Title of Invention

"AN IMPROVED SURFACE APPLICATOR FOR COATING FLEXIBLE SUBSTRATES"

Abstract

An improved surface applicator for coating flexible substrates which utilizes a juxtaposed conveyor system capable of being operated in either direction using a single power source, for causing movement, for a predetermined time, to the material the surface of which is to be coated with a liquid / paste kept in a container, resulting in surface coating of the flexible substrate without involvement of any manual operations. The applicator is useful for coating liquid(s) / paste(s) on flexible materials.

Full Text

The present invention relates to a novel surface applicator for coating flexible substrates. The present invention particularly relates to a surface applicator useful for coating liquid(s) / paste(s) on flexible materials. This applicator has enormous potential industrial application for mechanical application of any liquid on the surface of any flexible material. This will be specially useful for the leather processing industry which requires surface application of liquids on leather surface at different stages of operation, such as pasting during beam house processing, seasoning during finishing. This applicator besides being very useful for the above mentioned operations in leather industry is also envisaged to be useful for similar potential application in different material processing industries which require flexible substrates to be coated with liquid(s). Conventionally, application of a liquid on the surface of a flexible material is done manually for most of the material processing industries. In leather processing industry, unhairing is an important pretanning operation whereby lime sulfide paste is applied on the flesh side of skins before they are piled flesh to flesh for about 12 hours resulting in the complete loosening of the hair or wool, that is scrapped off thereafter. Although this is a popular hair saving process practiced in tanneries, the environmental considerations in respect of the toxicity associated with chemicals used in the paste has prompted the tanners to adopt much more eco-benign option by way of using enzyme, which partially or completely replaces toxic chemicals. But the mode of application of the paste has remained unchanged: Similarly, in the leather finishing yard, grain surface of the leather is coated with finishing season, which is applied manually either by brush or pad. Individual side or piece is then dried before piling. The limitations associated with these manual applications are as follows: 1. It is labor intensive and tells upon the productivity of the system. 2. The open pits, which are normally used for storing the paste to be applied on the surface of the hide or skin, pose obvious danger to workers, who not only risk accidents of falling inside but also are exposed to vapors during the cleaning of the pits, resulting in severe health hazards. 3. Physical contact of the chemicals during manual application involves possibilities of developing physiological problems like joint damage and arthritis to the concerned workers. 4. The application of the mixture solution is done manually which causes fatigue to the personnel and the efficiency of the men involved in the job shows a declining trend as the operation time proceeds and such a process increases the drudgery on labor and affects productivity. 5. Significant quantities of chemicals are wasted due to handling and spillage in manual system. The above limitations have prompted the researchers to explore better options for surface application of liquids / pastes on hides and skins. Lakshmanan et al (LERIG 2000) demonstrated a surface applicator for application of enzyme paste on calfskins, as shown in figure 1 of the drawings accompanying this specification. Figure 1 shows the assembly drawing of the existing surface applicator for application of enzyme paste on calfskins. Different parts of the existing applicator as shown in figure 1 are: (1) refers to frame assembly. (2) refers to chemical container. (3) refers to main shaft connected with leather holding pipes. (4) refers to power transmission assembly. (5) refers to bush bearings and housing. (6) refers to discharge valve of chemical container. The applicator comprising a chemical container (2) being held by a frame assembly (1) having a shaft with two bush bearings at each end and bearings housing (5). The shaft is provided with leather holding pipes (3). The shaft is powered with the help of power transmission assembly (4). The left over enzyme solution is discharged through a discharge valve (6) by gravity provided at the bottom of the chemical container (2). Although this applicator ensures that the physical contact of the workers with the chemicals is reduced to a great extent, thereby improving their health conditions, yet there are major limitations associated with it. The hydro-friction between the raw material and the solution causes variation in processing time due to the eccentric load acting at th'e leather holding pipe resulting in higher consumption of power, thereby a'dding to cost. The main objective of the present