# US 11,306,422 B2 · Method for making a fiber fleece

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- Number: US 11,306,422 B2
- Document ID: US11306422B2
- Status: Granted
- Kind: B2
- Application number: 15/784,636
- Filed: 2017-10-16
- Published: 2018-04-19
- Granted: 2022-04-19
- Earliest claimed: 2016-10-18
- Assignees: Reifenhaeuser GmbH & Co. KG Maschinenfabrik
- Applicants: Reifenhaeuser GmbH & Co. KG Maschinenfabrik
- Inventors: Jens Mager; Andreas Roesner; Christian Stelter; Asmir Vodencarevic; Thomas Fett; Mark Hilgers; Christoph Lettowsky
- Web page: https://patentgrep.com/patent/US11306422B2

## CPC

- D04H 3/02: characterised by the method of forming fleeces or layers, e.g. reorientation of yarns or filaments
- B29C 43/245: {Adjusting calender parameters, e.g. bank quantity}
- B29C 43/58: Measuring, controlling or regulating {(for bank adjustment in calendering B29C43/245)}
- B29C 48/05: Filamentary, e.g. strands
- B29C 48/69: Filters or screens for the moulding material
- B29C 48/92: Measuring, controlling or regulating
- B29C 69/02: of moulding techniques only
- B29D 99/0078: {Producing filamentary materials}
- D01D 4/02: Spinnerettes (alloys therefor C22C)
- D01D 5/088: Cooling filaments, threads or the like, leaving the spinnerettes
- D01D 5/0985: {by means of a flowing gas (e.g. melt-blowing)}
- D01D 5/12: Stretch-spinning methods ({D01D5/098 takes precedence} finishing by stretching D02J1/22)
- D01D 7/00: Collecting the newly-spun products ({D01D5/0076 takes precedence;} collecting newly-spun products with the imparting of twist D01H)
- D01D 11/00: Other features of manufacture
- D04H 3/005: Synthetic yarns or filaments (D04H3/013 takes precedence)
- D04H 3/14: with bonds between thermoplastic yarns or filaments produced by welding
- D04H 3/16: with bonds between thermoplastic filaments produced in association with filament formation, e.g. immediately following extrusion
- B29C 2043/5808: {pressure or compressing force}
- B29C 2043/5833: {movement of moulds or mould parts, e.g. opening or closing, actuating}
- B29C 2043/5875: {the material feed to the moulds or mould parts, e.g. controlling feed flow, velocity, weight, doses}
- B29C 2948/92409: Die; Nozzle zone
- B29C 2948/92428: Calibration, after-treatment, or cooling zone
- B29C 2948/92438: Conveying, transporting or storage of articles
- B29C 2948/92904: Die; Nozzle zone
- B29C 2948/92923: Calibration, after-treatment or cooling zone
- B29C 2948/92933: Conveying, transporting or storage of articles
- B29K 2101/12: Thermoplastic materials
- B29L 2031/726: {Fabrics (nets B29L2028/00)}
- D04H: MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL (weaving D03; knitting D04B; braiding D04C; net-making D04G; sewing D05B; tufting D05C; finishing non-woven fabrics D06); FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING {; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION}(non-woven fabrics having an intermediate or external layer of a different kind, e.g. of woven fabric, B32B)
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- B29D: PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE (making granules B29B9/00; making preforms B29B11/00)
- D01D: MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES

## Abstract

A system for making a nonwoven nonwoven spun-bond or melt-blown fabric has a spinneret for spinning fibers or filaments, a cooler downstream of the spinneret for cooling the spun fibers or filaments, a stretcher downstream of the cooler for stretching the cooled fibers or filaments, and a conveyor downstream of the stretcher. The stretched and cooled fibers or filaments are deposited as a nonwoven web on the conveyor. Sensors measure input parameters at the spinneret, at the cooler, at the stretcher, and/or at at least one diffuser or at the conveyor. An evaluating unit for determining an output parameter from the measured input parameter with respect to a predetermined reference parameter.

## Claims

### Claim 1

A method of making a nonwoven spun-bond or melt-blown fabric, the method comprising the steps of:
extruding thermoplastic filaments from a spinneret in a travel direction;
receiving and cooling the spun filaments downstream in the direction from the spinneret with a cooler;
stretching the cooled filaments downstream in the direction of the cooler with a stretcher;
depositing the stretched and cooled filaments on a conveyor to form thereon a nonwoven web;
determining respective different reference parameters for the spinneret, cooler, stretcher, and/or conveyor representing normal trouble-free operation thereof;
generating respective input parameters different from one another and from the respective different reference parameters with respective sensors at the spinneret, cooler, stretcher, and/or conveyor during operation of the system;
evaluating the input parameters and generating respective different output parameters representing the evaluation;
comparing the output parameters with the respective reference parameters and, when the comparison reveals a deviation of at least one of the output parameters from the respective reference parameter, generating an alarm signal;
feeding a thermoplastic plastic to the spinneret with at least one extruder and feeding molten plastic emerging from the extruder to the spinneret with a melt pump, the reference parameters or output parameters being from the group comprised of: raw material density, bulk density, dosage amount, melt density, feed rate, and melt leakage pertaining to the plastic used, the input parameters being from the group comprised of: melt pressure, extruder temperature, extruder speed, extruder torque, pump speed, and melt temperature; and
feeding the molten plastic through at least one cleaning screen upstream of the spinneret, at least one of the input parameters being from the group comprised of: melt pressure upstream of the cleaning screen, melt pressure downstream of the cleaning screen, and hours of operation of the cleaning screen.

