DESC:FIELD
The present disclosure relates to a process for treating a card clothing wire.
DEFINITIONS
As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used indicate otherwise.
Carding refers to a mechanical process that disentangles, cleans and individualizes fibres to produce a continuous web suitable for subsequent processing.
Card clothing wire refers to a metal/alloy strip having plurality of teeth embedded on a base for disentangling and cleaning textile fibers.
Alloy steel refers to steel having carbon content in the range of 0.61% to 1.50% and alloying components comprising chromium, tungsten, vanadium, and the like.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
Carding is a common technique in spinning mills, used for removal of impurities in textile fibres as well as enabling parallel alignment of the fibres. The carding machine mainly comprises rollers with saw toothed wires through which fibres are passed. Typically, the card clothing component of a carding machine comprises saw toothed wire tips on a metal base or wire teeth embedded in a foundation of multiple fabric layers with rubber toppings. The component is used to cover rollers i.e. cylinder, doffer or flat bars, stationary flats and the like, on a carding machine. The saw toothed wire of the component, is in continuous contact with the fibres, and are therefore susceptible to wear and abrasion.
Various processes are known in the art for improving the abrasion resistance of material such as hardened and tempered steel. One such process is cryogenic treatment wherein hardened and tempered steel is soaked at a temperature lower than 0°C for a substantial time, and then tempered. However, the step of tempering after cryogenic treatment could also lead to undesirable changes in the microstructure, which in case of card clothing wire can consequentially lead to improper carding action.
There is, therefore, felt a need for an effective treatment for manufacturing card clothing wires that overcomes the above mentioned limitations.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
It is an object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
An object of the present disclosure is to provide a process for treating a card clothing wire.
Another object of the present disclosure is to provide a treated card clothing wire.
Still another object of the present disclosure is to provide card clothing wire with improved hardness and toughness.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure provides a process for treating a card clothing wire. The process comprises a step of obtaining a card clothing wire having a plurality of teeth structures. The wire is hardened at a temperature in the range of 800 °C to 900 °C to obtain a hardened wire. The hardened wire is tempered at a temperature in the range of 150 °C to 200 °C to obtain a tempered wire. The tempered wire is spooled to obtain a wire spool. The wire spool is placed in a cryogenic environment at a temperature in the range of -200 to -190°C for a time period in the range of 18 to 22 hours to obtain a treated card clothing wire.
The present disclosure further provides a treated card clothing wire comprising a plurality of teeth structures characterized by having a hardness in the range of 800 to 1000 VHN, wherein the card clothing wire is characterized by having nanocarbides.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
The card clothing wire of the present disclosure will now be described with the help of the accompanying drawing, in which:
Figure 1A illustrates a card clothing wire tip and wire rib, in accordance with the present disclosure;
Figure 1B illustrates a card clothing rib, in accordance with the present disclosure;
Figure 2A illustrates a clipped cleaning fillet type card clothing substrate used for cryogenic treatment in accordance with one embodiment of the present disclosure;
Figure 2B illustrates a flat tops card clothing substrate used for cryogenic treatment in accordance with another embodiment of the present disclosure;
Figure 2C illustrates fillet type card clothing substrate used for cryogenic treatment in accordance with another embodiment of the present disclosure;
Figure 2D illustrates a cleaning fillet type card clothing substrate used for cryogenic treatment in accordance with another embodiment of the present disclosure;
Figure 3A illustrates SEM image of sample 1 before cryogenic treatment;
Figure 3B illustrates SEM image of sample 1 after cryogenic treatment;
Figure 4A illustrates SEM image of sample 2 before cryogenic treatment;
Figure 4B illustrates SEM image of sample 2 after cryogenic treatment;
Figure 5A illustrates SEM image of sample 2 subjected to low flame hardening prior to cryogenic treatment; and
Figure 5B illustrates SEM image of sample 2 subjected to high flame hardening prior to cryogenic treatment.
DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," “including,” and “having,” are open ended transitional phrases and therefore specify the presence of stated features, integers, steps, operations, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.
The conventional processes for cryogenic treatment are not suitable for card clothing wires wound on bobbins. Similarly, the cryogenic process followed by tempering at high temperature is also not suitable for the type of card clothing having plurality of wires supported on rubber topping.
Therefore, the present disclosure provides an effective process to treat card clothing wire in wound condition.
