By [email protected] — Charting the depths of expertise
Industry Definition of Cleanroom Wipe Classes
What is a Class 100 or Class 1000 cleanroom wipe? Although there is no universally recognized standard for classifying cleanroom wipes, the standards for cleanroom classifications are well-defined (the class relates to the number of airborne particles; the fewer particles, the higher the class). Since cleanroom wipes are used in cleanroom environments, they must not become a source of contamination by releasing a significant number of particles. This performance is directly related to the wipe's APC (Airborne Particle Count). Therefore, most manufacturers use APC as the basis for defining wipe classes, specifically by measuring APC data with the Helmke Drum test: if the test result shows ≤100 particles of ≥0.5μm in size, it can be called a Class 100 cleanroom wipe.
The table below is a reference for cleanroom wipe classifications. The values other than APC are for reference only and may not be completely accurate:
| Class | Wet Particle Release (LPC) ≥ 0.5 µm | Dry Particle Release (APC) ≥ 0.5 µm | Ion Content (IC) | NVR (IPA Extraction) |
|---|---|---|---|---|
| Class 10 | ≤1200 particles/cm² | ≤ 10 particles/ft³ | ≤1.0 µg/g | ≤0.5 mg/g |
| Class 100 | ≤3000 particles/cm² | ≤ 100 particles/ft³ | ≤2.0 µg/g | ≤0.8 mg/g |
| Class 1000 | ≤6000 particles/cm² | ≤ 1000 particles/ft³ | ≤3.0 µg/g | ≤1.0 mg/g |
Introduction to the Helmke Drum Test
The Helmke Drum test is the method recommended in the IEST-RP-CC004.4 standard for testing the APC performance of cleanroom wipes.
The test method involves placing a 9-inch cleanroom wipe inside a slowly rotating stainless steel drum. The drum has an internal volume of 1 cubic foot, rotates at 10 rpm, and has an air flow of 28.3 L/min. The rotation of the drum simulates the friction and flexing during use, causing particles from the surface to be released and suspended in the air inside. A laser particle counter then draws an air sample from inside the drum through an isokinetic probe and measures the number of particles of a specific size (typically ≥0.3μm or ≥0.5μm) in real-time. By continuously monitoring over a preset time (10 minutes or 1 minute), the number of particles released per minute is calculated, serving as a quantitative measure of its cleanliness performance.
China Class 100 / Class 1000 Cleanroom Wipe Manufacturer
PICOWIPE has over 20 years of experience producing Class 100 and Class 1000 cleanroom wipes. It has its own testing laboratory and can provide APC test data for each batch of cleanroom wipes upon request.
