Title:
Device with means for avoiding the condensation of water in cans filled with sliver
Kind Code:
A1


Abstract:
A device with a drafting device (3) for drafting at least one sliver (FB) supplied to the drafting device (3) comprises a sliver depositing apparatus (4) downstream from the drafting device (3) for depositing the drafted sliver (FB′) into a can (6). Furthermore, the device comprises a can replacement device (15) for replacing a filled can (6′) by a can (6) to be filled. Means (17) is provided on the device for lowering the temperature (T) and/or the relative moisture (LF) of the fibrous material (FB, FB′) before or after it is deposited in the can (6). Furthermore, means (17) for raising the temperature TU of the machine parts (13, 20) that make contact with the uppermost sliver layers (BL) in the filled can (6′) can be provided, with which means (17) a condensation of water on the cited machine parts (13, 20) is at least reduced. A combination of a card (1) with a drafting device (3) comprises a sliver depositing apparatus (4), downstream from the drafting device (3), for depositing the drafted sliver (FB′) into a can (6) as well as comprises a can replacement device (15). During the replacement of a filled can (6′) by a can (6) to be filled the filled can (6′) is pushed from the filling position (18) to an adjacent ejection position (19). No machine part (13, 20) covering and touching the uppermost sliver layers (BL) is provided in the ejection position (19) in order to avoid a condensation of water.



Inventors:
Strobel, Michael (Eichstatt, DE)
Mattis, Helmut (Vohburg, DE)
Cherif, Chokri (Ingolstadt, DE)
Schulz, Peter (Maxhutte-Haidof, DE)
Application Number:
11/269138
Publication Date:
06/22/2006
Filing Date:
11/08/2005
Assignee:
RIETER INGOLSTADT SPINNEREIMASCHINENBAU AG
Primary Class:
International Classes:
D01H5/00
View Patent Images:



Primary Examiner:
HURLEY, SHAUN R
Attorney, Agent or Firm:
DORITY & MANNING, P.A. (GREENVILLE, SC, US)
Claims:
1. A device with a drafting device (3) for drafting at least one sliver (FB) supplied to the drafting device (3), with a sliver depositing apparatus (4) downstream from the drafting device (3) for depositing the resulting, drafted sliver (FB′) into a can (6) as well as with a can replacement device (15) for replacing a filled can (6′) with a can to be filled (6), which filled can (6′) is pushed from the filling position (18) to an ejection position (19), characterized by means (17) for lowering the temperature (T) and/or the relative moisture (LF) of the fibrous material (FB, FB′) before or after it is deposited in the can (6) and/or by means (17) for raising the temperature (TU) of the machine parts (13, 20) that make contact with the uppermost sliver layers (BL) in the filled can (6′) in the ejection position (19), with which a condensation of water on the cited machine parts (13, 20) is at least reduced.

2. The device according to the previous claim, characterized in that a sliver-producing apparatus, in particular a card (1), is connected in front of the drafting device (3) which apparatus directly supplies an individual sliver (FB) to the drafting device (3) without an intermediate depositing.

3. The device according to one of the previous claims, characterized in that it is designed as a draw frame (2) and that the sliver-producing apparatus is a card (1) connected in front.

4. The device according to one of the previous claims, characterized in that it comprises the drafting device (3) and the sliver-producing apparatus, in particular a card (1).

5. The device according to one of the previous claims, characterized in that the means (17) for lowering the temperature (T) and/or the relative moisture (LF) of the fibrous material (FB, FB′) is arranged after the drafting device (3).

6. The device according to one of the previous claims, characterized in that the means (17) for raising the temperature of these machine parts (13, 20) comprises at least one heating apparatus (21) by means of which the temperature (TU) of the machine parts (13, 20) can be raised in such a manner that the state point (Z2) of the air in the state diagram for moist air (Mollier diagram) is raised above the dew-point curve (TL).

7. The device according to one of the previous claims, characterized in that the heating apparatus (21) comprises at least one heating foil (22).

8. The device according to one of the previous claims, characterized in that the temperature of these machine parts (13, 20) can be controlled or regulated by the heating apparatus (21).

9. The device according to one of the previous claims, characterized in that the heating device (21) is arranged between a plate (13) of the carrier frame (23) and said machine part (20), that is designed in an areal manner and makes contact with the uppermost layers (BL) of the sliver (FB′).

