HEATED IRON OR ROLLER FOR A TEXTILE PRINTING APPARATUS

Abstract

The present invention provides a fabric compressor for applying heat and or pressure to a textile before or after applying ink to a textile during a screen printing operation to prevent fibrillation, to provide a smooth base coat, and/or to cure ink.

Claims

1. A fabric compressor for a screen printing press having a squeegee mounting bar comprising: a housing having a roller and an attachment member for mounting the housing to the squeegee mounting bar for reciprocal translational motion along a first line between a first location and second location, and along a second line generally perpendicular to the first line from a disengaged position to an engaged position where the roller is in contact with a substrate or in sufficient proximity to heat the substrate; a heater element connected to the housing for heating the roller; and a control unit connected to the heater element having an input area and a status area, the input area having controls for setting a desired temperature of the roller and the status area having a display for indicating the actual temperature of the roller.

2. The fabric compressor of claim 1 wherein the roller is mounted within the housing for rotational movement about an axis generally perpendicular to the first direction.

3. The fabric compressor of claim 2 wherein the housing has an opening and a portion of the roller can be accessed through the opening.

4. The fabric compressor of claim 3 wherein the roller rotates about the axis during movement of the housing from the first location to the second location.

5. The fabric compressor of claim 4 wherein the roller rotates in response to contact with the substrate.

6. The fabric compressor of claim 4 further comprising a motor for rotating the roller about the axis.

7. The fabric compressor of claim 1 wherein the control unit has inputs for setting the speed for moving the housing from the first location to the second location.

8. The fabric compressor of claim 7 wherein the control unit has inputs for the speed for moving the housing along the second direction.

9. The fabric compressor of claim 1 wherein the control unit has inputs for specifying the pressure applied by the roller to the substrate.

10. The fabric compressor of claim 1 wherein the control unit has inputs for specifying the distance from the heating element to the substrate when moving the housing from the first location to the second location.

11. The fabric compressor of claim 1 wherein the housing has a heat vent.

12. The fabric compressor of claim 11 further comprising a fan mounted over the heat vent.

13. The fabric compressor of claim 1 wherein the desired temperature is from ambient temperature to 400 F. (204 C.).

14. An assembly for treating a textile before or during a screen printing operation comprising: an object support for supporting a textile; a bar extending across a portion of the object support; a fabric compressor mounted to the bar for reciprocating translational motion along a portion thereof between a first position to a second position, the fabric compressor having a roller facing the object support; a first member for moving the fabric compressor between the first position and the second position; a second member for moving the fabric compressor or the object support along a line generally perpendicular to the bar back and forth between a disengaged position and an engaged position; a heater element connected to the roller; a temperature sensor connected to the roller; and a control unit connected to the heater element and capable of generating a signal to the heater element representative of a desired temperature of the roller.

15. The assembly of claim 14 further comprising an endless conveyor and the object support attached to the conveyor and moveable with the conveyor along a path.

16. The assembly of claim 15 further comprising a plurality of print heads spaced from one another long the path, each of the plurality of print heads are connected to a source of ink and have an applicator for applying the ink to the textile.

17. The assembly of claim 14 wherein the control unit is capable of generating a signal to the second member representative of the desired pressure for the roller to apply to the textile or a distance to maintain from the textile.

18. The assembly of claim 14 wherein the desired temperature is from ambient temperature to 400 F. (204 C.).

19. The assembly of claim 14 wherein the textile has a printing area having a length dimension and a width dimension, the roller spans the width dimension and the length dimension is between the first location and the second location so that the roller contacts the entire print area in a single pass from the first location to the second location.

20. The assembly of claim 19 wherein the roller is mounted for rotation about a second axis in response to contact with the textile during movement from the first position to the second position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] To understand the present invention, it will now be described by way of example, with reference to the accompanying drawings and attachments in which:

[0022] FIG. 1 is perspective view of a prior art screen printing press manufactured and sold by the M&R Companies, the assignee of the present invention, under the tradename SPORTSMAN EX.

[0023] FIG. 2 is perspective view of a prior art screen printing press manufactured and sold by the M&R Printing Company, the assignee of the present invention, under the tradename STRYKER.

[0024] FIG. 3 is a perspective view of a fabric compressor with a roller in accordance with the present invention.

