RO Membrane Adhesive and Glue Data Sheet
This RO membrane adhesive and glue data sheet covers the two adhesives used in element production — polyurethane glue for membrane rolling and epoxy resin for the industrial fibreglass overwrap.
- PU glueMembrane rolling
- Epoxy resinIndustrial overwrap
- FormTwo-part
- MixingStatic mixer
Two Adhesives, Two Jobs
Element production uses two different adhesives. Polyurethane (PU) glue seals the three glued edges of every membrane envelope as the element is rolled — it is what makes the element hold a vacuum. Epoxy resin is used for the fibreglass overwrap that forms the hard outer shell of industrial elements; household elements use a tape overwrap instead and need no epoxy.
Both are two-part systems mixed at the point of use, usually through a static mixer tube. Estimate quantities with the glue consumption calculator, and keep glue behaviour in your QC checklist.
Adhesive Specifications: PU vs Epoxy
Typical specifications for the two adhesives. Exact values depend on the product grade and are confirmed per order.
| Property | Polyurethane (PU) | Epoxy Resin |
|---|---|---|
| Main use | Membrane rolling / glue lines | Industrial fibreglass overwrap |
| System | Two-part (resin + hardener) | Two-part (resin + hardener) |
| Mix ratio | [Confirm per product] | [Confirm per product] |
| Pot life / working time | [Confirm] — match to line speed | [Confirm] |
| Cure time | [Confirm per temperature] | [Confirm per temperature] |
| Viscosity | [Confirm] | [Confirm] |
| Used on | All elements | Industrial elements (4040, 8040) |
| Storage | Cool, dry, sealed; within shelf life | Cool, dry, sealed; within shelf life |
Get the Mix and Timing Right
Adhesive performance is mostly about discipline: the correct mix ratio, fresh material within pot life, and a cure that fits your line speed. Mix through a static mixer tube for a consistent ratio, and never push past pot life — partly cured glue gives weak, leaky seals.
Because gluing problems surface downstream as failed leak tests and rolling defects, glue control is one of the highest-leverage steps in production.
Glue discipline
- Exact mix ratio, every batch
- Use a static mixer tube
- Never exceed pot life
- Match cure time to line speed
- Store sealed; respect shelf life
Glue Decides Whether the Element Holds
A spiral-wound element only holds a vacuum if its glue lines are complete and fully cured. Glue is where most leak failures begin.
Starved Glue Lines
Too little glue or a poor bead leaves gaps that fail the vacuum leak test.
Past Pot Life
Glue used after pot life cures weakly, so seals fail under pressure.
Wrong Mix Ratio
An off-ratio mix cures slowly or incompletely and undermines reliability.
Need PU glue or epoxy resin for production?
Tell us your element types and line speed — we’ll recommend the right adhesives and supply them with matched pot life and cure.
Adhesive & Glue FAQ
What glue is used to make RO membrane elements?
Two adhesives are used: polyurethane (PU) glue seals the glue lines when rolling the membrane, and epoxy resin is used for the fibreglass overwrap on industrial elements. Both are two-part systems mixed at the point of use.
What is the difference between PU glue and epoxy resin here?
PU glue forms the internal seals that let the element hold a vacuum, so it is used on every element. Epoxy resin forms the hard fibreglass outer shell on industrial elements only — household elements use a tape overwrap and no epoxy.
Why does pot life matter for RO membrane glue?
Once mixed, two-part glue starts to cure and only stays usable for its pot life. Applying it after pot life gives weak, partially cured seals that fail the leak test, so fresh glue and a static mixer are essential.
How much glue does an element need?
PU glue scales with membrane area (around 30 g/m²), and industrial elements add epoxy for the overwrap. Use the glue consumption calculator to estimate both per element and per batch.