CARD

Description

[0001] The present invention relates to a carding machine with an inlet side for fiber flakes, wherein the carding machine is configured to feed the fiber flakes to a rotating drum by means of at least one pre-tearer. On the drum, the fiber flakes are broken down, aligned, and cleaned between fixed carding elements and circulating cover bars down to the individual fiber. The resulting fiber mat is transferred from the drum to a receiver, to which a device for converting the fiber mat into a fiber sliver is arranged.

[0002] According to the prior art, traveling carding machines are known that essentially comprise a large main cylinder, the drum or tambour, on which fibers are carded by a specific number of traveling cards and fixed carding elements. The material-feeding working element is the feeder, and the material-discharge working element is the take-up element. The carding length, and in particular the number of engaging rotating card bars of the traveling card, has a significant influence on the carding quality. The carding area and the rotational speed of the drum, in turn, are crucial for the productivity of the carding machine. Increasing the drum rotational speed is possible, but this results in very high centrifugal forces that lead to convex deformation of the drum. This increases the carding gap towards the drum edges, assuming a constant carding gap is maintained in the center of the drum.Another disadvantage of increased drum speed is the associated heating and thermal expansion of the drum, as the speed of the fibers between the drum and carding elements increases, leading to increased friction. For carding with mobile covers, a drum diameter of less than 1300 mm is generally used. To increase the carding length around this drum, the common method is to position the pre-tearer and / or the take-up unit further below the drum. This increases the usable circumference to accommodate a desired number of additional mobile covers.

[0003] This method has its limitations when the rollers are offset to such an extent that their attachments almost touch. This inevitably leads to two mutually reinforcing disadvantages: The drum must be positioned very high in the machine, at least high enough to be above the pickup. This pickup typically has a fairly large diameter, around 700 mm, which necessitates a very high position for the large drum. The higher the heavy, high-speed drum is positioned at approximately 600 rpm, the worse the running stability and vibration stiffness become. The supporting frame structure must be correspondingly large and robust and cannot be too slender.

[0004] Accessibility for frequent (sometimes daily) cleaning and maintenance is severely limited. Depending on the design, this even necessitates a complex, rail-guided sliding mechanism for the ripper unit.

[0005] Both disadvantages increase manufacturing costs and make maintenance more difficult.

[0006] EP 3162927 A1 discloses a carding machine with a carding length greater than 3000 mm, where the drum diameter is between 1150 mm and 1250 mm. The increased carding length is achieved by relocating the pre-tearer and take-up unit below the drum. A drum speed of 500 to 600 revolutions per minute is specified. This allows for an increase in the number of fixed carding elements and cover bars used in the carding process. A disadvantage is the increased overall height.

[0007] EP 2527505 discloses a traveling carding machine which proposes a specific geometric arrangement of the pre-tearer and take-up unit to achieve high productivity. The entire geometry is aligned with a horizontal orientation of the carding machine. A disadvantage of the device is that the arrangement of the pre-tearer and take-up unit results in a large overall height of the carding machine and thus does not utilize a potential transport path on the drum. The diameter of the drum is up to 1200 mm.

[0008] Document IN351271B also describes a "high-rise" carding machine with a drum diameter of up to 1100 mm, in which at least 36 circumferential cover bars are always engaged. This document clearly emphasizes the relationships between drum size, thermal expansion, and centrifugal forces at constant speed, concluding that from a drum diameter of 1287 mm upwards, there are more disadvantages than advantages.

[0009] Document EP 0894876 A1 discloses a carding machine whose drum is made of a fiber-reinforced plastic to reduce the thermal and speed-dependent expansion of the drum compared to a drum made of steel or cast iron.

[0010] EP 0905293 A1 describes carding elements of a traveling canopy that are equipped with rows of different wire lengths in order to minimize the distance between the front and rear heel of a canopy bar across its width. Accordingly, the invention is based on the objective of further developing a carding device in such a way that the carding length is increased without the aforementioned disadvantages occurring.

[0011] The invention solves the stated problem by means of a system with the features specified in claim 1. Advantageous embodiments of the invention are defined in the dependent claims.

