the tire flatproofing experts

Catapol  Reseal    Carefree Tire Dealers 
Newsletter Volume 17 
UNDERGROUND MINES
Underground Coal Mine in Australia Insists on Arnco Flatproofing
Article by: Richard Blacker, Sales and Marketing Manager 
Springvale Colliery is based in Lithgow, a city with a population of about 25,000 people. It is a coal mining and farming community situated about 170 kilometers west of Sydney in Australia. Springvale Colliery is serviced by Mr. Paul Lindsay, the manager of Berry's Tyre Service in Lithgow, who has serviced Springvale Colliery for 6 years. During this time, Springvale Colliery has been using Arnco tyre flatproofing material in the majority of their underground vehicles. These vehicles are Joy shuttle cars using 17.5-25 20 Ply Hard Rock Lug tyres and Eimco LHD Loaders also using 17.5-25 16 and 20 Ply rated tyres. When these tyres require replacing they are sent to Bearcat Tyres in Sydney to be unfitted and the wheel is then returned to Berry's. Due to safety regulations in underground coal mining, all wheels have to be crack tested and the wheel components checked for excessive wear. If these parts fail, they have to be replaced with new wheels and components. New tyres are then fitted to these wheels and returned to Bearcat Tyres for Arnco tyre flatproofing. Bearcat carefully pressurizes these tyres to the correct pressure. It is very important that the tire is pressurized correctly for load carrying capacity and so a comfortable ride level is maintained. Occasionally pressures will change as underground operations change to allow larger loads or if better underground road surfaces are maintained at a high level where there are limited rocks on the roads. Bearcat Tyres uses Arnco RePneu® material in most underground vehicle tyres. Springvale Colliery engineer, Mr. Dennis Edwards, said the mine is capable of producing up to 2.6 million tons of coal each year. Dennis said that using Arnco tyre flatproofing material in their heavy vehicles served two main purposes: 1. Safety - because a tyre filled with Arnco material will not blow out or explode causing injury in a confined area and 2. Productivity - a tyre filled with Arnco material once badly cut will not stop production, unlike a tyre filled with air. This tyre can then be changed during the programmed maintenance schedule. Other vehicles using Arnco tyre flatproofing material are Domino PET transporters using 8.25-20 and 15.5-25 12 Ply tyres and PJB Personnel Carriers using 10-16.5 10 Ply tyres. Thanks to Arnco tyre flatproofing, Springvale Colliery is more efficient, has eliminated flat tires forever, and has created a safer working environment.

Bearcat Tyres is the Australian distributor for Arnco Tyre Flatproofing Material. They have enjoyed a close relationship with Arnco since 1987, distributing Arnco products through a dealer network in Australia. Bearcat Tyres now has a branch network of 6 outlets in 5 states in Australia and has appointed 19 dealers throughout Australia as authorized Arnco Certified Dealers. A large number of these dealers are involved in filling tyres that are used in the mining industry. From the hard rock underground, open cut iron ore, open cut and underground coal mining these dealers help keep mining production up by using Arnco Tyre Flatproofing Material in all types of mining tyres up to and including 35/65-33. Most modern mining companies must maximize production. To help maintain production, these companies insist on using Arnco Tyre Flatproofing Material inside their tyres with most mines buying good quality tyres at reasonable prices.
In Australia, Bearcat Tyres uses Arnco SuperFlex® for low pressure tyres up to 40 PSI, Arnco RePneu® for tyres requiring pressures up to 130 PSI, and Arnco HeviDuty® for special mining low profile tyres and special high pressure air bridge walkway tyres, which use aircraft tyres that require pressures up to 275 PSI. Arnco is happy to provide our flatproofing material to such a well-respected, professional company as Bearcat Tyres.

