An Improved Impervious Sack or Sacking, and a Method and Means for the Production thereof.
Year: 1893

page_text: 0
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COMPLETE SPECIFICATION.
An Improved Impervious Sack or Sacking, and a Method and Means
for the Production thereof.
I, EMILE PIERRET of Vilvorde in the Kingdom of Belgium, Manufacturess do
hereby declare the nature of this invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:-
The present invention is for the purpose of the production of an impervious
sacking and for the manufacture of sacks or bags therefrom, and it concerns also
a method of manufacturing the said sacking and sacks or bags made thereof and a
machine for the production of the said sacking.
The sacking consists first of a woven fabric or ordinary sacking or other finer
material, made of either flax, jute or hemp. This fabric of suitable coarseness.
according to the use it is to be put to, is coated on one side with a compound
adapted to render it impervious to damp or atmospheric influence. This compound
consists of a mixture of artificial bitumen (refuse from petroleum distillation), pitch
such as is obtained as refuse or residue in the saponification of palm oil, and chalk..
Since the composition of this bitumen varies very greatly and cannot be relied on
for exhibiting always the same physical or chemical characteristics, it is necessary
to find a corrective by addition of a suitable quantity of which the bitumen may
As such a
be brought to a sufficient degree of elasticity and fluidity when hot.
corrective I use soft or hard pitch such as aforesaid, while the chalk is added to
give body to the compound and weaken its oily nature. Convenient proportions.
for the said mixture are 60 to 80 parts of bitumen, 5 to 20 parts of pitch and about
20 parts of chalk.
After application of this mixture, a layer of thin paper such as the so called
silk, hair, or satinised paper is pressed down thereof and adheres thereto to act as
a protection against adhesion of other matters to the compound.
This sacking or material may be prepared in the piece and may then be cut up.
to form sacks or bags.
To make this sacking or material I employ machinery such as is shown in side.
being a cross.
elevation in the diagram Fig. 1 of the annexed drawings, Fig.
sectional view on line ab Fig. 1.
The compound is poured hot into the vessel A heated from below by furnace B..
In this vessel turns a drum C dipping partially into the melted compound in vessel
and kept heated by steam in the usual way such drums are heated. The fabric
rolled on the beam X is carried over guiding rollers to the roller D and between
the cross bar G and the drum C, the fabric passing over the drum becomes coated
on its under side with the compound on the surface of the drum and passes
under guiding roller F upward in front of an adjustable scraper bar H which
removes superfluous compound which flows back into vessel A. Beyond the
scraper H is a smoothing knife K which equalizes the coating, before the fabric
passes on to the roller L. Here paper is brought to the coated surface of the
fabric from a beam L' on which it is rolled and this paper passes with the fabric
between rollers M M which press the whole firmly together. After passing thence
over a sufficient space to allow the compound to solidify the finished fabric is rolled
up on the beam N.
This fabric can now be cut into broad strips for the bodies of the sacks or bags
and narrow strips for the edgings. Figs. 3 to 6 show the fabric P with paper
surface P' having an edge bent over at a to form a selvidge at the open edge of
the sack or bag. Figs. 7. 8 and 9 illustrate the closing of the edges which are to
be closed, by means of cover strips a' sewn through as indicated by the dotted

page_text: lines after being folded in at the corners as shown on a larger scale in Figs. 10
and 11 so that there may be a secure closing at every seam especially at the
corners. By this method of folding at the corners one strip a' only is needed to
close the bottom and one side of the bag, the other side being already closed by
the fold of the body piece of the bag. The papered face should be inside.
Having now particularly described and ascertained the nature of this said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The method and means illustrated in Figs. 1 and 2 and substantially as
herein described for the production of a composition coated and paper faced
fabric.
2. A fabric consisting of a flax, jute or hemp woven material, and having on
the one face an impervious composition and above the same
substantially as and for the purpose set forth.
a paper facing
3. The combination with a woven fabric of a protected composition consisting
of artificial bitumen resulting from the distillation of petroleum, the pitch obtainable
as residue in the saponification of palm oil and chalk.
4. Sacks or bags made substantially as herein described of fabric rendered
impervious by coating cut into one body piece and one edge covering strip, the
latter being folded at the corners as set forth.
Dated this Oth dor of Sontember 1802
R. HADDAN,
Herbert Haddan & Co.,
18, Buckingham Street, Strand, London, Agent for Applicant.