[0012] The invention relates to a carding machine with an inlet side for fiber flakes, wherein the carding machine is configured to feed the fiber flakes to a rotating drum by means of at least one pre-tearer. On the drum, the fiber flakes are broken down, aligned, and cleaned between fixed carding elements and circulating cover bars down to the individual fiber. The resulting fiber mat is transferred from the drum to a receiver, to which a device for converting the fiber mat into a fiber sliver is arranged.

[0013] The invention includes the technical teaching that the diameter of the drum is at least 1400mm and that the carding length, which is determined by a partial circumference of the drum between the contact point of the pre-tearer and the drum and the contact point between the drum and the take-up end, is at least 3190mm.

[0014] By positioning the ripper and take-up unit in almost the same position relative to the drum, the maximum height between the underside of the frame and the drum axis is 1230 mm. This allows the existing frame and bearing design to be used with only minor modifications.

[0015] In combination with the previously mentioned drum diameter, the carding length, determined by a partial circumference of the drum between the contact point of the pre-scraper and the drum and the contact point between the drum and the take-up roller, can be at least 3170 mm. This increases the carding intensity without requiring the pre-scraper and take-up roller to be moved below the drum, which would make the carding machine less stable and necessitate a larger design. The disadvantages of the prior art, namely the vibration associated with the increased height, are compensated for by the arrangement of the pre-scraper and take-up roller. Since these rollers are arranged within almost the same circumferential angle range as in the applicant's previous carding machine, neither the vibrations and thus the uneven running occur, nor is the carding machine's height significantly increased.

[0016] Increasing the drum diameter while maintaining approximately the same carding length results in a more favorable arrangement of the pre-tearer and take-up unit, with only a slight increase in the carding height. Simultaneously, the gap difference between the end bar assembly and the drum assembly is reduced.

[0017] With an assigned carding length of at least 3190mm, carding performance and carding quality are ensured even with reduced drive power.

[0018] A further improvement can be achieved by ensuring that the distance difference between the front and rear heel of a flat deck bar set, over a width of 20 mm, is less than 12 / 1000 inch (0.30 mm) relative to the deck bar set on the drum. Due to the increased radius of curvature of the drum, which brings the carding surface between the deck bar and the drum closer to the ideal of a flat carding surface, the carding gap becomes more consistent across the width of the deck bar. This distance difference can also occur with a narrower or wider deck bar set, for example, 25 mm or 30 mm wide. The distance difference is determined over a measured distance across a width of 20 mm, even if the deck bar set has a smaller or larger width. The carding intensity increases, regardless of the length of the carding surface.

[0019] By increasing the drum diameter to at least 1300 mm, the gap difference between the rear and front heels of a lid bar set can be reduced by at least 4 / 1000" (0.1 mm) compared to the state of the art. This increases carding performance and quality without requiring higher power. Conversely, the carding machine can be operated with reduced drive power because the increased diameter allows the drum mass to be accelerated and operated at a lower speed than with the state of the art. A further advantage lies in the larger surface area of ​​the drum, which allows for better heat dissipation and less deformation when heated. The essential dimensions of the carding machine are determined by varying the drum diameter in conjunction with the carding length.

[0020] According to the invention, the carding intensity can be further increased by enlarging the drum to a diameter of at least 1400mm, so that with the same arrangement of pre-tearer and take-up unit, the carding length is at least 3190mm.

[0021] If the distance difference between the front and rear heel of a flat set of a cover bar, over a width of 20 mm, and the drum set is a maximum of 11 / 1000 inch (0.28 mm), the carding intensity is further increased. This distance difference can also occur with a wider or narrower set, for example, one that is 25 mm or 30 mm wide. The distance difference is determined over a measured distance of 20 mm, even if the set has a smaller or larger width.

[0022] By increasing the drum size, at least 38 cover bars of a rotating moving cover can be permanently engaged with the drum. Increasing the number of engaged covers allows for better heat dissipation during carding. Simultaneously, carding performance and quality are improved.

