CN111356799A

CN111356799A - Monitoring technology for non-woven fabric production equipment

Info

Publication number: CN111356799A
Application number: CN201880073758.4A
Authority: CN
Inventors: E·哈伯雷; A·迈耶
Original assignee: Autefa Solutions Germany GmbH
Current assignee: Autefa Solutions Germany GmbH
Priority date: 2017-11-14
Filing date: 2018-11-14
Publication date: 2020-06-30
Anticipated expiration: 2038-11-14
Also published as: WO2019096818A1; WO2019096823A1; CN111356799B; EP3710623A1; DE102017126753A1; CN111344446A; US20200299870A1; US20200362479A1; EP3710624A1

Abstract

The disclosure relates to a monitoring technique for a production process of a nonwoven fabric product, wherein properties of a nonwoven fabric semi-finished product (3), in particular the moisture, the charge, the weight distribution, the fiber orientation, the fiber mixing ratio and/or the fiber opening of a not yet treated fiber yarn layer, are detected by means of a detection device (41) having one or more sensors (410).

Description

Monitoring technology for non-woven fabric production equipment

Technical Field

The invention relates to a monitoring technology for non-woven fabric production equipment.

Background

Nonwovens made of different types of fibers and fiber mixtures are used in a wide range of fields (for example, sanitary articles, automobile cladding, packaging or building materials).

Synthetic fibers are preferably used as raw material. Nowadays, also regenerated fibers, for example fibers made of plastics or carbon materials, are processed to form nonwovens.

The production of nonwovens, i.e. finished nonwoven products, is usually carried out in a plurality of steps. First, the fibers are released from the pressed bale and prepared in most cases in a fiber preparation device. If necessary, different types of fibers are mixed into a fiber mixture. The fibers produced form a loose fiber yarn layer (Faserflor), a so-called semi-finished nonwoven. For this purpose, a yarn layer forming device, in particular a mechanical or pneumatic teaseler or carding machine, is used. The semi-finished nonwoven does not yet have the structure, in particular the thickness or strength, required for the finished nonwoven. The semi-finished nonwoven is processed in further steps in order to produce the finished nonwoven. During further processing, for example in a nonwoven fleece layer or a needle loom, the structure of the previously formed fiber yarn layer is changed. Depending on the application, the semi-finished nonwoven is processed into a finished nonwoven according to a different number of processing steps and processing techniques.

In the nonwoven production plants known in practice, measurements need to be carried out on the finished nonwoven at the end of the production plant or after the strengthening machine.

Disclosure of Invention

The invention aims to provide a better monitoring technology for non-woven fabric production equipment. The invention solves this technical problem with the features of the independent claims.

The present disclosure includes a monitoring technique that includes a monitoring method and suitable apparatus. The disclosure includes, inter alia, a non-woven fabric pre-production apparatus and a monitoring device.

The combinations of known processing steps and processing machines are very diverse. The disclosed monitoring techniques are particularly applicable to different device configurations. Depending on the application, specific requirements are placed on the quality of the nonwoven products produced. These requirements may relate to the thickness, composition, structure, feel, color or load bearing capacity of the nonwoven product.

In the multi-stage manufacturing process of nonwoven products, there are many adjustment options and process parameters that can affect the quality of the finished product. It is particularly advantageous to carry out the machine regulation automatically, in particular in an early production step. At the start of a production run (commissioning time), adjustments can be made once and/or continuously during production.

The nonwoven fabric pre-production apparatus may be part of a larger nonwoven fabric production apparatus. The non-woven fabric pre-production equipment processes the fibers into a non-woven fabric semi-finished product. This represents the first process stage in larger nonwoven production plants. The nonwoven-fabric preproduction plant may in particular comprise one or more fiber-preparation devices and one or more yarn-layer-forming devices, for example a picker. The whole non-woven fabric production equipment processes the fibers into finished non-woven fabrics. The semi-finished non-woven fabric is an intermediate product in the whole non-woven fabric production process.

The monitoring device can be part of a nonwoven preproduction plant. In a subsequent further processing machine, the semifinished nonwoven is further processed to form a nonwoven.

A first important aspect of the invention relates to the acquisition of the properties of the raw nonwoven semifinished product.

