One consistent rule in engineering, a law likely to remain in place as long as we depend on gravity, is the need for a foundation. Cranes exemplify this principle with their steel and concrete bases. Buildings follow the same convention, standing with the support of reinforced metal girders and a foundation that descends into the ground. The same concept governs the movement and operation of loaded vehicles. Case in point, forklifts and other suspension-deprived lift trucks must come equipped with rubber-like wheels, impact absorbing supports that offset the weight of a heavy load while delivering a smooth ride.
Knowing the importance of a foundation is one matter, but we can also see how these specialized wheels are serving a dual role, that of maintaining a bump-free and stable journey while providing a reliable foundation when the vehicle is either static or mobile. Remember, the stability factor we’ve mentioned, unlike a motionless load, is engaged in turns and loading cycles, meaning the centre of gravity is always varying. While this scenario is generally catered for by the fitting of durable rubber wheels, wear and tear is an ever-present force, a degenerative phenomenon that must be attended to before stability turns to rocky imbalance.
The rebonding process is a widely accepted method of replacing the rubberised external treads that outline industrial wheels before this wear compromises the operational ability of a working vehicle. Polyurethane is a popular replacement medium for this task, a substance that spurns abrasion and can be graded to balance durability with elasticity while offering superior resistance to the oil and chemical spills that trouble factory floors. The science of rebonding lays in evaluating the hub of the wheel for bonding viability. Plastics and metals can be rebonded, but the aged material has to be removed before beginning the replacement process. Heat is the galvanizing force used in stripping away a damaged rubber coating, and it’s the operation of specialized heating elements that breaks the adhesive contact between wheel and hub.
Once the hub has been evaluated for signs of damage, it’s time to clean it in a chemical bath. The rims of the restored wheel core are then coated with a powerful adhesive, layers of fixative that bond to a new polyurethane rim covering. At this point the work is nearly finished, but there are optional stages that will add detail to the wheel. One example is the cutting of wheel grooves on to the polyurethane. It sounds like a straightforward factory-authorized process, rebonding, but there are details to manage. The application of the adhesive and the curing of the polyurethane rim must take place in a contaminant-free environment. Additionally, an expertly executed inspection spots issues that will compromise the final product, checking for air bubbles and process impurities.