MXPA99010338A - Methods and apparatus for elaborating rollers painters with nucleos termoplasti - Google Patents

Abstract

The present invention relates to a method for the production of rolls, characterized in that it comprises the steps of spirally winding a hot thermoplastic film around a thermoplastic tubular shape, and a strip of fabric is wound spirally around the thermoplastic film, while the thermoplastic film is hot enough to cause the hot film to strip the fabric to the tubular shape

Description

METHODS AND APPARATUS FOR ELABORATING ROLLERS PAINTERS WITH THERMOPLASTIC NUCLEI FIELD OF THE INVENTION The present invention relates to methods and apparatuses for making rollers by adhering a roll cloth to a thermoplastic tubular shape by means of an extruded thermoplastic film which is spirally wound on the tubular form immediately before the roll cloth . BACKGROUND OF THE INVENTION It is generally known to prepare paint rollers with thermoplastic cores. The development of thermoplastic core cores has the advantage that the cores will not delaminate even after prolonged impregnation as is the case with most cardboard cores. However, there may still be a problem with the roll fabric that prematurely separates from the thermoplastic cores, either because the adhesive does not provide a very effective bond between the fabric backing and the cores, or the adhesive does not it stops after prolonged impregnation in certain types of solvents. SUMMARY OF THE INVENTION The present invention relates to methods and apparatus for making paint rollers that are completely impermeable to water and to most solvents, even after prolonged impregnation. According to one aspect of the invention, the roller cores are made of a thermoplastic material, and the roller cloth is permanently attached to the roller cores by means of a thermoplastic film which is completely impermeable to water and most of the cores. solvents, even after prolonged impregnation. According to another aspect of the invention, the rolls are made by spirally winding a strip of hot thermoplastic film onto an outer surface of a thermoplastic tubular shape and spirally winding a strip of fabric having a thermoplastic backing onto the strip wound on it. spiral of thermoplastic film, while the thermoplastic film is still hot enough to cause the thermoplastic film to flow into the interstices in the thermoplastic back of the fabric and attach the fabric to the outer surface of the tubular shape. According to another aspect of the invention, a continuous strip of thermoplastic core material is wound in a spiral around a mandrel, then a hot thermoplastic film spirally wound around the spirally wound core material, and a strip of cloth was spirally wound around the thermoplastic film, while the thermoplastic film is hot enough to bond the fabric strip to the core material. According to another aspect of the invention, a spacer member is placed between adjacent edges of each successive fold of the core strip material around the mandrel in order to prevent adjacent edges of the core strip material from overlapping each other on the core. mandrel, thereby forming a spiral bond line along the length of the core material. According to another aspect of the invention, the spacer member is free to move to a limited degree, in a direction parallel to the longitudinal axis of the mandrel, to compensate for slight changes in the helix angle of the spiral fold of the core strip material on the mandrel. According to another aspect of the invention, the adjacent edges of the hot thermoplastic film are superimposed on the spiral bond line between the adjacent edges of the thermoplastic core strip material in order to provide sufficient film material flowing towards the line of spiral bonding and also towards the interstices in the cloth backing, to form a strong bond between the fabric strip and the core strip material along the length of the spiral bond line. According to another aspect of the invention, the thermoplastic back may include relatively long nylon or other thermoplastic filaments extending longitudinally to the fabric strip. According to another aspect of the invention, a first drive belt can actively engage the fabric strip to spirally advance the fabric strip and underlie the core strip material along the length of the mandrel. Also, a second drive belt can drive engagement to the core strip material upstream of the place where the hot thermoplastic film is applied to the core strip material to assist the spiral advance of the core strip material and the core strip. fabric along the length of the mandrel. According to another aspect of the invention, movable heads of different diameter can be used to drive both drive belts at different speeds to compensate for the different outer diameters of the spiral bends of the fabric strip and the core strip material on the mandrel, so that both drive belts spirally advance the fabric strip and the core strip material at the same speed on the mandrel. According to another aspect of the invention, separate, electronically coupled actuators can be used to drive both drive bands in order to compensate the different outer diameters of the spiral bends of the fabric strip and the core strip material on the outside. mandrel, so that both drive belts spirally advance the fabric strip and the core strip material at the same speed on the mandrel. These and other objects, advantages, features and aspects of the present invention will be apparent as the following description proceeds.