[0025] FIG. 4 is perspective view of a fabric compressor with a flat iron in accordance with the present invention.

[0026] FIG. 5A is a side elevation view of a fabric compressor mounted for reciprocating translational movement over an object support in a first location and disengaged from the support.

[0027] FIG. 5B is a side elevation view of a fabric compressor mounted for reciprocating translational movement over an object support in a position engaging the object support and between a first location and a second location.

[0028] FIG. 6 is perspective view of a fabric compressor mounted to a screen printing press as a fabric compressor station among other stations such as printing stations, curing stations or other stations.

[0029] FIG. 7 is a schematic view of a control unit for entering and displaying operating parameters of the fabric compressor of the present invention.

[0030] FIG. 8 is a flow chart of the steps of a method of pressing a textile on a screen printing press.

DETAILED DESCRIPTION

[0031] While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated.

[0032] FIGS. 1 and 2 show prior art screen printing machines 10 one having a circular track 12 or rail (FIG. 1) and the other an oval track 12 or rail (FIG. 2). An endless conveyor is mounted for movement about an axis of rotation of the track in a clockwise or counterclockwise direction. A plurality of object supports 14 are attached to and extend radially away from the conveyor and move therewith through a common horizontal plane (i.e., the same distance above the surface supporting the press). Textiles are loaded on to the object supports and are moved with the conveyor from station 16 to station 16 in an indexed fashion and pause at each station for a sufficient period of time for a printing operation, or other operation, to be performed. The conveyor is moved by a motive source such as an electric motor and the movement is controlled by an indexer control mechanism to set the speed of rotation and the period at rest at each station. There are a variety of station types including a screen printing station 16, an ink drying or curing station, a loading station 18, an unloading station 20 and other stations to serve other purposes that are well known to those of ordinary skill in the art. The present invention provides a fabric compressor station that can be independent of the printing press as shown in FIGS. 5A,5B or can be one of the stations of the screen printing press 10 as shown in FIG. 6.

[0033] A screen printing station has a head assembly having an arm 24 pivotally connected on a frame 22 to overlie a pallet 14 and is mounted for movement between a printing position and a non-printing position. The printing head 24 includes a screen frame 25 for supporting a printing screen 26 that has a desired pattern for printing a white base coat or other desired color. Each station prints a single color. A squeegee 28 and a flood bar 29 are movably mounted to a squeegee bar 30 mounted to the arm 24 for traversing a printing stroke when the head assembly is disposed in the printing position and a flood stroke when the head assembly is in the non-printing position. The printing stroke requires moving the squeegee 28 and the flood bar 29 from a first position to a second position, and the flood stroke requires moving the squeegee and the flood bar from the second position to the first position. The movement of the squeegee and flood bar is accomplished using a pneumatic controls and is well known to those of skill in the art or manually by an operator of the press. As will be discussed below, these controls can also be used to control the movement of the fabric compressor assembly of the present invention.

[0034] Operatively connected to the frame of the head assembly are one or more locating bars 39 which are cooperatively associated with the object supports so as to ensure proper registration of the object supports when the printing head assembly is disposed in the printing position. The conveyor is driven on its endless path by a drive mechanism such as a chain or belt which is threaded about a sprocket journaled on a main drive shaft which is coupled in driving relationship to a drive motor. Operatively associated with the drive mechanism is an indexing system to effect an intermittent indexing of the respective object supports from station to station during machine operation.

[0035] FIGS. 3 and 4 show a fabric compressor assembly 40 having a housing 42 defining a chamber 44 with an opening 46 to provide access to a surface contact member 50. The surface contact member 50 can be a roller 52 (FIG. 3) or a flat iron 54 (FIG. 4). The roller 52 is journaled at opposed ends 56 for rotation about an axis of rotation 58. The roller 52 can rotate in response to a motive force, such as a motor (not shown), or rotate in response to being moved in contact with a surface such as a textile. The housings 52 have side walls, and end walls, a top wall, and vent openings through one of the sidewalls and exhaust fans 60 for removing heat from the housings 42. While four fans 60 are shown spaced along a length dimension of the housing, a different number of vents and fans could be used, and could be positioned elsewhere on the housing, without departing from the scope of the present invention.