10. The device according to one of the previous claims, characterized in that the machine part (20) is designed as a sliding sheet, e.g. in the form of a noble-steel plate or a ceramic plate, as a coating or as some other covering of the carrier frame plate (13).

11. The device according to one of the previous claims, characterized in that at least one passage opening communicating with the ambient air is provided in the machine part (13, 20).

12. The device according to one of the previous claims, characterized in that at least one passage opening is provided in the machine part (13, 20) which opening is connected to an apparatus (25) for supplying room air or conditioned air, e.g., from an air conditioning unit, into the interior of the can.

13. The device according to one of claims 1 to 4, characterized in that the means (17) for lowering the temperature and/or the relative moisture of the fibrous material before it is deposited in the can (6) comprises at least one cooling apparatus (27) that is capable of cooling the fibrous material (FB, FB′) before, in and/or after the drafting device (3).

14. The device according to one of the previous claims, characterized in that the cooling apparatus (27) cooperates with a structural component that makes contact with the fibrous material (FB, FB′) during operation of the device.

15. The device according to one of the previous claims, characterized in that the cooling apparatus (27) is arranged on a sliver forming unit (5) connected in after the drafting device (3) in which the drafted fibrous material is combined to a sliver (FB′).

16. The device according to one of the previous claims, characterized in that the cooling apparatus (27) is designed for supplying a gas or gaseous mixture that is cooler than the ambient temperature (TU) through bores (29a, 29b) or slits of the sliver forming unit (5) into its inner space (30) through which the fibrous material (FB′) passes.

17. The device according to one of the previous claims, characterized in that the cooling apparatus (27) is arranged between the sliver-producing apparatus, in particular a card (1), and the drafting device (3).

18. The device according to one of the previous claims, characterized in that the cooling apparatus (27) comprises one or more Peltier elements.

19. A machine part (20), especially a carrier frame plate (13), of a device with a drafting device (3), a sliver depositing apparatus (4) for depositing a sliver (FB′) drafted in the drafting device (3) into a can (6) as well as with a can replacement device (15) for replacing a filled can (6′) with a can to be filled (6), which filled can (6′) is pushed from the filling position (18) to an ejection position (19), which machine part (13, 20) makes contact with the uppermost sliver layers (BL) of the filled can (6′) in the ejection position (19), characterized in that means (17) for raising the temperature (TU) of the machine part (13, 20) is provided with which a condensation of water on the machine part (13, 20) is at least reduced.

20. The machine part (13, 20) according to the previous claim, characterized in that a heating apparatus (21) is arranged on the machine part (13, 20) as means (17) for raising the temperature TU of the machine part (13, 20).

21. The machine part (13, 20) according to the previous claim, characterized in that the heating apparatus (21) comprises a heating foil (22).

22. The machine part (20) according to one of claims 19 to 21, characterized in that the machine part (20) that makes contact with the uppermost sliver layers (BL) is a sliding plate or a covering arranged on the carrier frame plate (13).

23. The machine part (20) according to one of claims 19 to 22, characterized in that the heating apparatus (21) is arranged between the machine part (20), that makes contact with the uppermost sliver layers (BL), and the carrier frame plate (13).

24. A machine part (20), in particular a carrier frame plate (13), of a device with a drafting device (3), a sliver depositing apparatus (4) for depositing a sliver (FB′) drafted in the drafting device (3) into a can (6) as well as with a can replacement device (15) for replacing a filled can (6′) with a can to be filled (6), which filled can (6′) is pushed from the filling position (18) to an ejection position (19), which machine part (13, 20) makes contact with the uppermost sliver layers (BL) of the filled can (6′) in the ejection position (19), characterized in that at least one passage opening is arranged in the machine part (13, 20) in order to lower the temperature (T) and/or the relative moisture (LF) of the sliver (FB′) and to prevent the condensation of water on the machine part (13, 26).

25. The machine part (20) according to the previous claim, characterized in that the passage opening communicates with the ambient air.

26. The machine part (20) according to claim 24, characterized in that the passage opening is connected to an apparatus for supplying room air or conditioned air.

27. A combination of a card (1) with a drafting device (3) for drafting at least one sliver (FB) supplied to the drafting device (3) directly from the card (1), with a sliver depositing apparatus (4) downstream from the drafting device (3) for depositing the resulting, drafted sliver (FB′) into a can (6) as well as with a can replacement device (15) for replacing a filled can (6′) with a can to be filled (6), which filled can (6′) is pushed from the filling position (18) to an adjacent ejection position (19), characterized in that no machine part (13, 20) covering and touching the uppermost sliver layers (BL) is provided in the ejection position.

