HOW
IS
MADE
?
ERASERS
?
Make
no
mistake
about
it
an
eraser
is
a
student's
best
friend
whether
it's
attached
to
the
top
a
____________________
or
on
its
own
,
only
in
a
racer
can
quickly
rub
out
an
error
.
White
erasers
are
made
a
flexible
vinyl
,
while
pink
erasers
are
made
of
synthetic
____________________
.
In
1736
a
French
explorer
observed
South
American
native
Indians
using
a
search
in
tree
resin
to
make
bouncing
____________________
.
He
brought
this
resin
back
home
and
before
long
Europeans
discovered
it
could
rub
out
lead
pencil
marks
,
hence
the
term
rubber
.
There
was
just
one
problem
.
After
a
while
rubber
would
rot
that
the
level
assault
a
____________________
later
by
one
Charles
Goodyear
who
developed
a
curing
process
to
prevent
rubber
from
rotting
.
A
lot
of
ingredients
going
into
making
a
simple
pink
eraser
____________________
measured
fillers
accelerators
,
curing
agents
,
oils
,
coloring
,
and
the
main
ingredient
,
synthetic
rubber
.
They
start
by
putting
a
beater
rubber
into
a
mill
.
The
robber
passes
repeatedly
between
large
heated
rollers
.
They
throw
in
any
defective
erasers
the
last
____________________
run
recycling
into
this
new
batch
.
Then
,
they
add
sulfur
,
a
securing
agent
,
accelerators
to
help
the
sulfur
do
its
job
and
red
coloring
.
They
blend
everything
for
five
to
ten
____________________
until
the
mixture´s
the
consistency
up
heavy
dough
.
Next
,
vulcanize
vegetable
oil
.
That's
a
vegetable
oil
treated
with
sulfur
than
regular
vegetable
____________________
then
calcium
carbonate
as
a
filler
.
When
the
color
and
thickness
are
just
right
workers
remove
the
rubber
which
by
now
is
hot
as
____________________
as
a
result
of
all
that
milling
believe
it
too
cool
and
hard
in
a
room
temperature
for
about
half
the
day
.
When
the
robbers
are
ready
they
cut
out
large
squares
each
weighing
between
five
and
eight
____________________
depending
on
the
thickness
of
eraser
the
client
has
ordered
.
The
squares
go
into
a
steam
heated
pressed
to
cure
for
about
20
minutes
at
____________________
degree
Celsius
.
The
pressure
compacts
the
rubber
while
the
intense
heat
harden
set
.
They
trim
off
the
excess
then
submerge
the
hot
rubber
squares
in
cold
water
to
stop
the
____________________
process
.
To
make
a
eraser
that
erase
both
lead
ending
they
cut
double
strips
from
two
batches
a
robber
one
pink
and
one
blue
.
The
blue
contains
comments
which
gives
it
that
extra
abrasiveness
to
erase
____________________
.
They
pier
up
each
pink
with
a
blue
to
form
a
two
color
strap
.
Then
it's
into
the
steam
press
.
After
____________________
minutes
workers
removed
the
trays
,
trim
off
the
excess
and
submerge
the
strips
in
cold
water
to
stop
the
curing
process
.
Then
,
an
automated
machine
chops
the
strips
into
pieces
the
____________________
of
erasers
.
Now
,
back
to
the
all
pink
eraser
,
the
robber
squares
come
out
of
their
cold
water
bath
and
go
through
a
machine
that
cuts
strips
with
beveled
edges
.
The
chops
strips
into
erasers
and
there
,
the
erasers
drop
into
a
giant
barrel
.
____________________
throw
into
some
stock
to
prevent
them
from
sticking
together
.
Then
they
said
the
barrel
spending
for
three
to
five
hours
as
the
eraser
tumble
against
each
other
the
abrasion
rounds
of
their
edges
.
The
last
____________________
is
printed
it
,
a
machine
stamps
each
eraser
,
but
the
company
name
and
the
model
number
.
It's
not
the
rubber
that
gives
the
eraser
the
ability
to
erase
but
rather
the
____________________
vegetable
oil
than
in
it
.
That
makes
the
eraser
crumbled
when
rubbed
on
paper
taking
away
the
pencil
marks
with
it
.