[0023] Because the rotating cover is arranged symmetrically to a vertical center line through the drum's axis, further advantages arise regarding the carding height, as the pre-tearer and the take-up unit do not need to be positioned further below the drum despite the increased carding length. Likewise, the heat generated by the carding process is dissipated more evenly.

[0024] Preferably, the circumferential angle formed by the carding length between the contact point of the pre-tearer and the drum and the contact point between the drum and the take-up unit is a maximum of 280°, preferably a maximum of 270°. Since, according to the invention, the increased carding length results from the increase in the drum diameter, the limited circumferential angle ensures a low overall height of the card, as the pre-tearer and take-up unit interact with the drum in almost the same position as before.

[0025] Because the drum's working width is a maximum of 1300 mm, the thermal stress has a less pronounced effect on changes in the carding gap than in prior art. In particular, in combination with the increased drum diameter, the centrifugal force can be reduced, as the drum can be operated at a lower speed while maintaining the same productivity.

[0026] Preferably, the carding unit is designed to operate the drum at a maximum peripheral speed of 2450m / min, thereby reducing the drive power and limiting the centrifugal force.

[0027] With the increase in drum diameter, the simultaneous symmetrical arrangement of the enlarged traveling cover, and the virtually unchanged position of the pre-carder relative to the drum, the pre-carding area is enlarged. This allows it to accommodate an additional cleaning element of a suction hood with or without a knife, or an additional fixed carding element. Although the circumferential angle of the pre-carding area decreases due to the larger traveling cover, the larger drum diameter increases the arc of the pre-carding area to at least 900 mm around the drum's circumference. This further reduces the load on the traveling cover's circulation system, increasing the service life of the cover bar sets and improving carding quality. According to the current state of the art, eight cleaning elements are arranged between the suction hood below the traveling cover and the pre-carder.The pre-carding area increases in a circular arc to at least 900 mm, with the arc in the pre-carding area being defined from the center of the pre-tearer engaging the drum to the center of the deflection roller of the traveling cover. This allows the elements of the pre-carding area to be enlarged along the circumference of the arc, or an additional cleaning or fixed carding element to be used.

[0028] Further measures improving the invention are described in more detail below together with a description of a preferred embodiment of the invention with reference to the figures.

[0029] They show: Figure 1: a side view of a schematically represented carding machine according to the prior art; Figures 2a - 2c: further schematically represented carding machines according to the prior art; Figure 2d: a schematically represented carding machine of the invention; Figure 3: an enlarged view of a cover bar with the curvature of a drum; Figure 4: an enlarged view of the pre-carding zone; Figure 4a: an enlarged detail view in the area of ​​the pre-tearer.

[0030] Fig. 1Figure 1 shows a carding machine according to the state of the art, in which fiber flakes are guided via a chute to a feed roller 1, a feed table 2, via several pre-tears 3a, 3b, 3c, to the drum 4 or the tambour. On the drum 4, the fibers of the fiber flakes are parallelized and cleaned by means of stationary and rotating carding elements. The resulting fiber web is then conveyed via a take-up roller 5, a stripper roller 6, and several squeeze rollers 8, 9 to a web guide element 10, which forms the fiber web into a fiber ribbon with a hopper 11. This ribbon is then transferred via take-up rollers 12, 13 to a downstream processing machine or a can 15. The removal of the fibers from the take-up roller 5 is supported by a web guide profile 7, which is arranged below the stripper roller 6.Above the stripping roller 6 is a cleaning roller 6a, with which fiber residues are removed from the stripping roller 6 and fed to a suction device not otherwise specified.