The raw fiber yarn layer, i.e. the nonwoven semifinished product, is produced in a nonwoven preproduction plant. This first process stage is also referred to as yarn layer formation or "web formation". The production of the semifinished nonwoven fabric, i.e. the raw yarn layer, can likewise be carried out in a plurality of steps. The semifinished nonwoven product can be produced continuously, for example in a plurality of teasel raising machines, in order to achieve the desired thickness of the yarn layer for further processing.

The raw yarn layer of the nonwoven semifinished product also has a low cohesion between the fibers (Zusammenhalt). The nonwoven semifinished product is not processed, in particular after the formation of the yarn layer (for example from the outlet of a piercing machine). The fiber yarn layer (nonwoven semi-finished product) formed in the yarn layer forming device is unchanged in the acquisition region. The structural modification of the nonwoven semifinished product (for example by bundling, stiffening or laying) takes place only after the acquisition zone.

The structure of the semifinished nonwoven products is usually changed after the nonwoven preproduction plant in a reprocessing plant. The reworking includes, for example, the strengthening of the yarn layer, also referred to as "bonding". Various mechanical, thermal and chemical strengthening techniques are known in practice. For example, the yarn layer is calendered, needled or strengthened by means of water jets during the reprocessing. The structure of the scrim layer will be altered (e.g., strengthened) to achieve the desired product performance of the nonwoven product.

One aspect of the invention is to automatically collect the characteristics of the semi-finished nonwoven fabric in order to monitor the production process. The properties of the collected nonwoven semifinished product can include, for example, the weight per unit area of the fibers, the moisture content, the fiber orientation, the openness of the fibers, the fiber mix ratio, the temperature, the density and/or the electrical or electrostatic charge of the fiber yarn layer (elektrische oderlektrostustsch Ladung). Not only a plurality of property selections, but also certain property selections may be collected by measurement.

The characteristics of the collected non-woven fabric semi-finished product have a plurality of different advantages. The properties of the nonwoven semifinished product can decisively influence the processing in the reprocessing device of the nonwoven production plant. For example, the opening of the fibers in the nonwoven semifinished product can influence the subsequent strengthening. The fiber orientation in the nonwoven semifinished product influences the mechanical load-bearing capacity of the nonwoven product. It is therefore advantageous to collect the properties of the nonwoven semifinished product. The collection of the characteristics of the semi-finished non-woven fabric is particularly beneficial to the optimization of the quality of the finished non-woven fabric. The collection of the characteristics of the non-woven fabric semi-finished product is also beneficial to the optimization of a reprocessing device of non-woven fabric production equipment.

Furthermore, it is advantageous to collect the properties of the nonwoven semifinished product before further processing of the nonwoven semifinished product. Certain characteristics are more difficult to measure after further processing. In particular, certain measuring methods, for example measurements using infrared radiation or radioactive radiation, can be used particularly well on the tissue yarn layer of the nonwoven semifinished product. For example, transmission can be better measured on a thin fiber yarn layer than on a reprocessed nonwoven. It is particularly advantageous to use infrared radiation and/or radioactive radiation for the measurement on the nonwoven semifinished product.

Another important aspect of the present disclosure is the collection of the characteristics of the non-woven semi-finished product over its width. The semifinished nonwoven product is conveyed in the direction of production as a web-shaped fiber yarn layer. The spatial or planar distribution along and/or transverse to the production direction is of particular interest for the product quality. Properties such as weight per unit area, fiber opening or fiber orientation may have local differences. Local errors, material build-up, clumping, or similar effects are collectable in the spatial or planar distribution of properties.

Preferably, these properties are taken over the entire width of the nonwoven semifinished product. Width in the sense of the present disclosure means the spread of the fiber flow or the nonwoven semifinished product (i.e. the yarn layer web) transversely to the production direction (i.e. the conveying direction). The collecting region preferably extends over the entire working width of the yarn layer forming device (for example a stabbing fleece machine).

The acquisition can be performed by means of stationary or movable sensors. The collection is preferably carried out with constant precision over the entire width of the nonwoven semifinished product. Preferably a (near) continuous distribution of the properties is acquired. From this, the cross-sectional profile and/or the longitudinal distribution of the properties can be determined.