Description:

The present invention relates to a device with a drafting device for drafting at least one sliver supplied to the drafting device. The device comprises a sliver depositing apparatus downstream from the drafting device for depositing the drafted sliver into a can as well as comprises a can replacement device for replacing a filled can with a can to be filled. The filled can is pushed from the filling position to an ejection position.

There is the danger in traditional devices with a drafting device, conditioned by strong temperature differences in the course of the drafting of at least one sliver, that after the sliver has been deposited in the can the moisture contained in the air and/or in the sliver condenses in the can.

As a result of the compression of the fibrous material on parts of the drafting device and friction on the roller pairs, the temperature of the fibrous material sharply rises when running through the drafting device. The fibrous material is subsequently deposited into a ready can. The can is pushed into an ejection position after it has been filled, where the fibrous material is relaxed and a high degree of sliver fungus is thus avoided. During the relaxing the moisture contained in the fibrous material evaporates into the air contained in the can. The uppermost sliver layers of the fibrous material deposited in the can make contact with the machine parts covering the can, so that the space inside the can is largely closed. When the air contained in the can meets these machine parts, which as a rule have a lower temperature, the air cools off so that the relative moisture of the air rises. If the air reaches the saturation limit (dew-point curve or saturation line in a state diagram (Mollier diagram) for moist air), a condensation of water occurs on the cited machine parts. This has the result that the moisture collects on these machine parts, from which it drips onto the fibrous material deposited in the can and thoroughly moistens it, which results in significant disturbances in the further processing.

Furthermore, devices with a drafting device that fill rectangular cans are known in the state of the art. These filled cans are directly ejected without a relaxation phase so that a condensation of the moisture contained in the fibrous material does not occur on adjacent machine parts here. However, these devices have the disadvantage that the filling amount of the can must be more sharply limited on account of the high band fungus produced.

If another sliver-producing apparatus, e.g., a card, is connected in front of the drafting device, the fibrous material has an elevated temperature at the drafting input already. The temperature of the fibrous material at the exit from the drafting is consequently also higher so that the danger of condensation of the moisture contained in the deposited sliver is especially great in this instance.

The present invention has the problem of creating a device with a drafting device that largely prevents in a simple manner a condensation of water on machine parts covering the cans.

This problem is solved by the features of the independent claims.

The invention relates to devices with a drafting device as well as to combinations of such devices with other equipment producing sliver. A device with a drafting device for drafting at least one sliver supplied to the drafting device comprises a sliver depositing apparatus arranged downstream from the drafting device for depositing the resulting, drafted sliver into a can. Furthermore, the device contains a can replacement device for replacing a filled can by a can to be filled. The filled can is pushed from the filling position to an ejection position. According to the invention means are provided on the device for lowering the temperature and/or the relative moisture of the fibrous material before or after its deposition in the can. In addition to or also instead of these means, means can be provided that raise the temperature of the machine parts that make contact with the uppermost sliver layers in the filled can located in the exit position. Accordingly, means for raising the temperature of the machine part are provided on a machine part in accordance with the invention, e.g., a plate of the carrier frame which plate contacts the uppermost sliver layers. To this end the machine part can comprise, e.g., a heating installation, especially a heating foil.

The state of the air located in the can or the state of the environment or of the adjacent machine parts can be varied in such a manner by the means of the invention that a condensation of water or on the machine parts in contact with the uppermost sliver layers is at least partially reduced. This means in the presentation of these means in a state diagram that the saturation line or dew-point curve is no longer dropped below during the change of state of the moist air in the can during the relaxation. The means of the invention can be provided individually or also in combination with each other so that the state of the air present in the can as well as the state of the environment can be changed and thus a dropping below the dew-point curve can be prevented in an even more reliable manner. This can largely prevent the condensation of the water contained in the moist air. The means for lowering the temperature and/or the relative moisture of the fibrous material can be provided before or after the depositing of the fibrous material in the can.

If the means for lowering the temperature and/or the relative moisture of the fibrous material are arranged after the drafting device the invention can be implemented in an especially simple manner. In particular, these means can be readily retrofitted on traditional devices.