invention is to provide a novel surface applicator for coating flexible substrates, which obviates the limitations as stated above. Another objective of the present invention is to provide an applicator that ensures economy of the chemicals used by way of reducing wastage. Still another objective of the present invention is to provide an applicator capable of ensuring mechanical control over the uniformity of surface coating depending on the flexible substrate. The present invention provides a novel surface applicator for coating flexible substrates which utilizes a juxtaposed conveyor system capable of being operated in either direction using a single power source, for causing movement, for a predetermined time, to the material the surface of which is to be coated with a liquid / paste kept in a container, resulting in surface coating of the flexible substrate without involvement of any manual operations. In the drawings accompanying this specification figure 2 represents the line diagram of the novel surface applicator of the present invention and figure 3 represents the isometric view of the novel surface applicator of the present invention. The various parts / components which constitute the novel surface applicator of the present invention as depicted in figures 2 and 3 of the drawings are as follows: (7) refers to a trough shaped container for holding chemical to be applied on a substrate. (8) refers to the main roller having one or more longitudinal blades for agitation of the chemical to be coated on the flexible substrate. (9) refers to the bottom supporting rollers of lower conveyor system [11 (L)]. (10L) refers to the top supporting rollers of lower conveyor system [11 (L)] 10(U) refers to the top supporting rollers of upper conveyor system [11(U)]. (11) refers to two juxtaposed conveyors, lower conveyor [11(L)] and upper conveyor [11(1))]. (12) refers to the outlet for draining the chemical solution from the container (7). (13) refers to the supporting frame. (14) refers to the bearings with housings. (15) refers to adjustable brackets for holding rollers and providing gap adjustment. (16) refers to the variable drive power transmission assembly. The novel surface applicator of the present invention comprises a trough shaped container (7) having a main roller (8) provided with one or more longitudinal blades. The said main roller (8) being moved by a juxtaposed two conveyor system (11) passing through bottom supporting rollers (9) and top supporting rollers (10). The bottom supporting rollers (9) being held in bearing and housing (14) and connected to a variable drive power transmission assembly source (16). The top supporting rollers (10) being housed in brackets (15) provided for adjusting gap between the top and bottom conveyors. The container (7) being provided with an outlet (12) at the bottom for draining the chemical solution from the container. The whole assembly is being housed in a supporting frame (13). Accordingly the present invention provides an improved surface applicator for coating flexible substrates comprising a frame (13) supporting a trough shaped container (7) having a longitudinal main roller (8) rotatably fixed by bearings(14) with housings, the said main roller (8) characterized in that being provided rotational movement by a juxtaposed two conveyer system (11) essentially consisting of: (i) an upper conveyor (11U) passing through the bottom of the main roller (8) and over a set of upper top supporting rollers (10U) rotatably fixed on frame (13) by adjustable brackets (15), and (ii) a lower conveyer (11L) juxtaposed to the bottom of the said upper conveyer (11U) passing through the bottom of the said main roller (8), the said lower conveyer (11L) being kept taught by a set of lower top supporting rollers (10L) rotatably fixed on the said frame (13) below the said upper top supporting rollers (10U) by said adjustable bracket (15) and bottom supporting rollers (9) rotatably fixed by said bearings (14) on to the said frame (13), the said bottom supporting roller (9) being connected to a variable drive prime mover (16). In an embodiment of the present invention the main roller is provided with one or more longitudinal blades. In another embodiment of the present invention the trough shaped container is provided with a closable bottom draining outlet (12). In yet another embodiment of the present invention, the bearings are such as self-aligned ball bearing, journal-bearing assembly. In still another embodiment of the present invention, the drive for power transmission is selected from chain drive, gear drive, belt drive. In still yet another embodiment of the present invention, the prime mover is such as electrical, manual. In a further embodiment of the present invention, the variable drive is such as cone and roller drive, disk and roller drive, drum and roller drive, split pulley drive, variable speed electric drive. The novel applicator of the present invention is described below in detail. The surface applicator is an assembly housed in a supporting frame (13). There is a trough shaped container (7) for storing the liquid to be applied on the surface of a