-

1. * GB785814 (A)
Description: GB785814 (A) ? 1957-11-06
Improvements in or relating to the production of articles from aluminium
nitride
Description of GB785814 (A)
Translate this text into Tooltip
[75][(1)__Select language]
Translate this text into
The EPO does not accept any responsibility for the accuracy of data
and information originating from other authorities than the EPO; in
particular, the EPO does not guarantee that they are complete,
up-to-date or fit for specific purposes.
PATENT SPECIFICATION
Inventors: RAYMOND BOLLACK and MARCEL REY 785,814 4 Date of
Application and filing Complete Specification April 16, 1956.
No 11559156.
Complete Specification Published Nov 6, 1957.
Index at Accepttance:-1 -iass 227, J(I 2: 7: 1 i 2: 16: 21: 24 33).
International Classification: -uC 04 b.
COMPLETE SPECIFICATION
Imnprovenments in or reltammzg to the Prodluction of Articles from
Alum inium Nitride We, SOCIETE D'ELECTRO-CHIMIE, D'ELECTRO-METALLURGIE
ET DES ACIERIES ELECTRIQUES D'UGINE, a French body corporate, of 10,
Rue du General Foy, Paris (Seine), v France, do hereby declare the
invention, for which we pray that a patent may be granted to us, and
the method by which it is to be performed, to be particularly
described in and by the following statement:-
This invention is concerned with improvements in or relating to the
production of articles from aluminium nitride.
Aluminium nitride which has the general formula AIN, is a very hard
industrial material having a hardness on Mohs' scale of 9; it is
chemically inert at temperatures up to 20000 C unless submitted to an
oxidising atmosphere and it is particularly resistant to liquid or

2. gaseous aluminium Its dissociation tension is nil at 20000 C and its
melting point is 22300 C Furthermore aluminium nitride possesses good
thermal conductivity and very poor electrical conductivity.
In view of these properties, aluminium nitride could advantageously be
used industrially as a refractory or abrasive material; however,
attempts to produce manufactured articles of aluminium nitride
hitherto have, for one reason or other, been unsuccessful or
uneconomic.
If a refractory material composed only of aluminium nitride is
required, the nitride must be agglomerated by sintering and this
necessitates heating the material to a temperature of 1800 to 20000 C,
which renders the cost of the product prohibitive If, on the other
hand, a refractory composed of aluminium nitride agglomerated by a
ceramic bond is sufficient, the requisite bonding may he obtained at
industrially economic temperatures, for example about 14000 C, but the
refractory properties of the nitride are then partly impaired.
lPrice 3 s 6 d l The nitriding of alumina in situ has been proposed
for the fabrication of these products, but owing to the fact that the
molecular volume of alumina is higher than that of aluminium nitride,
the products obtained by this procedure have a porous structure which
impairs their refractory properties.
Other methods, employing carbon, are unsatisfactory as they give rise
to products wvhich are unstable in the presence of atmosphere moisture
due to the fact that they contain aluminium carbide.
It is therefore an object of the present invention to provide a
process for the commercially economic production of articles composed
principally of aluminium nitride, which articles possess substantially
the same properties as aluminium nitride.
According to the present invention, there iv provided a process for
the production of articles from aluminium nitride which cornprises
intimately mixing powdered aluminium nitride having a particle size of
not more than 1 mm, a minor proportion of one or more powdered metals
of group m, IV or V of the periodic classification having a particle
size of not more than 1 mm, a non-aqueous binder capable of increasing
the compactness of the mixture on moulding and of being completely
removed from the mixture after moulding, and a non-aqueous solvent for
the binder, removing the solvent from the intimate mixture, moulding
the resulting mixture into the desired shape under pressure and
heating the moulded mixture at a temperature above 500 C in a
nitriding atmosphere substantially free from oxidising gases and
gaseous carbides, out of contact with carbon, the proportion of metal
to aluminium nitride in the initial mixture being such that the
article obtained after firing has a higher compactness than the
mixture after moulding.

3. The product obtained by the process 785,814 according to the invention
is composed essentially of aluminium nitride crystals assembled in a
compact structure and bonded together by the nitride(s) of the
metal(s) of group III, IV or V of the periodic classification.
The particle size distribution of the constituents of the aluminium
nitride and metal mixture should be such that its compactness, which
expresses the relationship between the apparent volume and the actual
volume of the powdered mixture, is as great as possible It is also
necessary to eliminate aluminium nitride particles in the form of
aggregates of porous and brittle crystals and this may be done, when
employing industrial aluminium nitride as the starting material, by
eliminating particles of a size greater than 1 mm.
The particle size distribution giving the maximum compactness may be
continuous or discontinuous The first is given by the general equation
of Wilhelmi: Y=A+( 100 A&; ( where Y is the percentage by weight of
particles whose apparent diameter is less than a, and D the largest
particle of the mixture; the exponent N varies from 0 3 to 0 5 The
particular forw of this general equation most used in Europe is
represented by the Boloney parabola which relates to permanent
structures d Y= 12 + 88 D Discontinuous particle size distribution is
obtained by eliminating a part or the mole of one or more fractions of
particles of a chosen size from a powdered material with continuous
particle size distribution Typical particle size distributions which
are suitable for the materials to be used in the process according to
the invention are, for example, as follows: Particle size Particle
size distribution A distribution B Components (parabolic), %
(discontinuous), %.
Particles from 0 5 to 1 mm 30 50 Particles from 0 1 to 0 5 mm 40 10
Particles below 0 1 mm 30 40 With either type of particle size
distribution the maximum compactness which can be obtained after
moulding the mixture, but before fixing is approximately 74 %.
The proportion of metal to aluminium nitride in the initial mixture is
a critical feature of the process according to the invention.
Theoretically the quantity of metal to be included in the initial
mixture should be such that the secondary nitride formed from this
metal completely fills the voids between the particles of the orginal
2 Auminium nitride.
This void must be at least equal to 100-74 = 26 % by volume and to
fill it completely, it may be calculated that at least the following
proportions of metal (based on the combined weight of metal and
aluminium nitride) will be required:22 % of powdered aluminium or 23 %
of powdered silicon or 45 % of powdered titanium or 48 % of powdered
vanadium these meals being chosen as typical examples within the
invention, as each belongs to one of the groups m, IV and V of the

