GB2035393A - Textile apron - Google Patents

Abstract

A textile apron and method of making same are provided wherein such apron is adapted to be operated in an endless path and comprises a polymeric matrix material having a plurality of discrete reinforcing fibres randomly disposed substantially uniformly therethrough and defining the sole reinforcing means of said apron.

Description

SPECIFICATION Textile apron This invention relates to a textile apron and a method of making same.

The processing oftextileyarns or fibres usually includes the very important step of drafting or texturing, depending on the type of fibres or yarns being processed. The older and more conventional processing systems utilized discontinuous natural or synthetic fibres which were treated in either single or double long draft apron systems. In this process, drafting aprons were used to draw out the bundle of fibres into greater length and smaller cross-sections, thus creating a strand having uniform properties.

When processing continuous filament synthetic yarns, texturing mechanisms are utilized, and the yarns are passed between texturing aprons which usually impart a twist to the yarns while drawing them out in a manner similar to the drafting system.

The yarns are then heat set in a state imparted by the aprons, resulting in increased bulk and improved surface effect that promotes the processing of the yarns into fabrics.

A common problem with existing aprons, whether employed as texturing aprons or drafting aprons used in either the single or double long draft apron system, is the tendency for such aprons to stretch after extended use. Further, conventional aprons, whether new or stretched, have a further problem in tracking precisely during operation thereof in an associated system. In an effort to prevent such undesirable stretching, aprons proposed heretobefore have utilized helically wound substantially inextensible cords and/or woven fabric layers embedded in a matrix material. However, such cords and/or fabric layers are expensive and do not provide uniform tensioning of the apron across its width.

According to the present invention there is provided a textile apron adapted to be operated in an endless path, said apron comprising polymeric matrix material having a plurality of reinforcing fibres disposed in a substantially uniform manner and defining reinforcing means of said apron.

The fibres may be disposed throughout said matrix in substantially parallel relation and parallel to said endless path.

The polymeric matrix material may be comprises of a plurality of layers each having a plurality of parallel reinforcing fibres dispersed therethrough, said layers being fused together as a single-piece mass free of fusion lines therebetween.

The fibres may be disposed in said matrix roughly in sets with the fibres of one set being disposed in parallel relation at an angle relative to said endless path and with the fibres of another set being disposed in parallel relation and at an angle relative to said endless path which is opposite from said particular angle to provide a complementary disposal of reinforcing fibres.

The plurality of layers may be defined by a ribbon having said fibres disposed therein and with said ribbon being wound in a plurality of turns.

The polymeric matrix material may be a rubber compound such as nitrile rubber.

The polymeric matrix material may alternatively be a synthetic plastic material.

Each of said fibres may have a length generally of the order of 2 millimeters.

The fibres may be wood-cellulose fibres having an elastic modulus of 2 to 5 x 106 psi and a tensile strength of 6 to 9 x 104 psi.

Also according to the present invention there is provided a method of making a textile apron adapted to be operated in an endless path comprising the steps of, forming a sleeve of a polymeric matrix having a plurality of reinforcing fibres disposed in a substantially uniform manner and defining reinforcing means of said sleeve, curing and cooling said sleeve and cutting said sleeve to define an apron whereby said substantially uniform disposal of fibres provides uniform reinforcement of said apron.

The forming step may comprise forming said sleeve in a plurality of layers which during said curing step are fused together as a single-piece mass free of fusion lines therebetween.

The forming of said sleeve in said plurality layers may comprise winding a ribbon having said fibres disposed therein in a plurality of turns.

The forming step may comprise forming said sleeve by an extrusion process.

The forming step may alternatively comprise providing a rubber compound to define said matrix.

The forming step may comprise providing said rubber compound in the form of a nitrile rubber.

The forming step may alternatively comprise providing a synthetic plastic material to define said matrix.

The invention may include a further step of grinding said sleeve prior to said cutting step.

The forming step may comprise providing said fibres as wood cellulose fibres.

The step of providing wood cellulose fibres may further comprise providing said fibres each having a length generally of the order of 2 millimeters.

Following is a description with reference to the accompanying drawings of one method of carrying the invention into effect.

