RO Membrane Manufacturing Terms Glossary
A plain-English glossary of the materials, components, processes and tests used to make spiral-wound RO membrane elements — each term links to a full resource.
Raw Materials
The thin-film composite (TFC) sheet that performs the salt rejection — the functional core of the element.
Membrane specifications →Diamond-mesh netting in the feed channel that keeps the flow path open and sets feed-side pressure drop.
Feed spacer data sheet →Grooved tricot fabric inside the membrane envelope that carries product water to the central tube.
What is a permeate carrier →The perforated core the element is wound around; collects permeate and channels it out the end.
What is the central tube →EPDM lip seal that forces feed water through the element instead of bypassing it in the vessel.
Why a brine seal →PU glue seals the membrane glue lines; epoxy resin forms the industrial fibreglass overwrap.
Adhesive data sheet →Outer-wrap (bonding) tape and central-tube tape that hold and protect the finished element.
Tape data sheet →Anti-telescoping end cap fitted to each end of an industrial element to brace it under pressure.
What is an ATD cap →Element Anatomy
The standard RO element format: membrane envelopes and spacers wound around a central tube.
Element size reference →One membrane envelope — two membrane faces sealed around a permeate carrier. An element has several leaves.
Sheet usage calculator →The membrane area that actually produces water (e.g. ~7.9 m² for a 4040), excluding glue lines.
Estimate sheet usage →Model number = nominal diameter (inches) + length (inches). 4040 = 4.0″ × 40″.
Size reference chart →Production Process
Winding the membrane leaves and feed spacer around the central tube at controlled tension.
Rolling machine guide →The finished outer diameter of the wound element, set by leaf count, thicknesses and tension.
Roll diameter calculator →A defect where pressure pushes the wound layers forward into a cone — prevented by the ATD cap.
Common rolling defects →The standard 8-stage sequence from material prep through testing and packaging.
Workflow template →Equipment
The core machine that winds the element — manual, semi-automatic or fully automatic.
How to choose one →The automation level of the production line — a key cost and output decision.
Semi vs fully automatic →Machines that verify element integrity and performance — vacuum, salt rejection and flow.
Testing equipment guide →How many elements a line can produce per hour, shift, day or month at real efficiency.
Capacity calculator →Quality & Testing
A non-destructive integrity test — the element should hold a vacuum without decay.
Leak testing guide →The percentage of dissolved salts the membrane removes — a core performance measure.
Salt rejection & flow test →Checking surface, ends and wrap for defects before and after final testing.
Visual inspection reference →The stage-by-stage quality-control checklist from incoming materials to final test and records.
QC checklist →New to RO membrane production?
Whatever stage you are at, our engineers can help you choose materials and equipment. Tell us what you are building.