[0031] Figure 2aFigure 1 shows a schematic representation of a carding machine manufactured by the applicant, marketed under the product name TC19. The carding machine has a drum diameter (excluding the carding attachment) of 1287 mm and a working width of 1280 mm. The traveling cover 16 has a total of 84 cover bars 17, 28 of which are constantly engaged with the drum 4's carding attachment. The carding length KL (angle arc) is 2800 mm around the drum circumference, corresponding to an active circumferential angle of 250° between the center of the pre-carder 3c and the center of the take-up end 5. At a maximum rotational speed of approximately 600 rpm, the maximum circumferential speed is 2450 m / min. The carding length KL comprises the pre-carding section VK, the main carding section HK, and the post-carding section NK. The pre-carding area VK is determined by the angular circumference on the drum 4 between the center of the pre-tearer 3c and the center of the first deflection roller 16a of the traveling cover.The main carding area HK ​​corresponds to the cover circulation area of ​​the traveling covers 16 with the traveling covers 17 on the drum 4, which is determined by the angular circumference between the centers of the deflection rollers 16a and 16b on the drum circumference. The angular circumference of the post-carding area NK extends from the center of the deflection roller 16b to the center of the take-up unit 5 on the drum circumference.

[0032] Figure 2bFigure 1 shows a schematic diagram of a carding machine according to the prior art, featuring a smaller drum diameter of 1180 mm and a working width of 1500 mm. The traveling cover 16 has a total of 116 cover bars 17, 40 of which are constantly engaged with the drum 4. The carding length KL is 3160 mm across the drum circumference (=angle arc), corresponding to an active circumferential angle of 307° between the center of the pre-tearer 3c and the center of the take-up end 5. At a maximum rotational speed of 600 rpm, the circumferential speed is approximately 2224 m / min. The increased working width of 1500 mm compared to the prior art has the disadvantage that the thermal influence on the carding gap is greater, as the drum 4 assumes a convex shape with increasing temperature.Despite the smaller diameter of the drum 4, this carding machine is very tall because the pre-tearer 3c and the take-up unit 5 have been moved below the drum 4 to increase the carding length. Accordingly, the frame 18 was also designed, which raises the drum 4 higher than in the prior art. The lower positioning of the pre-tearer 3c and the take-up unit 5 created space to pull the traveling cover 16 down into the area of ​​the pre-tearer 3c, a circumferential area on the drum previously used by fixed carding elements in combination with suction hoods and reject elements. This embodiment is described in EP 3162927 A1.

[0033] Another carding geometry according to the state of the art is described in Figure 2cThe embodiment shown has a drum 4 diameter of 1017 mm and a working width of 1500 mm. The traveling cover has a total of 101 cover bars, 36 of which are constantly engaged with the drum 4 assembly. The carding length KL (angle arc) is 2620 mm, which corresponds to an active circumferential angle of 295° between the center of the pre-tearer 3c and the center of the take-up unit 5. This embodiment is described in document IN351271B.

[0034] The invention avoids the previous disadvantages by using a carding machine with a drum diameter of at least 1400mm while maintaining a working width of 1280mm.

[0035] Figure 2dFigure 1 shows a schematic embodiment of the carding machine according to the invention with a drum diameter of 1400 mm. The carding length KL is 3190 mm, which corresponds to an active circumferential angle of 261° between the center of the pre-tearer 3c and the center of the take-off unit 5. In this embodiment, the traveling cover 16 has a total of 105 cover bars 17, 38 of which are constantly engaged with the drum 4 assembly. The engaged cover bars 17 are distributed symmetrically along the center line arranged perpendicular to the drum axis, so that the carding heat is also dissipated symmetrically around the drum circumference. The increase in carding length KL is achieved by increasing the drum diameter, which leaves the arrangement of the pre-tearer 3c and the take-off unit virtually unchanged. The frame 18 can retain its wide support structure without restricting the installation space of the pre-tearer 3c and the take-off unit 5.This allows the maximum height H of 1230 mm from the underside of the frame to the drum axis to be maintained with this drum diameter. A further significant advantage is the increased radius of curvature, which brings the carding surface between the cover bar 17 and the drum 4 closer to the ideal of a flat carding surface. The carding gap across the width of the cover bar 17 becomes more consistent.

