Title: Apparatus and Method for providing a total and effective solution for removal of lint fibers from knitting machines and its associated creel.
Technical field: The present invention relates to apparatus and method of removing lint fibers from knitting machines and its associated creel.
Background & Prior Art
It is well known that creels are a major source of lint generation particularly during unwinding. There is a tendency for lint to be shed at points where the yarn touches any part of the tubes conveying the yarn to the knitting machine.
It is well known that lint is shed in the knitting machine at various points such as IRO's, feeders, needles & sinkers. The lint so generated accumulates on various locations on the knitting machine. Once the fabric roll is complete, it is doffed from the knitting machine. Prior to starting a new roll the knitting machine is manually cleaned by blowing compressed air on the points on which lint has accumulated on the knitting machine. Compressed air pressure dislocates and discharges this accumulated lint to the air surrounding the knitting machine. The lint becomes air borne contaminating the working environment and giving rise to many problems.
Air borne lint migrates to knitting zones of adjacent knitting machines and gives rise to faults in fabrics being knitted and consequential loss in production.
In order to deal with this problem, return air systems are deployed, by which huge volume of air is continuously injected and exhausted into the knitting area. The return air moves lint to the lint trapping systems. Return air is faulted on many accounts, air velocities are quite low, air can not be made to follow a desired path, this system is energy intensive etc.
Primarily, the return air system is not able to prevent cross contamination, that is, if one knitting machine is being cleaned by compressed air, then the lint which is blown off is carried to adjacent knitting machines, causing contamination.
Cross contamination is mitigated by using polythene curtains, which help to contain lint, but this too presents many technical problems such as static buildup which causes lint to stick to the polythene curtains and the affinity of polythene for dust accumulation is well known.
Other solutions include filter creels, in which creels are encased in an enclosure through which air flow is created. The air flow entrains most of the lint generated in the creel and the lint is then removed by a filtering process. This however does rely upon the filter being cleaned regularly, which as such is a time consuming process. Enclosed creels present operational difficulties. Access to parts or loading of yarn cones or mending yarn breaks or tailing is problematic and restrictive.
The lint generated in the filter creel is arrested but there is no solution for the lint that is generated on the knitting machine.
Prior art EP 0160 231 wherein compressed air is blown outwardly through a tubular structure from above the creels and is directed towards the full circumference and full height of the creel to blow off lint accumulation off the creel as well as blow off any airborne lint fibers. The tubular structure has a downward decline by which the lint accumulated on the floor also gets blown off thereby keeping the floor clean. However, the lint which is blown off to the floor gets accumulated and has to be cleaned frequently and meticulously which is often not the case. Furthermore, the cleaning has to be done manually which results in wastage of precious labor hours.
Prior art DE-A-40 30 940 discloses a yarn creel in which the lint is dislodged from the yarn cones or packages by means of streams of gas directed from the openings in a series of ducts. However these ducts are not placed particularly close to the cones or packages and their cleaning action is consequently not particularly efficient.
Prior art, EP 0679 202 which describes blowing of gas stream on the points where the yarn is conveyed on the creel through duct enclosed tubes. The patented invention also includes a provision for reverse gas flow to blow off the lint accumulated on the filter means. The creel includes valves which open to the reverse flow of gas and direct the lint from the filter means to the collection point. The collection point communicates with the chamber, which is placed either above or below the creel, again through a valve which opens in response to reverse flow of gas stream. The gas stream then flows downwards, drawn through the filter and the lint free air is re-circulated. The creel is contained in a housing or enclosure which is open in the front.
Summary of the invention:
The present invention describes an apparatus and method for effective removal of lint fibers from knitting machine and its associated creel and for solving all problems of lint extraction. The apparatus and method comprise of providing for a return air flow system with a controlled air flow direction, which blows away the lint from the knitting machine and its associated creel to the automatically cleaned lint extracting filters.
Brief description of the drawings:
FIG I: shows a top perspective view of the area enclosing the knitting machine along with the return air system of the present invention.
FIG II: shows the top perspective view of the area enclosing the knitting machine along with the various components integrated with the return air system of the present invention.
Description of the illustrated embodiment:
Referring now to the accompanying drawings and initially to FIG I, a conventional
multi-feeder circular knitting machine 16 and its associated yarn creel 15 is seen which
includes 2 sets of 48 feeder + 48 reserve cone flat vertical creels 15 are installed in the creel area of the totally sealed enclosure 10. The creels are placed over the slits 13 in the floor to enable return air to extract all the lint that is generated during unwinding of cones placed on the creels. The approximate dimensions of the creel area 15 are 2.5 m width, 3.5 meter height and 5.6 meter length. The volume of this creel area within the enclosure 10 is about 49 meter cube. The approximate dimensions of the knitting machine area 16 are 4.0 m width, 3.5 meter height and 5.6 meter length. The volume of this knitting machine area within the enclosure 10 is about 77 meter cube. However, the dimensions may be modified in accordance to application.
The enclosure 10, being top covered, is made of masonry or aluminum or glass partitions on top of the return air trench 11. In another embodiment, the top covered portion of the enclosure 10 is a ceiling of a building, factory, workshop and the likes. For the current embodiment, the approximate dimensions of the enclosure 10 are 3.5m height, 5.6 m width and 6.5 m length and the volume is about 126 meter cube. However, the enclosure dimensions may need to be modified for specialized knitting machines. The conventional multi-feeder circular knitting machine of the present embodiment is selected from a standard single or double jersey machine. The creel 15 is placed on top of the return air trench 11, integrated with floor slits 12 and trap door with closed slits 13 which together comprise of the return air system apparatus (FIG II). The slits 12 and a trap door with closed slits 13 placed in the floor for return air flow. The slits in the trap door 13 may be opened to provide additional orifices to increase the return air volume. In operation, air is forced to flow from front of the knitting machine and then from top of the creel 15 and then to flow from the slits in the floor to the return air trench.
