SYSTEM FOR TREATMENT OF A MULTI-LAYERED CUSHIONING PRODUCT AND OPERATING METHOD FOR A SYSTEM FOR EXPANDING A MULTI-LAYERED CUSHIONING PRODUCT

Abstract

A system for treatment of a multi-layered cushioning product includes at least one web layer and at least one expandable layer including a water-based heat-expandable adhesive (WBHEA), comprising: (a) at least one radiator module for irradiating the multi-layered cushioning product including at least one emitter, such as a filament, panel or the like, emitting infrared radiation at an operative temperature of at least 600° C. and at most 3000° C. wherein the at least one radiator module having a power output density of at least 10 kW/m2 and/or at most 300 kW/m2 and (b) a conveyor for moving the, cushioning product relative to the at least one radiator module.

Claims

1-21. (canceled)

22. A system for treatment of a multi-layered cushioning product including at least one web layer and at least one expandable layer including a water-based heat-expandable adhesive (WBHEA), wherein it comprises (a) at least one radiator module for irradiating the multi-layered cushioning product including at least one emitter, such as a filament, panel or the like, emitting infrared radiation at an operative temperature of at least 600° C. and at most 3000° C., wherein the at least one radiator module having a power output density of at least 10 kW/m2 and/or at most 300 kW/m2, and (b) a conveyor for moving the cushioning product relative to the at least one radiator module.

23. The system according to claim 22, wherein the at least one emitter has a peak wavelength between 0.8 μm and 4.0 μm, in particular 2.0 μm to 3.5 μm.

24. The system according to claim 22, wherein the at least one radiator module is arranged at a distance 50 mm to 500 mm, in particular of 100 mm to 200 mm, more particularly 150 mm, relative to the cushioning product.

25. The system according to claim 24, wherein at the least one radiator module comprises two radiator modules, one of which is arranged above the cushioning product and the other below the cushioning product.

26. The system according to claim 22, wherein the conveyor is a belt conveyor, more particularly an open-meshed belt conveyor.

27. The system according to claim 22, comprising a controller for controlling the dose of radiation caused to the cushioning product by the at least one radiator module.

28. The system according to claim 27, wherein the controller is configured for setting a movement speed of the cushioning product relative to the at least one radiator module and/or for setting a radiation output of the at least one radiator module.

29. The system according to claim 27, comprising a temperature sensor, particularly a surface temperature sensor and/or an air temperature sensor, the controller being operatively coupled to the temperature sensor for controlling the dose of radiation caused to the cushioning product by the at least one radiator module based on the sensed surface and/or air temperature.

30. The system according to claim 22, wherein a shut-off trigger causes the radiator module to cease irradiating the cushioning product within 10 seconds or less, in particular 5 seconds or less, more particularly 2 seconds or less.

31. An arrangement comprising a multi-layered cushioning product including at least one web layer and at least one layer comprising a water-based heat-expandable adhesive (WBHEA) and the system according to claim 22.

32. An operating method for a system for expanding a multi-layered cushioning product including at least one web layer and at least one expandable layer including a water-based heat-expandable adhesive (WBHEA), wherein the cushioning product is irradiated by an infrared radiator module including at least one emitter, such as a filament, panel or the like, emitting infrared radiation at an operative temperature of at least 600° C. and at most 3000° C., wherein the cushioning product is provided with no less than 10 mJ/cm2 and no more than 50 mJ/cm2, particularly 17 mJ/cm2 to 25 mJ/cm2, for causing expansion of the WBHEA in the expandable layer, and wherein the cushioning product is conveyed relative to the radiator module through a treatment zone irradiated by the at least one radiator module.

33. The operating method of claim 32, wherein radiation is provided to the cushioning product at a wavelength of at least 0.7 μm and at most 5.0 μm; particularly peak wavelength between 2.0 μm and 4.0 μm, in particular 3.0 μm±0.5 μm.

