The Richmond Virginian. (Richmond, Va.) 1910-1920, 1912-03-08

Every motor car owner KNOWS that
tires are made of rubber and cotton
! fabric put together in layers; that
they generally stand up under a ire
= 4faeH4ises- amount .Near,-hat-
times go to pieces upon slight provo
cation. He knows also that tires for
motor vehicles have been wonderfully
! improves in recent years in wearing
| qualities and in convenience of hand
| ling. but there are comparatively rev
/ who know the processes through
| which tire goes 10 make 1t sum-
! GENTLY strong to stand up under n
| heavy motor car on all sorts of road
! surfaces for thousands of miles.
! The rubber that goes into first class
tires comes principally from the Para
| district of Brazil Africa. Central
! America and the East Indies supply
/ considerable quantities, Rubber Is
bought by the tire factories, largely
| by sample. but sometimes on a defi-
| mite guarantee as TO what IL VIII ac-
J compIish. With the terrific demand
that Is being exerted in the market
| the tendency is to emphasize rhe
! former practice, and, as a result. the
| buyers Of tire making houses are re-
! ouired to be the keenest sort OF ex-
perts in their line. Having received
| a shipment of crude rubber at his
1 factory, the superintendent aubJCS - IL
| to the following processes:
The split balls are first washed
This process Is considerably more IN
| yoived than the term might seem 10
| imply. The washing machines con-
| sist ofsa series of warm cylinders and
the cleansing material is pure water.
The appearance of the rubber before
il goes into the bath Is dark brown.
with fairly smooth surface and q
! pungent odor that was given IL IN
the smoke of the nut fire. 1t Is rolied
and washed and washed and rolled
In the machines until all the SAND.
| sticks, dirt and other foreign suo-
stances have come away, and then
it issues forth In band that may De
as much as four feet wide. Coming
from the rolls. the crude rubber takes
the trade form of Grape II may
be half an inch thick and is porous
to a degree, somewhat sticky. and
Is considerably lighter in color. THIS
last quality. however. is temporary,
for upon exposure to the air the
Grape darkens somewhat under the
action Of atmospheric oxygen,
Goes TO Drying Machines.
1t then goes to the drying machines.
where a percentage of the moisture
contained in the Grape Is extracted
by gentle heat. Coming from TINS
process the Rubber 10 In the form or
Irregular masses and looks only re, re-,
motely related TO the perfected
article. The third step in manufac-
turing is to subject the product to
the process OF mastication. This IL
| done with friction rolls, which re-
| duce the mass to condition of plas-
ITCHY. Having been reduced to small
grains and shreds. the rubber is run
| between warm rolls and the admix-
ture OF sulphur and other vulcanixfng
chemicals IL introduced. The mass II
| then rolled out and taken to the cal
| enders or hot presses, where 1t Is
shaped into sheets. 1t is still crude
rubber. and at this stage OF manu-
facture IL called mixed stock" From
three 1t goes to the making room.
where workmen are ready to convert
it into tires and other #nlerchaIstatas
articles.
In the process of tire making there
| is another important element. BY
weight automobile tires are composed
| of from one-Quarter to one-third OF
| the stoutest, heaviest kind of cotton
| fabric. This fabric In not woven In
the tire factory. but 10 purchased from
the cloth weavers in large quanti-
ties. Each tire contains from four
| to six piles OF this material. 1t Is
made of the longest and strongest
!. fihre cf Sea leland cotton, and in Its
condition pricr to manufacture into
/ tires it seems strong enough 10 turn
| buckshot Before the actual work OF
{! making the tires commences great
/ quantities OF this cotton fabric are
associated with mixed stock" under
| the pressure or the rolls.
Ready Fer Making.
When ii il ready for tire making
the cotton fabric Is thoroughly i'm
J pregnate5 with the rubber and each
| layer Of the material Is exceedingly
! sticky on one of its surfaces 1t Is
| called friction cloth" at this stage.
! The process CT building a tire is then
taken mp. A layer Of the friction
/ cloth 10 laid on an iron mould and
/ shaped to meet the various convolu-
1 tions Of the tire. Another IS placed
! upon it, and another and another un-
| nj the required thickness is secured.
/ This. as has been said. is from four
/ to six plies. On top OF the cloth
| 4 thick layer Of mixed stock Is ap-
| Piled, and then another single ply
OF the friction cloth.
/ On top OF thic mass the main body
! OF the rubber is plsced. Tires vary
| in weight from about 10 pounds TO So
| pounds, depending upon size and
| amount Of material involved. Z Tho
tires are shaped on the motilds by
| the workmen, and when the correct
size and shape have been Efven the
tire 10 inspected by the superintendent
and taken to the vulcanixer. Thie II
simply q steam press whore live heat
can be applied to the articles to b.
made The action OF the heat n 10,
change the chemical status OF the ruh-
Der. N
! 4 wide range Of heat pressure ana
composition are used A certain -.
gree Of heat n necesaAry for I certain
length of time under certain SfN1oure
to 81 the Ge9t Aait4 60sn r AZ
| ~ vRxteti4 ~