Device for applying hot adhesive powder to print media

Abstract

The invention relates to a device for applying hot adhesive powder to print media (4). The device is constructed as an aluminium frame. The frame forms a support surface similar to a bench on which a printer (1) can be placed. The print medium (4) is conveyed from the printer (1) through a powder unit (2) and to a winding device (8) via deflection rollers (5).

Description

[0001] Device for applying hot melt adhesive powder to printing media

[0002] The invention relates to a device for applying hot melt adhesive powder to printing media.

[0003] The present invention essentially relates to the printing of textiles. These are often individually printed with motifs, such as images, logos, text, or the like. This printing method is known as the direct-to-film (DTF) process. The desired design or motif is usually created on a computer. The finished design is then mirrored, which is particularly important for text, so that it remains legible after being applied to the garment.

[0004] The printing media is usually a transfer film. The film is typically PET film. It can be used in sheet form or as a continuous film wound onto a roll.

[0005] For individual, one-off printing for private or commercial use, the sheet-shaped transfer film is inserted into an inkjet or laser printer, and the design is printed. After printing is complete, a cover film on the transfer film is removed. The next step is to heat up an iron and place the garment on a flat surface, such as an ironing board. The transfer film with the motif is then applied to the garment and ironed over the film until it adheres to the garment. In commercial applications, so-called heat presses are used instead of irons.

[0006] Larger systems are used for the serial printing of clothing. These use continuous transfer film wound onto a roll. The roll is clamped into a transport device. The transfer film is unwound from this and conveyed through a printer, which is also an inkjet or laser printer. In this printer, the desired motifs are printed onto the transfer film. After the transfer film has been printed, it is conveyed horizontally towards a powder unit located adjacent to the printer. In the powder unit, pressure is applied to the film as it is pulled through a reservoir containing a heat-setting powder, also colloquially known as hot melt powder. This powder adheres to the printed areas of the film. From the unprinted areas of the film, the powder falls into a collecting container with the help of a vibrating device.The film is then conveyed through a heating and drying system located adjacent to the powder unit. This system gels the fixing powder. At the end of the system, the film is wound onto a roll.

[0007] To print onto the respective textiles, the film is unwound and positioned on a textile in a heat press. The press is then closed, exerting pressure and heat on the textile and the film. After the press is opened, the film is removed, leaving only the design on the textile.

[0008] Devices for treating the surface of the printing medium after printing, in the form of a film, are usually installed in front of the printer, taking up a lot of space to enable horizontal transport. This requires a lot of floor space. Conventional powder machines for textile printers also require regular manual transfer of excess powder, as the fallen powder must be transported back from the collection container to the storage container. In addition, the powder creates a static charge on the film during transport, which causes the powder to adhere to the film, even in areas that are not printed. This can lead to a loss of quality when the motif is applied to the textile.Against this background, the invention is based on the object of creating a device for applying hot-melt adhesive powder to printing media that is compact and thus requires a smaller footprint than is the case with devices known from the prior art. According to the invention, this is achieved with the features of patent claim 1.

[0009] The invention defined in claim 1 eliminates the space problem known from the prior art due to the design of the device, since the printer is placed inside the machine.

[0010] The invention specified in claim 2 enables a space-saving construction because the powder unit is arranged below the printer.

[0011] Patent claim 3 eliminates the need for manual transfer of the powder. The powder is continuously sprinkled onto the printing medium. Excess coating material enters the storage tray, from which it is then transported back to the medium.

[0012] The invention defined in claim 4 facilitates feeding the media roll to roll up and remove the printing medium.

[0013] Further developments and refinements of the invention are specified in the remaining subclaims. An exemplary embodiment of the invention is illustrated in the drawing and described in detail below. The sole figure shows a schematic representation of the device according to the present invention.

[0014] The device chosen as an exemplary embodiment is constructed as an aluminum frame with a substantially C-shaped configuration. The frame forms a support surface similar to a bench. The printer 1 is placed within the device. It is positioned on the support surface and is freely accessible from the front of the device. The medium 4 to be printed on is arranged in the printer 1 as a continuous film wound onto a roll. In the exemplary embodiment, the medium 4 to be printed on is a transfer film in the form of a PET film. The film is heat-resistant and coated for digital printing.

[0015] In the printer 1, the medium 4 is printed with the desired motifs. The printed medium 4 is transported from the printer via deflection rollers 5 to a take-up device 8, which is arranged above the printer 1. For this purpose, a drive is built into the device. The drive can drive the roller in the printer 1. The take-up device 8 can also be provided with a drive. In addition, all or individual deflection rollers 5 can be provided with a drive. The medium 4 passes through a powder unit 2, which sprinkles powder onto the medium 4. The powder is a thermosetting or hot-melt powder.