In one aspect, the present disclosure provides a process for treating a card clothing wire. The process is described in detail herein below:
Initially, a card clothing wire having a plurality of teeth structures is obtained.
In an embodiment, the card clothing wire is made of an alloy steel comprising carbon in the the range of 0.61% to 1.50%.
Alloy steel refers to steel having carbon content in the range of 0.61% to 1.50% and alloying components comprising chromium, tungsten, vanadium, and the like.
In accordance with the present disclosure, the step of obtaining the card clothing wire comprises cold rolling a round wire to obtain a flat strip. Typically, the cold rolling comprises passing the round wire through a set of rollers separated by a gap. The flat strip thus obtained varies in thickness across the width such that the flat strip has a thick side and a thin side. The thick side of the flat strip has a thickness in the range of 0.4 mm to 4.5 mm and the thin side of the flat strip has a thickness in the range of 0.04 mm to 0.5 mm.
The round wire has a diameter in the range of 1mm to 4mm. In one embodiment, the round wire has a diameter of 1.3 mm. In another embodiment, the round wire has a diameter of 2.35 mm. The flat strip has a width in the range of 2 mm to 10 mm.
Typically, a wire rod is rolled to obtain the round wire, wherein the wire rod has a diameter in the range of 5 mm to 6 mm. In an embodiment, the wire rod has a diameter of 5.5 mm.
The flat strip is subjected to profile cutting at one of the edges to obtain the card clothing wire having a plurality of teeth structures.
In an embodiment, the profile cutting is carried out by using die and punch. In an exemplary embodiment, the profile cutting is carried out by using carbide based die and punch. The profile cutting is done by punching the wire by using a machine selected from rotary puncing machine and vertical punching machine.
In an embodiment, the card clothing wire is preheated at a temperature in the range of 600°C to 700 °C, prior to the step of hardening. In an embodiment, the step of preheating is carried out at 650 °C.
The heated wire is hardened at a temperature in the range of 800 °C to 900 °C to obtain a hardened wire. In an embodiment, the step of hardening is carried out at 850°C.
In an exemplary embodiment, the step of hardening is carried out on the plurality of teeth structures of the card clothing wire. In an exemplary embodiment, the step of hardening is carried out by flame hardening of tip portion of each of the plurality of teeth structures followed by soaking the teeth structures in a fluid medium.
The fluid medium is selected from water and oil. In one embodiment, the fluid medium is oil.
The flame hardening done on the plurality of teeth structures ensures relatively high hardness of the teeth structures than the uncut part of the wire, to obtain a hardened wire tip with softer base. The hardened wire is subjected to tempering at a temperature in the range of 150 °C to 200 °C to obtain a tempered wire. In one embodiment, the step of tempering is carried out at 175 °C.
The tempered wire is spooled to obtain a wire spool. In an embodiment, the tempered wire is spooled on a bobbin.
The so obtained wire spool is placed in a cryogenic environment to a cryogenic treatment at a temperature in the range of -200 to -190°C for a time period in the range of 18 to 22 hours to obtain a treated card clothing wire. In one embodiment the step of cryogenic treatment is carried out at -196 °C and for 20 hours.
In accordance with the present disclosure, the step of cryogenic treatment is carried out by placing the spooled wire in a cryogenic chamber followed by diffusing a cooling medium into the cryogenic chamber.
In an embodiment, the cooling medium is liquid nitrogen. In an embodiment, the cryogenic chamber is airtight.
The cryogenic treatment enables formation of nanocarbide in the whole mass as well as on the surface of the card clothing wire thereby enhancing the surface characteristics and leading to reduction of wear loss.
Typically, the spooled wire is wrapped in vacuum sealed polythene before placing in the cryogenic chamber.
In an embodiment of the present disclosure, the treated card clothing wire is allowed to attain a temperature in the range of 20 °C to 40 °C after cryogenic treatment. In one embodiment, the treated card clothing wire is allowed to attain 25 °C after cryogenic treatment.
In another aspect, the present disclosure provides a treated card clothing wire comprising a plurality of teeth structures characterized by having a hardness in the range of 800 to 1000 VHN, wherein the card clothing wire is characterized by having nanocarbides. In one embodiment of the present disclosure, the treated card clothing wire has hardness of at least 800 VHN at 0.1 mm. Further, the wear resistance of the cryogenic treated wire prepared by the process of the present disclosure is increased at least by 38% in SAE52100 and at least by 33 % in 83VW3 grade alloy steel respectively.