BATTLEBOTS
A while ago, Gage Cauchois asked us if we thought Carefree Tires would work for his BattleBot, Vlad the Impaler (sponsored by Loctite). Well, three years and a few championships later, Vlad the Impaler is still riding on the original set of Carefree Tires! "Even with parts of the tire missing, I still plan to have a few more ‘duels’ with this same tire before I change it.” BattleBots is the emerging sport of live robotic combat. Each contestant designs and builds radio controlled robots weighing up to 488 lbs, that employ an array of destructive weaponry such as hammers, saws, and spikes with the goal of destroying the opponent's robot. Vlad the Impaler, as well as all the other BattleBots can be seen Tuesday and Saturday nights on the Comedy Central.
 For information on Carefree Tire call 323-249-2868.

EMPLOYEE HIGHLIGHT - SAM CAPPS
By Sally Steele 
 Our "Wheel" this issue is Sam Capps, National Accounts Manager. From uranium to urethanes, from the Grand Old Opry to flatproofing presentations, Sam has experienced a variety of duties in his career spanning forty-six plus years. Sam's thirty-one years in the tire industry began with Goodyear Tire and Rubber Company in 1957. He began working with Goodyear at the district level, later moving to management at the corporate level. Prior to leaving Goodyear in 1973, Sam was National Manager of Customer Relations.
In 1974, Sam joined Brad Ragan as Director of Accounting. While still with Brad Ragan Inc., Sam was invited to be a member of President Ronald Reagan's Independent Staff to study and make revisions to the OSHA Program and to establish the ERISA and MSHA Programs for American Industry. In his capacity as President of Stallion Tire Company, Sam was instrumental in growing the urethane flatproofing market from its development to over eight million pounds annually in less than five years. Prior to joining Arnco, Sam served as President and CEO for the Synair Corporation.
While in the military, Sam was a participant in Nuclear Bomb Tests in Nevada and New Mexico. His education consisted of studying Accounting at the University of Tennessee in Knoxville, TN and Business Law at Harvard University in Boston, MA. He studied personnel policies and management at Akron and Duquesne Universities and at Maryland Technical Institute. He also taught courses on human and industrial relations for the American Management Institute and at Texas A & M.
Sam is married to Phyllis, a former Goodyear employee. They have four married children and four grandchildren. His son "Chuck" is a member of the Arnco Sales Team. After utilizing his technical expertise to fine-tune our technical department, Sam is currently part of the Marketing Department servicing National Accounts. Sam’s vast knowledge and expertise continues to help Arnco grow. I am sure you will all agree that Sam is a very colorful and vibrant part to the Arnco Team.