### Claim 2 (depends on 1)

The method defined in claim 1, further comprising the step, when an alarm signal is generated, of:
recording the alarm signal in an independent memory.

### Claim 3 (depends on 1)

The method defined in claim 1, wherein the reference parameters are determined either from input parameters generated during reference operation of the nonwoven fabric-making system or are determined empirically.

### Claim 4 (depends on 1)

The method defined in claim 1, wherein at least one input parameter is predefined as a fixed or constant system parameter and used to determine the output parameter, and that the other input parameters are measured.

### Claim 5 (depends on 1)

The method defined in claim 1, wherein at least one reference parameter is calculated and used as the basis of the comparison with the output parameter, or that at least one input parameter is calculated and a calculated input parameter is used in the determination of the output parameter.

### Claim 6 (depends on 1)

The method defined in claim 1, wherein the evaluation consists in determining a deviation of one of the output parameters from the respective reference parameter and signaling the determined deviation as an anomaly.

### Claim 7 (depends on 6)

The method defined in claim 6, further comprising the steps of:
determining a reference model from the plurality of reference parameters;
determining an initial model from the plurality of input parameters of the reference model; and, in the event of a deviation of the initial model from the reference model,
signaling an anomaly of the initial model.

### Claim 8 (depends on 1)

The method defined in claim 1, further comprising the step of:
determining a majority of the input parameters continuously; and
determining therefrom at least one output parameter with a sampling period of 0.5 s to 10 min.

### Claim 9 (depends on 1)

The method defined in claim 1, further comprising the steps of:
forming with the cooler and stretcher a closed assembly; and
blocking entry of additional air except process air of the cooling chamber into the closed assembly.

### Claim 10

A method of making a nonwoven spun-bond or melt-blown fabric, the method comprising the steps of:
extruding thermoplastic filaments from a spinneret in a travel direction;
receiving and cooling the spun filaments downstream in the direction from the spinneret with a cooler;
stretching the cooled filaments downstream in the direction of the cooler with a stretcher;
depositing the stretched and cooled filaments on a conveyor to form thereon a nonwoven web;
determining respective different reference parameters for the spinneret, cooler, stretcher, and/or conveyor representing normal trouble-free operation thereof;
generating respective input parameters different from one another and from the respective reference parameters with respective sensors at the spinneret, cooler, stretcher, and/or conveyor during operation of the system;
evaluating the input parameters and generating respective different output parameters representing the evaluation;
comparing the output parameters with the respective reference parameters and, when the comparison reveals a deviation of at least one of the output parameters from the respective reference parameter, generating an alarm signal;
compacting the nonwoven web with a calender of a compacter, the reference or output parameters being from the group comprised of: firmness of the nonwoven web in a machine direction, firmness of the nonwoven web transverse to the machine direction, stretchability of the nonwoven web in the machine direction, stretchability of the nonwoven web transverse to the machine direction, and nonwoven web thickness, the input parameters being selected from the group comprised of: process air pressure, process air temperature, process air volumetric flow rate, speed of at least one calender roll, calender temperature of at least one calender roll, calender engraving, speed of the mesh conveyor belt, and melt flow index of the plastic used for the filaments; and
using a mesh conveyor belt as the conveyor, the reference or output parameters being selected from the group comprised of: screen belt wear, particularly screen belt attrition and screen belt clogging, the input parameters being from the group comprised of: process air volumetric flow rate of the process air suctioned through the screen belt, process air speed of the process air suctioned through the screen belt, screen belt speed, process air temperature, and monomer volumetric flow rate.

### Claim 11

A method of making a nonwoven spun-bond fabric, the method comprising the steps of:
extruding thermoplastic filaments from a spinneret in a travel direction;
passing the extruded filaments through a cooling chamber;
introducing process air into the cooling chamber from at least one air-supply compartment with a blower and thereby cooling the filaments in the chamber;
extracting monomers between the spinneret and the cooling chamber;
stretching the cooled filaments downstream in the direction of the cooler with a stretcher;
passing the stretched filaments through a diffusor;
receiving the filaments from the diffuser and depositing them on a conveyor to form thereon a nonwoven web;
determining a single reference parameter s for the spinneret, cooler, stretcher, and/or conveyor representing normal trouble-free operation thereof;
selecting input parameters different from one another and from the reference parameter from the group comprising melt temperature, monomer-flow rate, process-air temperature, blower speed, width of a downstream end of the stretcher, and position of walls of the diffuser;
evaluating the input parameters and generating a single output parameter representing the evaluation, the reference parameters or the output parameter being cooling-chamber pressure;
comparing the output parameter with the reference parameter and, when the comparison reveals a deviation of the output parameter from the reference parameter, generating an alarm signal.