating Procedure" (sop-pws040).

4.4 Precautions

4.4.1 Clean with a clean cloth after each use.

4.4.2 Do not place flammable items in the pass box .

4.4.3 When using the pass through box , do not open both doors at the same time.

4.4.4 Do not overfill the pass box , and maintain a certain distance between each item.

4.4.5 Handle with care to avoid damage.

Characteristics of the pass box

1. The work surface of the short-distance pass box  is made of stainless steel plate, smooth, clean and wear-resistant.

2. The work surface of the long-distance pass box  uses non-powered rollers, making it easy and convenient to transfer items.

3. Both doors are equipped with mechanical interlock or electronic interlock, electronic touch lock device to ensure that both doors cannot be opened at the same time.

4. Customized non-standard sizes and floor-mounted pass box s can be made according to customer requirements.

5. The wind speed of the air outlet of the air nozzle can reach 20s or more.

6. Efficient filter with partition is used, with a filtration efficiency of 99.99%, ensuring purification level.

7. EVA sealing material is used for high sealing performance.

8. Can be paired with intercom.

Working principle of the pass box

1. Mechanical interlock device: Internally, a mechanical form is used to achieve interlocking. When one door is opened, the other door cannot be opened, and the other door must be closed before the other door can be opened.

2. Electronic interlock device: Internally, integrated circuits, electromagnetic locks, control panels, indicator lights, etc. are used to achieve interlocking. When one door is opened, the indicator light of the other door does not light up, indicating that the door cannot be opened. At the same time, the electromagnetic lock is activated to achieve interlocking. When the door is closed, the electromagnetic lock of the other door starts working, and the indicator light will light up, indicating that the other door can be opened.

Composition of the pass box

1. All stainless steel pass box

2. UV sterilization lamp

3. Buzzer

4. Intercom

5. Electronic interlock

6. Technical parameters of pass box s

Standard pass box

Name: Electronic interlock pass box ; mechanical interlock pass box

Specifications: PB-1 PB-2

Outer dimensions (L*W*Hmm) 785*600*690

Inner dimensions (L*W*Hmm) 600*600*600

Interlock method: Electronic interlock, mechanical interlock

Box material: High-quality cold-rolled steel plate, surface electrostatic spray treatment, matte white (customizable in various colors)

Inner wall material: Stainless steel plate

Air shower pass box : Clean air filtered by efficient filters can be sprayed onto the goods from all directions by rotating nozzles, effectively and quickly removing dust particles. The dust particles that have been removed are then filtered again by primary and high-efficiency filters before being recirculated back into the air shower area. In order to achieve the best blowing effect, the wind speed at the nozzle outlet can reach above 25m/s.

Name: Air shower room mechanical interlock pass box ; air shower room electronic interlock pass box

Specifications: PB-3 PB-6

Outer dimensions (L×W×H mm) 980×700×1800

Inner dimensions (L×W×H mm) 660×700×600

Wind speed: 25m/s or above

Number of nozzles: 4

Air shower cycle: 15s

Door interlock method: Mechanical interlock, electronic interlock

Box material: High-quality cold-rolled steel plate, surface electrostatic spray treatment, matte white (customizable in various colors)

Inner wall material: Stainless steel plate

Power supply: 380V 50Hz three-phase

Power: 0.75KW

7. Installation Method

Choose a convenient location on the wall, then drill a hole. The hole is generally about 10mm larger than the outer diameter of the pass-through window. Place the pass-through window into the wall, usually installing it in the middle of the wall, keeping it balanced and secure. Use rounded corners or other decorative strips to decorate the gap between the pass-through window and the wall, seal it with glue, and decorate it.

8. Operating Procedures

8.1 Turn on the main switch.

8.2 Open one side of the door, place the items that have been removed from the packaging and cleaned into the pass-through window, and close the door tightly.

8.3 Turn on the ultraviolet lamp switch. Objects transferred from a non-clean area to a clean area must be exposed to the ultraviolet lamp in the pass-through window for at least 30 minutes before being transferred; objects transferred from a higher clean level area do not require ultraviolet disinfection.

8.4 Notify the operator on the other side to open the pass-through window door and remove the items.

8.5 Turn off the main power switch, open the Pass-Through Chambers

door, remove the items, close the window door, and record the time of ultraviolet lamp exposure.

8.6 Clean the pass-through box.