|Title of Invention||
A PROCESS AND DEVICE TO DETERMINE THE ADHESION TENDENCY OF COTTON
|Abstract||The present invention relates to a process and to a device for the determination of the adhesion tendency of cotton by using cotton samples, whereby the sample taken from the material to be tested is opened down to the individual fiber as in the spinning process, and the fibers thus obtained are deposited on a testing surface under the influence of a certain centrifugal force in the form of a fiber ring. Following complete feeding of the sample, the deposited fiber ring is removed and the quantity of the fibers remaining caught on the testing surface is counted.|
XTV - Institut fur Textile und Verfahrenstechnik
Kdrschtalstrafte 26, D-73770 Denkendorf
Process and device for the determination of the tendency of, cotton_to adhere
The present invention relates to a process and a device to determine the tendency of cotton to adhere. In processing cotton it has been a long-known problem to process sticky fibers as these adhere to each other in drafting and during the spinning process and also tend to form laps on the pressure rollers of the drafting equipment. There are several causes of this adhesion. The so-called "honeydew" which is deposited on the fibers of the open pods is to be mentioned. This is mainly a secretion of flies and other insects, but also micro-organisms assailing the cotton plant. There;is however also the phenomenon whereby the cotton tends to adhere only during its processing. This adhesion is produced by crushed trash particles during ginning, i.et when separating the cotton fibers from the seed grains.
Whatever the origin of this adhesiveness nay be, the effect is however the samer resulting in difficulties in processing such fibers in! the spinning process. It is therefore important for the spinning manufacturer to be able to ascertain already when purchasing the cotton whether or not it tends to adhere Since the different kinds of cottdn are nixed together after the harvest, and since the mixing is also a precondition in the spinning plant for a good yarn that meets its application requirements/ the danger exists that cotton which tends to
adhere may apoil the entire mixture. It is therefore especially important to find out preferably in the raw cotton whether a tendency to adherence exists, so that this fiber material may be eliminated in time or may be subjected to a special treatment by which this'adhesion is removed, so that perfect cotton may in no case be mixid together with such cotton tending to adhere.
adhere has taken a prominent importance since the fight against parasites has been more and more restricted fox-reasons of cost but also for ecological reasons. It is therefore especially important to recognize early this cotton which tends to adhere in order to prevent this affected fiber
material from being mixed with perfect fiber material,
i > i
Different processes for the recognition and evaluation of the adhesion tendency of cotton have already become known* Ih the "Orcin" test for example, a color test is conducted with; a chemical solution. The cotton samples to be thus tested are extracted in soxhlet apparatus with methanol. The methanol extract is taken up with water and is colored by adding ,the sulfuric acid orcin solution in function of the carbon hydrate contents. With a suitable concentration of the solution/ color , tones going from lemon yellow to dark red and brown are obtained, and these can be evaluated by colorimetric means The different colors result from the cotal sugar concentration in the cotton sample.
With this method suitable indications on the adhesion tendency of the coton are obtained with the analogy process, but this test is very time consuming and requires expensive equipment, in particular if a large quantity of cotton samples are to be tested.
It is a further disadvantage that ratios have to be established each time between the photometric results and the experience gathered in operation with adhesion-prone cotton to ascertain to what degree a certain photometric result makss it possible to process the cotton, to process it under certain conditions, or whether unsustainable difficulties would result -
Another method to ascertain the adhesion tendency of cotton is the so-called "thermo-detection process". In order to obtain information on the behavior in process to be expected in the spinning plant, influenced by the adhesion tendency, the tendency of the cotton to adhere is simulated on metallic surfaces- Under the influence,of heat and pressure upon the sample/ the natural adhesion tendency is amplified and thus a longer exposure time is simulated, with this process cotton flakes out of the bale and open cotton flakes and fiber ; slivers can be tested.
It xs a disadvantage in this process that an expensive sample preparation is required. A uniform fleece in the format of the testing surface must be formed. The fleece is spread out on an aluminum film. Care must be taken so that the surface of the sample covers at least 95 \ of the testing surface. The sample spread out between aluminum films is finally placed on a pressing plate and is subjected to pressure ard heat for 12 seconds. At the end of that period of time the heating plate must be lifted off immediately. This is followed by another two-minute pressing with the post-pressing device. The sample is thsn taken out of the deive and after a cooling period of at least 30 minutes the upper film is carefully removed front the sample, the sample fibers which do not adhere on the aluminum film are carefully wiped off with a viper by heand. > The adhesion points remaining on the film, with adhering fiber bunches, are counted, special conditions must also be jadhered to for the counting in order to avoid counting mistakes. At
results fall into one adhesion tendency class and the third result can be assigned to one adhesion tendency class. Here too the disadvantage exists that this process is not only expensive, but that the relationship betv;een the counting result and the experience of treatability must be established.