For the fulfillment of the above and the related purposes, the invention then comprises the features described in full below and particularly pointed out in the claims, the following description and the annexed drawings establishing in detail certain illustrative embodiments of the invention, these being indicative, however, in many of the various ways in which the principles of the invention may be employed. BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings: Figure 1 is an enlarged perspective view of a form of paint roller made in accordance with this invention; Figure 2 is an enlarged cross section through the paint roller of Figure 1, taken generally along the plane of line 2-2 thereof; Figure 3 is a schematic top plan view of a form of the apparatus for making the paint rollers of Figures 1 and 2, - Figure 4 is a side elevation, fragmentary, schematic, enlarged, of the automatic feed mechanism in tube of the apparatus of figure 3; Figure 5 is a fragmentary, enlarged, side elevational view of the mandrel used in such an apparatus; Figure 6 is an enlarged, schematic, side elevational view of the portion of the apparatus of Figure 3, in which the fabric and the bonding film are spiral wound onto the tubular core material; Figure 7 is a side elevational, schematic, enlarged view of the blade and fixed stop facility of such an apparatus; Figure 8 is a fragmentary, longitudinal section enlarged through another form of paint roller, made in accordance with this invention; Figure 9 is a schematic top plan view of another form of the apparatus for making the paint rollers of Figure 8; Fig. 10 is a schematic, enlarged top plan view of the core strip edge separator of the apparatus of Fig. 9, which prevents the adjacent core strip edges from overlapping each other during the spiral winding of the material of core strip on the mandrel; Figure 11 is a schematic, enlarged top plan view of a portion of the apparatus of Figure 9 showing the hot thermoplastic film being entrained from an extruder nozzle and spirally wound around the outer surface of the core strip material wound on spiral with the adjacent edges of the hot thermoplastic film, overlapping each other on the spiral bond line of the core strip material; Fig. 12 is a schematic top plan view of a modified form of the apparatus of Fig. 9, which includes the same drive belt for driving the fabric strip and a second drive belt for actuation engagement of the web material. core strip upstream of the extruder nozzle head; Fig. 13 is a schematic, fragmentary, enlarged plan view of the woven back of a strip form of fabric used to make rolls according to this invention; and Figures 14 and 15 schematically show two different actuators for driving two belt drives at different speeds to compensate for the different outer diameters of core strip material and the high pile fabric strip driven therewith. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now in detail to the drawings, and initially to Figures 1 and 2, a roll form according to this invention is generally indicated at 1 and includes a tubular thermoplastic core 2 having a uniformly thick layer of bonding film 3 on the outer surface thereof to permanently attach a suitable fabric 4 to the core. The core 2 can be made from any suitable unsaturated crystalline or semicrystalline polyolefin polymer, such as natural polypropylene and filler and high density polyethylene. A currently preferred polyolefin polymer is a polypropylene copolymer comprising any of from about 90 to 96% polypropylene and 4 to 10% ethylene monomer, with about 93% polypropylene and 7% ethylene monomer being preferred. Also, the polyolefin copolymer used for the core material desirably has a melt flow rate of between about .3 and .7 dg./min. Polypropylene has excellent chemical resistance to solvents and water and has a total rigidity. The ethylene monomer is added to the polypropylene in small amounts for its highest impact strength, to allow the core to be subjected to low temperatures or severe impacts without rupture and to facilitate extrusion of the material in the desired tubular shape and cut precise the pipe in the individual pieces of paint roller desired. The fabric 4 can be a conventional roll fabric which preferably has a thermoplastic back of open weave, weft 5, woven into the fabric to allow a superior mechanical bond between the fabric backing and the bonding film 3. The pile fabric or Lint 6 can be made of different materials or mixtures and be of different heights depending on the particular application. The thermoplastic bonding film 3 must be compatible with both the core material and the cloth backing in order to achieve a permanent bond between them. In the case where the core material is a polypropylene copolymer, the binding film is desirably made of polypropylene and the back of the fabric is made of a suitable thermoplastic such as polyester or polypropylene. Also, the polypropylene bond film desirably has a melt flow rate of between about 30 and 45 dg./min., With a melt flow rate of about 40 and with good casting strength being preferred, to allow the material is extruded into a film of desired width and thickness and spirally wound onto the tubular core material immediately prior to spirally winding the fabric over the core material to permanently attach the fabric to the core material, as described below. During the manufacturing process, the hot bonding film 3 of the desired width and thickness is drawn from an extruder equipped with a covered suspension nozzle and spirally wound around the extruded tubular core material 2. Within about one turn of winding of the hot bonding film on the tubular core material, a strip of the fabric material 4, which is substantially the same width as the bonding film, spirals around the bonding film to permanently bond the strip from fabric to tubular core material. In order to be able to spirally wind the hot bonding film and the fabric on the outer surface of the tubular core material and still maintain the desired tubular shape and integrity of the tubular core material, the tubular core material desirably has a wall thickness between approximately .030 and .070 inches, with a thickness of approximately .060 inches being preferred. Also, the layer of bonding film on the tubular core material desirably has a thickness of between about 0.010 and 0.30 inches, with a thickness of about 0.020 inches being preferred, to ensure that there is sufficient bonding material and latent heat in the core. bonding material to allow the bonding