The tip portion of the treated card clothing wire comprises a plurality of teeth structures 102 and a rib 104 as shown in Figure 1A and Figure 1B.
The plurality of teeth structures and the rib are obtained as a result of profile cutting.
Figure 2 (A to D) illustrate different substrates of card clothing used for cryogenic treatment including clipped cleaning fillet, flat tops, fillet type and cleaning fillet respectively.
The treated card clothing wire comprises nanocarbides on the surface of the wire as well as in the bulk of the wire, that leads to relatively greater wear resistance than untreated card clothing wire.
The present disclosure provides a simple and economical process for obtaining treated card clothing wire which is cryogenically treated to enable formation of nanocarbide in the total mass as well as on the surface, thereby enhancing the surface characteristics and wear resistance thus leading to reduction in wear loss.
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
The present disclosure is further described in light of the following experiments which are set forth for illustration purpose only and not to be construed for limiting the scope of the disclosure. The following experiments can be scaled up to industrial/commercial scale and the results obtained can be extrapolated to industrial scale.
EXPERIMENTAL DETAILS
Example 1:
The round wire (diameter = 1.3 mm) (sample A) (grade - 83VW3) obtained from rolling of spherodized steel wire rod of 5.5 mm diameter was cold rolled to rolled strip and then subjected to profile cutting at one of the edges of the rolled strip to obtain a card clothing wire having a plurality of teeth structures. The opposite side remained uncut called as rib.
The card clothing wire was subjected to preheating at 650 °C. followed by flame hardening of the teeth structures at 850 °C and immediate soaking in oil, to obtain a hardened wire. The hardened wire was subjected to tempering at 175 °C to obtain a tempered wire. The tempered wire was spooled over a bobbin to obtain a wire spool.
The wire spool was wrapped in vacuum tight polythene and placed in a cryogenic chamber and then temperature was gradually lowered to -196 °C and kept for 20 hours. After adequate cryosoaking, the spooled wire was allowed to reach at 40 °C from -196 °C, to obtain a treated card clothing wire (sample 1).
Example 2:
The procedure as given in Example 1 was repeated, except that round wire (diameter =1.3 mm) (sample B) (grade - SAE52100) was used, instead of the sample A (grade - 83VW3), to obtain a treated card clothing wire (sample 2).
Example 3:
The procedure as given in Example 1 was repeated, except that round wire (diameter =2.35 mm)(sample C having SF2291 design, grade SAE 52100) was used instead of the sample A (grade - 83VW3), to obtain a treated card clothing wire (sample 3).
Measurement of wear loss:
The samples 1-3 were subjected to measurement of wear loss by using a wear tester. Testing conditions - load of 2 kg, at 490 rpm and time duration of 30 minutes.

Table 1: Comparative testing of wear loss of samples 1-3 (of the present disclosure) and untreated samples
Sr. No. Treated Card clothing wire sample
Wear loss (weight loss in g)
Observation
1 Sample 1 ( 83VW3) 0.0772 15.07% decrease in wear rate in cryotreated wire
2 Untreated sample (83VW3) 0.0909

3 Sample 2 (SAE52100) 0.008 38.46% decrease in wear rate in cryotreated wire

4 Untreated sample (SAE52100) 0.013
5 Sample 3 (SF2291 design, grade SAE 52100)
0.0010 16.67% decrease in wear rate in cryotreated wire
6 Untreated sample (SF2291 design , grade SAE 52100) 0.0012

As observed in Table 1, the cryogenic treated samples 1-3, as per the present disclosure, showed reduced wear loss than the untreated samples.
Effect of soft tempering on wear loss after cryogenic treatment:
The sample 1 was subjected to soft tempering after cryogenic treatment and the wear loss of the resulting sample was measured by using a wear tester. Testing conditions - load of 2 kg, at 490 rpm and time duration of 20 minutes.

Table 2: Comparative testing of wear loss of sample 1 (of the present disclosure) and untreated sample
Sample No. Material Description
Wear loss (weight loss in g)
Remarks
1 Untreated sample (83VW3)
0.0090
2 Sample 1 (83VW3)
(soft tempered at 100°C / 1 hr) 0.0079 12.22% decrease in wear rate in cryotreated wires.