34. The operating method of claim 32, wherein the at least one radiator module is operated with a power output density of at least 10 kW/m2 and/or at most 150 kW/m2, particularly 30 kw/m2 to 50 kW/m2.

35. The operating method of claim 34, wherein the at least one radiator module may be run at a first power output level during a start-up mode an at a second power output level during a continuous mode, wherein the second power output level is lower than the first power output level.

36. The operating method of claim 32, wherein the cushioning product is heated to a peak temperature of at least 80° C., in particular at least 90° C., and/or at most 160° C., in particular at most 140° C.

37. The operating method of claim 32, wherein the cushioning product is irradiated for 1 to 10 seconds, particularly 4 to 8 seconds, more particularly 5 to 6 seconds.

38. The operating method of claim 32, wherein the cushioning product is conveyed relative to the radiator module through a treatment zone irradiated by the at least one radiator module for a dwell time of 1 to 10 seconds, particularly 5 to 6 seconds, and/or at a particularly continuous conveying speed of at least 5 mm/s and/or at most 20 mm/s.

39. The operating method of claim 38, wherein a conveyor for conveying the product relative to the radiator module is run at a first conveying speed during a start-up mode an at a second conveying speed during a continuous mode, wherein the second conveying speed is faster than the first conveying speed.

40. The operating method of one of the claim 32, wherein the cushioning product is held at a distance of 50 mm to 500 mm, in particular of 100 mm to 200 mm, more particularly 150 mm, relative to the at least one radiator module.

41. The operating method of claim 40, wherein the least one radiator module comprises two radiator modules, and the cushioning product is irradiated by a radiator module arranged above it and by a radiator module arranged below it.

42. The operating method of claim 32, wherein in a shut-off mode, the at least one radiator module is caused to cease irradiating the cushioning product within 10 seconds or less, in particular 5 seconds or less, more particularly 2 seconds or less.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The following schematic drawings show aspects of the invention for improving the understanding of the invention in connection with some exemplary illustrations, wherein

[0055] FIG. 1 shows a schematic of a system for expanding a multi-layer cushioning product;

[0056] FIG. 2 shows a cross-sectional view of the system of FIG. 1 along the section line II; and

[0057] FIG. 3 shows a schematic view of a radiation module for a system for expanding a multi-layer cushioning product.

DETAILED DESCRIPTION

[0058] A system for treatment of a multi-and layered cushioning product for expansion of thereof in accordance with the invention is generally designated with the reference numeral 1. The system 1 comprises as its main constituent at least one radiator module 5, 6 for irradiating the multi-and layered cushioning product 3a, 3b, 3c, the radiator module 5, 6 including at least one emitter 7, such as a filament, panel or the like. The emitter 7 is configured to emit infrared radiation 9 during operation, and an operative temperature of the emitter of at least 600° C. and at most 3000° C.

[0059] Although the schematic illustrations according to FIGS. 1 and 2 depict the same system 1, the illustrations differ in that FIG. 1 shows the individual items of multi-layered cushioning products 3a, 3b whereas FIG. 2 illustrates an arrangement 2 comprising a system 1 processing a continuous, web-like cushioning product 3c.

[0060] In the illustrations, the direction designated with an X designates the direction in which the “width” of the components of the system or arrangement are may be defined. The direction designated with Y generally relates to the length by direction that may be arranged horizontally and/or correspondingly, particularly in parallel, relative to the conveying direction C. The Z direction is the vertical direction in relation to gravity. The vertical direction Z may generally correspond to a normal relative to a plane defined by the floor on which the system 1 rests. The terms “above” and “below” may relate to a relative arrangement of two or more components relative to one another in regard to the vertical direction Z.

[0061] A radiation module 5 is shown in detail in FIG. 3. The radiation module 5 comprises six infrared emitters 7. The infrared emitters 7 of the radiation module 5 may particularly be realized as infrared emitters comprising a heating element made of a carbon filament.