4. periodic classification For the purpose of this invention silicon is
to be considered as a metal.
It is found in practice, however, that if the theoretical quantities
of pulverulent metals are employed in the initial mixture, a part of
the the molten metal exudes to the surface of the moulded article with
consequent loss of metal and obstruction or blocking of the pores of
the moulded mixture so that the interior of the mixture is not
nitrided; the finished article thus remains porous.
We have found by experience that to obtain compact articles, the most
suitable proportions are about one half of the theoretical proportions
calculated as above, that is to say: % 2 % of aluminium 12 % 2 % of
silicon %+ 4 % of titanium 22 % 4 % of vanadium Suitable binders for
use in the process according to the invention are organic compounds of
high molecular weight which are soluble in organic solvents Examples
of such binders are industrial waxes, such as paraffin waxes, ceresine
and ozokerite, and highly viscous polyglycols Such binders have the
requisite bonding and lubricating properties, the latter allowing the
particles of the mixture to slide over each other so as to take up
positions giving the highest compactness, under the moulding pressure.
Suitable non-aqueous solvents for the binder, in particular the
binders specifically mentioned above will be apparent to those skilled
in the art In general all organic solvents for waxes are suitable; the
least expensive of these is trichloroethylene.
In order that the invention may be well understood the composition of
certain suitable 785,814 initial mixtures which give good results (the
parts being by weight) will now be given, by way of illustration
only:MIXTURE 1 > Aluminium nitride, (particle size distribution
A)Powdered aluminium for paints sized 100, and finer Ceresine
TrichlorethyleneMIXTURE 2 Aluminium nitride, (particle size
distribution B) Iron-silicon alloy containing 96 + 2 % Si sized 75
pand finer Ceresine Trichlorethylene MIXTURE 3 Aluminium nitride,
(particle size distribution B) Sponge titanium pulverised 100 k and
finer Polyglycol 400 TrichlorethyleneMIXTURE 4 Aluminium nitride,
(particle size distribution A) Iron-vanadium alloy containing 78 %
vanadium pulverized 150 u and finer Ozokerite Trichlorethylene 2 12 2
3 22 4 As already stated the mixtures whose compositions are set out
above are given by way of example only and combinations of other
metals from groups III, IV or V of the periodic classification, other
binders and other solvents may be used Thus in Mixture 3 above, the 20
% of pure titanium may be replaced by 18 % of titanium-aluminium alloy
(containing 72 % of titanium) pulverised to a fineness of 100 ga.
The preparation of the initial mixture used in the proces according to
the invention is preferably carried out in three stages Firstly the
powdered metal, the binder and the solvent are intimately mixed in a

5. suitable mixer, the mixture obtained is then poured on to the powdered
aluminium nitride which is contained in a second mixer and all the
constituents of the mixture are thoroughly mixed together Finally the
solvent is evaporated whereby the mixture takes on a sand-like
consistency; it is then ready for moulding.
Moulding is preferably carried out in steel moulds under hydrostatic
pressure The most compact manufactured articles are obtained by
pressing the sandy mixture slowly under a high pressure, which should
not however exceed approximately 3000 kg/cm', the moulds being kept at
a temperature of about 800 C.
Nitriding of the moulded mixture may be carried out directly by
heating the formed articles at a temperature above 5000 C pre 65
ferably at 14000 C or higher, in, for example an electric furnace, and
in a nitriding atmosphere The nitriding atmosphere may consist of
purified commercial nitrogen, or ammonia, or a mixture of these two
gases, provided how 70 ever: that these gases or their mixtures do not
contain more than 0 3 % of oxygen in any free or nascent state,
arising for example from the decomposition reaction CO 2 =CO+O The
articles should also be prevented from coming 75 into contact with
carbon during the firing, as if they do the nitrides are decomposed
and the corresponding carbides are formed in their place; the latter
are undesirable as they are unstable and decompose in the presence of
80 atmospheric moisture with the result that if carbides are present
to any appreciable extent in the products of the invention the latter
tend to split and break up when stored in cold air.
For the same reason it is also highly desirable 85 to avoid the
presence of gaseous carbides in the nitriding atmosphere.
After such treatment, relatively compact articles are obtained but
their compactness does not exceed 78 % Although such a result 90 is in
accordance with the invention, a modification of this nitriding
procedure has been developed whereby articles having a compactnes of
88 % or more may be obtained.
According to this modification the moulded 95 mixture is first fired
at a temperature of about 4500 C in an oxidising atmosphere, for
example in air; this initial firing eliminates all carbon from the
article so that no carbon which may impair a part of the nitride by
car 100 bonisation is present during the further firing.
The article at this stage is porous and brittle and holds in its pores
adsorbed oxygen which, if it were not removed prior to the succeeding
nitriding treatment, would oxidise the 105 powdered metal In order to
remove this adsorbed oxygen from the fired article it is maintained in
an atmosphere of amomnia for about 48 hours; by this treatment ammonia
replaced the adsorbed oxygen and the weight 110 of the article
increases by 10 % or more.

6. The article is then submitted to a nitriding treatment as described
above, that is to say it is heated at a temperature above 5000 C,
preferably of 1400 C or more in a nitriding 115 atmosphere.
The articles obtained by the process according to the invention show
no irreversible variation in volume, not only after firing, but also
after long storage in cold air They may be 120 employed for all
refractory purposes, for example as furnace linings, muffles,
crucibles, burners and diffusers, even under reducing conditions; they
are also suitable for all abrasive purposes, for example as grinding
wheels, 125 785,814 buffing stones, cutting stones, wire drawing dies
and thread guides, and for combined abrasive and refractory purposes.
* Sitemap
* Accessibility
* Legal notice
* Terms of use
* Last updated: 08.04.2015
* Worldwide Database
* 5.8.23.4; 93p
* GB785815 (A)
Description: GB785815 (A) ? 1957-11-06
Improvements relating to methods of and apparatus for analysing gases
Description of GB785815 (A)
A high quality text as facsimile in your desired language may be available
amongst the following family members:
FR1133575 (A)
FR1133575 (A) less
Translate this text into Tooltip
[79][(1)__Select language]
Translate this text into
The EPO does not accept any responsibility for the accuracy of data
and information originating from other authorities than the EPO; in

7. particular, the EPO does not guarantee that they are complete,
up-to-date or fit for specific purposes.
COMPETE SPECIFICATION
Improvements relating to Methods of and Apparatus for Amalysang Gases
I, EIEINRICH FEICHTINGER, a citizen of
Liechtenstein, of Place Chevelu 6, Geneva,
Switzerland, do hereby declare the invention, for which I pray that a
patent may be granted to me, and the method by which it is to be
performed, to be particularly described in and by the following
statement:
Methods of analysing gases are known in which the gases are reacted
with various absorption or other reagents in several stages and in
which the component gases are determined quantitatively from the
volumes of gas absorbed from time to time in the process. In these
cases, the gases are frequently tested in a single reaction chamber
which, according to the course of the analysis operation, is filled in
stages with the different reagents. Owing to the charging with
absorbents and to the washing out of the reaction chamber necessary
before and after each charge, however, gas residues or residues of
other substances are left from time to time which frequently cause
appreciable errors of measurement, so that precision analyses, in
particular analyses of small volumes of gas, cannot be carried out
therewith. It is furthermore, known, in gas microanalysis methods, to
measure the gas volumes in graduated capillary tubes, similar errors
of measurement however occur.
Finally, it has also already been proposed to convey the gas to be
analysed through different reaction chambers arranged in series.
However, as the latter are separated from one another by cocks or
valves, dead spaces occur in which gas residues are left behind and
which again cause inaccurate measurements.
The object of the present invention is to provide a method of, and
apparatus for carrying out gas analyses, even of small volumes of gas,
quickly and with precision.
Amongst other purposes, such analyses are commonly made of the flue
gases of blast furnaces for the purpose of controlling the ore
refining operation. According to the invention, this is achieved
essentially by forcing the mixture of gases to be analysed step by
step through a series of interconnected chambers, in each of which the
mixture is reacted with an absorbent or other reagent, by means of a
conveying liquid, the volume of the mixture entering or leaving each
chamber at a constant pressure being determined by measuring the
volume of conveying liquid required to force the mixture past a
measuring mark associated with the chamber.

