Also known as: Irradiation Cross-Linked Polyethylene Foam, IXPE, Electron-beam cross-linked PE foam
IXPE foam is polyethylene foam cross-linked by electron-beam irradiation rather than by a chemical agent. It has a very fine, uniform closed-cell structure, a smooth skin, low compression set and consistent thickness from about 0.5 mm to 10 mm, which makes it the preferred grade for gaskets, adhesive-backed pads, electronics cushioning and premium die-cut fitments.
Two routes exist for cross-linking polyethylene foam. Chemically cross-linked foam (XPE or XLPE) uses a peroxide or silane agent mixed into the resin before the foaming oven. Irradiation cross-linked foam (IXPE) passes the extruded polyethylene sheet under an electron beam, which knits the polymer chains together without any additive, and the sheet is then expanded in a hot-air oven. The irradiation route gives tighter control of cross-link density and therefore of cell size, so IXPE is generally finer, smoother and more uniform in thickness than chemically cross-linked grades.
The numbers that distinguish it: cell sizes typically under 0.3 mm, density from roughly 25 kg/m³ up to 200 kg/m³ or more (30–33 kg/m³ is the common general-purpose grade, often labelled by its expansion ratio), and continuous sheet thicknesses from 0.5 mm to about 10 mm with tolerances around ±0.1 mm on thin gauges. Thicker blocks are made by heat lamination of multiple sheets, exactly as with EPE. Service temperature extends to around 80–90 °C, higher than non-cross-linked EPE.
Because the surface is closed and smooth, IXPE takes pressure-sensitive adhesive extremely well. This is the base foam for double-sided foam tapes, appliance and HVAC sealing strips, mobile-phone camera and speaker gaskets, and the thin anti-rattle pads inside automotive trims. In protective packaging it is used where a fitment must look clean on opening — medical device trays, camera and optics inserts, presentation cases — and where a thin sheet must be dimensionally reliable, for example interleaving between glass or lens surfaces.
Compared with EPE at the same density, IXPE is firmer, has higher tensile and tear strength, lower compression set and a much better cut edge, so it holds tight tolerances in die-cutting. Compared with EVA, it is lighter for the same firmness and more temperature-stable, though EVA still gives a more rigid, load-bearing wall at 80–120 kg/m³. It costs more than EPE per kilogram and is normally reserved for the product-contact layer or for thin technical parts.
IXPE is available in white, black, grey and custom colours, in flame-retardant and anti-static grades, and with film, fabric or aluminium-foil lamination. It is polyethylene and recyclable in principle, but cross-linked material cannot be re-melted and re-extruded, so it enters the mechanical-recycling stream as ground filler rather than as re-usable resin — worth knowing for EPR reporting.
When quoting a fitment we usually propose EPE for outer cushioning and IXPE or EVA only for the visible cavity or for parts under 5 mm thick where EPE tolerance would be inadequate.
IXPE Foam at a glance
| Cross-linking method | Electron-beam irradiation (no chemical agent) |
|---|---|
| Cell structure | Closed-cell, very fine (typically < 0.3 mm), smooth skin |
| Density range | Approx. 25–200 kg/m³; 30–33 kg/m³ general purpose |
| Sheet thickness | 0.5–10 mm continuous; laminated for thicker blocks |
| Thickness tolerance | Around ±0.1 mm on thin gauges |
| Service temperature | Approx. −40 °C to 80–90 °C |
| Typical uses | Foam tapes, gaskets, electronics pads, premium die-cut fitments, interleaving |
| Recyclability | Polyethylene, but cross-linked — ground and reused as filler, not re-extruded |
Common questions
What is the difference between IXPE and XPE foam?
Both are cross-linked polyethylene foams. XPE is cross-linked chemically with a peroxide or silane agent; IXPE is cross-linked by electron-beam irradiation. IXPE tends to have finer cells, tighter thickness tolerance and a cleaner surface, and is preferred for thin gauges and adhesive-backed parts. For thick blocks the two perform similarly.
Is IXPE foam better than EPE for packaging?
It is better for finish, tolerance and compression set, and worse on cost. For general cushioning of engineering goods EPE does the job at lower cost. IXPE earns its price where the fitment is visible to the end customer, where parts are thinner than about 5 mm, or where the foam must stay dimensionally stable through repeated use.
Can IXPE foam be die-cut and self-adhesive backed?
Yes, and that is its main technical use. The fine closed skin gives adhesive a consistent bond, and the material die-cuts and kiss-cuts cleanly on release liner. Thicknesses from 0.5 mm to 10 mm can be supplied as adhesive-backed rolls or finished die-cut parts.
Is IXPE foam waterproof?
It is closed-cell, so water absorption is negligible and it does not wick moisture. It is widely used as a sealing and gasket foam for that reason. Like all foams it is not a vapour barrier at very thin gauges, so it should not be relied on as the sole moisture protection for a corrosion-sensitive part.
Need EPE Foam Sheets & Rolls for your product?
We manufacture epe foam sheets & rolls at our Rajkot unit and dispatch across India. Send the product, size or weight and monthly quantity and we specify and quote within one working day.
Or read the full specification: EPE Foam Sheets & Rolls