It is therefore; the object of the present invention to create a process and a device which ensures a true to experience finding on the adhesion tendency of the cotton. Furthermore the testing of raw cotton should he possible so that a mixing of adhering cotton with perfect cotton may be avoided as early
This object is attained through the characteristics of claims
1 end 11
Due.to the fact that the cotton samples are separated down to single fibers and are placed on a testing surface 41 without requiring any heat treatment or similar measure which is . foreign to the -spinning process, this testing method is extremely close to actual experience. An imitation of the spinning conditions is taking place and of the effects v/hich occur in it, because only these are of interest for the spinning process. No relationships and analogies need be established between phenomena v/hich have actually nothing in common with the spinning process. In addition, the process is simple and its implementation and even the evaluation can be automated, so that human influences are for the most part eliminated.
Additional details of the invention are explained through the drawings.
Fig. 1 shows the structure of the device to carry out the process according to the invention;
Fig* 2 shows the opener unit of the device According to
Fig- 3 shows the feed of the fibers to the testing surface 41 in detail.
In Fig. 1 the total structure of the device for the determination of the adhesion tendency of cotton is shov;n schematically. The cotton sanple is placed on the feed conveyor belt 1 and is fod to the draw-in roller 22 which interacts with the draw-in trough 21. The fiber material is held back by the nip formed by the draw-in roller 22 and the draw-in trough 21, so that the opener roller 23 of the opener device 2 is able to detach individual fibers from the presented fiber tuft. For better retention, the draw-in roller 22 is covered with a saw wire clothing in which the teeth are inclined in a direction opposite to the direction of rotation, while the opener roller 25 rotates at high speed (approx, 8.000 r.p.m) the drawing-in speed of the draw-in roller 22jis low (approximately 0.5 m/min) so that good opening down to the individual fiber may be achieved.
The fibers detached from the fiber tuft are conveyed via a trash 'elimination opening 23 to a fiber channel 3 through which the fibber with 4, Depending on the position of the trashe knife 24, trash elimination can bo Effected or can be omitted.
The testing surface unit 4 is shown in detail in Fig. 3. The ; testing surface 41 itself is formed by the inside wall of a : rotor which is mounted on ehaft 45 and is driven via same. The ' testing surface 41 is located in a rotor housing 44 which can be closed by a housing cover 42 capable of swiveling around a linge 46- The housing cover 42 is provided with an extension 53 which extends into the interior of the rotcr while the lousing cover 42 is closed and whose circumferential surface
faces the testing surface 41. The fiber channel 3 lets out at
the circumferential surface of the extension 43 and through it
the fibers are guided from the opener device 2 to the testing
surface 41. The testing surface 41 in fern of a rotor is
advantageously made of a synthetic material* The testing
surface 41 which comes into contact with the fibers is
smoothed so that the fibers are able to glide over this :■
surface without getting caught, the testing surface 41 is
concave, so that the fibers fed through the fiber channel,3
accumulate into a ring on this testing surface 41. The testing
surface 41 must be sufficiently large so that approximately 90
h of the fibers of the sample to be tested may come intfc
contact v/ith the testing surface 41. i
It has now proven to be advantageous if the testing surface 41 in form of a rotor has a diameter of approximately 300 mm. In this way, a sliver length of 3 m is obtained when the fiber * ring is-opened. The width of the testing surface 41 is approximately 6 cm, so that the entire testing surface 41 measures; 600 cm5. If the sample weighs approximately 2 g/m, the necessary conditions for the testing surface 41 of 600 cm2 are met.
The rotation of the rotor at approximately 4.000 r.p.ra. and with the sizes as indicated above, the fibers that are fed are subjected to a centrifugal force which amounts to
approximately two thousands times the fiber weight. The centrifugal force presses the fibers against the rotor wall
which is the testing surface 41. Upon feeding the entire
amount of the sample the rotor is stopped and the fiber ring which is thus produced is taken out of the rotor- Because the testing surface 41 is smoothed so that the fibers without adhesive characteristics do not cling to it, the rotor is empty after removal of the fiber ring, and no fibers remain. However, if a sample is involved in which the fibers are affected by sticky substances, these will adhere to the
testing surface 41 after the removal of the fiber ring. The quantity of the fibers left on the testing surface 41 is then a measure of the adhesion tendency of the cotton. To obtain this adhesion effect which is relevant for the spinning process on the testing surface, a certain minimum pressing force is necessary. In different tests it has been shown that with the dimensions of the testing surface 41 being as indicated above, a pressure force equal to approximately two thousand times the fiber weight is advantageously used in order to determine the adhesion tendency relevant for the spinning process.
( As mentioned earlier, the quahtity of the remaining fibers
provides information on the adhesion tendency of the cotton.
