There are two methods that can be used for tyre retreading: hot retreading and cold retreading. Only carefully selected and properly inspected casings are employed for either of these methods. The manufacturing process itself is also identical for both methods, up to the point of applying the tread material and performing the vulcanisation.

Hot retreading

During hot retreading, the process of applying the tread material is virtually identical to the production of a new tyre.

The tread material is taken directly from the extruder and applied to the buffed casing. Afterwards the tread/casing assembly is cured in a vulcanisation mould with the required tread pattern. The pattern on the tread is formed during the vulcanisation process like it is when a new tyre is made.

Hot retreaded truck tyres from Continental are retreaded from bead to bead. The main advantage of this principle is that the sidewalls are renewed, ensuring that the quality of the hot retreaded tyre is comparable with that of a new tyre.

Cold retreading

Using the cold retreading method, a patterned and pre-vulcanised tread is applied to the buffed casing. This tread is placed, under constant tension, together with an unvulcanised bonding ply onto the buffed casing; pretensioning ensures already prior to vulcanisation that the tread adapts optimally to the tyre contour and guarantees that the parts are bonded together as best possible while the tyre is in the autoclave (curing chamber). Then the prepared tyre is “packed” into a curing tube (envelope) and cured under pressure in the autoclave.

ECE 109

ECE Regulation No. 109 defines type approval standards in the production of retreaded pneumatic tyres for commercial vehicles and their trailers. This regulation defines strict quality control measures that have been compulsory for retreaders since September 2006 to ensure high-quality retreaded tyres.