[0016] The powder unit 2 is positioned in the area of ​​the device facing the floor, or rather, is located on the lower side of the device. It is arranged below the printer 1. The powder unit 2 transports the powder from a storage trough 3 onto the medium 4. For this purpose, a conveyor device is provided, which is equipped with chains or, optionally, a toothed belt drive. These can be equipped with paddles. Alternatively, the powder can be transported upwards using a spindle. The powder adheres to the printed areas of the film 4; excess powder falls back into the storage trough 3.

[0017] The medium 4 is heated with the powder by a heat source 6, causing the powder to gel. The heat source 6 can be designed in the form of a heating mat or plate, or also in the form of a radiant heater. The exhaust air is filtered by an extractor 7 and passed onto the medium 4 as drying air. This simultaneously cools the medium 4. In the area of ​​the extractor 7, a cover (not shown) is formed which, when opened, releases the extractor 7 and thus enables maintenance or the replacement of filter elements. In addition to the exemplary embodiment, fans can also be arranged in the area of ​​the extractor 7 for cooling. The winding device 8 rolls up the printed, coated, and dried medium 4 again. For this purpose, a roll, which is usually made of cardboard, is suspended in the winding device 8. To simplify handling, the roll is magnetically fixed in the winding device 8.Adapter plates can also be used that are adapted to the design of the front ends of the rollers.

[0018] The device is equipped with sensors (not shown) that monitor the movement of the printing medium 4 within the device. These sensors can determine whether the medium 4 is being transported at a consistent speed. They can also determine whether the printing medium 4 is running low. As soon as the sensors detect a deviation or something similar, a warning can be sent to the operator, which can be acoustic and / or visual, for example.

[0019] Likewise, monitoring is carried out in powder unit 2, including the powder level and the function of the conveyor system. The same applies to printer 1, which is equipped with a monitoring system for the printing inks.

[0020] Threading aids are located at various points in the device. These aids are installed particularly in the area of ​​the powder unit 2 and the winding device 8 to ensure error-free transport of the printing medium 4.

[0021] In addition, to simplify threading the printing medium 4, the device can have a chain hoist that can be operated via a crank, with the aid of which the printing medium 4 can be conveyed upwards toward the winding device 8. This creates the possibility of manual threading, so that automated operation is only started after the beginning of the printing medium 4 has been correctly arranged on the roll.

[0022] The device according to the invention is very compact compared to the devices known from the prior art for applying hot melt powder to printing media. This is due to the fact that the printer 1 is installed in the frame of the device and the powder unit 2 - unlike in the prior art - is arranged below the printer 1. At the same time, the winding device 8, as well as the heating source 6 and the extraction and drying system 7, are arranged above the printer 1. As a result, the device according to the invention requires considerably less space than the devices known from the prior art, in which the printer, powder unit, heating source, extraction, drying system, and winding device are arranged horizontally next to one another. Consequently, the space requirement is considerably greater than with the device according to the invention.Unlike the prior art, in which the transport of the printing medium takes place in a horizontal direction, the transport of the printing medium 4 in the invention takes place essentially in a vertical direction.

[0023] Due to the space-saving design of the device according to the invention, it is possible to equip the frame with casters, allowing the device to be moved within the installation space. This can be accomplished by a single person.

[0024] The arrangement of the printer 1 in the aluminum frame on the support surface and its location at the front of the device allow for easy access. This allows for easy replacement of the rolls in the printer, unlike prior art devices in which the powder unit, heat source, extraction, drying, and take-up device are positioned in front of the printer.

[0025] The positioning of the take-up device 8 above the printer 1 on the front of the device enables very user-friendly handling when loading or removing the roll. The take-up device 8 is also freely accessible from the front. The roll can therefore be replaced from the front. The take-up device 8 is positioned approximately at shoulder height, making it easy to reach.

Claims

Patent claims Device for applying hot-melt adhesive powder to printing media (4), characterized in that it is constructed as an aluminum frame which forms a storage surface similar to a bench, on which a printer (1) can be placed. Device according to claim 1, characterized in that a powder unit (2) is located on the lower side. Device according to claim 2, characterized in that the powder unit (2) is equipped with chains or a toothed belt drive. Device according to one or more of claims 1 to 3, characterized in that a winding device (8) and a heat source (6) are mounted at its upper end. Device according to one of the preceding claims, characterized in that the printing medium (4) can be transported from the printer (1) to the winding device (8) via deflection rollers (5).Device according to one of the preceding claims, characterized in that the powder unit (2) is arranged below the printer (1) and the winding device (8) is arranged above the printer (1). Device according to one of the preceding claims, characterized in that a drive is installed. Device according to claim 7, characterized in that the drive drives the roller in the printer (1). Device according to claim 7, characterized in that the winding device (8) is provided with a drive.

10. Device according to claim 7, characterized in that at least one deflection roller (5) is provided with a drive.

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