In high-precision fields such as semiconductors, biomedicine, and precision manufacturing, clean rooms are the core infrastructure to ensure product quality. The completion acceptance not only concerns the compliance of the project, but also directly affects the subsequent production efficiency and cost control of the enterprise. However, many companies, due to a lack of professional experience, neglect key details in the acceptance process, resulting in frequent rework or operational risks in the later stages. As Shenzhen Huajianjing Construction Engineering Co., Ltd. (referred to as Huajianjing), which has been deeply involved in the field of purification engineering for more than ten years, we have combined hundreds of project experiences to sort out the six most overlooked precautions in the acceptance stage, helping enterprises avoid potential risks.
1、 Air Purification System: Performance Verification Beyond Parameter Surface
The core of a clean room is the air purification system, but checking only basic parameters such as fan power and filter level during acceptance is far from enough. The Huajianjing technical team pointed out that the following details need to be verified:
1.Airflow organization simulation verification : Through smoke tests or particle counters, confirm whether the layout of the air supply and return ports forms unidirectional flow, avoiding local pollution caused by vortex areas. For example, in an electronics factory, a design defect in the return air duct resulted in the accumulation of 0.5 μ m particles behind the equipment, ultimately requiring a re adjustment of the air duct direction.
2.Pressure gradient control : A positive pressure difference of 5-10 Pa should be maintained between areas of different cleanliness levels to prevent cross contamination. Continuous monitoring for 24 hours is required during acceptance, and the range of pressure fluctuations should be recorded. Huajianjing once discovered that a certain pharmaceutical factory had a sudden drop in pressure difference from 15Pa to 8Pa due to the aging of the sealing strip of the airtight door, which directly affected the stability of the sterile environment.
3.Filter integrity testing : Use DOP (dioctyl phthalate) aerosol method to detect the leakage rate of HEPA filters, ensuring a rate of 0.01%. A certain chip factory found a decrease in product yield after three months of production due to the failure to conduct this test. The root cause was traced back to a 0.5mm gap in the filter frame.
2、 Enclosure Structure: Concealed Engineering; Microscope style; Check
The walls, floors, and ceilings of a cleanroom form a sealed barrier, but the following hidden issues are often overlooked:
1.Joint treatment process : The color steel plate joint needs to be sealed with silicone and protected with aluminum alloy profiles. Hua Jianjing discovered in a medical project that the construction party only used ordinary sealant, resulting in cracks appearing at the joints three months later, which needed to be completely removed and redone.
2.Wall penetrating pipeline sealing
Sex : When water and electricity pipelines pass through walls, special sealing sleeves and fireproof mud filling must be used. A certain food factory failed to carry out this treatment, resulting in an uncontrolled pressure difference between the sterilization area and the ordinary area, leading to a microbial contamination accident.
3.Ground anti-static performance : The surface resistance (10 ⁶ -10 ⁹Ω) of epoxy self leveling ground needs to be tested; ）A certain electronics factory suffered losses of over one million yuan due to excessive ground resistance, resulting in electrostatic breakdown of chips.
3、 Mechanical and Electrical Systems: Stability Test under Dynamic Operation
The electromechanical system of the purification project needs to simulate actual working conditions for acceptance:
1.Air conditioning unit linkage test : Run continuously for 72 hours and record the temperature and humidity fluctuation range. Hua Jianjing found in a laboratory project that the humidity control deviation of the unit during low load operation at night reached± 8%RH， Far beyond± Process requirements for 3% RH.
2.Emergency power switch : After a power outage, the UPS needs to complete the switch within 0.15 seconds. A data center experienced server downtime due to a delay in the switch, which taught a profound lesson.
3.Air tightness of drainage system : The floor drain needs to be designed with a liquid seal to prevent reverse odor. A certain pharmaceutical factory used ordinary floor drains, resulting in a threefold increase in the bacterial count in the clean area air.
4、 Process equipment matching: overlooked; The Last Mile;
The connection between purification engineering and process equipment often encounters the following problems:
1.Equipment exhaust interface matching : The exhaust volume of a certain coating machine is designed to be 5000m³ /h， But the reserved interface for the purification project is only 3000m; /h， Causing the concentration of volatile organic compounds (VOCs) in the workshop to exceed the standard.
2.Vibration isolation treatment
Precision equipment requires the installation of shock-absorbing pedestals. In a certain optical factory project, Huajianjing reduced the vibration value of the equipment from 0.5mm/s to 0.1mm/s by adding spring isolators, meeting the process requirements.
3.Static grounding network : All metal equipment needs to form equipotential connections. Due to excessive grounding resistance in a semiconductor factory, the lithography machine frequently reported errors.
5、 Documents and Training: The Hidden Threshold of Soft Power
The acceptance stage should focus on:
1.Complete technical documentation : including equipment list, maintenance manual, circuit diagram, etc. A certain enterprise is unable to claim compensation during the warranty period due to the lack of maintenance records for air conditioning units.
2.Operator Training : Provided by Huajianjing; Theory+Practice; Dual track training ensures that operation and maintenance personnel master key skills such as differential pressure adjustment and filter replacement.
3.Emergency plan drill : Simulate scenarios such as fires and power outages, and test the response speed of personnel. A certain pharmaceutical factory was unable to shut down the air supply system in a timely manner during a fire due to the lack of drills, resulting in the spread of the fire.
6、 Long term cost considerations: smart choices beyond initial investment
Excellent purification projects should consider both initial costs and full lifecycle costs:
1.Material Durability : A certain food factory chose ordinary color steel plates to save costs, but after three years, they were replaced due to corrosion, resulting in a total cost 2.3 times that of using 316 stainless steel.
2.Energy Efficiency Optimization : Huajianjing adopts a variable frequency fan+heat recovery system, which reduces the energy consumption of air conditioning in a certain electronic factory by 35% and saves over 500000 yuan in electricity bills annually.
3.Scalability Design : Reserve device interfaces and increase modular space. Through this design, a biopharmaceutical company has shortened the second phase expansion cycle by 40%.
The acceptance of clean rooms is a systematic project that requires comprehensive evaluation from multiple dimensions such as technical parameters, construction processes, and operation and maintenance management. Huajianjing suggests that companies should choose purification engineering companies with GMP certification qualifications; Establish an acceptance team composed of process, equipment, and quality personnel; Use third-party testing agencies for key indicator review. Only by changing the acceptance criteria from '; Compliant with specifications; Upgrade to“ Satisfy the process; Only by doing so can we truly maximize the value of clean workshops.
As a national high-tech enterprise, Huajianjing has always adhered to the principle of; Technology Purifies the Future; To fulfill our mission, we provide customers with a full lifecycle solution from design, construction to operation and maintenance through innovative technologies such as BIM positive design and intelligent operation and maintenance platforms. We are well aware that every 0.1 μ m particle control and precise adjustment of pressure difference are related to the core competitiveness of our customers' products. Choosing Huajianjing means choosing a trustworthy commitment to cleanliness.
