Paper-Making
an account of paper-making from its earliest
known record down to the present time by
J.W. Butler Paper Company 1901
applying a mixture of clay and glue to ordinary paper. When
referred to in connection with coated paper, this ordinary paper is
called raw stock or body paper. It is manufactured in the regular
way, but is made slack-sized and sent to the coating factory in
web or roll form, and before it has been calendered. The clay
used is pure kaolin or china clay, formed by the disintegration of
feldspathic rock. The clay is largely found near Cornwall, England,
and the pure white variety, principally used, is known as leemore
clay, while the finest is called blanc fixe. The clay is ground to the
fineness of fine wheat flour and mixed into solution of about the
consistency of milk. Its purpose in the paper-coating process is to
cover the body paper, giving it an even surface, susceptible of a
high and glossy finish. The glue used is of the ordinary sort so
well known in the regular market. Its presence renders the clay
solution very adhesive when applied to the body paper.
The cost of illustrations having been greatly reduced through the
perfection of photogravure or half-tone processes, a large and
increasing demand exists for a paper of extremely smooth, firm,
finest half-tone cuts; a paper with such delicate fineness
and susceptibility that the minute lines of a photogravure
cut - so minute in instances as to be indistinguishable to the
touch of the finger-will be perfectly reproduced when printed
upon its enameled surface.
Large factories are devoted entirely to the coating process.
They do not necessarily make their own body paper, but
frequently purchase it from outside sources. At first, this clay
solution was carried to and spread upon the surface of
paper by the use of a fine hair brush. This was applied to
one side or surface of the paper at a time, the same process
being repeated on the opposite side, if both were to be
coated. Since its earlier introduction, the process of surface-
coating paper has undergone great improvement, and the
method to-day in vogue, while seemingly complete and
exceedingly rapid, is yet readily understood, and the
machinery required is quite simple. This consists of:
First-A vat, to hold the enameling solution.
Second-Rollers, to regulate its distribution upon the web of
paper.
Third-Brushes, to work out small lumpy particles and
overcome any tendency to unevenness of coating. .
Fourth-An automatic carrier, to convey the coated web
through a drying-room; after which it is calendered to the
surface wanted and cut into sizes required.
A roll of body paper ready to be enameled is placed before
the vat which contains the coating solution. The end of the
paper-web is started through the solution by being passed
of the web. After passing under the roller the paper-web leaves the vat, and is passed between two rollers that
regulate the thickness of the coating and remove all surplus. From the rollers the web passes forward through two
sets of brushes, one above and one below, both sets working back and forth transversely upon the top and bottom
of the coated web. Each set of brushes is comprised, first, of a coarse, then intermediate, and finally of extremely
delicate brushes, made usually of camel's hair, which as they play upon the coated surface work out all roughness or
small lumpy particles, and reduce the coating to uniform fineness. Upon leaving the brushes, the paper reaches an
automatic carrier. This consists of wooden slats conveyed at intervals upon two endless chains that pass at either
side of the machine just outside of the coated web, the chains supporting the slats at their ends. As the paper
reaches the slats it falls upon one, which by an ingenious device is carried forward and upward, permitting the coated
web of damp paper to fall in long loops or folds succeeding slats follow upon the carrier at regular intervals, and
prevent any marring of the damp surface by keeping it from foreign contact. The slats upon the carrier convey the web
in this festooned form through a drying-room, kept at a temperature of about 140° Fahrenheit, thus thoroughly drying
the coated web. The paper, dried by its passage through the drying room, is rerolled upon reels, and is then finished
by being passed rapidly between alternate steel and paper rollers, after the ordinary method of calendering paper.
The rollers are susceptible to regulation or adjustment, so that almost any degree of gloss can be put upon the
coated surface; hence, for the highest finished paper the rolls are set slightly closer together, giving greater pressure;
and if necessary, the web can be run through a second or third time. After calendering, the paper is cut to sizes
required, this being done in the same manner all rolled paper is cut into sheets, except that if three or four rolls are
run through the cutter at once - as is frequently the case to facilitate rapid cutting-a device is used that causes the
sheets from each roll to fall in separate piles, so that all of the sheets in each pile will be from one roll, insuring
uniformity.