material to flow into the interstices in the fabric backing and to obtain the desired chemical and mechanical bond between the bonding film and the fabric backing. The first step in the development of paint rollers shown in Figures 1 and 2 according to the present invention, is to provide a supply of extracted tubes 10 from the cut of thermoplastic core material to the desired length, for example, 65 inches. Before the fabric material is applied to the extracted tubes, the tubes are stored in an upright position for a minimum period of time after their manufacture., for example, 24 hours, to give the tubes enough time to normalize, crystallize, contract and stabilize. After the tubes 10 have been stored for a sufficient period of time they are loaded into a hopper 11, shown schematically in Figure 3. Connected to the hopper 11 is a vertical conveyor 12, shown schematically in the figure 4, to continuously feed the tubes one at a time, to a machine / device for spiraling plastic tube 14. As the tubes are fed continuously through the apparatus, the apparatus spirally winds the bonding film and the fabric on the tubes and permanently attaches the fabric to the outer surface of the tubes. Accordingly, the tubes wound with cloth are cooled sufficiently to allow them to separate from each other and be discharged from the apparatus, as described below. The tubes 10 that are loaded in the hopper are collected by the vertical conveyor 12 (see Figure 4) and discharged on a rail 16 that feeds the tubes, one at a time, on a grooved installation 17. From there, the tubes 10 they are pushed axially on a floating tube mandrel 18 by a tube cam 19 moving axially along the length of the channel 17, from one end to the other. The mandrel 18 supports the tubes 10 during the spiral winding of both the bonding film and the fabric on the tubes, as described below, and desirably is of considerable length, eg, 195 1/4 inches, to support three 65-inch long tubes in the chuck at any given time. In addition, the mandrel desirably comprises a plurality of tubular sections made, for example, of extruded aluminum and connected together in a suitable manner at their ends. In the preferred embodiment shown in Figures 3-6, the mandrel is composed of five sections 20-24 (see Figure 5). The first two sections 20 and 21 (as seen from the upstream end of the apparatus in the downstream end direction) have a length of approximately 37 1/8 inches and 30 3/8 inches, respectively (for a combined length approximately 67% inches), and are connected together at their ends by a support sleeve 25 which allows relative rotation between sections. The third section 22 has a length of approximately 33 3/4 inches and is connected to the second section 21 by a connector socket 26 which defines a notch or slot 27 between such sections for releasable clutch by a mandrel stop 28 (see figure 4), which, when engaged, prevents axial movement of the mandrel. A similar groove or groove 29 is formed by the shaft 30 of a tube guide 31 extending towards the upstream end of the first mandrel section 20 for releasable clutch by another mandrel stop 32. The mandrel sections fourth and fourth. fifth 23 and 24 are approximately 45 3/4 and 48 1/4 inches long, respectively, and are connected together and to the third section 22 by support sleeves 25 to provide rotatable connections therebetween, similar to the rotary connection between the first two sections 20, 21. The mandrel 18 ends immediately downstream of the area A (see figure 3) of the apparatus 14, in which the bonding film 3 and the fabric 4 are spirally wound on the pipe 10. In addition , the mandrel 18 desirably includes a stepped portion 35 in this area or area A having an outer diameter greater than the remaining length of the mandrel in order to drive the mandrel to a size that more accurately matches the diameter of the mandrel. Inside the tubes to provide better support to the tubes at the critical point where the bond film and the fabric are applied to the tubes. This stepped portion 38 of the mandrel can, for example, have an outer diameter of about 1473 inches, wherein the inner diameter of the raw pipes 10 is about 1.5 inches and an axial length of about 13 inches. The outside diameter of the remaining length of the mandrel including a length 36 of 6 inches at the most downstream end of the mandrel, is desirably somewhat less, for example, of about 1437 inches, to provide a greater space between the outer diameter of the mandrel and the inner diameter of the tubes over the majority of the length of the mandrel to reduce the advance on the tubes when The tubes are driven both rotationally and axially relative to the mandrel by planetary drive assemblies, as described below. In order to be able to push the tubes 10 over the first two mandrel sections 20, 21 by the tube cam 19, the upstream mandrel stop 32 must be disengaged from the mandrel 18 so as not to interfere with the movement of the tube over such sections of mandril. At the same time, the downstream mandrel stop 28 must engage the mandrel to prevent the mandrel from moving axially. If the two mandrel stops 28, 32 are always disengaged simultaneously from the mandrel, the mandrel can start its travel below the line, in which case a metal detector 37 located immediately downstream of the application area A of the Bond film and cloth (see figure 3) will detect the movement of the mandrel and will automatically stop the apparatus to avoid any damage to the apparatus beyond downstream of the metal detector. Once the tube 10 slides into place on the first two mandrel sections 20, 21, the upstream mandrel stop 32 is engaged and the downstream mandrel stop 18 is disengaged to allow a tube take-off 38 to clutch the rear end (upstream) of the tube and push the tube axially downstream on the third mandrel section 22 when the tube is engaged by one of the various planetary drive devices 39 which drive the tubes both axially and rotatably through the device. After the trailing end of a tube 10 is removed from the downstream mandrel stop 28, the downstream mandrel stop 28 is re-engaged and the upstream mandrel stop 32 is disengaged to allow the next tube 10 to be pushed Accordingly, the upstream mandrel stop 32 is reengaged and the downstream mandrel stop 28 is disengaged to allow the next piece of tube to be pushed over the third section. of mandrel 22 and towards the contact clutch with the rear end of the previous one, and so on. Two such tubes 10 are schematically shown in end-to-end contact clutch with each other in Figure 