Monitoring process for nonwoven fabrication plants

Abstract

A monitoring process is provided for a method for producing a nonwoven product. Properties of a nonwoven pre-product ( 3 ), in particular the humidity, the electric charge, the weight distribution, the fiber orientation, the fiber mixing ratio and/or the fiber opening degree of an unprocessed fiber web, are detected by a detection unit ( 41 ) having one or more sensors ( 410 ).

1 . A monitoring process for a process for producing a nonwoven pre-product, the monitoring process comprising:
 detecting properties of a nonwoven pre-product, including one or more of weight per unit area, fiber orientation, fiber-blending ratio fiber opening degree, moisture content, temperature and electrical charge, with a detection unit in a detection zone;   processing detection results in a data processing unit, wherein the nonwoven pre-product in the detection zone is still an unprocessed fiber web and the properties of the nonwoven pre-product are detected over the width of the nonwoven pre-product across a production direction; and   generating actuation commands fora nonwoven pre-production plant comprising a fiber processing device or a web forming device or both a fiber processing device and a web forming device.   
     
     
         2 . A monitoring process in accordance with  claim 1 , wherein the detection zone is located directly at or close to the discharge of the nonwoven pre-product from the web forming device comprising a card, airlay or spunbond machine. 
     
     
         3 . A monitoring process in accordance with claim  1 , wherein the detection zone is located in the production direction in front of the web structure-changing web processing device comprising a cross lapper or a bonding device. 
     
     
         4 - 5 . (canceled) 
     
     
         6 . A monitoring unit in accordance with  claim 1  wherein the three-dimensional distribution of properties of the nonwoven pre-product is detected along and or across the production direction with a movable sensor or with a stationary sensor beam. 
     
     
         7 - 8 . (canceled) 
     
     
         9 . A monitoring process in accordance with  claim 1  wherein a frequency analysis of the detection results is carried out, especially on the basis of a Fourier transformation. 
     
     
         10 . A monitoring process in accordance with  claim 9 , wherein a damage to or a need for maintenance of a component of the nonwoven pre-production plant is determined on the basis of frequency analysis, comprising a comparison of a periodic movement of the component and frequency analysis of the detection results. 
     
     
         11 . A monitoring process in accordance with  claim 1 , wherein the detection results are compared with desired properties of the nonwoven pre-product and deviations of the properties are determined. 
     
     
         12 . (canceled) 
     
     
         13 . A monitoring process in accordance with  claim 1 , wherein actuation commands are generated, which are configured to influence and/or to set and/or to regulate properties of the nonwoven pre-product locally in an actuation zone in a partial area of a width of the nonwoven pre-product across the production direction. 
     
     
         14 . A monitoring process in accordance with  claim 1 , wherein a local property of the nonwoven pre-product or the three-dimensional and/or two-dimensional distribution of a property across and/or along the production direction, is regulated or controlled. 
     
     
         15 . (canceled) 
     
     
         16 . A monitoring process in accordance with  claim 1 , wherein a process parameter comprising a fiber volume flow, a speed of a conveying device, a position of a fiber guide mechanism, or air conditioning, is changed at the fiber processing device and/or at the web forming device. 
     
     
         17 . A monitoring process in accordance with  claim 1 , wherein by changing a process parameter, a detected property of the nonwoven pre-product is influenced to compensate deviations of properties. 
     
     
         18 . (canceled) 
     
     
         19 . A monitoring process in accordance with  claim 1 , wherein the weight per unit area, especially a three-dimensional and/or two-dimensional distribution along and/or across the production direction, of the nonwoven pre-product is influenced in a specific manner by setting the fiber conveying speed of the nonwoven pre-production plant, the feed characteristic of a feeder or the inlet of a web forming device. 
     
     
         20 . A monitoring process in accordance with  claim 1 , wherein the fiber orientation in the nonwoven pre-product is influenced in a specific manner by setting the web forming device, including a card or aerodynamic card (airlay). 
     
     
         21 . A monitoring process in accordance with  claim 1 , wherein the fiber blending ratio of the fiber components in the nonwoven pre-product is set in a specific manner by setting a bale opener, a dispensing device, a fiber opening device or a fiber blending device. 
     
     
         22 . A monitoring process in accordance with  claim 1 , wherein the opening degree of the fibers in the nonwoven pre-product is influenced in a specific manner by setting a fiber opening device or the web forming device. 
     
     
         23 . (canceled) 
     
     
         24 . A monitoring unit for a nonwoven fabrication plant, the monitoring unit comprising:
 a detection unit configured to detect properties of a nonwoven pre-product in a detection zone, wherein the detection unit comprises one or more of an infrared sensor, a radioactive radiation sensor and an X-ray sensor, wherein the detection unit is configured to detect properties of an unprocessed nonwoven pre-product over a width of the nonwoven pre-product across a production direction; and   a data processing unit configured to generate actuation commands for a nonwoven pre-production plant comprising a fiber processing device or a web forming device or both a fiber processign device or a web forming device.   
     
     
         25 - 28 . (canceled) 
     
     
         29 . A monitoring unit in accordance with  claim 24 , wherein the one or more sensor of the detection unit is movable along and/or across the production direction over the nonwoven pre-product. 
     
     
         30 - 31 . (canceled) 
     
     
         32 . A nonwoven pre-production plant comprising
 a fiber processing device;   a web forming device cooperating with the fiber processing device for forming a nonwoven pre-product; and   a monitoring unit comprising:
 a detection unit configured to detect properties of the nonwoven pre-product in a detection zone, wherein the detection unit comprises one or more of an infrared sensor, a radioactive radiation sensor and an X-ray sensor, wherein the detection unit is configured to detect properties of an unprocessed nonwoven pre-product over a width of the nonwoven pre-product across a production direction; and 
 a data processing unit configured to generate actuation commands for a nonwoven pre-production plant comprising a fiber processing device or a web forming device or both a fiber processing device or a web forming device. 
   
     
     
         33 . A nonwoven pre-production plant in accordance with  claim 32  wherein the fiber processing device and/or a web forming device is set by the monitoring unit to regulate, properties of the nonwoven pre-product. 
     
     
         34 . A nonwoven pre-production plant according to  claim 32  in combination with one or more web structure-changing web processing devices to form a nonwoven fabrication plant for producing a nonwoven fabric, wherein the one or more web structure-changing web processing devices comprises a cross lapper or a web bonding device or a cross lapper and a web bonding device, wherein the detection zone of the monitoring unit is located between a web forming device of the nonwoven pre-production plant and a web processing device.