WO1994005837A1

WO1994005837A1 - Fibre opening apparatus

Info

Publication number: WO1994005837A1
Application number: PCT/EP1993/002143
Authority: WO
Inventors: Karl-Heinz Schmolke
Original assignee: Carclo Engineering Group Plc
Priority date: 1992-08-28
Filing date: 1993-08-10
Publication date: 1994-03-17
Also published as: GB9218377D0

Abstract

An opening roller (80) includes a helical groove in which card-clothing wire (34) is fixed. The card-clothing wire includes an outwardly facing shoulder (38) and a fibre opening element (40) which has a saw-tooth shape. Lands (42) are defined between adjacent fibre opening elements (40). The whole working surface of the opening roller (80) is coated with a chrome oxide, tungsten carbide or nickel diamond surface coating (52) and the outwardly facing shoulder (38) and the lands (42) have been roughened up, to increase their coefficient of friction, by knurling. It has been found that such an arrangement leads to an increased yarn quality compared to the case wherein the surface characteristics of the working surface of the opening roller is uniform.

Description

FIBRE OPENING APPARATUS

This invention relates to fibre opening apparatus, for example, to opening rollers for open-end spinning machines and to card-clothed regions of carding machines.

A known open-end spinning apparatus is shown in Figure 1 of the accompanying diagrammatic drawings. Referring to the Figure, the apparatus 2 includes a housing 4 within which an opening roller 6 is arranged to rotate in the direction of arrow 20. The opening roller 6 includes a cylindrical working surface 7 which is clothed with saw-tooth shaped card clothing wire 8. Adjacent the cylindrical working surface 7 and spaced therearound in a clockwise direction are a feed roller 10 and feed table 12, a trash removal orifice 14 and a fibre channel 16. In use, a fibre sliver 18 is fed between the feed roller 10 and feed table 12 to the opening roller 6. In a first zone, zone A, extending from the feed roller and feed table, fibres of the sliver are accelerated by the working surface and/or the card-clothing wire from 0 to approximately 1,500 m/min and thereby to a degree separated from each other. In a second zone, zone B, the fibres are generally disengaged from the working surface and/or the card-clothing wire 8. In a third zone, zone C, the fibres swim in an airstream defined between the wire 8 and an inwardly facing wall 20 of the housing 4.

It will be apparent from the above that for maximum acceleration and hence fibre individualisation in zone A, the frictional force between the cylindrical working surface and/or card clothing wire 8 of the opening roller 6 and fibres of the fibre sliver should be maximised. However, in contrast, the disengagement of fibres in zone B may be encouraged by reducing the frictional force between the cylindrical working surface and/or the card clothing wire 8 and fibres. As a consequence, there must be a compromise between these competing requirements. To this end, known opening rollers 6 are provided with a coating which increases the frictional force between the opening roller and fibres entering zone A but which does not adversely effect, to any great extent, the necessary disengagement of fibres in zone B.

Although the use of a coated opening roller may lead to the production of better quality yarn in comparison to that produced using a non-coated roller, there exists a need to optimise the effect of an opening roller still further.

Similar problems to those described above also exist in relation to the engagement and disengagement of fibres from card-clothed regions of carding machines.

It is an object of the present invention to address the aforementioned problems.

According to a first aspect of the present invention, there is provided a fibre opening apparatus comprising a support member for fibre opening elements and a plurality of fibre opening elements which are supported by and project away from said support member, wherein the surface characteristics of outer parts of the fibre opening elements differ from the surface characteristics of other fibre engaging parts (hereinafter referred to as "said inner parts") of the apparatus disposed inwardly of said outer parts.

Preferably, the outer parts are adapted to exert, in use, a lower force, for example a lower frictional force, on fibres than the force exerted on fibres by said inner parts. Preferably, the respective surface characteristics of said outer and inner parts are such that the outer parts have a lower coefficient of friction than said inner parts.

Said outer parts of said fibre opening elements may be highly polished in order to lower their coefficient of friction relative to that of said inner parts. Alternatively and/or additionally said outer parts may be coated with a friction coating.

Said inner parts of said apparatus may be coated with a friction coating for increasing the coefficient of friction of said inner parts relative to that of said outer parts. Preferably, the surface of said inner parts is a non-smooth surface. Suitably, said surface of said inner parts is undulant so as to provide the desired surface characteristics. Thus, preferably, said undulant surface of said inner parts has a higher coefficient of friction than the surface of said outer parts. The desired surface characteristics of said surface of said inner parts are preferably formed by mechanical means. For example, said undulant surface may include a plurality of ridges which may be formed by knurling. Said surface of said inner parts may be defined, at least in part, by an outwardly facing surface of a length of carding wire. Said outwardly facing surface of said length of carding wire may include a plurality of projections arranged to define, at least in part, the desired undulating surface.