In the drawings: Figure 1 is a perspective view illustrating a pair of exemplary textile. aprons of this invention mounted on associated components comprising a typical double apron system; Figure 2 is a perspective view illustrating a single exemplary textile apron mounted on associated components comprising a single apron system; Figure 3 is an end view illustrating another embodiment of a single textile apron and associated components comprising another exemplary single apron system; Figure 4 is a perspective view illustrating one method which may be employed informing the exemplary aprons of Figures 1-3 wherein an elongated ribbon having reinforcing fibres dispersed therethrough is initially wound in at least one turn and then subsequently suitably processed to define an apron;; Figure 5 is a perspective view illustrating the completed apron defined from the construction of Figure 4 after processing thereof; Figure 6 is a fragmentary cross-sectional view taken essentially on the line 6-6 of FigureS; Figure 7 is a perspective view with a fragmentary portion broken away illustrating another exemplary embodiment of the apron of this invention which may be used interchangeably with the apron illustrated in FigureS; and Figure 8 is a fragmentary cross-sectional view similar to Figure 6 illustrating that the apron of this invention may be made of a polymeric material in the form of a synthetic plastic.

Referring now to Figures 1, 2, and 3 of the drawings there is shown texturing of drafting aprons as used in a double apron system (Figure 1) and as used in single apron systems (Figures 2 and 3). Each of these aprons though of different physical size is of the same construction and for simplicity and ease of presentation, each of these aprons is designated by the same general reference numeral 10.

The apron 10 is particularly adapted to be operated in an endless path which is parallel to a central longitudinal axis of such apron 10; and, as seen in Figure 6 the apron 10 comprises a polymeric matrix material 12 which is shown by cross-hatching as being in the form of a rubber compound which may be either a natural rubber compound or a synthetic rubber compound.

The matrix material 12 has a plurality of discrete elongate reinforcing fibres 13 randomly disposed therethrough and such fibres define the only or sole reinforcing means of the apron 10. The fibres 13 are disposed through the matrix material 12 in a substantially uniform manner with such fibres being in substantially parallel relation; and, the substantially uniform dispersal of the fibres is indicated at 14 in Figure 6 by the uniform placement of dots representing the fibres 13. The uniform fibre disposal provides uniform reinforcement of the apron 10 at each cross-sectional position thereof across its width which assures precise wobble-free tracking during operation of the apron in an associated drive system.

The apron 10 may be made utilizing one example of the method of this invention which will now be described with reference to Figures 4 and 5. Accordingly, the apron 10 may be defined by providing an elongate sheet or ribbon 15 of polymeric matrix material 12 having reinforcing fibres 13 suitably dispersed therethrough in parallel relation and parallel to the elongate dimension or longitudinal axis of the ribbon. The fibres 13 may be suitably embedded in the ribbon 15 using any suitable technique such as calendering or the like.

The ribbon is suitably wrapped around a suitable building mandrel to define an apron construction of either a single ply or a plurality of plies such as two plies or layers as illustrated at 16 in Figure 4; and, the opposite ends of the ribbon 15 are radially aligned as shown at 17 so that once cured the apron has a substantially uniform thickness throughout. With this arrangement it will be seen that the fibres 13 are disposed in parallel relation and parallel to the endless path of the apron 10 defined from such construction. The apron construction thus defined is then cured in a suitable curing apparatus whereupon the individual layers or plies are fused together as a single-piece mass free of fusion lines and such mass has a homogeneous character throughout, i.e., the properties of the polymeric matrix with its embedded fibres are substantially uniform throughout.The cured construction at this point is in the form of a tubular sleeve of substantial height parallel to its central longitudinal axis and such sleeve is suitably cooled, ground, and cut to desired width to define a plurality of aprons 10. The curing, cooling, grinding and cutting is achieved utilizing any suitable method and apparatus known in the art.

Another exemplary embodiment of the textile apron of this invention is illustrated in Figure 7 of the drawing. The apron of Figure 7 is very similar to the apron 10; therefore, such apron will be designated by the reference numeral 1 OA and representative parts of such apron which are similar to corresponding parts of the apron 10 will be designated in the drawing by the same reference numeral as in the apron 10 followed by the letter designation A and not described again in detail.