If a sliver-producing apparatus, in particular a card, is connected in front of the drafting device which apparatus directly supplies an individual sliver to the drafting device without an intermediate depositing, the temperature difference between the air temperature in the can and the ambient temperature is especially large so that the danger of a condensation of water on machine parts is increased. The means in accordance with the invention can be used especially effectively in such a device.

The means in accordance with the invention can also be used especially advantageously if the device is designed as a draw frame with a card in front of it as sliver-producing apparatus. Moreover, the use of this means in a compound machine consisting of a drafting device and a sliver-producing apparatus is advantageous.

An advantageous embodiment of the invention provides that the means for increasing the temperature of said machine parts comprises at least one heating apparatus. The temperature of the machine parts can be raised by the heating apparatus in such a manner that this temperature and thus the point of the state of the air after cooling off is raised over the dew-point curve in the state diagram for moist air. During the cooling off of the air contained in the can from its initial state to the ambient temperature when meeting the cited machine parts the dew-point curve is therefore no longer dropped below and a condensation of water is thus prevented.

It is advantageous if the heating apparatus comprises at least one heating foil. The temperature of the machine parts in contact with the uppermost sliver layers can be increased in an especially simple manner with such a heating foil.

In order to be able to operate the heating apparatus in an especially economical and energy-saving manner, it is advantageous if the temperature of said machine parts can be controlled or regulated by the heating apparatus.

It is especially advantageous if the heating apparatus is arranged between a plate of the carrier frame and the machine part that is designed in an areal manner and makes contact with the uppermost layers of the sliver. This makes it possible to heat in an energy-saving manner only the layer that makes contact with the fibrous material and/or the air in the can. This can avoid a flow-off of heat via the plate of the carrier frame into the carrier frame.

The machine part in contact with the uppermost layers of the sliver is preferably designed as a sliding sheet, e.g. in the form of a noble-steel plate or a ceramic plate. It is also advantageous if the machine part is designed as a coating or some other covering of the carrier frame plate. This significantly facilitates the shifting of the filled cans from the filling position into an ejection position since the uppermost sliver layers can slide along the sliding sheet.

Another advantageous further development of the invention provides that at least one passage opening that communicates with the ambient air is provided in the machine part that contacts the uppermost layers of the sliver. As a result, moisture can escape from the can during cooling off and a state of equilibrium of the air in the can with the ambient air is adjusted that is between the state of the air in the can and that of the ambient air. This state of equilibrium is also above the dew-point curve, given appropriate parameters of the ambient air, in the state diagram so that this also makes it possible to avoid a condensation of water.

It is furthermore advantageous is the passage opening is connected to an apparatus for supplying room air or conditioned air, e.g., from an air conditioning unit, in the inner space of the can. This makes possible an improved dehumidifying and cooling off of the air in the can. If appropriately conditioned air is brought into the inner space of the can via the apparatus the state of equilibrium that is adjusted can be reliably brought above the dew-point curve, even if the ambient air has unfavorable climatic conditions, e.g., elevated air moisture or temperature.

A machine part in accordance with the invention with a passage opening can be attached in an especially simple manner to the device or to the carrier frame plate. No changes to the device or to the can replacement device are required for this but rather only a replacing of the corresponding machine part is required. Likewise, such a passage opening can also be added subsequently to a traditional carrier frame plate or to an appropriate machine part, which can reduce problems caused by condensation in an especially simple and economical manner.

Another advantageous embodiment of the invention provides that the means for lowering the temperature and/or the relative moisture of the fibrous material before it is deposited in the can comprises at least one cooling apparatus. A cooling of the fibrous material is possible in this instance in front of, in and/or after the drafting device. The initial state of the air in the can be changed in such a manner by such a cooling apparatus that when the air meets adjacent machine parts the dew-point curve is also not dropped below.

The cooling apparatus advantageously cooperates with a structural component that makes contact with the fibrous material during operation of the device. As a result of the contact, the cooling of the fibrous material can take place in an especially efficient and energy-saving manner.

It is especially advantageous if the cooling apparatus is arranged on a sliver forming unit downstream from the drafting device in which unit the drafted fibers material is combined to a sliver. Consequently, the construction expense for such a cooling apparatus can be kept especially low. It is especially advantageous in this connection if the cooling apparatus is designed for supplying a gas or gaseous mixture that is cooler than the ambient temperature through bores or slits of the sliver forming unit. The cooling agent can be introduced through the bores or slits in an especially simple manner into the inner space of the sliver forming unit through which the fibrous material passes.