[0036] FIGS. 5A,5B show the fabric compressor assembly 70, separate from a printing press as a stand-alone unit, and mounted on a surface 71 for reciprocal translational movement along a first line 73 (horizontal as shown), from a first position 72 to a second position 74 and then back to the first position 72. FIG. 5A shows the fabric compressor 40 in the first position 72 and FIG. 5B shows the fabric compressor 40 in a location intermediate of the first and second positions 72,74. The fabric compressor can be moved between the first and second positions manually or automatically using a motive force. The fabric compressor can be positioned manually by an operator during a setting-up procedure in a vertical direction to contact the object support with a desired pressure or to pass over the textile at a desired distance but not contacting the textile. The object support can also be positioned vertically with respect to the fabric compressor instead of moving the fabric compressor. An operator of the press can move the fabric compressor by hand back and forth between the first position 72 and the second position 74.

[0037] The fabric compressor 40 can optionally be mounted for automatic movement using a first member 84 to move the fabric compressor along the first line 73 back and forth between the first position 72 and the second position 74. A second member 86 is shown for moving the fabric compressor along the second line 75 back and forth between the engaged position and the disengaged position. One example of such controls are those used to move a squeegee bar and flood bar in an automated screen printing press. During a printing operation, the squeegee is moved vertically downward into engagement with a screen at a desired pressure and the flood bar is moved vertically upward and is not in contact with the screen. The squeegee and flood bar are moved together from the first position to the second position over an area known as the printing area. This is known in the industry as a print stroke. When moving from the second location to the first location, the vertical movement of these elements is reversed and the squeegee is moved upward out of contact with the screen and the flood bar is moved downwardly in contact with the screen. The squeegee and the flood bar are then moved along the first line 73 from the second position to the first position. This is known in the industry as the flood stroke.

[0038] The fabric compressor 40 can be automatically, vertically positioned to contact or be in near contact in any desired fashion and is not limited to the print stroke and flood stroke mentioned above. The fabric compressor can be programmed to contact the textile during movement from the first location to the second location and during the return trip from the second location to the first location. The fabric compressor can be programmed to apply one pressure to a textile in one leg of the trip and another pressure during the opposing leg. The fabric compressor can also be programmed to make several trips between the first and second location as desired. In one preferred aspect, the fabric compressor will operate like the squeegee bar and be in contact with a screen interposed between the textile and the roller, or moved at a desired distance therefrom, and in the return trip from the second location to the first location be positioned spaced from the screen and not in contact therewith. More preferably, fabric compressor will be directly exposed to the textile without the use of a screen interposed between the textile and the fabric compressor. The roller will be either in direct contact with the textile or will be in sufficient proximity to heat the textile.

[0039] The fabric compressor assembly 70 has a heater element 82 and a temperature sensor 83 to maintain the roller 50 at the desired temperature. The desired temperature can be ambient temperature up to 400 F. (204 C.). A controller 90 (FIG. 7) is connected to the heater element 82 and has inputs 98 for setting the desired temperature, and a status section 92 for displaying the actual temperature measured by the temperature sensor 83. The controller 90 is capable of generating a signal representative of the desired temperature and sending the signal to the heater element 82, and for receiving a signal from the temperature sensor of the actual temperature of the roller 50.

[0040] FIG. 6 shows the fabric compressor assembly 70 as a station in screen printing press 10. There are numerous varieties of suitable screen printing presses 10 including automatic and manual varieties. Suitable screen printing presses include, for example, those sold by M&R Companies under the tradenames STRYKER, CHALLENGER, GAUNTLET, SPORTSMAN, DIAMONDBACK, VICTORYONE, PREDATOR, PRE-RUNNER ALPHA 8, KRUZER, SIDEWINDER, CHAMELON, and ABACUS. The fabric compressor assembly 70 can be used on textiles prior to printing or after. The roller 52 of the fabric compressor can directly contact and apply heat and pressure to the textile or can work through a screen interposed between the roller and the textile. In one aspect, the screen is a PTFE screen. The fabric compressor can also be passed over the textile in sufficient proximity to heat the textile without contacting it or applying pressure to the textile. This process can be used to cure or partially cure ink.