3 Sample 1 (83VW3)
(no soft tempering 0.0060 gm 33.33% decrease in wear rate in cryotreated wire

As observed in Table 2, the cryogenic treated sample 1, as per the present disclosure, showed reduced wear loss than the untreated sample. Further, soft tempering at 100°C for 1 hr increased the wear loss relatively than the Sample 1 which was not soft-tempered.
SEM analysis:
The samples 1-2 were subjected to SEM analysis to understand the surface characteristics and nanocarbide formation. The SEM images of samples 1-2 before cryogenic treatment is as shown in Figures 3A and 4A respectively, whereas the SEM images of the samples 1-2 after cryogenic treatment is illustrated in Figures 3B and 4B respectively. As observed in Figure 3B, the SEM image microstructure of cryogenic treated wire sample 1 obtained from 83VW3 steel has microstructure consisting of largely nano-sized carbides dispersed in tempered martensitic structure. Further, as observed in Figures 4B, the SEM image microstructures of cryogenic treated wire sample 2, obtained from SAE52100 steel also has microstructure consisting of largely nano-size carbides dispersed in tempered martensitic structure.
Effect of flame hardening:
The sample 2 was studied for effect of flame hardening on nanocarbide formation by method of SEM analysis. Figure 5A represents the effect of low flame hardening (below 800 °C) prior to cryogenic treatment on sample 2, whereas figure 5B represents the effect of high flame hardening prior to cryogenic treatment on sample 2. It was observed that adequate flame hardening temperature enables to dissolve carbides in the tip region during hardening, which ensures reappearance of fresh formation of nanocarbides upon cryogenic treatment.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a simple and economical process for treating a card clothing wire, that has
- improved wear resistance; and
- improved tip hardness.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the invention to achieve one or more of the desired objects or results. While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Variations or modifications to the formulation of this invention, within the scope of the invention, may occur to those skilled in the art upon reviewing the disclosure herein. Such variations or modifications are well within the spirit of this invention.
The numerical values given for various physical parameters, dimensions, and quantities are only approximate values and it is envisaged that the values higher than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the invention unless there is a statement in the specification to the contrary.
While considerable emphasis has been placed herein on the specific features of the preferred embodiment, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiment without departing from the principles of the disclosure. These and other changes in the preferred embodiment of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.
,CLAIMS:WE CLAIM:
1. A process for treating a card clothing wire, said process comprising the following steps:
(i) obtaining a card clothing wire having a plurality of teeth structures;
(ii) hardening said wire at a temperature in the range of 800 °C to 900 °C to obtain a hardened wire;
(iii) tempering said hardened wire at a temperature in the range of 150 °C to 200 °C to obtain a tempered wire;
(iv) spooling said tempered wire to obtain a wire spool; and
(v) placing said wire spool in a cryogenic environment at a temperature in the range of -200 to -190°C for a time period in the range of 18 to 22 hours to obtain a treated card clothing wire.
2. The process as claimed in claim 1, wherein step (i) of obtaining said card clothing wire comprises the following sub-steps:
(a) cold rolling a round wire to obtain a flat strip; and
(b) profile cutting at one of the edges of said flat strip to obtain the card clothing wire.
3. The process as claimed in claim 2, wherein said round wire has a diameter in the range of 1 mm to 4 mm or wherein said flat strip has a width in the range of 2 mm to 10 mm.
4. The process as claimed in claim 2, wherein said profile cutting is carried out by using carbide based die and punch.
5. The process as claimed in claim 1, wherein the card clothing wire is made of an alloy steel comprising carbon in the the range of 0.61% to 1.50%.
6. The process as claimed in claim 1, wherein said card clothing wire is pre-heated at a temperature in the range of 600°C to 700 °C, prior to said hardening, or wherein said hardening is carried out on the plurality of teeth structures of said wire.
7. The process as claimed in claim 1, wherein the step of cryogenic treatment is carried out by placing the spooled wire in a cryogenic chamber followed by diffusing a cooling medium into the cryogenic chamber, wherein said cryogenic chamber is airtight, or wherein said cooling medium is liquid nitrogen.
8. The process as claimed in claim 1 or 7, wherein said wire spool is wrapped in vacuum sealed polythene before placing in a cryogenic chamber.
9. The process as claimed in claim 1, wherein the treated card clothing wire is allowed to attain a temperature in the range of 20 °C to 40 °C after cryogenic treatment.
10. A treated card clothing wire comprising a plurality of teeth structures characterized by having a hardness in the range of 800 to 1000 VHN, wherein said card clothing wire is characterized by having nanocarbides.