CHAMPAGNE BUBBLE EFFECT
When I was first invited to become an engineering consultant for Arnco in 1982, I arrived with some prejudices -having been Assistant Director of Firestone's Central Research Laboratories. I "knew" what to expect when tires were filled with something other than air. Pneumatic tires filled with puncture-proofing materials available back then had a terrible ride, and they would overheat if driven too fast. I knew that even solid rubber tires, which were used on the rear wheels of trucks until the late 1930s, had to be limited to 15 miles per hour or they would get so hot they would melt and blow-out, despite the fact that they were made of a stiff natural rubber compound having a "hardness" of 70-80 durometer, with little deflection. But as along time fan of Lord Kelv's doctrine, "when you can measure what you are talking about and express it in numbers, you know something about it", I thought we should gather some real world data on this new product at an independent tire testing laboratory - one of two in the Akron area that regularly tests tires for Firestone, Goodyear, General Motors, and Ford. For comparison, we would run identical tests on tires filled with RePneu® ® and filled with air. We devised a set of tests that would yield hard engineering data on such properties as ride, rolling resistance, heat build-up, durability, and pressure retention (sagging). I was especially concerned about heat build-up and durability because some Akron tire companies had experimentally filled tires with urethane elastomers in the 40+ durometer range. Their performance was described as "thermal runaway." So when I learned that Arnco's RePneu®, in an effort to soften the ride, had a hardness of less than 30 durometer, I expected the worst. At Standards Testing Laboratories we ran durability and heat build-up tests in 11R 22.5 truck tires in accordance with the Federal Motor Vehicle Standard No. 119 - a government qualification test that all tires must pass before they can be sold in the United States. In this test, the tire is run at 55 miles per hour against a steel drum five feet in diameter under increasing loads for a total of 47 hours. To measure internal temperatures, each air-filled tire had an internal temperature probe wired through the Schrader valve. For the tires filled with RePneu®, we simply drilled probe holes through the sidewall, one just under the tread, and the other in the center of the tire section. We took temperature readings every four hours during the tests. The results were astonishing. The tires filled with Arnco's RePneu® actually ran cooler that the same tire filled with air! And it was true of both radials and bias tires. A clue as to what was happening could be seen in our footprint studies (where the first thing we learned was that "cold" footprint of the RePneu®-filled tire was only 8% smaller than that of the air-filled tire). We ran footprints "cold" at the start of the test, repeated them after 7 hours of running, and ran them again at the end of the 55 mph, 47-hour test.During the test, the footprint of the air-filled radial decreased 7% as it heated up to 152°F. But the footprint of the RePneu® filled tire decreased more than 18%. Furthermore, its temperature rose to only 111°F in the center of the tire section and 149°F in the highly flexed area under the tread. Bias tires of the same size got slightly warmer, but the results were equally dramatic. So what was happening? Measurements recorded during the tests showed that the deflection of the RePneu®-filled tires decreased by half an inch as they heated up. This meant that less energy was imparted to the tire (since energy [work] is force [load on the tire] times distance [deflection each revolution]). When we plotted temperatures against time, it became apparent that each time the load was increased during the test, the temperature rose a few degrees, then leveled off as the tire's deflection decreased. In later testing we extended the 47 hour durability run, increasing the load 10% every eight hours until tire failure occurred (usually simple tread separation). Sometimes running more than 80 hours, at very high loads by that time. Why do RePneu®-filled tires perform this way? Skeptics have suggested that it is simply thermal expansion of the incompressible elastomer. But when competitors have attempted to duplicate Arnco's performance, making urethanes of similar (30) durometer, "thermal runaway" loomed its head as tires filled with these competitive urethanes reached 350°F in the first 14 hours of running - blowing out and covering the wall and ceiling of the test lab with the hot, degraded liquid polymer. The difference, which we've proven more than once in court, is in Arnco's patented formulation. It contains a precisely specified amount of water. When water is used as a curing agent for urethane, carbon dioxide is a reaction product. Since the tire is filled under pressure, increasing the solubility of the gas, this CO2 is dissolved and/or chemically complexed into the tire fill while it is a liquid, and it stays dissolved in the solid urethane after it cures. When the tire begins to heat up while running under load, the CO2 , being less soluble in the hot elastomer, begins to come out of solution. The resulting "nucleation" or incipient formation of sub-microscopic "champagne bubbles" in the non-compressible elastomer (in combination with thermal expansion) reduces the tire's deflection. And this causes the temperature to level off-and sometimes to actually decrease. As the tire cools, this carbon dioxide redissolves (or complexes back) into the polymer and disappears. We first reported this remarkable property of RePneu® in a technical paper presented to Society of Automotive Engineers' Annual Engineering Congress in 1983. Two years later, in 1985, we presented a similar paper on our softer SuperFlex®, which performs the same way. Our third Arnco paper on these remarkable materials (reviewing the results of tests we ran in Alaska) generated so much interest that it was selected by SAE as a Teetor Industrial Lecture that I was invited to give at several universities and, since then, to the industry's Tire Society, and to the Akron Physics Club. The unique performance characteristics of Arnco elastomers have obviously earned the respect of automotive and rubber industry professionals. The "champagne bubble effect" really works, but so far only with Arnco flat-proofing materials.

Call Betsy at 1-800-821-4147 ext. 710 to request copies of SAE papers.