flexible material. The container (7) is provided with an outlet (12) at the bottom to drain out the unused liquid. It has a main roller (8) provided therein with one or more longitudinal blades. The main roller, which is supported by non-corrosive journal bearing (14), gets its drive from a juxtaposed two conveyor system (11), thereby facilitating the rotation of the blades provided on the roller and subsequent agitation of the liquid contained in the container (7). The said conveyor system has one set of supporting rollers each at the bottom as well as at the top. While the bottom supporting rollers, which are held in bearing and housing (13), are connected to a power transmission assembly source (16). The top supporting rollers (10) are housed in bracket (15) provided for adjusting the gap between the top and bottom conveyors depending on the thickness of the flexible materials to be used for surface application. The speed of the conveyors can be adjusted by variable drive power transmission assembly sources (16). The same system can also be used for change in the direction of rotation of the bottom-supporting roller (9), which leads to the movement of the conveyor system (11) in either direction, whereby both the conveyors move simultaneously at the same speed. The movement of the conveyor in turn results in the frictional rotation of the main roller (8), which is then capable of agitating the liquid with its blades provided thereon. The speed of the conveyor can be adjusted by the variable drive power transmission assembly source depending on the length and type of the flexible material to be used for surface application. The material to be used for surface application is fed between the two juxtaposed conveyor system (11). The material, which is carried by the conveyor, dips into the liquid thoroughly and comes out from the other side of the applicator by the conveyor. It is then taken out from the applicator. The novelty and non-obviousness of the present invention lies in providing a juxtaposed two conveyor system capable of being operated in either direction using a single power source, for causing movement to the material to be used for surface application, thereby enabling any flexible material to be passed for a predetermined time through the liquid kept in the container, resulting in surface coating of the same without involvement of any manual operations. The following examples are given by way of illustration only and therefore should not be construed to limit the scope of the present invention. Example 1 One wet salted calfskin was cut into 15 cutpieces of 8" x 6" size each uniformly. The cut pieces were then cleaned and weighed. The weight was noted to be 3 kgs. The pieces were soaked by putting them for 2 hours in 1 lit of water taken in a beaker followed by plain water washing and subsequent piling on a wooden platform. Then 1200 grams of powered lime, 120 grams of flaked sulfide and 150 grams of enzyme were mixed with 6 litres of water. The resulting solution was taken in the container of the surface applicator. The thickness of the skin cut pieces was measured to be 5mm. Hence, the bracket of the applicator was rotated to maintain the gap between the top and bottom conveyors at 4 mm. While the main roller was supported by journal bearing, the supporting rollers were held by self-aligned ball bearing. The bottom-supporting roller of the conveyor was rotated manually to maintain the speed of the conveyor at 0.5 m/minute. This resulted in the movement of the juxtaposed conveyor system as well as the rotation of the main roller that had 4 blades provided thereon. The mode of power transmission was belt drive. The rotation of the blades effected adequate stirring of the lime-sulfide-enzyme solution. The cutpieces were then fed in between the two conveyors, which dragged the cutpieces into the said solution. Thus the liquid was applied automatically on both the grain as well as flesh sides of the skin cut pieces, which again came out by the conveyor system automatically. The cut pieces were taken out of the applicator and piled on a wooden platform. Then the unused solution, which was still remaining in the container, was drained out by opening the outlet. Example 2 One wet salted buff calfskin was cut into 15 cut pieces of 8" x 6" of size each and one wet salted goatskin was cut into 20 cut pieces of 10" X 6" of size each uniformly. The cut pieces were then cleaned and weighed. The weight was noted to be 3 kgs and 4 kgs respectively. The pieces were soaked by putting them for 1 hour in 3 litres of water taken in a beaker followed by plain water washing and subsequent piling on a wooden platform. Then 2 kgs of powered lime, 200 grams of flaked sulfide and 250 grams of enzyme were mixed with 10 litres of water. The resulting solution was taken in the container of the surface applicator. The thickness of the buff side and goatskin cut pieces was measured to be 6 mm and 3.5 mm respectively. Hence, the bracket of the applicator was adjusted to maintain the gap between the top and bottom conveyors at 5 mm to feed buff side cut pieces first. While the main roller was supported by journal