8. Thus, in the method according to the invention, the volume of gas runs
through various measuring and absorption stages in an always constant
direction since the chambers are connected in series with each other
and is measured indirectly on passing the measuring marks provided in
the individual measuring and absorption stages.
Dead spaces and gas residues which are not determinable are thereby
completely obviated. The conveyance of the volume of gas to be
analysed is therefore effected exclusively by means of the hydrostatic
pressure of the conveying or displacement liquid or of the absorption
solution. Mercury, oil or some other suitable liquid is expediently
used for the former. It is, therefore, also possible for a
displacement liquid to be employed which dries the gas, or effects a
partial absorption which is desired to begin with, for example if
potash lye is used, which dissolves the COn out of the gas but does
not affect the other components.
Advantageously, for carrying out the method according to the invention
an apparatus is used which comprises a gas measuring chamber and two
or more absorbent or reaction chambers directly connected together in
series by capillary tubes, each chamber communicating with a pressure
equalizing vessel, the capillary tubes each having a measuring mark,
and means for forcing a measured volume of a conveying liquid through
the chambers, whereby the mixture or gases to be analysed is carried
into and through the chambers
With the chambers connected together in series, each intermediate
chamber has at least two capillary tube connections on opposite sides
and the mixture of gases and the conveying liquid pass into the
chamber through one connection through the chamber and out through
another connection. Since the connections between the chambers are
direct, that is to say there are no valves or cocks in the capillary
tube, the possibility of leakage occurring during the passage of the
gas between the chambers or the trapping of small quantities of gas in
dead spaces caused by valves, both of which occurrences would cause
inaccuracies in the analysis, is avoided. Control of the volume of gas
within the measuring and reaction chambers is carried out by opening
from time to time a valve which allows the pressure equalizing vessel
belonging to the chamber in question to communicate with the
atmosphere. In this way, the volume of gas to be analysed can be
carried round on its path as desired, without passing through shutoff
devices.
Two examples of apparatus according to the invention are illustrated
diagrammatically in the accompanying drawings in which:
Figure 1 shows a first embodiment of the gas analysis apparatus; and
Figure 2 shows an alternative arrangement of the measuring and
reaction chamber system.

9. The apparatus shown in Figure 1 is suitable for analysing mixtures of
gases, containing Carbon dioxide, Carbon monoxide,
Hydrogen and Nitrogen. The chamber system serving for the actual
analysis comprises a preliminary gas measuring chamber 1 and reaction
chambers 2 and 4 which are in communication with pressure equalizing
vessels 1', 2' and 4', respectively, each of which in turn is arranged
to be dosed by means of a valve 6, 7, 8. Between the reaction chambers
2 and 4 there is provided a sealing chamber 3 equipped with a bell 17.
The sealing chamber 3 is partly filled with a sealing liquid, for
example paraffin oil or silicone oil, which prevents the mixing of the
liquids provided in the chambers 2 and 4 or the migration of ions, and
has a deaerating closure device 10. On the outlet side of the chamber
4 a gas outlet chamber 5 is connected, which is also arranged to be
closed by means of a valve 9. All the chambers 1 to 5 are enclosed by
a jacket provided with inlet and outlet connections 13 and 13',
respectively, and through which a liquid is circulated for maintaining
the reaction chambers and measuring positions at a uniform temperature
and which also strengthens the apparatus.
The gas measuring chamber 1 is connected in series through the feed
pipe 18 with a gas collecting chamber 23 which is connected by way of
the valve 22 to the gas feed pipe 19 and by a flexible tube to the
levelling vessel 20 for receiving conveying liquid. To the gas
collecting chamber 23 there can furthermore be connected, through a
valve 24', a vessel 24 from which absorbents or suitable sealing
solutions can be introduced into the chamber 23. In addition, a feed
pipe 25' which can be closed by a valve 25 and which enables special
reaction gases, for example oxygen, to be supplied, is also provided.
Finally, there is also connected to the gas collecting chamber 23 a
supply container 26 for the conveying liquid which is constructed as a
pressure cylinder and the piston 27 of which is coupled to a precision
dial gauge 32 indicating the quantity of liquid displaced by said
piston. The displacement of the pressure piston 27 is effected by
means of a rack and pinion gear 31 or the like. The piston 27 is
advantageously provided with a plurality of packing rings 28, 23' and
30, in the intermediate spaces 29 and 29' of which there is a suitable
lubricant. The main sealing action is produced by the packing ring 28,
while the packing 30 prevents the lubricant 29' from flowing away to
the outside.
The result of this is that the main packing 28 is surrounded both in
front and at the back by the same lubricant, so that it is evenly
lubricated both on forward and on rearward movement, the lubricant
simultaneously acting as a seal. In fact, when the piston is moved
forward, a thin sealing film of lubricant travels out of the space 29
into the space 29' between the wall of the cylinder 26 and the packing

10. ring 28. On reverse movement of the piston, substantially the same
quantity of the sealing lubricant travels back again. In this way,
therefore, a measuring piston is obtained which enables very accurate
volumes to be displaced on forward and rearward movement and penmits
of reading said volumes off on the precision dial gauge 32.
At the start of the analysis, all the chambers and connecting pipes or
tubes of the apparatus are filled with displacement liquid. sealing
solution or liquid reagent and all the valves and cocks are closed. By
opening the cock 19' and lowering the levelling vessel 20, the gas to
be analysed is sucked into the supply container 21. Thereafter, the
cock 19' is closed, the valve 22 opened and the gas or a partial
quantity of the gas is introduced into the gas collecting chamber 23
by means of a rearward movement of the piston 27. The valve 22 is
thereupon closed, the valve 6 opened and the quantity of gas forced
through into the preliminary measur ing chamber 1 by forward movement
of the piston 27. By opening the valve 7 for a short time, the voluine
of gas is then allowed to advance into the transfer capillary tube
between the chambers 1 and 2 as far as a measuring mark 14, the piston
27 being moved forward a little. With the valve 6 open, the fluid
levels in the two chambers 1 and 1' can be equalized by a suitable
movement of the piston, the volume of gas contained in the chamber 1
is thus brought to outside pressure conditions. If the upper parts of
the pressure equalizing vessels 1', 2', 4' are in direct communication
with the atmosphere, the pressure is of course atmospheric; if as is
shown in the case of the vessel 1', the upper part of the pressure
equalizing vessels is closed against the external pressure by means of
a cap or dome 38, pressure equalization takes place through a
connection 39 and is equal to the pressure in a gas container 40. In
this case, the valve 6 is lifted, for example, by an electromagnetic
opening device 41. Closing the pressure equalizing vessels against the
atmosphere is only necessary when absolute gas measurements which are
independent of the atmospheric pressure and temperature are carried
out. In most cases, when it is only a question of determining gas
compositions on a percentage basis, the gas container 40 and the
closure 38 against the atmospheric pressure can be omitted, so that
the upper part of the equalizing vessels is in communication with the
atmosphere, as, for example, as is shown for the equalizing vessel 2'.
As soon as the quantity of gas in the chamber 1 which is to be
analysed has been brought to the desired pressure conditions, the
valve 6 is closed, the dial gauge 32 is set at zero and the valve 7
opened. Then the gas is transferred from the chamber 1 to the
succeeding second stage, that is to the reaction chamber 2. Initially
the gas is only displaced until the displacement liquid reaches the
measuring mark 14. In this way.