6. A plurality of axially spaced tube support rollers 40 support the mandrel sections 20, 21 and 22 and surround the tubes 10 upstream of the first planetary drive installation 39 (see Figure 4). Immediately upstream of the application area A of the fabric and the bonding film is a series of aligning roller 41, through which the pipe passes just before spirally winding the fabric strip material and film Union on the pipe (see figures 3 and 6). As the pipe in axial and rotary advance passes through the application area A of the fabric and bonding film, the hot bonding film 3 is established on the outer surface of the pipe at a helical angle desired by the head nozzle 42 of an extruder 43 equipped with a covered suspension nozzle, as mentioned above. The axial and rotational movement of the pipe causes the bonding film 3 to spirally wound on the pipe with the side edges 44 of the joining film in clutching close to each other (see Figure 6), while applying a Constant tension to the bond film to obtain the desired uniform width and thickness of the bond film on the pipe. Within about the next turn of the bonding film, a strip of fabric 4, which is substantially the same width as the bonding film, it spirals on the binding film to substantially the same helical angle as the bonding film and with the side edges 45 of the fabric strip also in contact clutch proximate to each other. In one form of the invention, wherein the pipe 10 is extruded from a polypropylene copolymer having an inner diameter of about 1.5 inches and a wall thickness of about .060 inches, and the fabric strip 4 has a width of about 2 7/8 inches and a heavy open weave reverse 5 made of a compatible thermoplastic material, a polypropylene bonding film 3 about 4 inches wide and a thickness of approximately .057 inches at the nozzle opening is decreased Extruder to a width of approximately 2 3/4 inches and a film thickness of approximately .020 inches as the bond film spirals onto the pipe. . When the bonding film comes into contact with the pipeline and as the fabric spirals onto the bonding film, the bonding film is still at a relatively high temperature, for example, between about 475 ° and 500 ° F. . At this temperature, the latent heat in the bond film is sufficient to cause the bond film to flow into the interstices in the back of the fabric and permanently attach the fabric to the pipe. Preferably, the tie lines 46 of the fabric are located between the tie lines 47 of the tie film when the fabric is spirally wound on the pipe. Fabric 4 comes in various lengths, for example, lengths of 100 feet. Accordingly, the ends of the fabric should slide together in order to provide a continuous supply of cloth to the pipe as the pipe continuously advances through the apparatus. As the fabric is wound in a spiral around the pipe / bonding film, a predetermined amount of bonding is maintained on the fabric to ensure that the fabric is tightly wound around the pipe and the bonding film flows towards the pipes. interstices on the back of the fabric to provide a permanent bond between the fabric and the pipe. The air towers 50 (see Figure 6) located adjacent the side edges of the fabric direct a flow of air against the side edges of the fabric to cause the hair / fabric fluff 6 to remain along the side edges. Further, a helically shaped cloth guide 52 extends approximately 360 ° about the pipe at the same helical angle as the edge of the fabric and picks up the fabric hair / fluff 6 on the inlet / upstream side and ends at the end. butted together where the edges of fabric come together. This helps form the fabric in the desired waviness by lifting the edges of the fabric hair / fluff so that the hair / fluff is not captured between or below the fabric edges in contact. The helical fabric guide 52 is supported by a mounting bracket 53 connected to the fabric guide on the underside thereof, as shown schematically in Figure 6. A set of elliptical rollers 55 , which can be operated by air or spring, is located immediately below where the fabric is spirally wound on the pipe to apply a pre-established pressure across the total width of the fabric to ensure a uniform, regular adhesion of the fabric to the pipe over substantially the total surface area of the fabric. A third roller 56, which can also be spring-loaded or air driven, is positioned vertically where the bonding line 46 of the fabric is initially joined to ensure uniform adhesion of the fabric to the pipeline along the bond line of the cloth. This has the benefit that, when the pipe is cut substantially into individual pieces of paint roller, if a cut should occur through a line of fabric bonding, the edge of the fabric will not separate from the pipe. As previously indicated, the pipe is supported internally by the stepped enlarged diameter portion 35 of the mandrel 18 during the spiral winding of both the hot bonding film 3 and the fabric 4 on the pipe. Also, the spirally wound tubing is internally supported by the mandrel during the application of a preset pressure to the fabric by the bonding roller 56 and the elliptical rollers 55 immediately after the fabric is wound onto the tubing. Beyond that point, the pipe covered with cloth is no longer supported internally. Instead, the fabric covered pipe is only supported on the outside by additional planetary drive facilities 58 and roller guide installations 59 strategically located along the length of the apparatus downstream of the pressure rollers 55. In addition, a set of alignment rollers 57 for the fabric covered pipe, is placed downstream of the pressure rollers 56 which cooperate with the pipe alignment rollers 41 immediately upstream of where the bonding film and the fabric are spirally wound about the tubing to help maintain proper alignment of the tubing during the application of the bonding film and the fabric to the tubing. All planetary drive installations 39 and 58 (ie, those waters below where the bond film and fabric are applied to the pipe, as well as those upstream thereof), are operated from a supply unit of common energy 60 by means of two input shafts 61, 62 (see FIG. 3), one of which controls the axial speed of the pipe and the other of which controls the rotary speed. The ratio of these two speeds defines the helical angle at which the fabric (as well as the bonding film) is rolled over the pipe, which is critical in producing a good butt joint between the adjacent fabric folds. If the beginning of a space between the adjacent fabric folds develops, this can be corrected simply by changing