Filtration grades
30 gsm meltblown: higher efficiency, higher pressure drop
30 gsm meltblown trades airflow for capture. It is used as a pre-filter ahead of a HEPA stage, and for absorption where capacity matters more than speed.
At a glance
Specification at a glance
| Property | 30 gsm typical range | Note |
|---|---|---|
| Fibre diameter | 1 to 2 µm | Finer than 25 gsm |
| Filtration efficiency | 90 to 97 % at 0.3 µm | Uncharged, NaCl |
| Pressure drop | 45 to 70 Pa | Higher than 25 gsm |
| Tensile MD | 12 to 18 N/5 cm | Still needs support |
| Absorbency | 10 to 15 g/g | Oil and glycol |
| Pleatability | Good with a scrim | Needs support for deep pleats |
Pre-filter economics
A pre-filter exists to protect an expensive final stage. At 30 gsm the web captures the coarse load at a pressure drop the fan can afford, which extends the HEPA stage life. Going finer on the pre-filter protects better and costs airflow, so the choice is made on the fan curve, not on efficiency alone.
Absorption and retention
For industrial spills the web is judged on how much it holds and how much it gives back under load. Retention, not absorbency, decides whether the floor is actually dry after the wipe-up.
Converting notes
Deep pleats need a scrim or a spunbond backing, because the web creeps under pleating tension. Shallow pleats can run unsupported if the pleater is set gently.
Other weights in this range
This grade sits in the Meltblown range. Buyers comparing across weights usually ask for two or three of these at sample stage, because the decision is made on the converting line rather than on the data sheet.
- 20 gsm meltblown - 20 gsm meltblown is the light filtration layer: enough fibre density to catch .
- 25 gsm meltblown - The middle layer of a three-ply medical mask is meltblown, usually 25 gsm, and.
Check the grade against your line
Send the application, the width and the monthly volume. We reply with the tolerance, the batch test values and a ship date.
Questions
Common questions
Is 30 gsm meltblown a HEPA filter?
No. It is a pre-filter layer. HEPA grades need higher efficiency and a different structure.
Why is pressure drop higher than at 25 gsm?
Finer fibre and more fibre per unit area. That is the trade for higher efficiency.
Can it be pleated alone?
Shallow pleats can run alone. Deep pleats need a scrim or a spunbond backing to stop creep.