IMPROVEMENTS IN THE MANUFACTURE OF SHEETS, SLABS, AND OTHER ARTICLES, WHEN FIBROUS MATERIALS ARE EMPLOYED
Year: 1863

page_text: LETTERS PATENT to Charles Frederick Bielefeld, of Gower Street, in
the County of Middlesex, for the Invention of "IMPROVEMENTS IN THE
MANUFACTURE OF SHEETS, SLABS, AND OTHER ARTICLES, WHEN FIBROUS
MATERIALS ARE EMPLOYED."
Sealed the 2nd November 1863, and dated the 8th May 1863.
PROVISIONAL SPECIFICATION left by the said Charles Frederick Bielefeld
at the Office of the Commissioners of Patents, with his Petition, on the
8th May 1863.
I, CHARLES FREDERICK BIELEFELD, of Gower Street, in the County of
Middlesex, do hereby declare the nature of the Invention for "IMPROVEMENTS
IN THE MANUFACTURE OF SHEETS, SLABS, AND OTHER ARTICLES, WHEN FIBROUS
MATERIALS ARE EMPLOYED," to be as follows:-
This Invention has for its object improvements in the manufacture of sheets,
slabs, and other articles when fibrous materials are employed.
I tako woven or other suitable fabric, such as fabrics of woven cocoa-nut or
other fibres, felt, paper, dry hair felt, and such like, and I thoroughly saturate
the same with a compound of water glass (soluble silica), clay, and lime, with
or without metallic oxides.

page_text: I also make a plastic material composed of the same, but adding quantity
of paper pulp or other like material in about the following proportions:
2 lbs. of a mixture composed of equal parts of clay, lime, and pumice stone,
8 lbs. of water glass, and 2 lbs. of pulp, which is trowelled over the prepared
pieces of fabric, filling up all the interstices of the fabric. Where greater thick-
ness is required, I place two or more thicknesses together, and gauge or trowel
the surfaces to the thickness or purpose required. I also make thick boards
by the like mixtures with paper pulp in a very fluid state. The mixture must
be kept in motion in order that it may becomo thoroughly incorporated. It
is then poured into frames according to the thickness required. To the
bottom of the frame I fix either gauze, wire, or perforated metal.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Frederick Bielefeld in the Great Seal Patent Office
on the 7th November 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
FREDERICK BIELEFELD, of Gower Street, in the County of Middlesex, send
greeting.
WHEREAS 1er most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of May, in the year of our Lord Ono
thousand eight hundred and sixty-three, in the twenty-sixth year of Iler
reign, did, for Ilerself, Her heirs and successors, give and grant unto me,
the said Charles Frederick Bielefeld, Her special licence that I, the said
Charles Frederick Bielefeld, my executors, administrators, and assigns, or such
others as I, the said Charles Frederick Bielefeld, my executors, administrators,
and assigns, should at any time agree with, and no others, from time to time
and at all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man, an Inven-
tion for "IMPROVEMENTS IN THE MANUFACTUEL OF SHEETS, SLABS, AND OTHER
ARTICLES WHEN FIBROUS MATERIALS ARE EMPLOYED," upon the condition (amongst
others) that I, the said Charles Frederick Bielefeld, my executors or ad-
ministrators, by an instrument in writing under my, or their, or one of their
bands and seals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed, and cause
the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.

page_text: The cheapeast fabric of fibrous material for making the pulp material is either
millboard or old brown paper, millboard is however preferred. Boil or soak
cuttings of millboard or of brown paper, and after they have been thoroughly
saturated with water they are reduced to pulp in the ordinary way. The pulp
is then thrown on an incline to draw off the water, or a centrifugal machine
may be used for separating the water. The pulp is added to the solution of
water glass, and well stirred until it is thoroughly incorporated; then add the
mixture, and keep stirring until it is all properly mixed; the compound is
then ready for use.
In order to form sheets or slabs a low bench is used, and by preference
about 2 feet 3 inches high, upon it place a slab of slate or any other
suitable material; this bed is to be flat and smooth. Upon the surface of
the bed I place a piece of damp woven fabric, such as sail cloth or other
suitably strong fabric; provision is made for stretching the canvas slightly
on the surface of the slab in order to prevent wrinkles. A frame to guage
the thickness of the material is used; it is by preference made of wood faced
with brass, with suitable fixings at the angles so that the four sides of the
frame may be readily taken apart. The mixture is worked into the interstices
with a plasterer's trowel, well filling them up; then gauge the thickness of the
fibrous material over the same. It is then taken up and placed within the frame
face downwards and filled up with the material, and gauged off to the thickness
of the frame; if half or about an inch, one thickness of the woven material is
sufficient. Care must be taken that the fabric is kept as near as possible in
the centre. When two or more thicknesses are required for greater strength
the process is the same, but great care will be required that sufficient
thickness is provided on both faces for rubbing down or planing. The sheet
should not be removed from the mould until it is set, which will be in about
24 hours. A platform made of cement or other suitable material, but gauged
to a perfect level, is used to receive the sheets. Slips of wood cut accurately to
one guage, say, about an inch and a half square are employed, to keep the sheets
separate when being dried; these slips are laid on the platform in order to
support the sheet at intervals. Many sheets should not be laid one on another
until they become sufficiently hard. In placing one sheet on another, the
slips of wood for ventilation are placed between the sheets alternately along
longitudinally and transverse.
In preparing mixtures to be placed between iron in several layers for the
purpose of affording greater resistance to shot or shell, I prefer to employ
fabrics of cocoa-nut fibre having an open mesh. I trowel the mixture as
described in order to fill up all the interstices. Layer after layer may be

page_text: applied until the thickness required is attained. Any form or shape may be
made to fit a ship's side by having a template or frame of the shape required.
In some cases when making sheets, I use unsized paper, or felt, or woven
fabric. I place them in a vessel in which is a mixture composed of 1 part
china clay and I part oxide of zinc combined with a solution of water glass,
until the china clay and oxide of zinc are in a liquid state and well mixed.
The unsized paper or felt is to be immersed in this solution, and remain until
thoroughly saturated; the sheets may then be placed together to obtain any
desired thickness. These sheets are applicable to a great variety of purposes,
amongst others, to the construction of billiard and bagatelle beds, panelling
generally, railway and other carriages, interior lining for ships, and for affording
resistence to shot and shell between the iron plating of ships, building and
other purposes, sheets or slabs for fresco panelling.
I claim the manufacture of sheets or slabs consisting of woven or other
fabrics of fibrous or other substances in combination with water glass mixed
with fibrous materials.
In witness whereof, I, the said Charles Frederick Bielefeld, have hereunto
set my hand and seal, this Seventh day of November, in the year of
our Lord One thousand eight hundred and sixty-three.
CHARLES F. BIELEFELD. (L.S.)