Another advantageous further development of the invention is characterized in that the cooling apparatus is arranged between the sliver-producing apparatus and the drafting device. The temperature of the sliver can be significantly lowered as a result already at the entrance into the drafting device.

It is also advantageous if the cooling apparatus comprises one or more Peltier elements. These can be used to cool defined areas, such as, in particular, structural components in contact with the fibrous material or the drafted sliver.

A combination in accordance with the invention of a card with a drafting device for drafting at least one sliver supplied to the drafting device directly from the card comprises a sliver depositing apparatus downstream from the drafting device for depositing the resulting drafted sliver into a can. Moreover, the combination in accordance with the invention comprises a can replacement device for replacing a filled can with a can to be filled, which filled can is pushed from the filling position to an adjacent replacement position. According to the invention no machine part covering and contacting the uppermost sliver layers is provided in the ejection position. As a consequence, an exchange of the air in the can with the ambient air is made possible so that after a compensation procedure a thermodynamic state of equilibrium is also adjusted that is above the dew-point curve.

Other advantages of the invention are described using the following exemplary embodiments.

FIG. 1 shows a schematic view of a combination of a sliver-producing apparatus with a following draw frame.

FIG. 2 shows a schematic top view onto a can replacement apparatus at the end of a draw frame.

FIG. 3 shows a schematic state diagram for moist air with a change of state of the air contained in the can as well as its change by the means of the invention.

FIGS. 4, 4a shows an embodiment of the invention with a heating apparatus and a corresponding state diagram.

FIGS. 5, 5a shows an alternative embodiment of means in accordance with the invention for avoiding a condensation of water and shows a corresponding state diagram.

FIGS. 6, 6a show another embodiment of means in accordance with the invention with an apparatus for supplying room air or conditioned air as well as a corresponding state diagram.

FIGS. 7, 7a show an alternative embodiment of the invention with a cooling apparatus for cooling fibrous material and show a corresponding state diagram.

FIG. 8 shows an insert for a fleece guidance nozzle in a sliver forming unit with bores for cooling the fibrous material.

FIG. 1 schematically shows a combination of a sliver-producing apparatus with downstream draw frame 2 comprising drafting device 3. In the present instance a known card 1 (not described in detail) is connected in in front of draw frame 2. In the compound machine shown a sliver FB contained in card 1 is transported directly into drafting device 3 where it is drafted, then conducted through sliver forming apparatus 5 and deposited via depositing apparatus 4 into can 6.

FIG. 2 shows a schematic top view onto can replacement apparatus 15 on the end of draw frame 2. Empty cans 6 are supplied to draw frame 2 on a slanting gravity roller conveyor 16. Empty cans 6 are pushed from rotary pusher into filling position 18 in which sliver FB′ is deposited in can 6. After the set filling amount has been achieved, full can 6′ is pushed out into ejection position 19. Can 6′ is filled here at first over its edge with fibrous material FB′ in order to achieve a maximum filling. In order to relax and reduce the filling height, can 6′ remains in ejection position 19 for a few minutes until it is finally ejected after the setting of fibrous material FB′. The uppermost sliver layers BL of sliver FB′ in the can and projecting over the can edge are in contact with plate 13 of carrier frame 23 directly or via an additional machine part 20, e.g., a sliding sheet, so that fibrous material FB′ slides along these parts 13, 20 during the ejection.

A condensation of water in filled cans 6′ frequently occurs in traditional draw frames 2, especially in compound machines, conditioned by temperature changes in the course of the production process, which is explained in more detail with FIG. 1. Sliver FB produced in card 1 leaves card 1 with temperature TKA and is supplied via deflection roller 7 to subsequent draw frame 2. The temperature TKA is usually significantly higher than ambient temperature TU. Sliver FB cools off slightly in the ambient air so that it has entrance temperature TE at feed funnel 8 on the entrance of draw frame 2. Feeler device 9 for sliver FB is arranged after feed funnel 8 for compressing sliver FB. Feeler device 9 is formed by two feeler rollers that compress entering sliver FB. One of the two feeler rollers is movably supported and is therefore deflected to a greater or lesser degree by fluctuations in volume of entering sliver FB. After having run through feeler device 9 the now compressed fiber entanglement FB is conducted into drafting device 3. As a result of differing circumferential speeds of roller pair 11 of drafting device 3, fiber entanglement FB is drafted in accordance with the ratio of the circumferential speeds.