[0062] In a preferred embodiment of the infrared radiation treatment system 1 according to the invention, the emitter 7 is a carbon infrared emitter, for example a Heraeus Noblelight CIR emitter 3750 W/230V with a total power output capability of 22.5 kW and a power density of the radiator module of 72 kW/m.sup.2. A radiator module 5, 6 casing 25 may have a width of 500 mm to 1000 mm, preferably 600 mm to 900 mm, for example 865 mm. The length of the radiator module may be between 200 mm and 800 mm, in particular between 400 mm and 700 mm, for example 550 mm. The heated width or emission window 8 of the radiator module 5, 6 may be approximately 625 mm wide and approximately 500 mm long. The meshed wire belt conveyor 13 may have a length of 3000 mm width of 950 mm. The belt height may be 900 mm from the ground.

[0063] The emitters 7 may be arranged in a casing 25 of the radiator module 5 behind an emission window 8. The emission window 8 may be provided with a glass window, preferably a quartz glass window and/or a protective mesh. The radiator module 5 may be equipped with one or more reflectors such as mirrors behind the at least one emitter 7 in relation to the emission window 8 for reflecting radiation 9 from the emitter 7 towards the emission window 8. The radiator module 5 may be provided with an exhaust duct 19 such that exhaust particles, steam and/or gas can easily be removed from the treatment zone 21.

[0064] The emission window 8 defines a heated width in the X-direction and a heated length in the Y-direction of the radiator module 5. For some emitters 7, in particular for carbon infrared (CIR) emitters, the heated width of the radiator module 5 may be between two thirds and ⅚; particularly approximately ¾ of the total width of the casing 25 of the infrared radiation module 5. The heated length of the radiator module 5 may be between three quarters and 95% of the total length of the radiator module 5 in the Y-direction. For some emitters 7, in particular for halogen and/or NIR emitters, the heated width of the radiator module 5 may be between three quarters and 95% of the total width of the radiator module 5 in the X-direction.

[0065] The system 1 may comprise only one radiator unit 5 or 6 arranged above or below a treatment zone 21 for a multi-layered cushioning product including at least one heat-expandable layer. As shown in FIGS. 1 and 2, the system 1 may comprise several radiator modules, in particular two radiator modules 5 and 6. One first radiator module 5 may be arranged vertically above the treatment zone 21 and another, second radiator module 6 may be arranged vertically below the treatment zone 21. The cushioning product is irradiated in the treatment zone 21 using infrared radiation 9.

[0066] The length and width of the treatment zone 21 corresponds to the area irradiated by the radiation modules 5 and 6, in particular to the size of their respective emission windows panes 8. The radiator modules 5 and 6 may be of the same design. The first and second radiator 5, 6 may have the same number of infrared emitters 7. Several, in particular all, emitters of the first radiator module 5 and/or second radiator module 6 may be equal to one another.

[0067] The controller 15 may comprise a first thermal control unit (not shown in further detail detail) to control the operative power level of the first radiator module 5 supplied from the power supply 27. The controller 15 may include a second thermal control unit for control of the operative power supplied from the power supply 27 to the second radiator module 6. The controller may comprise a velocity control unit for controlling the velocity of the conveyor 11. The velocity control unit may be realized as an open loop control which a constant velocity setting is provided to the electric motor 31 dependent upon a velocity control input. Alternatively, the velocity control may include a velocity sensor for a closed loop control of the conveyor belt 13 velocity.

[0068] The control 15 may be configured to run the system 1 at a continuous operating mode different from a start-up mode. In the start-up mode, the controller 15 may control the electric motor 31 to drive the conveyor belt 13 with a start-up velocity lower than the conveyor belt 13 velocity during normal operation. Furthermore, the controller 15 may be configured to control the one or more radiator modules 5, 6 to operate at or near maximum nominal power output during a start-up mode in order to quickly heat up the treatment zone 21 of the system 1.