bearing, the supporting rollers were held by self-aligned ball bearing. The variable drive mechanism used for the applicator was cone and roller drive. With this system the speed of the conveyor was adjusted to maintain a speed of 0.3m/minute. The power transmission assembly was switched on to rotate the bottom-supporting roller so that the conveyor moved at a speed of 0.'3 m/minute. This resulted in the movement of the juxtaposed conveyor system as well as the rotation of the main roller that had 8 blades provided thereon. The mode of power transmission was chain drive. The rotation of the blades effected adequate stirring of the lime-sulfide-enzyme solution. The cutpieces were then fed in between the two conveyors, which dragged the cutpieces into the said solution. Thus the liquid was applied automatically on both the grain as well as flesh sides of the cut pieces, which again came out by the conveyor system automatically. The cut pieces were taken out of the applicator and piled on a wooden platform. Then the speed of the conveyor was adjusted to maintain a speed of 0.4m/minute as explained before. The bracket of the applicator was adjusted to maintain the gap between the top and bottom conveyors at 6 mm to feed goatskin cut pieces. The power transmission assembly was switched on to rotate the bottom-supporting roller so that the conveyor moved at a speed of 0.4 m/minute. Then two cutpieces of goatskin placed by keeping hair side together, were then fed in between the two conveyors, which dragged trie cutpieces into the said solution. Thus the liquid was applied automatically on flesh sides of the cut pieces, which again came out by the conveyor system automatically. The cut pieces were taken out of the applicator and piled on a wooden platform. Then the unused solution, which was still remaining in the container, was drained out by opening the outlet. Example 3 One wet salted cow hide was cut into 15 cut pieces 8" x 6" size each and one wet salted sheepskin was cut into 20 cut pieces of 10" X 6" of each uniformly. The cut pieces were then cleaned and weighed. The weight was noted to be 3 kgs and 4 kgs respectively. The pieces were soaked by putting them for 1 hour in 3 litres of water taken in a beaker followed by plain water washing and subsequently for piling. Then 2 kgs of powered lime, 200 grams of flaked sulfide and 250 grams of enzyme were mixed with 10 litres of water. The resulting solution was taken in the container of the surface applicator. The thickness of the buff side and goatskin cut pieces was measured to be 6 mm and 3.5 mm respectively. Hence, the bracket of the applicator was adjusted to maintain the gap between the top and bottom conveyors at 5 mm to feed buff side cut pieces. While the main roller was supported by journal bearing, the supporting rollers were held by self-aligned ball bearing. The variable drive mechanism used for the applicator was drum and roller drive. With this system the speed of the conveyor was adjusted to maintain a speed of 0.3rn/minute. The power otate transmission assembly was switched on to r thep3423Xb8Uppiwting roller so that the conveyor moved at a speed of 0.3 m/mint *p3651XThis 875r3908Xes in the movement of the juxtaposed conveyor system as well as the rotation of the main roller that had 6 blades provided thereon. The mode of power transmission was gear drive. The rotation of the blades effected adequate stirring of the lime-sulfide-enzyme solution. The cutpieces were then fed in between the two conveyors, which dragged the cutpieces into the said solution. Thus the liquid was applied automatically on both the grain as well as flesh sides of the cut pieces, which again came out by the conveyor system automatically. The cut pieces were taken out of the applicator and piled on a wooden platform. Then the speed of the conveyor was adjusted to maintain a speed of 0.4m/minute as explained before. The bracket of the appJicator was adjusted to maintain the gap between the top and bottom conveyors at 6 mm to feed sheepskin cut pieces. The power transmission assembly was switched on to rotate the bottom-supporting roller so that the conveyor moved at a speed of 0.4 m/minute. Then two cutpieces of goat skin placed by keeping hair side together, were then fed in between the two conveyors, which dragged the cutpieces into the said solution. Thus the liquid was applied automatically on flesh sides of the cut pieces, which again came out by the conveyor system automatically. The cut pieces were taken out of the applicator and piled on a wooden platform. Then the unused solution, which was still remaining in the container, was drained out by opening the outlet. Example 4 One black colored cow crust leather was cut into 15 cut pieces of 8" x 6" of size and one black colored sheep crust leather was cut into 20 cut pieces of 10" X 6" of each uniformly. The pieces were then taken for application of finishing season on the surface. Then 300 grams of black colored pigment was mixed with 1 liter of water. The resulting solution was taken in the container of the surface applicator. The thickness of the buff side and goatskin cut pieces was measured to be 1.5 