Said outer parts of the fibre opening elements may extend more than about half of the height of the fibre opening elements. Preferably, said outer parts extend substantially along the whole extent of said fibre opening elements. Preferably, each of said outer parts extends around a respective fibre opening element. Preferably, the surface characteristics of the outer parts are constant along the extent thereof.

Said inner parts of the apparatus may include part of said opening elements. Preferably, said inner parts include at least a portion of said support member for said fibre opening elements.

Said fibre opening apparatus may comprise a cylindrical member in the form of, for example, an opening roller or ring for an open-end spinning machine, or to card-clothed regions of carding devices.

Where the fibre opening apparatus comprises a cylindrical member, said fibre opening elements preferably project away from a cylindrical working surface of said member. Said working surface suitably comprises regions situated between said projecting fibre opening elements. Said working surface preferably has a higher coefficient of friction than said outer parts of the fibre opening elements. The respective surface characteristics along the whole extent of the fibre opening elements are preferably substantially constant and the respective surface characteristics along the extent of the working surface are preferably substantially constant. Said working surface is preferably undulant, as described above with reference to the surface characteristics of said inner parts.

Where the cylindrical member of the fibre opening apparatus includes card-clothing wire (which includes said fibre opening elements) helically wound around its cylindrical surface, the wire itself may define, in part, the cylindrical working surface of the cylindrical member. In this respect, the wire may include a shoulder which faces substantially radially outwardly when fixed to the cylindrical member. The surface characteristics of this shoulder may be adapted as described in any statement herein with reference to the surface characteristics of said inner parts. The shoulder of the wire preferably defines, with a part of a cylindrical surface of the cylindrical member, said cylindrical working surface of the apparatus. A second length of wire may be interposed between each turn of said aforementioned card-clothing wire. A substantially radially outwardly facing surface of said second length of wire may be adapted as described in any statement herein to have the surface characteristics of said inner parts. Said substantially radially outwardly facing surface of said second length of wire may define, with said shoulder of said aforementioned card-clothing wire, said cylindrical working surface of the apparatus.

Preferably, said fibre opening apparatus comprises a ring for securement to an open-end spinning machine.

Where the fibre opening apparatus comprises card- clothed regions of a carding device, said support member for said fibre opening elements may comprise a flexible foundation, for example, of a laminated material, in which are embedded card-clothing wires. In this case, said inner parts of said apparatus may include an inward part of said wires. Thus, in this case, selected parts of the card- clothing wire may have different coefficients of friction.

According to a second aspect of the invention, there is provided a ring for a fibre opening apparatus as described in any statement herein, the ring including a helical groove in its outwardly facing cylindrical surface, lands being defined between adjacent turns of the helical groove, wherein the surface characteristics of the lands are as defined in any statement herein with reference to the surface characteristics of said inner parts.

The lands may have an undulant outwardly facing cylindrical surface.

According to a third aspect of the present invention, there is provided card-clothing wire for a fibre opening apparatus as described in any statement herein, the card- clothing wire including a base arranged to be secured to a wire support member and a plurality of fibre opening elements extending from said base, wherein the surface characteristics of parts of said fibre opening elements spaced furthest from said base differ from the surface characteristics of other fibre engaging parts of the card- clothing wire.

Preferably, said base of said card-clothing wire is arranged to be secured in a groove of said wire support member.

The invention extends to the use of fibre opening apparatus as described in any statement herein for fibre opening.

The invention further extends to the use of a ring as described in any statement herein in a fibre opening apparatus as described in any statement herein.

The invention further extends to the use of card- clothing wire as described in any statement herein in a fibre opening apparatus as described in any statement herein.

In another aspect, the invention provides a method of increasing the acceleration of fibres by an opening roller and/or a method of increasing the propensity for fibres to be disengaged from a rotating opening roller in an open- end spinning machine, wherein the opening roller supports a plurality of fibre opening elements which project away therefrom and the surface characteristics of outer parts of the fibre opening elements differ from the surface characteristics of fibre engaging parts (herein referred to as "said inner parts") of the opening roller disposed inwardly of said outer parts.

The method may utilise any of the apparatus described in any statement herein.