[0069] The temperature sensor 17 may be provided and operatively coupled to the controller 15. The temperature sensor 17 may sense the air temperature of the treatment zone 21. Alternatively or additionally, temperature sensor 17 may be arranged to detect the surface temperature of the outside of an irradiation treated cushioning product 3a, 3b, or 3c. The temperature sensor 17 may be operatively coupled with a controller 15 such that the controller 15 can control the at least one radiator module 5, 6 and/or the drive 31 of the conveyor belt 13 based on the readings of the temperature sensor 17.

[0070] The nominal maximum power output density of the first radiator module 5 and of the second radiator module 6 may be equal to one another. During a continuous normal operation, the control 15 may set the lower or second radiator module 6 to an operative power output density of between 60% and 80% of the nominal maximum output power density. The controller 15 may set the upper or first radiator module 5 during operative mode to a relatively lower power output density of 40% to 60% of the nominal maximum power output density of the radiator module 5.

[0071] During start-up mode, the controller 15 may drive at the first radiator module 5 and the second radiator module 6 to the maximum power output density, or at least 90% thereof. During operative mode, the power output density of the lower, second radiator module 6 may be set to a power density higher than that of the upper, first radiator module 5 to allow for the additional heating of the mesh conveyor belt 13 between the lower radiator module 6 and the cushioning product 3a, 3b, 3c.

[0072] It may be preferred that the controller 15 sets the velocity of the conveyor belt 13 and the power output densities at least one radiator module 5, 6 dependent upon the lengthwise extensions of the treatment zone 21 and/or the size of the cushioning product to be treated such that the cushioning product is provided with no less than 10 mJ/cm.sup.2, in particular no less than 17 mJ/cm.sup.2 and/or provided with no more than 50 mJ/cm.sup.2, in particular no more than 25 mJ/cm.sup.2.

[0073] During operative mode, the infrared emitters 7 of the at least one radiator module 5, 6 are run at an operative temperature of at least 600° C. and at most 3000° C. During operative mode, the emitters 7 may be operated with a peak wavelength between 0.8 μm and 4.0 μm, particularly between 2.5 μm and 3.5 μm. The peak wavelength of an emitter shall be understood to relate to the wavelength at which the infrared emitter 7 provides is maximum radiation power. Generally, infrared emitters 7 emit radiation spread over a relatively large spectral distribution, which may range from the visible spectrum through the shortwave spectrum, into the medium wave spectrum and possibly into long wave spectrum. The short wave spectrum shall be defined as radiation having a wavelength between 0.7 μm and 2.0 μm. The medium wave spectrum shall be defined as a spectrum ranging from 2.0 μm to 4.0 μm. The longwave spectrum shall be defined as radiation having a wavelength greater than 4.0 μm. Depending on its temperature, and infrared emitter may deliver distinctly different radiation at various wavelengths. The peak wavelength as used herein refers to the peak wavelength of the emitter at its nominal operative temperature.

[0074] It shall be clear that the controller 15 may control the power output density of the at least one radiator module 5, 6 indirectly. For example, the controller 15 may control the electric power supplied to the radiator module 5, 6. The power output density of the radiator module 5, 6 may be determined by dividing the cumulative electric power supply (power load) provided to the one or more emitters 7 of the radiator module 5, 6 by the size of the emission window 8 thereof.

[0075] The radiator modules 5 and 6 are supplied with electrical power from a power supply 27 of the treatment system 1. The conveyor 11 may also be supplied with electrical power from the power supply 27. The conveyor 11 may comprise an electric drive, such as an electric motor 31 the trigger 16 may be configured to interrupt the supply of electrical energy from the power supply 27 to the radiator modules 5, 6. The trigger 16 may be configured to cause the electric motor 31 to halt the conveyor belt 13 upon activation. Alternatively, the trigger 16 may be configured to accelerate the velocity of the conveyor belt 13 upon activation.