Since return air is being extracted from below the creel 15 hence return air is forced to enter from the openings left in the PVC curtains 14 in front of the knitting machine 16. Air flow has now been given a direction and is sweeping the knitting machine 16 and extracting the lint being generated at various points within the knitting machine 16. This same very air flow is also trapping and extracting the lint being generated in the creel 15 due to cone unwinding before being exhausted into the return air trench 11. The return air flow path is seen as 17.
The extracted lint is carried by the return air to the filters of the return air system. These filters are being cleaned automatically with automation and no manual intervention is required by operators. Hence operators have been spared of the tedious tasks of frequently cleaning lint filters.
Fabric rolls are removed from the front of the enclosure 10, yarn cones are loaded into the creel 15 from the back of the creel area and yarn breaks are mended by entering the creel area either from front or back, through the self sealing PVC curtains 14. The PVC curtains 14 are 4mm thick slat type and clear and transparent. The purpose of these PVC curtains to provide the necessary sealing of the enclosure and to allow easy ingress or exit of operators and for the curtains to shut automatically thereafter for sealing.
After completion of each fabric roll the knitting machine 16 is stopped, the roll is doffed and the knitting machine 16 is manually blow cleaned by compressed air, by blowing off the lint settled on the knitting machine 16. During the duration of this cleaning operation, the closed slits in the trap door 13 are automatically opened, causing increase in orifice size, resulting in greater volume of return air flow, air velocity increases. The lint that is blown off the knitting machine 16 is confined to the knitting machine area of the enclosure 10; this airborne lint is not allowed to escape the enclosure 10 and is arrested within the enclosure walls 10 and by PVC curtains 14. Increased volume of return air flow and higher air velocity extract the airborne lint faster into the return air system. Hence cross contamination problems caused due to blown off lint during machine blow cleaning is contained.
Lastly, the volume of the creel section and the knitting machine section within enclosure 10 has been reduced substantially. Hence the number of air replacements per hour has increased substantially. The smaller the volume of these areas, higher is the efficiency of the return air system, higher is the number of air replacements per hour. The volume of air flow created is directly proportional to power, by increasing efficiency of the return air system; power consumption can be optimized and reduced.
It will be therefore readily understood by those persons skilled in the art that the present
invention is of a broad utility and application. Many embodiments and adaptations of the
present inventions other than those herein described, as well as many variations, modifications and equivalent arrangements will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance and scope of the invention. Accordingly while the present invention has been described herein in detail in relation to its preferred embodiment, it is understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for the purpose of providing full and enabling disclosure of the present invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise exclude such other embodiments, adaptations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof.

We claim:
1. A very effective method for removing the lint fibers from knitting machines and its associated creel and solving all problems of lint extraction.
2. The method as claimed in claim 1 comprising of a return air system apparatus consisting essentially of a air trench, floor slits and floor trap doors with closed slits for removing the lint fibers from knitting machines and its associated creel.
3. The method as claimed in claim 2 comprises placing knitting machines and associated creels in separate areas of the enclosure and as such totally isolated from adjacent knitting machines. Thereby eliminating all possibilities of cross contamination.
4. The enclosure as claimed in claim 3 is closed on top and bottom and is open in front and rear side of the knitting machine and creel to allow for loading of yarns from the rear side, mending of broken yarns and removal of completed fabric rolls from the front side of the knitting machine.
5. The enclosure as claimed in claim 4 further comprises of the return air trench of claim 2 being placed underground below the floor on which the enclosure is placed. The floor slits and the floor trap door with closed slits open into the floor of the enclosure, connecting the return air trench and the enclosure.
6. The enclosure as claimed in claim 5 is further enclosed by curtains in the front and the rear side of the knitting machine such that the return air is not allowed to flow through the curtains thereby providing a direction to the flowing air as well as containing the air borne lint within this enclosure thereby eliminating cross contamination.
7. The method as claimed in claim 6 further comprises of the air flowing into the knitting machine from the front of the enclosure and then flowing from the top of the creel through the slits in the floor, to the return air trenches to be exhausted. Thereby collecting lint on and surrounding the knitting machine and creels and also collecting all air borne lint present in the enclosure for discharging to the return air trenches.
8. The method as claimed in claim 7 in which the return air either blows off lint fibers from the knitting machine, or collects air borne lint from its surroundings to be exhausted to lint trapping filters.
9. The method as claimed in claim 8 in which during blow cleaning of knitting machine, before starting a new fabric roll, the closed slits of the trap door are opened, leading to increase in the volume and velocity of the return air flowing through the enclosure, thereby increasing the speed at which air borne lint is trapped and discharged to the return air trenches, which is required as substantial lint is made airborne during blow cleaning operation of the knitting machine.
10. The method as claimed in claim 3 decreases the volume of space surrounding the knitting machine and its associated creels thereby increasing the number of air replacements per hour. The volume of air flow is directly proportional to power consumption. For a fixed volume of return air flowing through the enclosure, the smaller is the volume of the creel and knitting machine space higher is the number of air replacements per hour in these spaces and higher the cleaning efficiency of the return air system. Thereby creating scope for reduction in power consumption.