The apron 1 OA is comprised of a polymeric matrix material also in the form of a rubber matrix 1 2A and is provided with reinforcing fibres 13A. The main difference between the apron 10A and the apron 10 is that in the apron 1 0A the reinforcing fibres are disposed as will now be described.

In particular, the fibres 1 OA are disposed in a plurality of sets with the fibres in each set being in substantially parallel relation. Further, for each set of fibres disposed in parallel relation at a particular angle to the endless path of the belt there is basically another set of such fibres disposed in parallel relation at an angle to the endless path opposite the particular angle.

In the forming of a tubular sleeve from which aprons 1 OA are cut the disposal of fibres in a plurality of sets may be achieved by employing a plurality of ribbons, two for example, each having fibres parallel to its longitudinal axis and wherein one ribbon and its fibres is helically wound in tubular form and disposed at the previously mentioned particular angle to the endless path of the sleeve construction and the other ribbon and its fibres is helically wound at an angle opposite the particular angle. A similar result could be obtained with two sheets which are bias cut relative to their parallel fibres with one sheet being wrapped to define a sleeve construction as previously mentioned and having its fibres at the particular angle as described earlier and the other sheet being similarly wrapped and having its fibres at an angle opposite the one angle.

The above-described two techniques provide control of the orientation of parallel fibres by control of associated ribbons or sheets having such fibres embedded therein; however, it has been found that the disposal of parallel fibres in numerous sets with each set having its fibres at a particular angle to the endless path of its sleeve construction and a corresponding set with its fibres at an angle opposite thereto relative to the endless path of such sleeve construction (and hence each final apron) may be achieved by employing an extrusion die apparatus.

In such extrusion apparatus a polymeric mass containing fibres 13A is provided from an extruder and initially formed as a small diameter molten tube structure having fibres arranged parallel to its longitudinal axis whereupon the small diameter tube structure is flared rapidly perpendicular to the tube structure axis by a bullet-nosed die mechanism causing the formation of a final larger diameter sleeve construction. During the flaring action the fibres are disposed as explained in this paragraph.

The final sleeve construction is then cured, cooled, ground, and cut as described earlier to define a plurality of aprons 1 OA.

It has been found that an I-shaped test section cut with the vertical arm of such i parallel to the endless path of its associated apron 1 0A has substantial strength. Consistently such strength is generally of the order of 65 per cent the strength of a similar I-shaped test section taken from an apron 10.

The apron 10A made by extrusion of an associated sleeve and employing the above-decribed extrusion apparatus has fibres disposed in a plurality of directions which might appear to be uncontrolled yet it has been found that the number of fibres disposed with their elongated dimension in one direction relating to the endless path of the apron is compensated for roughly by a corresponding number of fibres having their elongated dimension in a direction relative to such endless path which is opposite the one direction thereby providing an offsetting action which results in the apron 10A not only having substantial strength but also having the precision tracking capability previously described.

The aprons 10 and 10A have been illustrated and described as comprised of matrix material which has been described in the specification and crosshatched in the drawing as being a rubber compound and preferably a nitrile rubber is employed. However, it will be appreciated that each apron 10 and 1 OA may be made as described above of a polymeric material in the form of a synthetic plastic material as shown in Figure 8 wherein such a synthetic plastic matrix material is designated 12M and has fibres 13M disposed therethrough essentially as shown and decribed in connection with Figure 6.

The fibres 13, 13A, and 13M which are utilized in the various exemplary aprons disclosed herein may be made of any suitable material. Satisfactorily results have been obtained using wood cellulose fibres manufactured by the Monsanto Company of St. Louis, Missouri, and such fibres are sold under the registered trademark of SANTOWEB. In one embodiment these fibres had an elastic modulus of 2 to 5 x 106 psi and a tensile strength of 6 to 9 x 104 psi with an average diameter of 8 to 16 microns and a length of 1 to 9 millimeters. These fibres are further described in U.S. Patent Nos. 3,836,412 and 3,709,845, and as disclosed therein are suitably treated to promote bonding thereof in the elastomeric matrix.

