Liquid tyre-sealing mechanism launching in South Africa

9th August 2013

An environment-friendly tyre protection sealant, which improves safety for the driver, reduces fuel consumption, lowers maintenance costs and has fewer rim assembly problems, is being launched by the automotive division of South Africa-based bearings supplier Bearing Man Group (BMG). The sealant is imported from Greece and manufactured by international tyre sealing company Best.

Consumers will extend the service life of their vehicles by preventing premature aging of their vehicles’ tyres, says BMG automotive GM John Black.

BMG automotive says the Best tyre-protec-tion sealant is a thixotropic and colloidal resin containing microfibres and recycled rubber crumb materials, with cooling agents and rust inhibitors that protect all metal components of a tyre.

“Best tyre-protection sealant is nontoxic and water soluble, and is injected into the tyre through the valve without needing to remove the wheel from the vehicle or the tyre from the rim,” notes Black.

He adds that in the event of a puncture, the sealant automatically creates patches and plugs, which seal holes caused by objects such as glass and stones.

The sealant eliminates leakages from unseen rubber pores, seals valve leakages and prevents air pressure leakage from the rim and the O-ring.

“The sealant seals around objects embedded in the tyre up to 50 mm, prevents internal rubber separation from occurring in the tyre and also reduces overheating of a tyre’s rubber mass and the armour casing,” says Black.

Further, he notes that Best tyre-protection sealant is breakdown, boil and freeze resistant up to –25 °C.

Hallite Seals

BMG is the exclusive distributor in Southern Africa for international sealing manufacturer Hallite Seals’ entire product range, including the 506 self-lubricating bearing strips, which are made from materials such as nitrile rubbers and rubber, as well as fabric compounds and thermoplastic elastomers, says BMG seals division GM Ken Steel.

The Hallite 506 is used on hydraulic cylinder rod and piston applications and can withstand side loads, preventing metal-to-metal contact.

The bearing strips material has micro-indentations on its surface to trap fluid and provide lubrication to a bearing. The Hallite 506 is manufactured with a woven-fabric reinforced polyester resin material that is compatible with different fluids, like various oils, water-based fluids and phosphate esters.

These bearing strips are available as cut rings, which are cut to size and customer specifications, allowing for immediate installation. This product is also supplied as spiral lengths in several preformed inside and outside diameters as well as a flat coil form.

Hallite also produces the 780 double-acting seal for hydraulic cylinder applications that are designed for one-piece pistons but is also suitable for two-piece pistons.

“One-piece pistons are manufactured from a solid piece of metal, whereas two-piece pistons are manufactured from two pieces of metal and assembled to the same dimensions of a one-piece piston,” notes Steel.

The 780 consists of a nitrile rubber sealing element as well as two support rings and two L-shaped bearings on either side of the seal. The sealing element is designed with multiple lips for dynamic sealing and minor friction at low pressures. The lips of the support ring are extended when pressurised to protect the system against extrusion damage.

Further, the support rings and the L-shaped bearings are grooved to ensure that the fluid pressure properly energises the sealing element and prevents pressure trapping within the seal assembly.

“These seals are subjected to tests using purpose-built equipment that reproduces continuous operating conditions where leakage, dynamic and breakout friction are recorded, with performance factors like pressure, speed and temperature carefully monitored,” says Steel.

The equipment replicates normal and extreme operating conditions in a cycle, while tests can be as long as 25 000 cycles.

Steel explains that Hallite’s design engineers and materials technologists consider seal profile design and material selection, adding that product properties are studied to ensure that the finished component is capable of coping efficiently in harsh operating conditions.