Specific embodiments of the invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which:

Figure 1 is a vertical cross-section through an open- end spinning apparatus which includes a rotatably mounted opening roller;

Figure 2 is an axial cross-section through a part of a known uncoated opening roller;

Figure 3 is an axial cross-section through a part of a known opening roller wherein the whole working surface of the opening roller is coated with a coating material; Figure 4 is an axial cross-section through a part of an opening roller wherein only the carding wire itself-.is coated with a coating material;

Figure 5 is an axial cross-section through a part of an opening roller wherein the working surface is uncoated but regions of the cylindrical working surface between adjacent fibre opening elements of the carding wire are roughened;

Figure 6 is an axial cross-section through a part of an opening roller wherein the whole working surface of the opening roller is coated with a coating material and regions of the cylindrical working surface between adjacent fibre opening elements of the carding wire are roughened; and

Figure 7 is an axial cross-section through a part of a carding cylinder.

In the following description, like reference numerals denote like or corresponding parts throughout.

By way of background, a known opening roller for an open-end spinning apparatus comprises a cylindrical roller body which includes a helical groove defined in the cylindrical outwardly facing surface of the body and extending from one axial edge of the body to an opposite axial edge thereof. Card-clothing wire is arranged in the helical groove so as to extend, in a helical fashion, around the entire cylindrical surface of the body.

Thus, referring to Figure 2, an opening roller 30 includes a cylindrical roller body 31 which defines a groove 32 in which card-clothing wire 34 is fixed. The card-clothing wire 34 includes a rectangular cross-section base 36 which includes an outwardly facing shoulder 38 and a fibre opening element 40 which extends outwardly from the base 36 and has a saw-tooth shape. Between adjacent grooves 32 of the roller body 31, lands 42 are defined, the lands being in substantially the same plane as that of the shoulder 38.

The known opening roller 50 of Figure 3 is similar to the roller 30 of Figure 2, except that the whole working surface of the opening roller 50 is coated with a surface coating 52. The surface coating 52 is provided to increase the friction between the working surface of the roller 50 and fibres contacted thereby. The surface coating 52 may be of chrome oxide, tungsten carbide or nickel-diamond.

The opening roller 60 of Figure 4 is similar to the opening roller 30 of Figure 2, except that only the fibre opening element 40 and outwardly facing shoulder 38 thereof is coated with the aforementioned surface coating

52; that is, the lands 42 are left uncoated.

The opening roller 70 of Figure 5 is similar to the opening roller 30 of Figure 2, except that the outwardly facing shoulder 38 and the lands 42 have been roughened up by knurling. The working surface of the roller 70 is wholly uncoated.

The opening roller 80 of Figure 6 is similar to the opening roller 30 of Figure 2, except that the outwardly facing shoulder 38 and the lands 42 have been roughed up by knurling and the whole working surface of the opening roller is coated with the aforementioned surface coating 52. Tests have been carried out on the quality of yarn produced in open-end spinning using the alternative opening rollers of Figures 2 to 6. The assessment of yarn quality involves measuring, for example, the coefficient of variation of unevenness, thick places/km, thin places/km, neps/km and yarn tenacity, by known techniques. The outcome of test results is tabulated below; the figure in the second column represents the relative overall quality of yarn, wherein the lower the figure the higher the yarn quality.

It should be noted that the highest yarn quality is achieved where the entire working surface of the opening roller is coated with a friction-increasing surface coating and the shoulders 38 and lands 42 are roughened by knurling. Also, in general, the yarn quality is improved by increasing (either by coating, knurling or both) the coefficient of friction of the shoulder 38 and lands 42.

In one further embodiment, the saw-tooth shaped fibre opening elements 40 are coated with a smooth-finish coating, for example in the form of a nickel-diamond base coating with an outer nickel coating, the shoulders 38 and the lands 42 having been knurled before coating. The smooth-finish coating is adapted to reduce the coefficient of friction of the fibre opening elements in comparison to the coefficient of friction of uncoated card-clothing. Thus, the smooth finish coating is arranged to encourage disengagement of fibres in zone B (Figure 1) , without affecting, to any significant extent, the acceleration of fibres in zone A, since acceleration of fibres in zone A takes place predominantly due to engagement of fibres with the knurled shoulders 38 and lands 42. It has been found that the quality of yarn produced using the arrangement of the additional embodiment is higher than that produced using the Figure 6 embodiment.

The aforementioned results may be explained as follows. It is believed that the acceleration and hence the individualisation of fibres of the fibre sliver in zone A (Figure 1) of the open-end spinning machine is caused, to a significant extent, by the frictional force between fibres of the sliver and the cylindrical working surface (comprising shoulders 38 and lands 42) of the opening roller and to a much lesser extent due to any frictional force between the fibre opening elements 40 and the fibres of the sliver. Thus, by increasing the coefficient of friction of the working surface only, the acceleration and individualisation may be optimised without affecting adversely to any great extent the ability of the fibres to be disengaged from the card- clothing wire 8 in zone B.

