TIRE CLINIC
from the September/October 2007 issue of Today's Tire Industry |
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Q:
We are considering the purchase of a new buffer for our truck tire retread plant and we are undecided on whether to buy a buffer with an expandable hub or one with flanges. What are the pros and cons of each
one?
A:
The expandable hubs tend to inflate the tire a little faster and can save a little time from one tire to the next. The flange units will inflate the tire so that it will run truer and is much less likely to leak at the beads. Some tires may stick to the flanges and require more
time for demounting the tire from the buffer. The flanges will always be less expensive to maintain. If I was running a mold cure retread plant I would prefer a flange type buffer, but if the buffers are set up
properly and well maintained, both types will do an acceptable job.
Q: Has the importing of low-price new truck tires from China and other countries had a negative effect on truck tire retread sales in the United States?
A: There is no doubt that the low cost imports are having a negative effect on truck tire retreading in the U. S. The hardest hit have been the intermodal retreaders. Some intermodal companies have switched nearly all of their cap and casing purchases to new imported tires and have drastically reduced the number of their own casings that they are retreading. Part of the reduction is due to a shortage of quality bias ply casings and the fact that many of the low-cost new tire imports will not retread when worn out. The low cost new radial tire imports are also starting to take a larger percentage of the retread business.
Q: Is there any chance that lasers could eventually be used to replace the buffing rasp in retreading or to do buzz-outs?
A: The only place I have seen anything relating to lasers used to work on tires is the cameras on shearography inspection machines. I have asked around and no one seems to think it would be possible to remove rubber or steel from a casing with a laser as it generates too much heat and therefore would scorch the surrounding rubber.
Q: I have told my retread plant manager that I can buff a casing as accurately with a manual buffer as with a computerized buffer. What’s your opinion?
A: You are correct if the manual buffer is properly set up and is well-maintained and the operator is thoroughly trained. The only problem is even if you have the training and the proper set up, it’s going to take the manual buffer a lot longer to buff the same number of tires.
Q: We use a hot knife to cut die size rubber that we use in a specialty retread operation. What are the chances of having splice problems from scorching the rubber when cutting it?
A: I have put together many thousands of retread splices using a hot knife without any problems, but there are a few precautions you should take. First, the knife blade should be kept clean and sharp and if possible, lower the temperature to 200 degrees Fahrenheit, and then train your builders to cut the rubber as
quickly as possible.
Send your questions to:
Today’s Tire Industry
1532 Pointer Ridge Place, Suite G
Bowie, Maryland 20716-1883
or e-mail publication@tireindustry.org.