11. the quantity of gas transferred is determined indirectly by measuring
the quantity of conveying liquid required for forcing the quantity of
gas past the measuring mark 14.
This quantity can be read from the precision dial gauge 32.
The gas is then completely transferred to the reaction chamber 2 and
the combustible component of the gas is burned by means of an ignition
coil 11 disposed therein. The remaining gas is thereafter brought up
to the next measuring mark 15 by raising the valve 8. If it is
necessary to add oxygen to the gas for combustion, the oxygen is
sucked in by way of the cock 25 through the first measuring stage 1
into the second measuring stage to the gas sample and is measured in
addition to the sample. After combustion, the measurement of the
volume of the gas is effected by the measuring method described for
the previous stage. If the pressure equalizing vessel 2' were closed
against the atmospheric pressure similarly to the vessel 1', the upper
part of the pressure equalizing vessel 2' would similarly be in
communication with the common gas container 40.
However, this has not been shown to simplify the drawing. After the
gas has been conducted completely through the sealing chamber 3 into
the last reaction chamber 4, which, in the case of the present
combination of gases, is filled, for example, with aqueous caustic
potash, the carbon dioxide produced during the combustion is absorbed
therein. Thereafter, measurement of the residual volume is effected at
the measuring mark 16, while the unabsorbed remainder of the gas is
finally expelled with the valve 9 open.
By means of the above-described method of operation the volumes of gas
are measured by the volume of liquid required to convey them and are
thus measured at the same time as they are conveyed thus greatly
reducing the time taken for the analysis. As there are no dead spaces
along the entire path of the gases through the apparatus which would
cause erroneous measurements, the method produces very accurate
results, even if only small quantities of gas of about 0.1 cc and less
are available for the analysis.
If less accurate gas analyses are to be carried out with the
apparatus, the conveyance of the gases is effected solely by the
levelling vessel 20, instead of by the piston 27 coupled to the
precision dial gauge 32.
In this case, the procedure is as follows:-
With the valves 22 and 6 open, the quantity of gas introduced through
the cock 19' into the supply container 21 is conveyed into the
measuring chamber 1 by raising the vessel 20. By opening the valve 7
for a short time, the gas is forced into the transfer capillary tube
as far as the mark 14. Then, with the valve 6 open, equality of the
levels is produced in the two chambers 1 and 1' by raising or lowering

12. the levelling vessel 20 and at the same time the liquid level is read
off in the levelling vessel 20 which is provided with a suitable
calibration. There after, the valve 6 is closed, the valve 7 opened
and by raising the vessel 20 the gases are again forced out of the
chamber 1 through the capillary tube into the chamber 2 until the
following liquid reaches the measuring mark 14. The valve 22 is again
closed and the new level is read off in the vessel 20. In this case,
the quantity of gas transferred again corresponds to the quantity of
conveying liquid displaced, and this can easily be determined from the
difference in the two readings at the levelling vessel 20.
On transfer to the further reaction stages or chambers, the same
procedure is followed.
The calculation of an entire analysis is obtained in the case of the
present type of gas from the quantity of gas introduced, which is
measured when the measuring mark 14 is passed, the contraction on
combustion, which is determined from the quantity of gas passing the
mark 15, and the absorption of carbon dioxide which can be read off at
the measuring mark 16. If the gas in the reaction chamber 2 is not
burned, the pure carbon dioxide content of the gas to be analysed can
be determined when the quantity of gas travels past the mark 16.
The apparatus shown in Figure 2 corresponds in principle to that shown
in Figure 1, but in this case two reaction chamber systems are
arranged in parallel and are directly interconnected without the
interposition of cocks or valves, through a distributor element 33
arranged after the gas collecting chamber 1 and its associated
measuring mark 14. The gas to be analysed is conducted through the
distributor element 33 either to one chamber system shown on the left
in the drawing, or the other right-hand chamber system, according to
requirements.
A gas sample is again received from the gas collecting chamber 21
(Fig. 1) through the chamber 23. The gas sample is transferred into
the collecting chamber 1 with the valve 6 open (Fig. 2). From the
collecting chamber, the gas sample can either follow the righthand
absorption path by opening the valve 34 or the left-hand absorption
path by opening the valve 36. Thus, two analyses are carried out in
this case for determining the quantities of two gas components,
reaction chambers 2 being charged with an absorption solution or solid
absorbents which absorb one of the gas components to be analysed,
while other reaction chambers 4, which are charged with another solid
or liquid absorbent, absorb the other component. It should be noted in
this case also that transfer is effected by way of the distributor
element 33 without the gas having to pass through a cock or valve in
the process.
Of course, it is also possible, instead of using the two-part gas

13. analysis apparatus shown in Figure 2, to design the apparatus so that
three or even more capillary tubes meet at the distributor element 33,
so that the gas coming from the collecting or preliminary measuring
chamber 1 can be conducted through suitable distributing pipes into an
equal number of the above-described absorption chamber systems and be
analysed therein. The distributor element 33 and the valves 34, 35,
36, 37 indirectly controlling the conveyance of the gas, thus render
it possible to combine as many analysis sys- tems as desired into a
single directly interconnected structural unit and to house them in a
common enveloping jacket containing circulation water at a constant
temperature.
so that uniform pressure and temperature conditions prevail everywhere
at the measuring and reaction positions.
If solid absorbents are to be used for certain gas absorption
operations, they are introduced into the individual absorption
chambers. In such cases, it is necessary to provide the individual
absorption chambers with additional closure devices through which the
solid absorbents are introduced or exchanged. For the sake of clarity,
such closures, for example ground glass stoppers, have not been shown
in the drawings.
What I claim is:
1. A method of quantitatively analysing a mixture of gases in which
the mixture is reacted in stages with absorbents or other reagents,
the change in volume of the mix- ture after each reaction being
measured, wherein the mixture is forced step by step through a series
of interconnected chambers by the pressure of a conveying liquid, the
volume of the mixture entering or leaving each chamber at a constant
pressure being determined by measuring the volume of conveying liquid
required to force the mixture past a measuring mark associated with
the chamber.
2. An apparatus for quantitatively analysing a mixture of gases,
comprising a gas measuring chamber and two or more absorbent or
reaction chambers directly connected together in series by capillary
tubes each chamber communicating with a pressure equalizing vessel,
the capillary tubes each having a measuring mark, and means for
forcing a measured volume of a conveying liquid through the chambers,
whereby the mixture of gases to be analysed is carried into and
through the chambers.
3. An apparatus according to Claim 2, in which the pressure equalising
vessels each have a valve for shutting off the vessel from the
associated reaction chamber and the means for forcing the conveying
liquid through the chambers comprises a storage vessel arranged to
discharge a measured volume of liquid into the gas measuring chamber.
4. An apparatus according to Claim 3, comprising two or more systems

