Does Anyone Else Do This ?

NeedforZ · 09-05-2009, 10:59 PM

I figured the "whiskers" were a side effect of the tire manufacturing process. A little research reveals why they are there.

The vast majority of tire molds in use today have vents
and/or microvents to expel air trapped between the green
tire surface and the mold surface as the bladder expands
the green tire into the mold cavity. Typically, the
microvents are between 0.020-0.040in (0.5-1mm) in
diameter and vents are between 0.040-0.060in (1-2mm)
in diameter.
Both types can extend an inch or more in depth into the
mold. A typical passenger car tire mold contains
thousands of these vents. The bladder expansion
pressure, combined with the elevated curing temperature,
causes some of the tire surface rubber to ‘extrude’ into
these vents during each cure cycle. When the cure cycle
is over and the tire is released from the mold, most of the
the extruded rubber in these vents remains attached to
the cured tire and pulls back out to form the familiar
rubber ‘whiskers’ on new tires.

Here's the full article. http://old.coldjet.com/trade/tiretech.pdf

09-05-2009, 10:59 PM	#5 (permalink)
NeedforZ Base Member Join Date: Mar 2009 Location: DFW Texas Posts: 163 Drives: 370z Touring 7AT Rep Power: 18	I figured the "whiskers" were a side effect of the tire manufacturing process. A little research reveals why they are there. The vast majority of tire molds in use today have vents and/or microvents to expel air trapped between the green tire surface and the mold surface as the bladder expands the green tire into the mold cavity. Typically, the microvents are between 0.020-0.040in (0.5-1mm) in diameter and vents are between 0.040-0.060in (1-2mm) in diameter. Both types can extend an inch or more in depth into the mold. A typical passenger car tire mold contains thousands of these vents. The bladder expansion pressure, combined with the elevated curing temperature, causes some of the tire surface rubber to ‘extrude’ into these vents during each cure cycle. When the cure cycle is over and the tire is released from the mold, most of the the extruded rubber in these vents remains attached to the cured tire and pulls back out to form the familiar rubber ‘whiskers’ on new tires. Here's the full article. http://old.coldjet.com/trade/tiretech.pdf