Truck Tyre Retreading Systems

Nearly one in every two truck tyres on the road in the UK is a retread. Unlike in the car tyre market the retreading process is considered by new tyre manufacturers, and major haulage companies to be an integral an essential part of the life cycle of the tyre. So, if you ever subscribed to the belief that retreads were a low quality, cheap alternative manufactured by second rate companies, think again. Today, retreading is a high quality process carried out by highly professional companies. Michelin, Goodyear, Bridgestone - all the major tyre manufacturers - They are all retreaders.

The aim of this article is to give some insight into the various processes involved in manufacturing retreaded truck tyres and an introduction to the main companies involved.

There are basically two ways in which truck tyres can be retreaded - the mould cure system (or hot cure) and the precure system (cold cure).

Left: Marangoni Tread's Ring Tread System in operation in the Portuguese retreader, Império

Mould Cure

The mould cure system of retreading, put simply, involves the following processes. Used tyres are inspected and subjected to any necessary repairs before being buffed to remove the old tread and sidewall rubber. Uncured rubber is then applied to the tread and sidewalls following which the tyre is cured in a mould in roughly the same way that a new tyre is manufactured. Mould cure retreads tend to be made by larger retreaders due to the large investment needed in moulds and would normally carry the retreaders own brand name.

Precure With the precured retreading system, the buffing process is followed by the application of a precured tread strip or ring to the tread area of the casing. The tyre is then cured at lower temperatures in an autoclave. The mould cure and precure systems each have their advantages in certain applications and most larger retreaders tend to offer both processes. However, smaller retreaders tend to prefer the precure system due to the low initial investment and high levels of flexibility in the production process.

A tyre casing being buffed in Bandvulc's hot cure retreading factory in Devon

The precured process is characterised by a number of rubber and equipment suppliers who offer complete franchise packages to the retreader,tyres being marketed with the brand name of the rubber supplier. Leading suppliers worldwide include Bandag, Marangoni (RTS), Oliver and Hercules. However, this sector is now being entered by the new tyre manufacturers with Goodyear, Michelin and Bridgestone all offering their own retreading packages.

The tyre building process carried out with the Bandag system

Precured retreads can be manufactured using three different kinds of rubber - Tread Rings - Precured tread rings have the advantage that they have no join and in the case of Marangoni's Ring Tread System have a concave tread profile which matches the casing exactly. Contoured Treads - Such as Kraiburg's Wave system, Bandag's Eclipse system and the Marangoni Wing Tread product are tread strips with a concave profile designed to match the casing profile and reduce stress on the casing.

Flat Treads - Manufactured by all leading manufacturers, these strips do not have a contoured profile. (8/98