Bondex, Granür and Rebonded Foam: What Is the Difference?

Whether the word is bondex, granür or rebonded foam, the process being described is the same: reclaimed foam is shredded to a set particle size, coated with binder, pressed in a mould under pressure and steam, and sliced once it has rested. The name chosen changes none of those steps.

The names come from different places. Bondex is a trade name taken from the bonding step; it spread through the Turkish trade until it became a generic word for the material itself. Granür is descriptive, naming the granules visible across the block's cut face. Rebond is the short form of rebonded, the international term meaning bonded again.

The confusion comes from vendors' speech habits. A buyer who asks three suppliers for a quotation may get three different words back and read them as three product grades. What is actually being compared is three vendors, not three materials.

Between two blocks carrying the same name, the heaviest difference is the density grade. Density says how much material was compressed into a given volume, and it is the first variable governing how the layer behaves under load. A quotation with no DNS figure on it is incomplete.

Second comes particle size. A block made from fine particles gives a more even surface and a cleaner cut face, which shows through thin cover fabric or a surface lamination. Coarse particles leave a more mottled section and a more pronounced texture after cutting.

Third is binder distribution. If the binder did not coat every particle evenly, the block is not equally strong throughout, and that reads on the cut face as voids or slack zones. Two blocks sharing a DNS figure can therefore behave differently.

Fourth is dimensional tolerance. Whether sheet thickness holds end to end, and whether the block's edges stay square, depends on how long the block was allowed to rest after pressing. Whatever name is on the label, material held to a tight tolerance wastes less at the later cutting and sewing stages.

The first move is to rewrite both quotations into the same fields: density grade, sheet or block dimensions, thickness tolerance, particle size, packing form. If a field is blank in one of them, ask for it rather than inferring it from the name — the word bondex fills in no field at all.

The second move is to bring quantities onto one unit. If one quotation counts sheets and the other counts cubic metres, the two numbers do not compare directly: the same block yields a different sheet count at a different slicing thickness. Comparing by volume is the safer basis.

The third move is to verify density independently. Weighing a piece of known dimensions is the simplest way to confirm a declared DNS figure, and if the declaration and the scale disagree, the name on the quotation stops mattering.

Finally, it is worth asking a vendor about their own naming convention. Some reserve bondex for one density and granür for another within their own list. That is one company's internal order, not an industry classification, and it does not carry across to anyone else's list.

Some materials do get confused with this family while genuinely being different. HR foam — high-resilience foam — is blown directly: its cell structure comes from a chemical reaction rather than from pressed particles, and its cut face is one colour and homogeneous.

Memory foam, or viscoelastic foam, returns to shape slowly after the load comes off and responds to temperature. Latex is cured in pin-cored moulds from natural or synthetic latex. Neither is another word for rebonded foam; they are separate materials.

These three — HR foam, memory foam and latex — are not part of YAYLA's range; they are defined here only for contrast.

The practical test is the cut face. Particles of mixed colour bonded to one another mean the rebond family, whatever the label says — bondex and granür alike. A continuous, single-colour cell structure means a different material.