How to Differentiate Low-End Air Filters from High-Quality Air Filters! First, Understand the Process Technology:
For instance, in galvanized steel frame HEPA filters, a high-quality HEPA filter uses a 1.0mm thick, smooth galvanized plate for the frame. The sealant is made from environmentally friendly polyamine ester, which is odorless and does not yellow for over three years. These filters use superfine, waterproof HEPA filter paper. In contrast, low-end filters use a thinner, 0.6mm galvanized rippled plate, which is not environmentally friendly and cannot resist humidity. The sealant in these lower-quality filters is made from acidic castor oil, which yellows quickly. Additionally, the filter paper is not waterproof, significantly shortening the filter's lifespan. Even worse, in mini-pleat or deep-pleat air filters, the pleat heights and fold counts are often poorly constructed, resulting in very low air volume.
Most factories use EVA (Ethylene Vinyl Acetate) for sealing strips (gaskets). However, EVA gradually releases trace amounts of toxic gases while sealing, leading to secondary pollution in the environment. This is especially harmful in high-demand clean environments, such as pharmacies or operating rooms. How can this problem be solved? The new polyurethane foam seamless sealing technology ensures zero leakage in HEPA filter installations, thereby maintaining the cleanliness of dust-free workshops and preventing the release of harmful gases. This environmentally friendly material prevents secondary pollution, making it suitable for clean environments.
The Importance of Testing Methods and Technology:
The most important priority is the testing methods and technology! Every air filter must be tested individually before leaving the workshop.
HEPA/ULPA Air Filter Testing:
Testing is performed in Class 100 (M3.5) clean zones within a Class 10,000 (M5.5) clean room. All testing follows the controlled and documented procedures of an ISO 9008-2000 certified quality system. To enhance upstream sampling capability, leak-scanning systems are equipped with dilution equipment for measuring high particle concentrations. Probe geometry has been optimized to maximize the traverse rate and eliminate undetected leaks while maintaining isokinetic sampling. The entire surface of the filter is scanned with overlapping strokes, including the media-to-frame interface. As per customer requirements, Polystyrene Latex Spheres (PSL) and Emery 3004 are used as standard challenge aerosols.
Smoke Test:
Similar to the scanning test, leaks are located using a heterogeneous, highly concentrated oil mist. The filter is placed horizontally, and the oil mist is gently filtered through it. With a dark background and appropriate lighting, any leakage is confirmed visually. Wisps of smoke passing through holes in the filter are clearly visible.
Scanning Electron Microscope:
This tool allows for the study and identification of contaminants as small as 50 nm (0.00005 mm) found in used filters and air samples. The microscope serves as a problem-solving and quality control tool for our customers, as well as for evaluating new filter media.
Inspection Label:
Once approved, each filter receives an inspection label with its serial number, efficiency for MPPS particles, and pressure drop at the test flow rate.
Building a Filter Performance Database:
Another important aspect is developing our own database to track how filters perform in real-world conditions. Standards have thus far focused on finding fast, economical methods to classify filters.
On-Site Testing:
For on-site measurements, we use particle counters, pressure gauges, airflow meters, energy data loggers, corrosion monitors, and gas analysis equipment. Combined with our expertise, we can help troubleshoot and improve ventilation systems.