one of the speeds of the two input shafts 61, 62 to close the helical angle. On the contrary, if the beginning of an overlap between the adjacent fabric bends develops, this can be corrected by changing one of the speeds of the two input axes 61, 62 to open the helical angle. The planetary drive installations 58 downstream from where the tie film and the web are applied to the pipe, may be substantially the same as the upstream planetary drive means 39, except that the upstream planetary drive facilities 39 include three sets of tires that engage the outer surface of the pipe and drive the pipe both axially and rotatably, while downstream planetary drive installations 58 include three sets of spike wheels that hold the fabric to drive the pipe both axially and rotatably . After the fabric strip has been spiral wound and over the pipe, the temperature of the fabric covered pipe is still relatively hot, in the range of 350 to 400 ° F, which is too hot to separate the pipes. each other by cutting through the fabric at the ends of the tubes. Preferably, the tubes are cooled to a temperature of no more than about 200 ° F, before the tubes are cut apart. In this way, it is important to cool the tubes as quickly as possible after the fabric strip is adhered to the tubes to maximize the production yield of the apparatus. In the form of the invention shown in Figures 1-7, the cooling of the fabric covered pipe is accelerated by the supply of air conditioning / cold air to one or more folds 65 located between several planetary drive installations 58 downstream of where the fabric is applied to the pipe, as shown schematically in Figure 3. One or more air conditioning units 66 can be used to supply cold air through air ducts 67 to the same or different folds 65, as desired. The ends of the folds 65 are of course open to allow unobstructed movement of the fabric-covered piping through the folds. After the pipe covered with cloth is cold enough, the pipe passes through a blade installation 70 (see Figures 3 and 7) which moves axially at the same linear speed as the pipe by a very long distance. It cuts, for example, approximately 1 inch, while a cut is made through the fabric between the ends of the tubes. The operation of the blade installation 70 is controlled by a fixed stop 61 which, as best seen in Figure 7, includes a target 72 in coaxial alignment with the pipe downstream of the blade installation. The objective 72 is separated from the blade mechanism 70 by a distance corresponding to each individual piece of pipe 10 (in this case 65 inches). According to the above, when the end most downstream of the pipe engages the target 72, both the fixed stop and the blade mechanism 70, which is fastened to the fixed stop through a connection rod installation, is caused. 73, move a very short distance, e.g., about 1 inch, during which the cutting blades move radially inwardly to cut through the fabric between a pair of tube ends. After the fixed stop 61 moves the short distance required for the knife mechanism 70 to cut through the fabric between a pair of tube ends, the objective 72 rotates out of the way above the tube that has just been separated. of the remaining pipe, as shown schematically in dotted lines in Figure 7 to allow the inlet end of the separate pipe to move beyond the target to the position also shown in dotted lines in Figure 7, where the pipe it is free to be pushed outwardly by an air-operated push rod 74 which causes the tube to discharge below a conduit 75 into a discharge hopper 76 (see figure 3). As soon as the objective 72 rotates out of the way, both the fixed stop 71 and the cutting mechanism 70 return to their original starting positions, shown in solid lines in figure 7. Also, as soon as the separate tube 10 has been discharged into the discharge conduit 65, the objective 72 is repositioned itself for its re-clutch by the inlet end of the next piece of pipe and the cutting cycle is repeated. Although the pieces of tube 10 are located in the discharge hopper 66, both ends of the tubes can be inspected for any possible type of defect. Following inspection, the tubes are removed from the hopper and stacked on their end until the cloth-covered tubes are cooled uniformly throughout their entire length. It is important to cool the tubes in a uniform proportion over their total length while the tubes remain on their end to ensure that the tubes remain round during cooling. The tubes desirably remain on their end for a day or two to allow the tubular core material to crystallize for strength before the tubes are cut into individual paint rollers having a length of for example 9 inches. Figure 8 is a longitudinal section, fragmentary, enlarged, through another form of paint roller 80, according to this invention, which, like the paint roller 1 shown in Figure 1 and 2, includes a thermoplastic core 81 which it has an adhesive bonding film 82 on the outer surface thereof for permanently bonding a suitable fabric 4 to the core. Nevertheless, in the manufacture of paint rollers 80 of the type shown in FIG. 8, instead of using extracted tubes for the core as in the embodiment of FIGS. 1 and 2, the core 81 is formed by the spiral winding of a single strip continuous or crease 84 of thermoplastic core material, preferably polypropylene, around a static mandrel with the adjacent edges 85 of the core strip 84 in spaced-apart relationship but without overlapping one another, as described below. It is important that the edges 85 of the single-ply core strip material 84 not overlap each other, since the overlap of edges would produce a non-uniform inner core surface 86 which would make it difficult to support the paint roller inside the a roller structure. Also the overlap of the core strip edges would produce a non-uniform external core surface 87, resulting in a non-uniform application of paint when the roller 80 turn on a surface, such as a wall or ceiling. For the same reason, it is important that not too much space 88 be left between the core strip edges 85 during the roll manufacturing process since too large a space could adversely affect the integrity of the core structure and greatly reduce the crush resistance of the roll 80. To prevent the adjacent edges 85 of the core strip material 84 from overlapping each other during the manufacturing process, but still ensuring the structural integrity of the core 81 so that the roll 80 has a good crush resistance when a turning force is applied to the roll during the application of paint or other liquid coating to a wall or