[0076] The treatment system 1 may comprise a frame 22 to which the radiator modules 5, 6, the conveyor 11, including its belt 13 and drive 31 are mounted. Further components of the system may also be attached to its frame 22. The controller 15, the trigger 16 and the power supply 27 may be attached to the frame 22 of the treatment system 1. Alternatively, the power supply 27 the controller 15 and/or the trigger 16 may be part of a separate structure, such as a control panel (not shown in further detail). The trigger 16 may be a sensor testing if the conveyor 11 is running which would send a stop signal to the controller 15 and/or radiator module(s) 5, 6 to cease irradiation.

[0077] The frame 22 of the IR radiation treatment system 1 may comprise support racks 26 for receiving the radiator modules 5, 6. A support rack 26 may comprise rails onto which are radiator module 5, 6 may be put. The rails of the support rack 26 can be used to slide the radiator module 5 or 6 into the treatment system 1. The support rack 26 may be shaped complementarily in relation to the casing 25 of the radiation module 5, 6. The support racks 26 may be provided with fixing means and/or safety means for holding the radiator module 5, 6 in position relative to the treatment zone 21, conveyor 11 and/or cushioning products 3a, 3b, 3c. The radiator modules 5, 6 may be arranged 300 mm apart. Each radiator module 5, 6 may be arranged at a distance of 150 mm from the cushioning product to be treated.

[0078] FIG. 1 schematically illustrates the treatment of multi-layered cushioning product 3a, 3b using infrared radiation to expand and heat-expandable layer of the multi-layered cushioning product 3a, 3b which includes the water-based heat-expandable adhesive (WBHEA). While the cushioning products 3a, 3b travel through the treatment zone 21 of the treatment system 1 in the conveying direction C, the cushioning product 3a, 3b are exposed to infrared radiation 9 from the emitters 7 of the radiator modules 5, 6. The infrared radiation 9 heats the surface of the cushioning product 3a, 3b, thereby heating the additional one or more layers of the cushioning product 3a, 3b including the heat-expandable layer.

[0079] For example, the treatment system 1 may be run via the controller 15 such that the cushioning product is fed through the treatment zone 21 with a dwell time of 5 to 6 seconds during which the radiator modules 5, 6 provided between 50 and 80 kW/m.sup.2. Between 20 and 40 kW/m.sup.2. It has surprisingly been shown that the short-term supply of sufficient infrared radiation suffices to cause the expandable layer which includes water-based heat-expandable adhesive to expand. In particular, the volume of the expandable layer may be increased by a factor of at least 2, at least 5, at least 10, at least 15 or at least 20 during treatment. When the cushioning product 3a, 3b is inside the treatment zone 21 and exposed to infrared radiation 9, the volume of the entire cushioning product is thereby increased from an initial compact state of the cushioning product 3a to an expanded state of the cushioning product 3b.

[0080] In comparison, FIG. 2 illustrates a continuous cushioning product 3c which is fed through the treatment zone 21 of the treatment system 1 in the conveying direction C such that different longitudinal sections in the lengthwise Y-direction of the cushioning product 3c undergo the treatment process and thereby expand from a compact state at the entry of the treatment zone 21, reaching an expanded state upon exit from the treatment zone 21.

[0081] The emission of infrared radiation 9 from the emitters 7 to the cushioning product 3a, 3b, 3c is a controlled by the controller 15 in conjunction with the velocity of the conveyor 11 such that the desired peak temperature is reached. It may be preferred that the radiator modules 5, 6 provide infrared radiation to the cushioning product 3a, 3b and to provide the cushioning product with a peak temperature of at least 80° C., in particular at least 90° C. It may be preferred that the treatment system is operated such that the peak temperature of the cushioning product does not exceed 160° C., particularly such that it does not exceed 140° C. Overheating of the cushioning product detrimentally affects the volume of the expansion layer and may even cause thermal damage to or ignite the cushioning product.

[0082] The features disclosed in the claims, the specification, and the drawings may be essential for different embodiments of the claimed invention, both separately and in any combination with each other.

[0083] While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. Thus, it is intended that the invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.