14. of reaction chambers arranged in parallel, the chambers in each system
being in series, and the first chamber of each system communicating
with the gas measuring chamber.
5. An apparatus according to Claim 3 or
Claim 4, having a sealing chamber for containing a sealing liquid
arranged between two reaction chambers, which prevents mixing together
of liquids contained in the reaction chambers but allows gases to pass
between the chambers.
6. An apparatus according to any one
* GB785816 (A)
Description: GB785816 (A) ? 1957-11-06
Combination radiant and convection heating system
Description of GB785816 (A)
PATENT SPECIFICATION
Date of Application and filing Complete Specification: August 29,
1955.
7859816 No 24758/55 ' Y 5 J J J Application made in United States of
America on September 1, 1954 Complete Specification Published:
November 6, 1957
Index at acceptance:-Classes 64 ( 2), G 1 A 5; 64 ( 3), 523 A; and
137, B 3 E.
International Classification:-F 24 d, f F 25 h.
COMPLETE SPECIFICATION
Combination Radiant and Convection Heating System We, VAPOR HEATING
CORPORATION, a corporation of Delaware, United States of America, 80,
East Jackson Boulevard, Chicago, Illinois, United States of America,
we pray that a patent may be granted to do hereby declare the
invention,,for which us, and the method by which it is to be
performed, to be particularly described in and by the following
statement:-
JO The improved heating system comprising the present invention has
been designed for use primarily An connection with the heating of
buses, house trailers, and other road vehicles The system is, however,

15. capable of other uses, for example, the heating of railway passenger
cars and other similar vehicles.
Specifically, the present invention relates to an improved system of
"trench heating", so-called because the heat radiating
instrumentalities proper are disposed within a trench-like depression
formed in a floor structure wherein they underlie the main floor and
are thus concealed from view.
It is among the principal objects of the invention to provide an
improved trench heating system for road or railway vehicles of the
type outlined above in which the heating effect obtained within the
enclosure to be heated As partly the result of heat radiation from the
main floor of the vehicle and partly the result of air entering the
trench and directed into contact with the heat radiating element of he
system, whereby the air is heated and passes through openings into the
enclosure, the heating effect produced in either instance being of a
uniform nature at all regions within the enclosure to produce uniform
temperature distribution and consequent maximum occupant comfort.
Another object of the invention, in a heating system of this
character, relates to the constructional aspects of the vehicle
wherein the heat radiating devices per se are assembled and installed
within a duct construction which constitutes a "package type" unit
capable of being manufactured at the factory as a prefabricated
transportable sub-assembly for shipment to the 5 e vehicle assembly
plant for installation in the floor trench of the vehicle sub-floor
during assembly of the vehicle body for subsequent connection in the
heating system 55 The provision of a duct construction or sub-assembly
of the type briefly outlined above which, in the main, may be
constructed of sheet metal and which therefore may be manufactured at
a low cost; one 6 G, which is of light weight construction, and one
which may with but slight modification or variation in its
constructional details be adapted for use in dfferent environments to
accommodate vehicles having differently 65 compartmented enclosures,
are further desirable features that have been borne in mind in the
development of the present invention.
In the accompanying drawings forming 7 O.
a part of this specification, several embodiments of the invention
have been shown.
In these drawings:
Fig 1 is a perspective view, somewhat schematic in its representation,
of an en 75 closed vehicle, for example, a house trailer to which the
heating system of the present invention has been applied; Fig 2 is an
enlarged fragmentary sectional view taken on the vertical plane re 8 B
presented by the line 2-2 of Fig 1; Fig 3 is a fragmentary perspective
view, partly in section, of a portion of the floor construction of the

16. vehicle of Fig 1 showing the heating system of the present in 85
vention applied thereto; Fig 4 is a fragmentary sectional view taken
substantially centrally and vertically through the rear end of the
vehicle shown in Fig 1; 9 O ,' 785,816 Fig 5 is a fragmentary plan
view of a portion of the sub-assembly units employed in connection
with the invention with the top plate thereof removed; S Fig 6 is a
fragmentary perspective view partly in section, of a modified form of
sub-assembly; and Fig 7 is a fragmentary perspective view similar to
Fig 6 showing another modified form of sub-assembly.
Referring now to the drawings in detail and particularly to Fig 1, the
heating system of the present invention has been shown as being
applied to a house trailer coach 10 but it will be understood that the
illustration is purely exemplary and the system may, with or without
modification, be used for the heating of buses or other road vehicles
or rolling stock such as railway passenger cars.
The coach 10, with certain exceptions that W 1 l appear presently, is
of conventional design and includes a composite floor 11, composite
side walls 12 and 13 (Fig.
2) and composite front and rear walls 14 and 15, respectively The
coach further includes a top wall or roof 16 which may be of a
suitable insulated type and which bears no specific relation to the
prosent heating system other than to complete the trailer enclosure 17
undergoing heating.
The composite floor 11 is best illustrated in Figs 2 and 3 and
comprises a sub-floor supported from a pair of longitudinally
extending metal side sills or beams 21 The sub-floor includes upper
and lower spaced sheet metal members 22 and 23 between which there is
interposed a suitable insulating material 24 which is preferably
either preformed or of the package type The members 22 and 23 may be
unitary or these expanses may consist of overlapping widths of the
sheet material The central regions of the sheet metal members 22 and
23 are deformed to provide a longitudinal trough or trench 25 which
extends substantially the entire length of the coach floor 11 and in
which trench there is adapted to be installed a completely assembled
"packagte type" heating unit, three forms of which have been
'illustrated ini Figs 3, 6 and 7, respectively, and which,
independently and in combination with the heating system as a whole,
constitutes a novel feature of the present invention The details of
these units Will be set forth presently.
Supported at their ends on longitudinally extending wooden beams 27,
which may be of the 2 " x 4 " variety are a plurality of d 60
transversely extending interlocking main floor channels 28 having side
flanges 29 (see also Fig 4) and intermediate depending ribs or flanges
30 The side flanges 29 are supported on the sub-floor assembly 20 and