The aprons 10 illustrated in Figure 1 may have a nominal circular diameter of 1 9/32 inches, a width of 1 3/4 inches, and a thickness of 0.060 inch. The apron 10 of Figure 2 may have a circular diameter of inches, a width of 1 15/32 inches, and a thickness of .035 inch. Similarly, the apron 10 of Figure 3 may have a circular diameter of inches, a width of 1 /8 inches, and a thickness of .060 inch. These sizes have been presented merely as examples of sizes which may be used; however, it is to be understood that the apron of this invention may be of any suitable size employed in the art.

While present exemplary embodiments of this invention, and methods of practicing the same, have been illustrated and described, it will be recognized that this invention may be otherwise variously embodied and practiced within the scope of the following claims.

Claims (22)

1. Atextile apron adapted to be operated in an endless path, said apron comprising polymeric matrix material having a plurality of reinforcing fibres disposed in a substantially uniform manner and defining reinforcing means of said apron.

2. An apron as claimed in claim 1 in which said fibres are disposed throughout said matrix in substantially parallel relation and parallel to said endless path.

3. An apron as claimed in claim 2 in which said polymeric matrix material is comprised of a plurality of layers each having a plurality of parallel reinforcing fibres dispersed therethrough, said layers being fused together as a single-piece mass free of fusion lines therebetween.

4. An apron as claimed in any one of the preceding claims in which said fibres are disposed in said matrix substantially in sets with the fibres of a set being disposed in parallel relation at an angle relative to said endless path and with the fibres of another set being disposed in parallel relation and at an angle relative to said endless path which is opposite from said particular angle to provide a complementary disposal of reinforcing fibres.

5. An apron as claimed in claim 3 or claim 4 in which said plurality of layers are defined by a ribbon having said fibres disposed therein and with said ribbon being wound in a plurality of turns.

6. An apron as claimed in any one of the preceding claims in which said polymeric matrix material is a rubber compound.

7. An apron as claimed in claim 6 in which said polymeric matrix material is a nitrile rubber.

8. An apron as claimed in any one of claims 1 to 5 in which said polymeric matrix material is a synthetic plastics material.

9. An apron as claimed in any one ofthe preceding claims in which each of said fibres has a length generally of the order of 2 millimeters.

10. An apron as claimed in any one of the preceding claims in which said fibres are woodcellulose fibres having an elastic modulus of 2 to 5 x 106 psi and a tensile strength of 6 to 9 x 104 psi.

11. A method of making a textile apron adapted to be operated in an endless path comprising the steps of, forming a sleeve of a polymeric matrix having a plurality of reinforcing fibres disposed in a substantially uniform manner and defining reinforcing means of said sleeve, curing and cooling said sleeve, and cutting said sleeve to define an apron whereby said substantially uniform disposal of fibres provides uniform reinforcement of said apron.

12. A method as claimed in claim 11 in which said forming step comprises forming said sleeve in a plurality of layers which during said curing step are fused together as a single-piece mass free of fusion lines therebetween.

13. A method as claimed in claim 12 in which said forming of said sleeve in said plurality layers comprises winding a ribbon having said fibres disposed therein in a plurality of turns.

14. A method as claimed in claim 11 in which said forming step comprises forming said sleeve by an extrusion process.

15. A method as claimed in claim 11 in which said forming step comprises providing a rubber compound to define said matrix.

16. A method as claimed in claim 15 in which said forming step comprises providing a rubber compound in the form of a nitrile rubber.

17. A method as claimed in claim 11 in which said forming step comprises providing a synthetic plastic material to define said matrix.

18. A method as claimed in claim 11 and comprising the further step of grinding said sleeve prior to said cutting step.

19. A method as claimed in claim 11 in which said forming step comprises providing said fibres as wood cellulose fibres.

20. A method as claimed in claim 19 in which said step of providing wood cellulose fibres comprises providing said fibres each having a length generally of the order of 2 millimeters.

21. A textile apron substantially as hereinbefore described and as illustrated in the accompanying drawings.

22. A method of making a textile apron substantially as hereinbefore described and as illustrated in the accompanying drawings.