The Mount Holly news. [volume] (Mount Holly, Burlington Co., N.J.) 1891-1942, 1905-03-07
THE MAKING OF PENCILS.


graphite or PlumbagO Is Used In
Them, but No Lead.
Lead pencils are not made of lead.
The first pencils were lead and had a
right to the name A stick of lead was
originally used for making marks upon
paper and wood The name has been
retained, though today all the pencils
are filed with graphite or plumbago.
This mineral is rather scarce, for it is
found in but few Cumberland,
England; along the Laurentian ranges,
in the province of Quebec, and at Ii
eonderoga, vt.
Nowadays the mineral is taken from
the mines in the lump and carried to
the reducing mill, where it is pulverized
in stamp mills under water. This dust
is collected, packed in barrels and sent
to the factories, where thousands of
pencils are made every day. This pull
really dust, dingy in color and smooth
and oily to the touch. 1t is divided in
to various grades of fineness by floating
it on water from one tank to another
The coarse dust sinks to the bottom
of the first tank, the next finer to the
down the line, the finest powder for the
finest pencils settling in the last tank.
Different grades of pencils, from very
soft to extra hard, are obtained by mix
ing the graphite with German pipe
clay, which is hoated in a series of
tanks in the same way The finest
clay is mixed with the finest graphite,
being ground together with stones, and
the hardness of the pencils is secured
by increasing the proportion of clay in
the mixture. After the graphite and
clay are mixed together the mixture is
squeezed out by means Of a hydraulic
press, leaving a mass the consistency of
putty. The plaster is then placed in a
forming press, which is a small iron
cylinder in which q solid plunger or
piston works up and down. A steel
plate having a hole the size and shape
of the lead is put under the open end
of the cylinder, and the plunger, press
ing down, forces the graphite through
the hole, making continuous thread or
wire of graphite.
AS long as this thread is moist it is
pliable, but when dry it becomes brittle
and must be handled rapidly. 1t is cut
into three lead lengths and Strengthened
i'll a crucible over a coal fire. When
taken from the crueible the lead is
ready for the wood, which is pine for
cheap pencils and cedar for the more
expensive ones. When the strips of
wood are received at the factory they
are run through a machine which cuts
in each six grooves, round or square,
and at the same time smooths the face
of the wood
The filling of the strips is done by
girls. The first girl takes a grooved
strip of wood in her left hand and a
bunch of leads in her right She spreads
the leads out in fan shape and with
one movement fills the six grooves
with lead. The next girl takes the
/ filed strips and quickly lays on anoth-
er grooved strip which has been coated
with hot glue by third. The filled and
grooved strips are piled one upon an
other and put in press to dry. The
ends of the strips are evened off under
sandpaper wheel, and then the strips
are fed into machine which cuts
them up into individual pencils, shapes
and delivers them smooth and ready
for the color and polish. The coloring
is done with liquid dyes, after which
the pencils are sent through the var
nishing machine.-New York Herald.