17. the ribs 30 are of lesser extent than the flanges 29 so that there is
a clear air space or duct 35 within each channel 28.
The channels 28 are preferably formed of aluminum on account of the
lightness of this metal and also on account of its ex 70 cellent
heat-conductive qualties A baffle 36 (Figs 2 and 3) extends
longitudinally of the vehicle through slots 37 formed:n the ribs 30 of
the floor element 28 for air distribution purposes as will be
described 75 subsequently A bottom shield or plate 38 is coextensive
with the floor 11 and is secured at its longitudflinal edges to skirts
49 which depend from the side sills 21.
The side walls 12 and 13 are of sim:lar 80 construction and each wall
includes an outer panel or "skin" 41, an intermediate wall panel 42
and an inner panel 43 which in part defines the enclosure 17 The
panels 41 and 42 are secured as by welding or 85 riveting to vertical
sill flanges 44 and insulating material 24 is disposed between these
two panels The inner wall panel 43 is supported at its lower edge by
means of curved metal strips 45 from the interlock 90 ing channels 28
The space 46 exist ng between the panels 42 and 43 communicates with
the various ducts 35 existing within the channels 28 Longitudinally
extending resilient sealing members 47 are supported 95 on the side
sills 21 between the wooden beams 27 and the inner sill flanges 44 The
side walls 12 and 13 are provided with the usual window openings 50
and, as shown in Figs 2 and 4, louvered air dischar-e 100 openings 51
establish communication be.
tween the space 46 and the enclosure 17 immediately below the window
openings 50.
The rear wall 15 (Fig 4) includes inner and outer wall panels 52 and
53, respec 105 tively, between which there is contained in.
sulating material 24 A space 54 is provide-1 for intake of air from a
louvered opening (see also Fig 1) and this space communicates with the
trench 25 through a 110 suitable blower 56 by means of which air is
circulated through the passages provided for it by the heat Ing system
as will be de.
scribed when the operation of the system is set forth A damper 57 on
the inner wall 115 panel 54 regulates the volume of fresh air admitted
to the system and also allows air within the enclosure 17 to be
proportionately recirculated through the svstem, an opening 58 being
formed in the wall panel 120 54 for this purpose.
In Figs 3, 6 and 7 there have been shown three forms of heating and
heat distributing assemblies capable of being operatively installed
within the trench 25 beneath the 125 floor channels 28 for operative
connection in the heating system Each of these assemblies is in the
form of a "package type" unit capable of being manufactured and
assembled at the factory and shipped ii 130 785,816 its entirety to

18. the coach assembly plant for installation purposes The unit shown in
Fig 3 is designated in its entirety at 60 and includes an elongated,
trough-like, US shaped member 61 of sheet metal having a flat bottom
62, and upstanding side walls 63 provided with laterally turned
flanges 64 extending along their upper edges A cover plate 65 extends
across the trough l O member 61 and is suitably secured to the flanges
63 by spot welding or screws, thus providing a tubuiar casing
structure.
Nested within the trough member 61 is an elongated duct or partition
member 66 i S ot irregular V-shape design -The duct member 66 is
suitably secured within the trough member 61 as by welding and is
provided with generally inclined side walls 67 which serve to divide
the composite tubular member 65, 66 into three longitudinally
extending air passages including a central passage 68 and side
passages 69 Disposed within each side passage 69 and extending
completely along the length thereof is a radiator assembly each
consisting of two aligned radiator units R of the type having a
central pipe section 71 for flow of a heating fluid therealong and
heat radiating fins 72 spaced therealong As shown, the fins 72 are of
rectangular design and are diagonally disposed within the passages 69
and serve to present a relatively large heat radiating area therein,
the radiators being arranged in their diagonal position in the flow
path of the air streams so that the air will wipe the entire area of
each fin 72.
A row of spaced openings 73 extends along the lower edge of each of
the side walls 67 and similar rows of spaced open.
-40 ings 74 are formed along the opposite edges of the cover plate 65
The openings 73 establish communication between the central passageway
68 and the two side passageways 69 while the openings 74 establish
communication between each of the side passageways 69 and the various
ducts provided by the floor channels 28.
Referring now to Fig 1, the radiator pipe sections 71 are adapted to
be connected in and from an integral part of a closed fluid heating
circuit including parallel heating loops one of which accommodates the
forward regions of the enclosure 17 and the other of which
accommodates the -S rear regions thereof The heating circuit extends
from a suitable heating coil 80 through a pipe section 81, leading to
a Pump 82, and from thence through a line 83 extending to a pair of
branch fittings 84 and 85 The radiator pipe sections 71 of the various
radiators are connected to the fittings 84 and 85 and return lines 86
and 81 extend from the ends of the radiator pipe sections 71 along the
side wall 13 adjacent i 65 the bottom thereof and communicate with a
common return pipe 88 leading to the heating coil 80 A suitable drip
and discharge fitting 89 extends through the floor below the return

19. pipe 88 A riser 90 extends upwardly from the end of the pipt 70
section 83 to an expansion tank 91 for the heating fluid used in the
system Any suitable heating fluid may be used, for example water or an
anti-freeze solution such as ethylene glycol A pipe 92 may extend 75
from the tank 91 and serve as an inlet for filiing the system with the
liquid.
A heater 93 is positioned below the heating coil 80 and may be
supplied with kerosene or other suitable fuel contained 80 within a
fuel tank 94 It will be understood of course that any form of heating
means may be employed whether the same be electrical or of the fuel
burning type.
During the operation of the system for 85 heating purposes, the system
is filled, as previously described, with water or other fluid through
the pipe 92 The burner 93 is then lighted for producing the desired
amount of heat and the pump motor M is 90 set into operation to
circulate the heating fluid throughout the closed loops provided for
it If desired automatic control of the system may be effected by
employing the usual "Aquastat" (Registered Trade Mark) 95 for the
heater and the usual thermostat for controlling the motor.
When the overall temperature of the heating fluid contained within the
system has been brought to a desired degree, the 100 radiator
assemblies including the pipes 71 and radiating fins 72 become hot and
air entering the system through the louvered opening 55 in the rear
wall 15 passes downwardly through the passage 54 and enters 105 the
blower 56 (Fig 4) by means of which the air is forced into the rear
end of the central passageway 68 provided in the heat distributing
unit 26 A certain amount of air pressure is developed within the
passage 110 68 and by virtue of the spaced row of openings 73, the air
is caused to traverse the entire longitudinal extent of the passage
and flow outwardly in opposite directions into the side passages 69
below the level of the 115 radiators R The air thus expelled through
the openings 73 flow upwardly between the spaced radiating fins 72 and
around the pipes 71 from whence it passes through the openings 74 into
the various ducts 35 120 existing within the walls of the aluminum
floor channels 28 The baffle 36 being positioned centrally of the
vehicle insures equal distribution of the air to opposite sides of the
vehicle through the various ducts 35 125 the size of the openings 74
may be pro.
gressively increased so that these openings gradually become larger as
they progress toward the front of the vehicle.
The air within the ducts 35 applies heat 130 785,816 to the main floor
so that heat is radiated into the enclosure The air issuing from the
two parallel rows of openings 74 flows outwardly in opposite
directions and enters the spaces 46 provided between the inner and