[0036] Figure 3 Figure 1 shows an enlarged view of a cover bar 17 with a fitting 17a, the rear heel of which is set at a distance of 3 / 1000 inch (0.076 mm) from the fitting of the drum 4 (not shown). In this embodiment, all cover bars 17 have a uniform flat dimension of 20 mm across the width of the fitting 17a, as shown in the following diagram. Due to the curvature of the drum 4, a dimension X is obtained at the front heel Fv of the fitting 17a, which varies with the curvature of the drum 4. Lid bar set to carding gap 3 / 1000" [inch]

[0037]

[0038] The first value, based on the state of the art, shows the example of a carding machine known on the market with a drum diameter of 800mm and a gap X of 23 / 1000"[inch], i.e. 0.7mm.

[0039] The other values ​​for column X relate to the examples of Figure 2c with 19 / 1000" [inch] (0.48mm) on a drum diameter of 1017mm, the Figure 2b with X = 16 / 1000" [inch] (0.41 mm) at a drum diameter of 1180 mm, and the Figure 2a with X = 15 / 1000" [inch] (0.38mm) at a drum diameter of 1287mm.

[0040] In conclusion, it can be seen that when the drum 4 is enlarged to at least 1300mm, the dimension X at the front heel Fv of the set 17a decreases even further, namely below 15 / 1000" [inch] (0.38mm), and in the embodiment from 1400mm to even 14 / 1000" [inch] (0.356mm). This results in a distance difference between the front and rear heel (Fv-Fh) of a flat 20 mm wide trim 17a of a cover bar 17 and the trim of the drum 4, regardless of the carding gap setting (here 3 / 1000"), of less than 12 / 1000" [inch] (0.30 mm) for a drum 4 with a diameter of 1300 mm and a distance difference of 11 / 1000" [inch] (0.28 mm) for a drum 4 with a diameter of 1400 mm. The dimension X can also occur with a narrower or wider trim, for example, one with a width of 25 mm or 30 mm.However, dimension X is determined over a measured distance of 20mm in width, even if the set has a smaller or larger width.

[0041] Increasing the drum diameter at the same rotational speed can increase the peripheral speed to such an extent that the carding quality decreases for some, but not all, fiber qualities. Simultaneously, the centrifugal force increases. Therefore, the drum speed is limited so that a peripheral speed of 2450 m / min is not exceeded. For this purpose, it can be advantageous to limit the rotational speed of drum 4 to 560 rpm, for example, with a drum diameter of 1400 mm. This not only saves energy with the large mass, but also results in smoother operation of the carding machine due to the reduced rotational speed and the resulting reduction in centrifugal force.

[0042] Simultaneously, increasing the number of engaged cover bars to 38 improves heat dissipation due to the carding action. Increasing the drum diameter also limits the thermal stress and thus the deformation of the drum 4, as it provides a larger surface area for heat dissipation and reduces convex deformation.

[0043] The measures according to the invention result in improved carding quality and reduce the known negative side effects caused by high drum speeds and the associated high temperature differences. As a result, carding quality and the associated yarn quality are improved. This allows for savings in raw material costs or increased productivity. Alternatively, the carding intensity can be reduced, and the potential quality gain can be converted into energy savings.

[0044] With Figure 4 and 4aThe details of the pre-carding area VK are shown, which has increased in size due to the larger drum diameter, as the symmetrical arrangement of the travel cover 16 and the almost unchanged position of the pre-tearer 3c relative to the drum 4 remain the same. Although the angle or arc of the pre-carding area has decreased slightly, the larger drum diameter has increased the available arc of the pre-carding area VK to at least 900 mm around the drum circumference. A flexible arc 21 is mounted on the outside of each of the two side plates 20 (only one is visible here) of the carding machine, which accommodate the drum 4 between them. These flexible arcs are adjustable in radius relative to the drum 4 by means of fastening elements 22.The cleaning elements, such as suction hoods 23, 27, fixed carding elements 24, gusset profiles 26, cover elements 25, or other cleaning elements, are arranged on the flexible arches 21. By increasing the drum diameter, the pre-carding area in the angled arc on the drum revolution can be enlarged, while maintaining the same arrangement of the pre-tearer and simultaneously symmetrically arranging the enlarged traveling cover 16. The angled arc of the pre-carding area VK thus increases and can accommodate an additional cleaning element of a suction hood 27 with or without a knife, or an additional fixed carding element 24. This further reduces the load on the cover circuit of the traveling cover 16, increasing the service life of the cover bar sets 17 and improving carding quality. According to the prior art, eight cleaning elements are arranged between the suction hood 23 below the traveling cover 16 and the pre-tearer 3c.The pre-carding area increases in an angular arc around the drum circumference to at least 900 mm, the angular arc in the pre-carding area VK being defined from the center of the pre-tearer 3c engaging the drum 4 to the center of the deflection roller 16a of the traveling cover 16. This allows the elements of the pre-carding area to be enlarged along the angular circumference, or an additional cleaning or fixed carding element to be used. Figure 4 The additional element has not yet been installed; instead, a simple cover element 25 has been inserted there. Figure 4a The cover element 25 was replaced by a fixed carding element 24, which performs an additional carding action. Instead of the fixed carding element 24, a suction hood with or without a knife, or another cleaning element, can also be used. Reference sign