The roughened surfaces 38, 42 of the Figure 5 and 6 embodiments may be produced by any suitable means. A mechanical means of roughening, such as knurling, may be of utility. Alternatively, roughening may be achieved by providing holes or slots in the surfaces 38, 42. Another alternative is to provide a second length of card-clothing wire wound between the card-clothing wire 34 described above. The second length of wire may have much smaller teeth than those of the wire 34, the smaller teeth having certain friction characteristics. Additionally, the outwardly facing shoulder 38 of the card-clothing wire 34 may be formed with smaller teeth which in combination with the smaller teeth on the second length of wire may provide the cylindrical working surface of the roller with desired friction characteristics.

In another alternative, the relative friction of the fibre opening elements and working surface may be affected by treating the opening elements to reduce their coefficient of friction. Polishing or coating the surfaces of the opening elements may achieve this goal.

The problem of engagement and disengagement of fibres with card-clothed regions in carding machines may also be solved in the manner described above. Referring to Figure 7, a carding cylinder 90 includes carding wire 92 wound around its cylindrical surface. Shoulders 94 of the carding wire 92 include knurled regions 96. The provision of knurled regions 96 may lead to better transportation of fibres by the cylinder 90 and, accordingly, to better carding (with fewer points per square inch required on the card-clothing) .

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings) , and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) , may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s) . The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings) , or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A fibre opening apparatus comprising a support member for fibre opening elements and a plurality of fibre opening elements which are supported by and project away from said support member, wherein the surface characteristics of outer parts of the fibre opening elements differ from the surface characteristics of other fibre engaging parts (hereinafter referred to as "said inner parts") of the apparatus disposed inwardly of said outer parts.

2. Apparatus according to Claim 1, wherein the outer parts are adapted to exert, in use, a lower force on fibres and the force exerted on fibres by said inner parts.

3. Apparatus according to Claim l or Claim 2, wherein the respective surface characteristics of said outer and inner parts are such that the outer parts have a lower coefficient of friction than said inner parts.

4. Apparatus according to any preceding claim, wherein said inner parts of said apparatus are coated with a friction coating for increasing the coefficient of friction of said inner parts relative to that of said outer parts.

5. Apparatus according to any preceding claim, wherein the surface of said inner parts is a non-smooth surface.

6. Apparatus according to any preceding claim, wherein said outer parts of the fibre opening elements extend more than about half of the height of the fibre opening elements.

7. Apparatus according to any preceding claim, wherein said inner parts include at least a portion of said support member for said fibre opening elements.

8. Apparatus according to any preceding claim, wherein said fibre opening apparatus comprises a cylindrical member in the form of an opening roller or a ring for an open end spinning machine.

9. Apparatus according to any of Claims 1 to 7, wherein said fibre opening apparatus comprises card-clothed regions for carding devices.

10. A ring for a fibre opening apparatus as described in any of Claims 1 to 8, the ring including a helical groove in its outwardly facing cylindrical surface, lands being defined between adjacent turns of the helical groove which lands define, at least in part, said inner parts of the apparatus.

11. A ring as claimed in Claim 10, wherein the lands have an undulant outwardly facing cylindrical surface.

12. Card-clothing wire for a fibre opening apparatus as described in any of Claims 1 to 9, the card-clothing wire including a base arranged to be secured to a wire support member and a plurality of fibre opening elements extending from said base, wherein the surface characteristics of parts of said fibre opening elements spaced furthest from said base differ from the surface characteristics of other fibre engaging parts of the card-clothing wire.

13. A method of increasing the acceleration of fibres by a fibre opening apparatus and/or a method of increasing the propensity for fibres to be disengaged from a fibre opening apparatus, wherein a support member supports a plurality of fibre opening elements which project away therefrom and the surface characteristics of outer parts of the fibre opening elements differ from the surface characteristics of fibre engaging parts (herein referred to as "said inner parts") of the apparatus disposed inwardly of said outer parts.

14. A method of increasing the acceleration of fibres by an opening roller and/or a method of increasing the propensity for fibres to be disengaged from a rotating opening roller in an open end spinning machine, wherein the opening roller supports a plurality of fibre opening elements which project away therefrom and the surface characteristics of outer parts of the fibre opening elements differ from the surface characteristics of fibre engaging parts (herein referred to as "said inner parts") of the opening roller disposed inwardly of said outer parts.