mm. Hence, the bracket of the applicator was adjusted to maintain the gap between the top and bottom conveyors at 1 mm to feed cow side cut pieces. While journal bearing supported the main roller, the supporting rollers were held by self-aligned ball bearing. The variable drive mechanism used for the applicator was variable speed electric drive. With this system the speed of the conveyor was adjusted to maintain a speed of 1 m/minute. The power transmission assembly was switched on to rotate the bottom-supporting roller so that the conveyor moved at a speed of 1 m/minute. This resulted in the movement of the juxtaposed conveyor system as well as the rotation of the main roller that had 6 blades provided thereon. The mode of power transmission was gear drive. The rotation of the blades effected adequate stirring of the pigment solution. Then two cutpieces of goat skin placed by keeping flesh side together, were then fed in between the two conveyors, which dragged the cutpieces into the said solution. Thus the liquid was applied automatically on grain sides of the cut pieces, which again came out by the conveyor system automatically. The cut pieces were taken out of the applicator and hooked for drying. The same procedure as mentioned above was adopted for cow side cut pieces also. Then the unused solution, which was still remaining in the container, was drained out by opening the outlet. The main advantages of the present invention are: 1. Two operators can simultaneously work on this device facing each other, thereby increasing productivity. 2. Automatic stirring of the liquid with the help of stirrer roller ensured that the consistency of the liquid is always maintained without-allowing any settling down of sparingly soluble solutes. 3. Reduction of stress and strain on workers. 4. Provides safe operations and eliminates health hazard in general and toxic effect particularly on human skin due to manual dipping of materials in to the chemical solutions as in conventional beam house operations. 5. Consistency in the application of solution is ensured, since the material is dipped into the liquid for a fixed time automatically through the conveyor mechanism. 6. Significant reduction in chemical consumption leading to reduced cost of production. 7. Eliminates human error and provides assured quality consistency. WE CLAIM: 1. An improved surface applicator for coating flexible substrates comprising a frame (13) supporting a trough shaped container (7) having a longitudinal main roller (8) rotatably fixed by bearings(14) with housings, the said main roller (8) characterized in that being provided rotational movement by a juxtaposed two conveyer system (11) essentially consisting of: (i) an upper conveyor (11 U) passing through the bottom of the main roller (8) and over a set of upper top supporting rollers (10U) rotatably fixed on frame (13) by adjustable brackets (15), and (ii) a lower conveyer (11L) juxtaposed to the bottom of the said upper conveyer (11 U) passing through the bottom of the said main roller (8), the said lower conveyer (11L) being kept taught by a set of lower top supporting rollers (10L) rotatably fixed on the said frame (13) below the said upper top supporting rollers (10U) by said adjustable bracket (15) and bottom supporting rollers (9) rotatably fixed by said bearings (14) on to the said frame (13), the said bottom supporting roller (9) being connected to a variable drive prime mover (16). 2. An improved surface applicator as claimed in claim 1, wherein the said main roller is provided with one or more longitudinal blades. 3. An improved surface applicator as claimed in claim 1-2, wherein the said trough shaped container is provided with a closable bottom draining outlet (12). 4. An improved surface applicator as claimed in claim 1-3, wherein the said bearings are self-aligned ball bearing, journal-bearing assembly. 5. An improved surface applicator as claimed in claim 1-4, wherein the said drive for power transmission is selected from chain drive, gear drive, belt drive. 6. An improved surface applicator as claimed in claim 1-5, wherein the prime mover is electrical, manual. 7. An improved surface applicator as claimed in claim 1-6, wherein the variable drive is cone and roller drive, disk and roller drive, drum and roller drive, split pulley drive, variable speed electric drive 8. An improved surface applicator for coating flexible substrates substantially as herein described with reference to the examples and figures 2 and 3 of the drawings accompanying this specification.

Documents:

967-DEL-2002-Abstract (13-11-2007).pdf

967-del-2002-abstract.pdf

967-DEL-2002-Claims (13-11-2007).pdf

967-del-2002-claims.pdf

967-DEL-2002-Correspondence-Others (13-11-2007).pdf

967-del-2002-correspondence-others.pdf

967-del-2002-correspondence-po.pdf

967-DEL-2002-Description (Complete) (13-11-2007).pdf

967-del-2002-description (complete).pdf

967-DEL-2002-Drawings (13-11-2007).pdf

967-del-2002-drawings.pdf

967-del-2002-form-1.pdf

967-del-2002-form-18.pdf

967-DEL-2002-Form-2 (13-11-2007).pdf

967-del-2002-form-2.pdf

967-DEL-2002-Form-3 (13-11-2007).pdf

967-del-2002-form-3.pdf