Barrier grades
35 gsm SMS: the entry barrier structure
35 gsm SMS is the lightest barrier structure we quote: a 15 gsm meltblown core between two 10 gsm spunbond layers, giving liquid resistance without the weight of a coated fabric.
At a glance
Specification at a glance
| Property | 35 gsm SMS typical range | Note |
|---|---|---|
| Structure | S10 / M15 / S10 | Spunbond, meltblown, spunbond |
| Hydrostatic head | 60 to 90 mm | AATCC 127 |
| Air permeability | 60 to 110 l/m²/s | Breathable barrier |
| Tensile MD | 30 to 38 N/5 cm | Spunbond skins carry it |
| Tensile CD | 18 to 24 N/5 cm | Seam strength follows |
| Colour | White, blue, green | Masterbatch on request |
What the middle layer does
Each spunbond skin carries mechanical load and resists abrasion; the meltblown core blocks liquid. At 15 gsm the core is thick enough to stop a splash and thin enough to keep air moving, which is the definition of a breathable barrier.
Which barrier level it reaches
For gowns, 35 gsm SMS typically meets the lower barrier levels of the EN 13795 and AAMI classifications. It is a light duty structure: short procedures, visitor gowns, non-critical isolation. Critical and long procedures move to 45 gsm and above.
Seams decide the result
A barrier fabric is only as good as its seam. Ultrasonic welding keeps the barrier better than stitching, because a needle hole is a leak. If the product is sewn, the seam has to be taped or the barrier claim is overstated.
Other weights in this range
This grade sits in the SMS / SMMS 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.
- 45 gsm SMS - 45 gsm SMS balances barrier and breathability for surgical packs, drapes and l.
- 55 gsm SMS - 55 gsm SMS is the heavy end of the breathable barrier range: higher hydrostati.
Compare this structure with your current fabric
Send the barrier requirement, the weight you run now and the monthly volume. We reply with the structure, the test values and a ship date.
Questions
Common questions
Is 35 gsm SMS waterproof?
It resists splash, typically 60 to 90 mm hydrostatic head. It is not waterproof for immersion or sustained pressure.
Can it be sterilised?
Ethylene oxide is the usual method for SMS packs. Gamma degrades polypropylene and needs a dose study.
What is the difference from 45 gsm?
Higher hydrostatic head and better abrasion, roughly 30 to 40 percent more. The step changes the gown class, so it is a clinical decision.