IMPROVEMENTS IN THE MANUFACTURE OF FIRE AND WATERPROOF BOARDS OR PAPER FROM ASBESTOS
Year: 1885

page_text: I WILLIAM EDWIN HEYS of 34 Blackfriars Street Manchester in the County
my invention
of Lancaster Mechanical Engineer, do hereby declare the nature of
for IMPROVEMENTS IN THE MANUFACTURE OF FIRE AND WATERPROOF BOARDS OR
PAPER FROM ASBESTOS and in what manner the same 18 to be performed, to be
particularly described and ascertained in and by the following statement
—
This invention relates to the manufacture of Fire and Waterproof Boards or
paper from Asbestos and these Improvements have for their object the production
of Boards sheets or paper that shall retain then coherence after a long continued
wetting and which shall not under ordinary conditions absorb moisture, Similar
boards sheets or paper manufactured from Asbestos have not hitherto been applicable
for many purposes because of their hygroscopic properties while the boards sheets
or papers made according to the hereinafter described process are fiee from those
properties
American or other soft fibrous Asbestos to the amount of about 20 to 25 per cent
of the entire dry finished Board is taken and mixed with about 25 to 35 per cent
of pulverised sulphate of alumina After being thoroughly mixed this compound is
moistened with a solution of zine Chloride in water and stirred until the whole mass
18 thoroughly permeated Only so much Solution must be used as is required for
thoroughly impregnating the mixture, if too much has been used the superfluous
quantity must be removed by well squeezing or pressing the mixture
Solution of zinc chloride for this purpose is best prepared by mixing approximately
equal weights of zinc chloride and water but sinall differences in the composition of
the Solution are not of essential importance to the process as Solutions containing
less anc chloride are also applicable for certain purposes
The
The compound obtained in this way is then further wasbed with common water
which is done in the same manner as the impregnating with the previously

page_text: described Solution and after this it is treated with a Solution of Ammonia in water
and after being washed again with common water it is mixed with a Solution
consisting of one part of resin soap and 8 to 10 parts of water which are mixed
with a similar quantity of Sulphate of Alumina so that the mixture forms a thin
paste This Sulphate of Alumina must however be as chemically pure as possible,
as the ordinary Sulphate of Alumina of Commerce does not give quite satisfactory
results as regards impermeability by water
The impregnations may be made in the rag engine but no superfluous ingredients
must remain in the pulp as they are detrimental to the finished article therefore the
impregnated stuff must each time be properly squeezed or pressed and the
superfluous mixture drained from the ag engine To the pulp thus prepared
about 35 per cent flour of ordinary or commonly called "green Asbestos stone"
then added which if possible is to be prepared by stamping or crushing the stones
in order not to pulverize the fibres contained therein too much
19
Finally about 5 to 8 per cent baryta white is added for coloring and the entie
mass can then as usual in paper manufacture be mixed in the rag engine with
addition of water to a homogeneous pulp and the latter be made into paper or paste
board on Machines in the well known manner or sheets of paper or paste board can
be produced according to the older method by means of hand sieves
In order to make from the fire and waterproof paper or paste board material a
cheap and strong board for covering roofs of light structures ordinary tarred or
otherwise impregnated roofing paste-board paper or felt may be covered either on
one or both sides with a layer or coating of the Asbestos paper or board prepared
in the manner described before in order to protect such roofs against ignition by
sparks In this case the Asbestos compound prepared by the process hereinbefore
described may be placed direct upon the roofing material prepared in the ordinary
manner and fixed by a cementing substance, or the material can be coated with the
prepared Asbestos on the paper or paste board machine in order to felt it together
with the underlying substance and thus to form a fire and waterproof layer on the
roofing board
It is not always necessary to adhere strictly to the sequence of the operations as
described as the whole of the materials to be worked up may be mixed together
and then subjected to the described impregnations and washings and afterwards the
compound may be worked in the usual manner into paper or paste board The
latter process is necessary only if hygroscopic Asbestos is used but the common or
green Asbestos is less hygroscopic and does not require to be impregnated with the
substances described
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim 18
(1) A process for making fire and waterproof board sheet or paper characterized
essentially by the following operations
(a) Mixing of about 20 to 25 per cent of soft Asbestos fibres with about 25 to
35 per cent of pulverized Sulphate of Alumina, (b) moistening this mixture oi
compound as described with a Solution of zinc chloride in water and by preference
with a solution of equal weights of water and zinc chloride to a consistent paste,
(c) treating the compound thus obtained with a Solution of Ammonia, (d) further
treating the stiff paste after washing out the before named chemicals with clean
water with a Solution of resin soap of any constitution in water to which so much
Sulphate of Alumina has been added that it also becomes of a pasty character,
(e) repeating the washing of the compound with clear water and adding about
35 per cent crushed Asbestos stone and about 5 per cent of baryta white for
coloring the entire mixture substantially as herembefore described
(2) The preparation of fire and water proof roofing paste boards by coating
ordinary tarred or otherwise impregnated roofing pasteboard paper or felt either on
one or on both sides with a thin covering of the Asbestos board or paper prepared

page_text: by the method described in the preceding claim or by felting such Asbestos material
with the ordinary paper or paste board stuff on a paper or paste board machine for
the purpose of rendering such paste board or paper impermeable to moisture and to
protect 100fs covered with such material against danger from fire substantially as
bereinbefore set forth and described
Dated the first day of Annul in the rea of our Lord
thousand night