IMPROVEMENTS IN PAPER FELT to be as follows:
Year: 1884

page_text: I ALEXANDER DAVIDSON of Addison Lodge Wimbledon in the County of
Surrey Paper Manufacturer do hereby declare the nature of my invention for
"IMPROVEMENTS IN PAPER FELT to be as follows:-
"
Where paper felt is composed of wool and other fibres it is liable to be penetrated
by moths and other insects. The object of this invention is to prevent this and
also to give a pleasant aromatic perfume to the paper felt. These objects are
attained by incorporating in the paper felt the essence of cedar wood, pine wood,
sandal wood or other aromatic wood, obtained by boiling down or by distilling or
by both or by incorporating in the paper felt the actual substance of any of those
woods having first reduced the same to pulp by mechanical action.
The essence or extract of the wood is got by boiling the wood in water for two
hours or more in a closed vessel by means either of fire directly applied to the said
vessel or by the injection of steam into the said vessel and then straining off the
liquor and mixing it with the pulp out of which the paper felt is made.
The essence or extract may also be got by boiling the wood in a closed retort
and condensing the vapour arising therefrom by means of distilling apparatus the
product so obtained is then mixed with the pulp out of which the paper felt is
made. When the actual substance of the wood is employed the wood itself is
reduced by the ordinary paper making rag engine or by millstones or other grinding
machinery to a fine state of division or pulp and then mixed in any desired
proportion with the pulp out of which the paper felt is made.
CARPMAEL & Co.,
Agents for the Applicant.

page_text: I ALEXANDER DAVIDSON of Addison Lodge Wimbledon in the County of
Surrey Paper Manufacturer do hereby declare the nature of my invention for
"IMPROVEMENTS IN PAPER FELT" and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:
This invention has for its object improvements in paper felt.
61
Paper felt is a very thick paper (say from 1 to 1% of an inch thick) mostly
made from woollen and other rags and in the same way as other paper is made.
It is much used for laying under carpets.
Where paper felt is composed of wool and other fibres it is liable to be penetrated
by moths and other insects. The object of this invention is to prevent this and
also to give a pleasant aromatic perfume to the paper felt. These objects are
attained by incorporating in the paper felt the essence of cedar wood, pine wood,
sandal wood or other aromatic wood obtained by boiling down or by distilling or by
both or by incorporating in the paper felt the actual substance of any of those
woods having first reduced the same to pulp by mechanical action.
The essence or extract of the wood is got by boiling the wood in water for two hours
or more in a closed vessel by means either of fire directly applied to the said vessel
or by the injection of steam into the said vessel and then straining off the liquor
and mixing the same with the pulp out of which the paper felt is made.
To obtain the extract from the woods by boiling I use an ordinary revolving rag
boiler.
I put the wood in in the form of chips or small pieces with the boiler from half
to three quarters full of water, raise the temperature of the contents by fire
directly applied underneath the boiler or by injecting steam until the pressure
reaches about 28 lbs. to the square inch I keep it at that pressure for about 2 hours
then blow off steam and draw off the liquor.
In this way three cwt. of wood will yield 40 to 50 gallons of extract and
this quantity may with advantage be used in the manufacture of one ton of
paper felt.
The essence or extract may also be got by boiling the wood in a closed retort
and condensing the vapour arising therefrom by means of distilling apparatus, the
product so obtained is then mixed with the pulp out of which the paper felt is
made.
To obtain the extract by distillation I place the wood in chips in a stationary
boiler with perforated diaphragın of metal to keep down the wood under the
surface of the water. I raise the temperature by fire or steam jacket underneath
and around the boiler and I conduct the vapour arising from the boiler through a
worm in a vessel kept cold by a continual flow of water through it. The condensed
vapour forms the desired extract for mixing with the pulp.
In this case the proportion of wood may also be about three cwt. to the ton of
paper felt and this will yield by distillation from 8 to 10 gallons of extract.
When the actual substance of the wood is employed the wood itself is reduced by
the ordinary paper making rag engine or by millstones or other grinding machinery
to a fine state of division or pulp and then mixed in any desired proportion with
the pulp out of which the paper felt is made.
When the wood fibre is thus incorporated into the substance of the paper felt
four hundred weight of wood to the ton of paper pulp will be found a suitable
proportion.

page_text: These quantities may however be varied within wide limits and more or less
protection against the ravages of moths and insects obtained.
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 is :-
-
First In the manufacture of paper felt incorporating with the pulp the essence
of cedar wood, pine wood, or other aromatic wood substantially as herein
described.
Second-In the manufacture of paper felt incorporating with the pulp, cedar
wood, pine wood or other aromatic wood, pulped ground or in a fine state of
division substantially as herein described.