[0041] FIGS. 6 and 7 show the control unit 90 attached to a front end of a printhead arm 24 and has a multifunctional display (FIG. 7). The control unit 90 has a status section 92 having a display 94, such as an LCD display for example, an input area 96 having controls 98, and a power section 99 for turning the fabric compressor on or off. The control 90 allows for a user to select the type of contacting member either a roller or a flat iron. The control 90 also allows for a user to select the desired temperature of the contacting member 50. The display 94 shows the desired temperature of the contacting member and the actual temperature. The control unit can also be programmed to allow for entry and display of other operating parameters such as the speed of moving the fabric compressor assembly from the first location 72 to the second location 74, the speed of the return trip from the second position to the first position, whether the fabric compressor contacts the surface and if so the desired pressure to apply to the textile. The speed of moving from the engaged to the disengaged position and the return trip can also be allowed for through appropriate programming of the control. The control unit 90 also has a port 100 that allows for electrically coupling the control unit 90 to the fabric compressor assembly 70 to control the temperature of the contacting member and any combination of the operating parameters mentioned. In one form, a military grade electrical connector 102 is used and has high-cycle flexible wiring, and a long-life flexible sheath to connect the port 100 on the control 90 to a similar port 104 on the fabric compressor assembly.

[0042] In one form of the invention, the fabric compressor 70 is connected to the squeegee mounting bar 30 with two clamps 110, and the existing squeegee and flood bar controls 106 that are part of the printing press can be used to control the movement of the fabric compressor. The fabric compressor 70 can be programmed to contact the textile, applying heat and pressure (pressure stroke) to the textile only when moving from the first location to the second location or from the second location to the first location and lifted in the opposing stroke (non-pressure stroke). The fabric compressor assembly 70 can be programmed to apply pressure during both outgoing and incoming strokes or in any number of pressure strokes and non-pressure strokes. The fabric compressor 70 can also be programmed to pass the contacting member in close proximity to the textile in a heating stroke.

[0043] The fabric compressor assembly 70 can be used in numerous printing operations to address problems that commonly occur during a screen printing operation. For example, one problem known as fibrillation occurs when a printed textile appears faded or fuzzy immediately after printing or upon washing one or more times. Fibrillation is due to fibers of the textile sticking out through the printed area to give a faded or fuzzy look. The laundering process can cause fibers to pop up that are not fully coated with ink thus reducing the sharpness of the printed image and making it look fuzzy or hairy. Using the fabric compressor assembly 70 to apply heat and pressure in a pressure stroke or pressure strokes to the textile prior to applying ink presses down the fibers to reduce the tendency for them to pop up later.

[0044] The fabric compressor can also be used after ink has been applied to a textile. For example, after applying a base coat the fabric compressor can be used to smooth out the ink to give a uniform surface for subsequent printing operations and provide a printed textile with a softer hand feel of the printed surface. The fabric compressor can also be used in a foil transfer process to cause the foil to more firmly adhere to the textile over the entire surface of the foil. The fabric compressor can also be used in a curing process of heat-discharge inks in a heating stroke. In this process, the fabric compressor can be passed over the textile in sufficient proximity to heat the textile but without contacting the textile.

[0045] FIG. 8 shows the steps in a process 200 of treating a textile before or during a screen printing press operation. The process steps do not necessarily have to be performed in the exact order shown. In a step 202 a textile is provided on an object support surface. In a step 204, a fabric compressor station is provided having a bar extending across a portion of the object support. In step 206 provides a fabric compressor assembly mounted to the bar for translational motion along a portion thereof, the fabric compressor having a roller facing the object support. In step 208 provides a first member for moving the fabric compressor between a first position and a second position (horizontally) along the bar. In step 210 provides a second member for moving the fabric compressor or the object support along a line generally perpendicular to the bar (vertically) from a disengaged position to an engaged position. In step 212 provides a heater element connected to the roller. In step 214 provides a temperature sensor connected to the roller. In step 216 the object support is moved into the fabric compressor station. In step 218 the roller is moved into contact with or close proximity to the textile to heat the textile with the second member. In step 220 the roller is moved along the textile from the first position to the second position.

[0046] Many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood within the scope of the appended claims the invention may be protected otherwise than as specifically described.