The compressing of sliver FB on the feeler rollers and the drafting bring about an elevation of temperature of sliver FB so that drafted sliver FB′ has exit temperature TA upon leaving drafting device 3 that is higher than entrance temperature TE and significantly higher than ambient temperature TU. As a result of the evaporation of the moisture contained in the fibrous material the air in the inner hollow space 12 of deposited sliver FB′ after the depositing of the sliver has can temperature TK and relative moisture LFK.

If the air located in can 6 with temperature TK and a relative moisture LFK meets adjacent machine parts 13, 20 with the ambient temperature TU, e.g., a carrier frame plate 13 covering cans 6, during the relaxation phase, there is a danger of a condensation of the moisture contained in the air and/or in the fibrous material in corresponding devices of the state of the art. This has the consequence that water collects on the condensation surface, in this instance on plate 13, drips onto the fibrous material FB′ deposited in can 6′ and thoroughly moistens it.

A corresponding change of state of the air contained in can 6′ is schematically shown in a state diagram for moist air (Mollier diagram) according to FIG. 3. The diagram shows temperature T and relative air moisture LF as a function of the absolute water content x. The air in can 6′ has at first temperature TK in state Z1 and relative moisture LFK that are above dew-point curve TL with 100% air moisture. When it meets adjacent machine parts 13, 20 with temperature TU the air experiences a cooling off (state Z2), represented here by an arrow, during which water condenses when dew-point curve TL is dropped below. Means are provided in a device in accordance with the invention that change state Z1 of the air in can 6′ and/or the state of the environment or of the adjacent machine parts 13, 20 in such a manner that upon a change of state of the moist air from Z1′ to Z2′ the dew-point curve TL is not dropped below. This can largely prevent a condensation of water. According to the invention the corresponding means 17 can provide an elevation of temperature of ambient temperature TU to TU′ or a lowering of temperature TK or of relative moisture LFK of the air in can 6′ which changes can take place before or after the depositing of sliver material FB′ into can 6. Any combinations of corresponding means 17 are also possible. In the present instance a change of all magnitudes of state are shown and both points Z1, Z2 are shifted to points Z1′, Z2′. This prevents a dropping below dew-point curve TL during the cooling off. However, means 17 in accordance with the invention can also provide only a dehumidifying of the air in the can so that state point Z1 is isothermally shifted into state point Z1′ (not shown here). It is also conceivable to shift initial state Z1 of the air contained in the can onto a line of constant relative moisture. It is furthermore possible to provide means 17 that make a compensation with the ambient air possible so that a thermodynamic equilibrium results in state Z2″, as is explained in detail in FIG. 5.

An embodiment of the invention in accordance with FIG. 4 provides that heating device 21 is arranged on carrier frame plate 13 covering cans 6 or on machine part 20 contacting uppermost sliver layers BL. In the present instance carrier frame plate 13 is provided with a sliding sheet on its side facing cans 6, 6′ in order to a ensure a smooth transport of cans 6, 6′ in can replacement device 15. Heating foil 22 that can be electrically heated with voltage source 24 is attached between carrier frame plate 13 and the sliding sheet in the area of ejection position 19 as heating apparatus 21. Temperature TU can be purposefully raised only in the area of ejection position 19 by a heating foil 22 arranged in such a manner, which makes an economical operation of the device possible. However, it is just as possible to heat the entire sliding sheet or carrier frame plate 13. Temperature TU of machine parts 13, 20 covering cans 6′ is raised by heating apparatus 21 so that even state point Z2 is raised to state point Z2′, as is shown in the state diagram of FIG. 4a. Therefore, upon the change of state of the air contained in can 6′ from Z1 to Z2′ when it meets machine parts 13, 20 dew-point curve TL is no longer dropped below and a condensation of the moisture contained in the air is largely prevented. This can also prevent an entering of moisture into adjacent machine parts and prevent consequent corrosion damage so that this embodiment of the invention is especially advantageous in constricted spatial conditions, e.g., in a compound machine.

If heating apparatus 21 is provided with a control-or regulating unit (not shown here) it can be operated in a particularly energy-saving and economical manner. To this end a sensor for temperature detection can be arranged on machine parts 13, 20.