[0045] 1 Feed roller 2 Feed table 3a, b, c Tearer 4 Drum 5 Take-off 5a Fitting 6 Stripper roller 6a Cleaning roller 7 Fleece guide profile 8 Squeeze roller 9 Squeeze roller 10 Fleece guide element 11 Hopper 12 Take-off roller 13 Take-off roller 14 Fixed carding element 15 Can 16 Traveling lid 17 Lid bar 17a Fitting 18 Frame 20 Side plate 21 Flexible bend 22 Mounting element 23 Extraction hood 24 Fixed carding element 25 Cover element 26 Wedge profile 27 Extraction hood Fh posterior heel Fv anterior heel HH height HK main carding area NK post-carding area VK pre-carding area KLK carding length XS gap

Claims

1. Card having an intake side for fibre tufts, wherein the card is configured to feed the fibre tufts by means of at least one licker-in (3a, 3b, 3c) to a rotating cylinder (4), wherein the fibre tufts are opened into individual fibres, aligned and cleaned between fixed carding elements and revolving flat bars (17) and the cylinder (4), and the fibre web thereby formed can be transferred from the cylinder (4) to a doffer (5), downstream of which there is arranged a device for converting the fibre web into a sliver, characterised in that the diameter of the cylinder (4) is at least 1400 mm and in that the carding length (KL), which is determined by a partial circumference of the cylinder (4) between the contact point of the licker-in (3c) and the cylinder (4) and the contact point between the cylinder (4) and the doffer (5), is at least 3190 mm, wherein the height between the underside of the frame (18) and the axis of the cylinder (4) is not more than 1230 mm.

2. Card according to claim 1, characterised in that the difference in the distance of a front heel and a rear heel (Fv-Fh) of a planar clothing (17a) of a flat bar (17) from the clothing of the cylinder (4) over a width of 20 mm is not more than 0,28 mm (11 / 1000" [inch]).

3. Card according to any one of the preceding claims, characterised in that at least 38 flat bars (17) of a revolving flat (16) are permanently in engagement with the cylinder (4).

4. Card according to claim 3, characterised in that the revolving flat (16) is arranged symmetrically to a vertical centre line through the axis of the cylinder (4).

5. Card according to any one of the preceding claims, characterised in that the circumferential angle, formed by the carding length (KL), between the contact point of the licker-in (3c) and the cylinder (4) and the contact point between the cylinder (4) and the doffer (5) is not more than 280°, preferably not more than 270°.

6. Card according to any one of the preceding claims, characterised in that the pre-carding region (VK) has at least an angle arc on the cylinder circumference of at least 900 mm.

7. Card according to claim 6, characterised in that the pre-carding region is configured to accommodate at least nine cleaning elements.

8. Card according to any one of the preceding claims, characterised in that the height between the underside of the frame (18) and the axis of the cylinder (4) is not more than 1230 mm.

9. Card according to any one of the preceding claims, characterised in that the card is configured to operate the cylinder (4) with a maximum circumferential speed of 2450 m / min.