20. outer side wall panels 42 and 43 Finally, the heated air after heating
the wall surfaces emerges from the louvered openings 51 at the level
of the windowsills and enters the passenger compartment 17 from whence
it may be recirculated through the system by entering the opening 58
for return to the blower 56 or it may be expelled from the passenger
compartment 17 by exfiltration when the damper 57 is closed upon the
opening 58.
From the above description it will be observed that by the heating
system just described the passenger compartment 17 is supplied with
heat both by convection of the heated air issuing from the openings 51
and by radiation of heat upwardly from the floor surface afforded by
the interlocking aluminum floor channels 28 Because of the relatively
large heat radiating surfaces afforded by the radiators R which are
confined within the relatively small enclosures 69, the air issuing
from the openings 74 has been brought to a relatively high degree of
heat This heat flows along the underneath surfaces of the floor
channels in direct contact therewith and as:i result thereof a
considerable portion (of this heat may be absorbed by the floor and
wall channels and radiated into the enclosure Such heat as is not
extracted in this manner from the air passes inwardly through the
louvered openings 51 to the passenger compartment 17 thus serving
principally to heat the upper regions of the compartment.
It should be observed that the wooden beams 27 prevent any direct
metal-to-metal contact between the side sills 21 or any 4 A other part
of the floor sub-structure and the metal floor proper These beams 27
thus serve both as structural and insulating members so that no
appreciable amount of heat will be lost by conduction through the
composite floor structure.
In Fig 6 a modified form of packagetype heating unit is disclosed This
unit is designated in its entirety at 100 and is similar in many
respects to the unit 60 shown in Fig 3 The trough member 101 and cover
plate 102 remain substantially the same as in the previously described
form but the radiators R 2 consist of pipe sections 103 having
associated therewith circular disk-like radiating fins 104 which nest
within the curved bottom regions of the trough member 101 An inverted
Ushaped baffle member 105 is welded or otherwise secured to the
underneath face of the cover plate 102 and has depending side flanges
106 which terminate short of the trough bottom thus providing in
effect elongated slots or openings 107 through which the unheated air
forced into the tubular structure by the blower 56 may 70 pass for
intimate contact with the heat radiaing fins of the radiators R 2 The
heated air passes outwardly through two rows of openings 108 and
enters the ducts as previously described 75 In Fig 7, yet another
modified form of package unit is shown In this form of the unit a

21. vertical partition wall 120 extendsbetween the bottom of the trough
member121 and cover plate 122 and is provided 80with longitudinal side
flanges 123 and 124 which may be welded to the bottom of the trough
member and to the cover plate re spectively The member 120 thus
divides the space within the trough member 121 85 into two passageways
125 and 126, respectively A radiator R 3 is disposed withi n the
passageway 125 adjacent the partition and includes pipe sections 127
having associated therewith rectangular heat radia 90ting fins 128
which are vertically disposed.
A row of openings 129 extends longitudinally along the partition 120
substantially medially thereof and a simliar row)f openings 130 are
provided longitudinally in 95 j the cover plate 122 on the side of the
radiator R 3 remote from the partition wall The trough member 121 is
generally rectilinear design and when it is installed within the
trench 25, the passageway 126 lo 00 is in communication with the
blower 56.
Thus it will be seen that air forced into the passageway 126 will be
discharged through the openings 129 from whence it will pass across
the heat radiating surfaces 105.
of the radiator R 3 and flow upwardly throuigh the openings 130 into
the various ducts 35.
* Sitemap
* Accessibility
* Legal notice
* Terms of use
* Last updated: 08.04.2015
* Worldwide Database
* 5.8.23.4; 93p
* GB785817 (A)
Description: GB785817 (A) ? 1957-11-06
Improvements in or relating to means for slidably mounting closure members
in a frame
Description of GB785817 (A)

22. PATENT SPECIFICATION
7859817 Date of Application and filing Complete Specification:
September 12, 1955 No 26087/55
Complete Specification Published: November 6, 1957
Index at acceptance:-Classes 20 ( 3), Bl(B 1 Bl:C), J( 1 R:21 H:2 J),
K; and 52 ( 1), C 4 B 5.
International Classification:-A 47 b E 04 f.
COMPLETE SPECIFICATION
Improvements in or relating to Means for Slidably Mounting Closure
Members in a Frame 1, RUBEN OSVALDO PERRONE, a citizen of the Republic
of Argentina, of Uriburu 335Beccar-Provincia de Buenos Aires, Republic
of Argentina, do hereby declare the invention for which I pray that a
patent may be granted to me, and the method by which it is to be
performed, to be particularly described in and by the following
statement: -
This invention relates to closures for openings.
The present invention provides a closure for an opening comprising a
frame including a lintel and a sill and a closure member, the closure
member being constrained for sliding movement within the frame by
means of a plurality of freely rotatable first rollers mounted on the
sill of the frame which are engagable by the side walls of a recess
formed in the bottom edge of the member, a plurality of freely
rotatable second rollers mounted on the top edge of the member which
engage the side walls of a recess formed in the lintel of the frame,
and a plurality of third rollers each freely rotatable about a
horizontal axis which bear on the upper surface of the sill of the
frame.
One embodiment of the present invention will now be described in
greater detail, by way of example only, with reference to the
accompanying drawings, of which, Fig 1 is an elevation, partly in
section, of the embodiment.
Fig 2 is a sectional view of the embodiment on the line A-A of Fig 1.
Fig 3 is a sectional view of the embodiment on the line B B of Fig 1,
and Fig 4 is a fragmentary plan view of the means for locating members
relative to each other when they are in their closed position.
As shown in the drawings, in which the closure is for a window
opening, there are provided two closure members or windows a each
slidable in the same plane within a frame b formed by a lintel 5, a
sill 3 and two jambs 4, the sill being stepped to provide I' three
horizontal faces 2, 27 and 28 On the middle face 2 of the sill are
mounted by means of screws 13 a plurality of freely rotatable first
rollers 12 which are engageable by the side walls of a recess 14
formed in the 50 bottom edge of the rail 1 of each of the windows.
Mounted on the top edge of upper rail 6 of each of the windows are

23. individual pairs of second rollers 15 each freely rotatable on 55 a
shaft 16 which extends from adjacent one end of its respective
supporting plates 17.
The rollers 15 engage the side walls of a recess 7 in the lintel 5 A
plurality of third rollers 9 each mounted on a shaft 10 within 60 a
cavity 8 in lower rail 1 are also provided, the rollers 9 bearing on
face 2 of the sill 3.
Secured to the face 2 of the sill 3 is a locating member 18
constituted by a plate of rhomboidal shape the divergent sides of 65
which, which start from respective points 19, form male wedging
surfaces which cooperate with the sides of notches 21 formed in plates
20, each of which is secured to the lower rail 1 of the respective
window a so 70 that the notches extend inwardly from the front edge of
the respective window When the windows are in their closed position
the points 19 each lie within their respective notches 21 in order to
locate the windows, 75 and thus ensuring that the windows are in a
position wherein a latch 22 can be engaged by means of a handle 23, on
one window, with a catch 24 on the other window.
Both windows a are provided with flanges 80 each of which etxends
downwardly from the lower rail 1 of its respective window to a point
below the plane of face 2 of the sill 3 in front of side face 26 The
uppermost face 28 of the sill is positioned above the 85 level of the
bottom edge of the rail 1 of each window This arrangement reduces the
ingress of foreign matter onto the face 2 which might otherwise
interfere with the free operation of the windows 90 785,817 It will be
seen that the above described apparatus, by virtue of the fact that
there are no sliding surfaces directly in contact one with another,
provides a particularly advantageous way for mounting closure members
in openings in which displacement of the members is constrained to
movement in the direction for opening and closing the members.
Although in the above described embodiment the present invention has
been described as applied to a window opening it will be appreciated
that the present invention is applicable to other closures for
openings of the type employing slidable closure members, for example,
doors, walls or partitions of buildings or to slidable doors in
articles of furniture.
The above described invention provides 20) means for slidably mounting
closure members which are vibration free and therefore reduce the risk
of damage to any glass or crystal which may form part of the closure
members Furthermore there is provided means which allow easier
movement of the closure members than was hitherto possible.
* Sitemap
* Accessibility