This quantity can be found by weight as veil as by counting*
The detection by counting is effected by counting the adhesion '
.points, and this can be done manually as well as,. automatically* In Fig- 3 a sensor 47 is installed on the extension 43 across from the testing surface 41 and using it the fibers which stand out as light against the black testing surface 41 can be counted, such sensor devices are known, so that they joeed not be described here in further detail. The
sensor 47 is mounted on a holding rod 48 so as to be capable of movement and can therefore be pulled back into the
the other hand the sensor 47 can be brought into the position across from the testing surface 41 which is optimal for counting. The sensor 47 can be connected directly to an evaluation device which evaluates the counting results
When determining the adhering fiber quantity by weight, the fibers remaining after removal of the fiber ring are stripped
from the testing surface and are weighed. The ratio of the weight of the adhering fibers and the sample weight in % is the measured magnitude of the adhesion tendency.
climate is known to be an influence on the adhesion tendency
of cotton during the spinning process. If the climate is modified e.g., with respect to temperature or humidity in the testing process described above, it can easily be found whether the adhesion tendency of a cotton variety can be influenced by changing the climatic conditions. It may be found thon that a cotton variety v/hich has provon to be unsuitable for spinning under normal climatic spinning conditions, can still be found to be proper for spinning by Changing the climatic conditions- The particularity of this process according to the invention lies in the fact that ithe spinning process is practically simulated, and that thus a direct relationship between the test results and the actual spinning conditions exist. No analogy between test results and experience parameters need to be established to begin with.
The process according to the invention can also be used to test cotton samples taken directly from the field, so that mixing with non-adhesive.cotton may be prevented in time. In this case it is however necessary to free the cotton fibers first of seed grains an a labor gin and to place the samples thus obtained on the feed conveyor belt. It is also possible to test fiber slivers which are placed on the conveyor belt directly. For this purpose a sliver guide 11 is provided: in addition.
Another variant of the process according to the invention consists in the fact that trash is eliminated upon opening by the trash elimination opening 23 and the trash knife 24. If the adhesion tendency can be traced to seed grains crushed on the gin, the sticky trash particles are then eliminated. It can thus be proven specifically whether the adhesion .tendency is really only due to the fibers. Based on this test, appropriate measures can be taken in order to prevent the crushing of the seed grains,
The simplicity and direct analogy of the process make it possible to test cotton fiber material, be it in form of raw cotton before ginning, or taken from bales, in form of flakes or as a fiber sliver, rapidly and easily. Thanks to the automated evaluation human error in evaluation are also
1 feed conveyor belt
11 sliver guide
2 opener device
21 draw-in trough
22 draw-in roller
23 trash elimination opening
24 trash knife
3 fiber channel
4 testing surface unit
41 testing surface
42 housing cover
44 rotor housing
45 rotor shaft
48 holding rod
61 control panel
1. Process to determine the adhesion tendency of cotton by
means of cotton samples, characterized in that the sample
taken to the material to be tested is opened in
accordance with the spinning process down to the
individual fibers and in that the obtained fibers are
deposited under the influence of a certain centrifugal
force in' form of a fiber ring on a testing surface (41),
in that the deposited fiber ring is removed after feeding
the entire sample and in that the fibers which have stuck
to the testing surface (41) are counted.
2. Process as in claim 1, characterized is that the test
taken from a cotton -bale is conveyed to an opener device
(2) and is conveyed via a fiber channel (3) in an air
stream t a rotaring testing surface (41).
3. Process as in claim 2, characterized in that the sample taken from raw cotton is taken first through a labor gin device for the removal of seed grains-
6. Process as in one or several of the claims 1 to 5,
characterized in that the quantity of the adhering fibers
is determined in percentage of the sample weight.
7. Process as in one or several of the claims l to 6,
characterized in that the adhesion tendency is determined
from the number of adhesion points.
8. Process as in claim 7, characterized in that the counting
of the fibers remaining on the testing surface (41) after
removal 'of the fiber ring is automatic in the rotor and is
transmitted to an outside device.
(25), as well as by a fiber channel (3) and a testing surfac© (41) in form of a rotor.
14. Device as in claim 13, characterized In that the feed
conveyor belt (1) is preceded by gin,
15. Device as in one of the claims 13 and 14, characterized in
that the inside surface of th* rotor has « circumference
of 100 Cm ami a width of 6 cm.
16. Device as in one or several of the claims 13 to 15,
characterized in that a counting sensor (47) is assigned
to the testing surface (41).
17. Device as in claim 16, characterized in that th9 counting
sensor;(47) is connected to an evaluation device.
18. Device as in one or several of the claims 13 to 17,
characterized in that the rotor i© made of a syntheticmaterial.
19. Process to determine the adhesion tendency of cotton,
substantially as herein described, with reference to
the accompanying drawings.
20. Device to carry out the process, substantially as
-herein described, with reference to the accompanying
|Indian Patent Application Number||2788/MAS/1997|
|PG Journal Number||27/2007|
|Date of Filing||05-Dec-1997|
|Name of Patentee||DEUTSCHE INSTITUTE FUR TEXTIL UND FASERFORSCHUNG STUTTGART|
|Applicant Address||KORSCHTASTRASSE 26,D-73770DENKENDORF.|
|PCT International Classification Number||G01N33/36|
|PCT International Application Number||N/A|
|PCT International Filing date|