RO Membrane Permeate Carrier Data Sheet
This permeate carrier data sheet covers the material, structure, thickness and dimensions of the tricot permeate carrier (permeate spacer) used inside spiral-wound RO membrane elements.
- MaterialPolyester tricot
- StructureWarp-knit
- Thickness7–12 mil
- WidthTo element size
What the Permeate Carrier Does
The permeate carrier — also called the permeate spacer or tricot — is a warp-knit polyester fabric sealed inside the membrane envelope. It gives permeate a low-resistance path to spiral inward to the central tube while supporting the membrane against collapse under pressure.
It is one of the two internal flow layers; see what a permeate carrier is and how it differs from the feed spacer. Use the values below as a production reference.
Permeate Carrier Specifications
Typical specifications for RO membrane permeate carrier. Exact values are confirmed per order.
| Property | Typical specification |
|---|---|
| Material | Polyester (PET) tricot knit |
| Structure | Warp-knit tricot with directional grooves |
| Treatment | Resin / epoxy-impregnated grades for stiffness (optional) |
| Thickness options | 7 mil (0.18 mm), 10 mil (0.25 mm), 12 mil (0.30 mm) |
| Groove direction | Channels run toward the central tube |
| Width | Cut to element leaf width (1812 to 8040) |
| Roll length | [Confirm per order] |
| Compatibility | Suitable for standard RO permeate conditions |
Choosing a Permeate Carrier
The permeate carrier must balance two demands: a low-resistance path for permeate and enough stiffness to support the membrane without intruding into it under pressure. Thickness, groove design and any resin treatment all affect this balance.
Match it to your membrane and operating pressure, then size the length with the permeate carrier length calculator. For the complete material set, see the raw material selection guide.
What to balance
- Low permeate-side resistance
- Enough stiffness to support membrane
- Groove direction toward central tube
- Compatibility with operating pressure
- Consistent thickness for clean rolling
The Permeate Carrier Quietly Caps Your Flow
It sits hidden inside the envelope, but the wrong permeate carrier limits product water and element life.
Low Permeate Flow
Too much flow resistance throttles product water on its way to the central tube.
Membrane Intrusion
Too soft a carrier lets the membrane press into the grooves under pressure, cutting flow.
Rolling Defects
Inconsistent thickness disturbs winding and finished element diameter.
Need permeate carrier for your element production?
Tell us your element sizes and membrane — we’ll recommend the right permeate carrier and supply it to spec.
Permeate Carrier FAQ
What is an RO membrane permeate carrier made of?
Permeate carriers are typically a warp-knit polyester (PET) tricot fabric, often resin or epoxy treated for stiffness. The grooved structure carries permeate to the central tube and supports the membrane under pressure.
How thick is a permeate carrier?
Typical permeate carrier thicknesses are 7 to 12 mil (0.18 to 0.30 mm). Permeate carriers are thinner and denser than feed spacers because they carry product water inside the membrane envelope, not feed water in the channel.
Is a permeate carrier the same as a permeate spacer or tricot?
Yes. Permeate carrier, permeate spacer and tricot all refer to the same component — the fabric inside the membrane envelope that carries permeate to the central tube.
How is the permeate carrier different from the feed spacer?
The permeate carrier sits inside the membrane envelope and carries product water, while the feed spacer sits in the feed channel and carries feed water. They are different materials with different thicknesses and are not interchangeable.