other surface, a space 88 is preferably maintained no more than. 050 inches and more preferably within the range of .010 inches to .015 inches between the core strip edges during the roller manufacturing process. This can be carried out, in accordance with the present invention, by placing a core strip edge insulation punch or separator 90 between adjacent edges 85 of each successive fold 91 of the core strip material 84 around a static mandrel 92. of a roller making apparatus 93 to maintain a minimum space 88 between the core strip edges, as shown schematically in Figures 9 and 10. The separator 90 may be a relatively thin cylindrical bolt or blade of diameter or thickness required, and supported adjacent the outer diameter of the mandrel 92 by means of an angular bracket 94 that maintains a detrimental clearance of eg .005 inches to .008 inches between the tip 95 of the spacer and the outer diameter of the mandrel (see figure 10). If desired, the separator 90 can also be threadably connected to the angle bracket 94 to allow limited movement of the spacer toward and away from the outer surface of the mandrel to adjust the detrimental space therebetween. To ensure that the spacer 90 follows or continues along between the adjacent core strip edges 85 and compensates for any slight change in the helical angle of the spiral fold of the core strip material around the mandrel, the spacer mounting bracket 94 it is supported by means of a pair of guide rods 95 slidably received in the guides 96 in a fixed support 97. This allows the spacer to float freely or move in a linear direction parallel to the axis of the mandrel at a limited distance, example, approximately 11/2 inches. During the start of the roll manufacturing process 80, shown schematically in Figure 9, a single strip 84 of thermoplastic core material, preferably polypropylene, of the desired width and thickness is fed onto the static mandrel 92 from one side at a desired helical angle. Then, a sufficient number of turns of the core strip material is manually wound around the mandrel to extend beyond the core strip edge separator 90 and an extruder nozzle head 100 for the hot thermoplastic bonding film 82 a sufficient distance in order to allow the fabric strip material 4 to subsequently be wound manually around the inlet end of the core strip material 84 at the same helical angle. The fabric strip 4 is preferably fed under the mandrel 92 from the other side, with the fabric reverse side 5 upward, and manually wound around the mandrel a sufficient distance to allow a band actuator 102 to be wound up in a manner tight around the strip of cloth on the mandrel. The web actuator 102, when operated by driving one of the two rollers 103, 104, about which the web actuator is also wound, will cause the web and the core strips 4 and 84 to spirally advance as far as possible. length of the mandrel 92 in a manner known in the art. Since the extruder nozzle head 100 is also shown located on the other mandrel side 92 of the core strip 84, the extruder nozzle head will feed the hot thermoplastic bonding film 82 under the mandrel and onto the core strip material immediately upstream of the point at which the fabric strip 4 spirally wound around the core strip material. The fabric strip 4 can have an amplitude substantially equal to the core strip material 84. In contrast, the bond film 82 desirably has a somewhat greater width than the core strip material to allow the adjacent edges 105 of the film Bindings are superimposed outwardly from the spiral bonding space or line 88 that is formed between the adjacent edges of the spirally wound core strip material, as shown schematically in Figure 11. This provides that the bonding film Additional 82 on the spiral bond line 88 flows from the bond film to the spiral bond line, as shown schematically in Figure 8, as well as to the interstices in the back of cloth 5 to form a relatively strong joint on the spiral joint line. Typically, the fabric 4 used to make the rolls with thermoplastic cores has a back 5 made of woven polyester filaments that are relatively short in both width and length of the fabric. However, the fabric 4 used to make the rolls 80 shown in Figure 8 preferably has a back of cloth 5 made of relatively long thermoplastic filaments 108, preferably nylon, running along the length of the fabric strip, and polyester or other relatively short thermoplastic filaments 109 running across the width of the fabric strip, as shown schematically in Figure 13. The nylon 108 filaments are much stronger than the polyester 109 filaments and are much greater length, which greatly increases the fabric back strength, preventing the cloth backing from tearing along the bond line 88 of the spirally wound core 81. Figure 12 shows a modified form of the apparatus 93 '. for the manufacture of rolls 80 of Figure 8, which is substantially the same as that shown in Figures 9 to 11. According to the foregoing, reference numbers if milar followed by a prime symbol (') are used to designate similar parts. The apparatus 93 'shown in Fig. 12 differs from that shown in Figs. 9-11 in that a second band driver 110 is provided between the separating mechanism 90' and the extruder nozzle head 100 'to directly drive the strip material. core 84 in order to assist in advancing the core strip material and the fabric strip 4 along the mandrel 92 '. This second band actuator 110 is particularly useful in the proportion of better control of the movement of the core strip material and the strip of fabric along the mandrel, especially when using relatively high pile fabrics. The different external diameters of the core strip material 84 and high pile fabric strip 4 on the mandrel 92 'can be compensated for by the production of movable driving heads 111 for the belt strip material actuator 110, of diameter somewhat larger than the movable head 103 'for the web band actuator 102', so that the core strip material and the web can be driven by a common drive motor 112 at the same speed that was shown in a manner schematically in Figure 14. Alternatively, two separate drive motors 116, 118 can be electronically held together via a suitable controller 119 to drive the respective movable heads 103 'and 111 of the same diameter, in order to synchronize or Attach the speeds of the core strip material and the web onto the mandrel. The web actuator 102 'which engages the web strip 4 by actuation immediately downstream of the place where the fabric strip is wound spirally around the bonding film 82., applies uniform pressure to the