FIG. 5 shows another embodiment of the invention in which passage openings are provided in machine parts 13, 20 covering cans 6, 6′ as means 17 for lowering the relative moisture and the temperature of fibrous material FB′ in can 6′. One or more openings are arranged in machine parts 13, 20 that communicate with the ambient air and via which moisture can escape from can 6′. The ambient air has temperature TU and relative air moisture LFU in this instance, which air moisture LFU is significantly below the relative moisture of the air located in the can (FIG. 5a). On the other hand, the air in can 6′ has temperature TK above ambient temperature TU and has relative air moisture LFK at state point Z1. The passage opening makes a compensation procedure possible between these two states Z1 and ZU so that a thermodynamic equilibrium is adjusted in state Z2″. Conditioned by the different temperatures and moistures, this state point Z2″ is above the dew-point curve, so that a condensing out of water is also largely prevented. Z2 shows the state here that the air in can 6′ would assume after a change of state without means 17 in accordance with the invention.

Another embodiment of the invention (not shown) provides that no machine part 13, 20 or one covering the cans only partially is provided at least in ejection position 19. Even this makes possible a compensation procedure possible between state Z1 of the air in the can and state ZU of the environment. However, the entering of moisture into adjacent structural components must be avoided here.

The condensing of water and the thorough wetting of fibrous material FB′ in can 6′ can be suppressed in an especially effective manner if the passage openings are connected to an apparatus 25 for supplying room air or conditioned air, as FIG. 6 shows. If a current of air is introduced by this apparatus 25 into the interior of can 6′ an improved removal of moisture from fibrous material FB′ and an improved cooling become possible by the circulation of the air in can 6′ (see arrow). The air current can be introduced for this purpose, e.g., via a blower; appropriately conditioned air, e.g., from an air conditioning unit, can also be introduced in particular in hot countries where air moisture or the temperature of the ambient air is comparatively high. This can hold state of equilibrium Z2″ reliably above the dew-point curve (FIG. 6a). By way of comparison, Z2 shows the state which the air in can 6′ would attain without the compensation procedure.

FIG. 7 shows another embodiment of the invention in which means 17 for lowering the temperature and/or the relative moisture of fibrous material FB′ comprise cooling apparatus 27. Cooling apparatus 27 can cool fibrous material FB′ before it is deposited in can 6′ before, in or after drafting device 3. In the present instance cooling apparatus 27 is arranged in front of drafting device 3 so that the temperature TE of fibrous material FB is lowered before its entrance into drafting device 3 already. This is especially advantageous if a sliver-producing apparatus is connected in front of drafting device 3 or draw frame 2 and therefore entrance temperature TE is comparatively high. Furthermore, even the formation of windings on the drafting device rollers can be avoided by a lower entrance temperature TE and the resulting lower temperature during the drafting. In spite of an elevation of temperature of fibrous material FB in drafting device 3, a condensation of the moisture still contained in fibrous material FB′ or in the air is not to be expected, conditioned by the lower temperature difference relative to ambient temperature TU. A dehumidification of fibrous material FB takes place conditioned by the lower absorption capacity for moisture of the cooler air before it is deposited in the can already so that the initial state of the air in the can is shifted into state point Z1′ (FIG. 7a). Therefore, given an appropriate change of state (see arrow) of the air into state Z2, the dew-point curve is also not dropped below. An especially reliable shifting of point Z1 into point Z1′ can be achieved if cooling apparatus 27 also brings about a dehumidification of fibrous material FB in addition to the lowering of the temperature. An appropriate cooling apparatus 27 can of course also be arranged in or after drafting device 3.

An especially efficient cooling of fibrous material FB can be achieved if cooling apparatus 27 cooperates with a structural component in direct contact with fibrous material FB. To this end, e.g., rollers 11 of drafting device 3 can be cooled or cooling apparatus 27 is arranged on sliver forming unit 5. Insert 28 for a fleece guidance nozzle (not shown) in a sliver forming unit 5, which insert makes possible the supplying of a cooling agent, is shown in FIG. 8. In sliver forming unit 5 fibrous material FB′ coming out of drafting device 3 is formed to a sliver in a fleece guidance nozzle with an insert 28 (sliver funnel). Insert 28 comprises flow openings 29a, 29b emptying into inner space 30 of insert 28 and of sliver forming unit 5. Fibrous material FB′ passes through this inner space 30 so that an especially effective and constructively simple cooling of fibrous material FB′ can take place via openings 29a, 29b. Conditioned air or also some other suitable gas, e.g., nitrogen, can be used for cooling.

The invention is not limited to the exemplary embodiments shown. Numerous modifications of the invention and especially combinations are possible within the scope of the claims.