24. * Legal notice
* Terms of use
* Last updated: 08.04.2015
* Worldwide Database
* 5.8.23.4; 93p
* GB785818 (A)
Description: GB785818 (A) ? 1957-11-06
Process for the production of regenerated cellulose threads and films from
viscose
Description of GB785818 (A)
A high quality text as facsimile in your desired language may be available
amongst the following family members:
BE540586 (A) CH337609 (A) FR1139301 (A) NL87098 (C)
US2974004 (A)
BE540586 (A) CH337609 (A) FR1139301 (A) NL87098 (C)
US2974004 (A) less
Translate this text into Tooltip
[86][(1)__Select language]
Translate this text into
The EPO does not accept any responsibility for the accuracy of data
and information originating from other authorities than the EPO; in
particular, the EPO does not guarantee that they are complete,
up-to-date or fit for specific purposes.
PATENT SPECIFICATION
785818 Date of Application and filing Complete Specification: Oct 3,
1955.
No 28119155.
Application made in Germany on Nov 25, 1954.
Complete Specification Published: Nov 6, 1957.
Index at acceptance:-Class 2 ( 2), B 2 V( 1 C 2 A: 7: 8: 9).
International Classification:-D Olf.

25. COMPLETE SPECIFICATION
Process for the Production of Regenerated Cellulose Threads and Films
from Viscose We, VEREINIGTE GLANZSTOFF-FABRIKEN A.G, of
Wuppertal-Elberfeld, Germany, a Body Corporate organised under the
laws of Germany, do hereby declare the invention, for which we pray
that a patent may be granted to us, and the method by which it is to
be performed, to be particularly described in and by the following
statement:-
This invention relates to a process for the production of regenerated
cellulose threads and films from viscose.
Regenerated cellulose threads having a strong peripheral zone are
acquiring ever increasing importance because they have good elastic
properties and low degrees of swelling, and for the production of such
threads processes have become known in which alkalisoluble monoamines
are added to the viscose from which the threads are spun These
monoamines must, however, be soluble in the spinning baths which are
used The amounts of the additives should not amount to more than 4
millimoles per 100 g of viscose Monoamines in substantially the same
amounts have also been introduced into the spinning baths The spinning
baths which are used contain zinc sulphate, the latter being present
in amounts of 3-25 % by weight It is well known that it is difficult
to spin viscoses which contain monoamines, as the spinning conditions
must be maintained within very narrow limits In addition, when using
these processes, it is necessary to maintain thread or film withdrawal
speeds of not more than 2025 m/min, if the desired effect is to be
obtained Consequently, the use of monoamines on a large scale is not
convenient and presents considerable problems in operation.
It has now been found that regenerated cellulose threads and films
with a strong peripheral zone and greatly improved strength and
elasticity properties are produced if imidazole lPdce 3 s 6 d l H-C N
11 11 H-C C-H H or a substituted imidazole is added to a viscose,
preferably with a gamma value of 42-50, from which the threads and
films are obtained Included among the substituted imidazoles are those
which are substituted in the 2 and/or 4-position by alkyl or alkanol
groups The 2-carbon atom can carry an organic acid radical, for
example a -CI 1 I CO OH radical It has been shown that the
difficulties arising when viscoses containing monoamines are spun are
obviated when using these imidazoles and that it is possible to use
thread or film withdrawal speeds of 40-50 m/min and still attain the
required result.
The said compounds are added to the viscose in an amount of 0 06-0 4 %
by weight, preferably 0 12-0 15;% by weight, and can if desired be
added during the dissolution of the xanthate The compounds can be
added to any viscose which has a conventional composition, examples of

26. which are those containing 7-8 % of cellulose and 5-7 % of sodium
hydroxide The aqueous coagulation baths to be used must contain zinc
sulphate in amounts of 30-50 g/l The sulphuric acid content of the
bath may fluctuate within the limits of 40-65 g/l The sodium sulphate
content of the bath is preferably within the usual limits, namely
between about 160 and 260 g/l The bath temperature should preferably
be between 45 and 700 C, and the thread or film withdrawal speed
between 40 and 50 m/min The withdrawal speed can be further increased
if known measures are taken which ensure that the bath, at least over
the first section of travel after the nozzle, has imparted to it a
speed which is substantially equal to the speed of the thread, so that
the friction between the thread and bath is substantially reduced The
bath should be at least cm long The thread is then stretched by 80-120
%, preferably 95-100 %, in a second, hot aqueous decomposition bath
which contains 2-10 g/l of H 504 and which preferably has a
temperature higher than 90 ' C.
The thread can thereafter be laid on to a bobbin, into a centrifuge or
on to a perforated band The threads spun by the process of the
invention have strength values of 400-420 g/100 den, and these values
can be increased to 430-460 g/100 den by after-stretching.
They are characterised by a very high shrinkage (a feature of value
for example in the production of very thick webs), a high rubbing
resistance value and a low degree of swelling.
The process of the invention is further illustrated in the following
example:
EXAMPLE:
Alkali cellulose made from linters and wood cellulose is xanthated for
5 hours with 42 % carbon disulphide and the xanthate obtained is
dissolved to form a viscose with 7 3-% of cellulose and 5 5 % of Na OH
During the dissolving operation, 0 12 % by weight of imidazole is
introduced into the-viscose The viscose is then filtered, de-aerated
and ripened in the usual manner and spun at a viscosity of 60 poises
and at a gamma value of 44 0.
The viscose is extruded into an aqueous coagulation bath which
contains 52 g/l of sulphuric acid, 40 g/l of zinc sulphate and g/1 of
sodium sulphate, and has a temperature of 580 C to form threads The
thread consists of 1000 individual threads with an individual count of
1 65 den and travels over a path of 65 cm in the bath and is withdrawn
by a roller at a speed of 21 m/min The thread then travels through a
second, aqueous decomposition bath which contains 8 g/l of H 2 SO 4
and has a temperature of 91 C and is withdrawn by a second roller at a
speed of 42 m/min, i e, it is drawn by an amount of % From the second
roller the thread runs into a centrifuge which is rotating at 4600 r.p
m and is given therein a twist of about turns per metre The thread is

27. then washed, softened and dried after a final afterstretching of 8 %
It has the following textile properties:
Strength dry 4.4 g/den wet 3.0 % Elongation dry wet 14 27
* Sitemap
* Accessibility
* Legal notice
* Terms of use
* Last updated: 08.04.2015
* Worldwide Database
* 5.8.23.4; 93p