outer surface of the fabric as the fabric passes through the belt impeller 102 to ensure uniform, even adhesion of the fabric to the core strip material over substantially the entire surface area of the fabric . During the manufacture of the rollers 80 shown in Figure 8, the bonding film 82 only applies to the core strip material 84 after the core strip material has been wound onto the mandrel 92 or 92 'and just before of the fabric strip being wound around the bond film. In this way, the entire roller 80 is formed in a single step as the fabric spirals around the bonding film. This eliminates the need to provide a fully formed core prior to the application of the bonding film and the web to the core strip material. The core strip material 84 is internally supported by the static mandrel 92 or 92 'during the whole roll manufacturing process until the time when the core strip material covered with cloth is cold enough and is cut to length. the desired length, for example, 65 inches, by using a 120 or 120 'oscillating saw (see figures 9 and 12). After this, the core strip material covered with fabric is removed from the outer end of the mandrel for subsequent finishing in individual paint rollers having a length of for example 7 or 9 inches, in a manner well known in the art. Although the invention has been shown and described with respect to certain preferred embodiments, it is obvious that alterations and equivalent modifications will occur to those skilled in the art upon reading and understanding the specification. The present invention includes all such alterations and equivalent modifications and is limited only by the scope of the claims.

Claims (29)

1. NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and therefore the property described in the following claims is claimed as property. A method for making rolls, characterized in that it comprises the steps of spirally winding a continuous length of thermoplastic core strip material around a mandrel while a spacer is placed between the adjacent edges of each successive fold of the strip material of core around the mandrel to prevent such adjacent edges of the core strip material from overlapping each other on the mandrel, thereby forming a spiral bond line between the adjacent edges of the core strip material; apply a layer of adhesive on the spirally wound core strip material; and spirally winding a strip of fabric over the adhesive layer to bond the fabric strip to the core strip material. The method according to claim 1, characterized in that the adhesive is a thermoplastic material that is sufficiently hot when the fabric strip is spirally wound over the adhesive layer to join the fabric strip to the core strip material in the cooling of the thermoplastic material. The method according to claim 1, characterized in that a hot thermoplastic film of the adhesive is spirally wound around the outer surface of the spirally wound core strip material immediately before spirally winding the strip of fabric onto the adhesive film. The method according to claim 3, characterized in that the fabric strip has a thermoplastic backing containing interstices into which the hot thermoplastic film flows to form a mechanical bond between the fabric strip and the core strip material. The method according to claim 4, characterized in that the adjacent edges of the hot thermoplastic film are superimposed on the spiral bond line between the adjacent edges of the core strip material to provide additional adhesive on the spiral bond line to end to flow into the spiral bond line and into the interstices in the thermoplastic back out of the spiral bond line. 6. The method according to claim 5, characterized in that the thermoplastic back is comprised of relatively long thermoplastic filaments that extend along the length of the strip of fabric to increase its strength, preventing the back of the fabric from tearing in the line of the fabric. spiral union of the tubular shape. The method according to claim 6, characterized in that the long thermoplastic filaments are made of nylon and the thermoplastic back also includes relatively short thermoplastic transverse filaments. The method according to claim 1, characterized in that the spacer maintains a space of not more than .050 inches between the adjacent edges of the core strip material during the spiral winding of the core strip material around the mandrel. The method according to claim 1, characterized in that the spacer maintains a space of not more than .015 inches between the adjacent edges of the core strip material during the spiral winding of the core strip material around the mandrel. 10. The method according to claim 1, characterized in that the spacer maintains a space of between about .010 inches and .015 inches between the adjacent edges of the core strip material during the spiral winding of the core strip material around the mandrel 1. The method according to claim 1, characterized in that the spacer is free to move to a limited degree in a direction parallel to the longitudinal axis of the mandrel to allow the spacer to follow between the adjacent edges of the core strip material during winding in spiral of the core strip material around the mandrel and compensate for any slight change in the helical angle in the spiral fold of the core strip material around the mandrel 1. The method according to claim 1, characterized in that the spacer has a tip that is maintained in closely spaced relationship with the outer diameter of the mandrel during the spiral winding of the core strip material around the mandrel. The method according to claim 1, characterized in that the separator is movable towards and away from the mandrel to adjust the detrimental space between the tip of the separator and the outer diameter of the mandrel. The method according to claim 1, characterized in that it is established that the detrimental space between the tip of the separator and the outer diameter of the mandrel is between about .005 inches and .008 inches. The method according to claim 1, characterized in that a first belt driver engages the fabric strip material in the mandrel to spirally spiral the fabric strip material and underlie the core strip material along the length of the belt. the length of the mandrel, and a second belt actuator engages the core strip material downstream of the separator and upstream of where the adhesive is applied to the core strip material to assist in spiraling the strip material from the core. core and the strip of cloth along the length of the mandrel. The method according to claim 15, characterized in that moving heads of different diameter are driven by a common drive motor to drive the belt drives at different speeds to compensate different outer diameters of the spiral bends of the fabric strip and the Core strip material on the mandrel so that both web actuators spirally advance the web strip and the core strip material at the same speed on the mandrel. The method according to claim 15, characterized in that two separate drive motors for the belt drives are electronically clamped together to drive the belt drives at different speeds to compensate different outer diameters of the spiral bends of the fabric strip. and the core strip material in the mandrel so that both web actuators spirally advance the web strip and the core strip material at the same speed in the mandrel. The method according to claim 1, characterized in that it further comprises the step of separating the tubular shape covered with fabric into a plurality of individual pieces of pipe covered with fabric. The method according to claim 1, characterized in that a strip of the hot thermoplastic film is directly extruded continuously on the tubular shape. 20. An apparatus for making rolls, characterized in that it comprises means for spirally winding a continuous length of thermoplastic core strip material around a mandrel, a spacer positioned between the adjacent edges of each successive fold of the core strip material around the core. mandrel to prevent such adjacent edges of the core strip material from overlapping each other, to provide a spiral bond line between adjacent edges, means for applying a layer of adhesive onto the spirally wound core strip material and means for spirally winding a strip of fabric over the adhesive layer to join the strip of fabric to the core strip material. The apparatus according to claim 20, characterized in that said means for applying an adhesive layer comprises an extruder nozzle head for extruding a hot thermoplastic film of the adhesive onto the spirally wound core strip material, the thermoplastic film being sufficiently hot. When the fabric strip is spirally wound around the thermoplastic film to cause the thermoplastic film to bond the fabric strip to the core material. 22. The apparatus according to claim 21, characterized in that the fabric strip has a thermoplastic back, and means are provided to cause the adjacent edges of the hot thermoplastic film to overlap each other on the spiral bond line between the adjacent edges of the core strip material to provide sufficient adhesive on the spiral bond line so that the adhesive flows into the spiral bond line and into the interstices in the thermoplastic back. The apparatus according to claim 20, characterized in that the spacer maintains a space of between approximately .010 inches and .050 inches between the adjacent edges of the core strip material during the spiral winding of the core strip material around the mandrel. . The apparatus according to claim 20, characterized in that it further comprises means for mounting the spacer for limited movement in a direction parallel to the longitudinal axis of the mandrel to allow the spacer to follow between the adjacent edges of the core strip material during winding spiral the core strip material around the mandrel and compensate for slight changes in the helical angle in the spiral fold of the core strip material around the mandrel. The apparatus according to claim 20, characterized in that it further comprises a guide to allow limited movement of the spacer in a linear direction parallel to the longitudinal axis of the mandrel to compensate for slight changes in the helical angle of the spiral fold of the core strip material around the mandrel. 26. The apparatus according to claim 20, characterized in that it further comprises means for adjusting the detrimental space between the separator and the outer diameter of the mandrel. The apparatus according to claim 20, characterized in that it further comprises a first web actuator that engages by pulling the fabric strip on the mandrel to spirally advance the fabric strip and underlying the core strip material along the length of the web. length of the mandrel, and a second band actuator that engages by driving the core strip material downstream of the separator and upstream of where the adhesive layer is applied to the core strip material to assist in spiraling the strip material of core and the strip of cloth along the length of the mandrel. The apparatus according to claim 27, characterized in that it further comprises two moving heads of different diameter driven by a common drive motor to drive the belt drives at different speeds to compensate different outer diameters of the spiral folds of the fabric strip and the core strip material in the mandrel so that both web actuators spirally advance the web strip and the core strip material at the same speed in the mandrel. 29. The apparatus according to claim 27, characterized in that it further comprises two separate actuators for the band actuators, and control means for electronically controlling the speed of the separate actuators to drive the band actuators at different speeds to compensate different outer diameters of the actuators. spiral bends of the fabric strip and the core strip material on the mandrel so that both web actuators spirally advance the web strip and the core strip material at the same speed on the mandrel. SUMMARY Methods and apparatuses for making paint rollers by spirally winding a strip of hot thermoplastic film on an outer surface of a thermoplastic tubular shape and by spirally winding a strip of fabric having a thermoplastic back on the spirally wound strip of thermoplastic film , while the thermoplastic film is still hot enough to cause the thermoplastic film to flow into the interstices in the backing of the fabric and permanently strip the fabric to the outer surface of the tubular shape. The tubular shape may comprise either a plurality of preformed tubes or may be formed by winding a continuous length of core strip material around a mandrel while holding the adjacent edges of the core strip material in relation without overlapping, spaced apart, to form a spiral bond line between the core strip edges. In the latter case, the adjacent edges of the hot thermoplastic film may overlap outwardly from the spiral bond line to provide additional adhesive in the spiral bond line for flow to the spiral bond line and to the interstices in the spiral. the cloth back out of the spiral binding line.