In particular, continuous measurements can be carried out at a plurality of local acquisition positions. The local acquisition positions may be offset from each other in the longitudinal and/or transverse direction. These local acquisition positions preferably overlap. The continuous characteristic profile can be generated in particular from a combination of overlapping acquisition positions of constant measurement accuracy. Preferably, location information and/or time information is acquired for each acquired characteristic.

Preferably, a two-dimensional distribution of the properties is acquired. Preferably, the weight is taken as a weight distribution per unit area. The spatial distribution of the properties preferably relates to the face of the veil layer web. Spatial distribution preferably refers to a distribution of planes parallel to the properties of the yarn layer web. For economical measurement techniques, it is particularly advantageous not to detect the third dimension of the property profile, in particular perpendicular to the yarn layer web. The measurement accuracy in the distribution perpendicular to the face of the veil web may lead to strong distortions or noise in the acquisition results.

The properties of the nonwoven semifinished products are already important for producing high-quality nonwovens. If the properties of the fiber yarn layer formed deviate from the desired properties, production problems can result in the reprocessing of the semifinished nonwoven fabric products or a loss of quality of the finished product. For example, moisture in the semifinished nonwoven product may influence the reprocessing in certain machines. It is therefore advantageous to acquire the properties of the fiber yarn layer before the first reprocessing, in particular when the yarn layer structure is changed accordingly. The structural change occurs in particular when the yarn layer is reinforced.

The properties of the semifinished nonwoven are adjusted or controlled by means of an automated servo intervention (stellengiff) and the higher quality requirements can be met.

In practice, the checking of the properties of the nonwoven product is only carried out at the end of the production process, if at all. The adjustments for optimizing the quality of the nonwoven products are usually made manually by the operator of the machine and depend to a large extent on the experience and qualification of the individual. Furthermore, the adjustment is usually only carried out at the start of a production run. By means of automated monitoring, the quality of the product can be ensured independently of the operating personnel.

Another advantage of the collection of the characteristics of the semifinished nonwoven is that the collection results are used for the automated adjustment of the nonwoven preproduction plant. The collected characteristics can be used for one-time adjustment during the start of a retrofit or production. Furthermore, these properties can be adjusted by adjusting the nonwoven preproduction apparatus as a function of the acquisition results during the production run. It is particularly advantageous to adjust the fiber production device and/or the yarn layer forming device on the basis of the properties of the collected nonwoven semifinished product. For this purpose, it is particularly advantageous to carry out the property detection in the vicinity of the outlet of the nonwoven semifinished product from the yarn layer forming device.

The earlier the properties of the nonwoven semifinished product are acquired in the production process, the shorter the down time (totzient) can be achieved when adjusting or controlling the machine. The short downtime improves the quality of the conditioning. By finding the characteristic deviation early, the waste can be reduced. By detecting the properties of the raw nonwoven semifinished product, in particular, tighter quality tolerances can be achieved for the nonwoven product produced.

For the acquisition of the properties of the nonwoven semifinished product, contactless measuring techniques, such as infrared, X-ray or radioactive radiation and optical measuring methods, can be used. One or more sensors or radiation sources may be arranged above and/or below the layer of fibre yarns. The sensor may be arranged stationary or movably. A combination of stationary and movable sensors is also possible. In particular, the sensor can be moved transversely to the production direction over the width of the nonwoven semifinished product. This is particularly advantageous for the spatial or areal distribution of the acquisition characteristics. It is also possible to use a sensor beam that extends along the width of the non-woven fabric blank.

The measurement is carried out in an acquisition region, which is particularly advantageous when the acquisition region is arranged inside the production device. Local and/or global measurements can be carried out on the nonwoven semifinished product. In particular, sensors for detecting moisture, for example, can make local measurements. Furthermore, the sensor can also perform measurements on a specific side of the nonwoven semifinished product.

The collecting region for collecting the properties of the nonwoven semifinished product is preferably located directly at or in the vicinity of the outlet of the nonwoven semifinished product from the ply forming device. This arrangement is advantageous because the acquisition characteristics can then be carried out at intervals which are as short as possible with respect to the layer formation process. In particular for adjusting the fiber preparation process or the yarn layer forming process on the basis of the collected properties, shorter downtime can be achieved by arranging the collection area close to the yarn layer forming device. In the case of conditioning, the conditioning quality can be improved by shortening the running time of the yarn layer between the yarn layer formation process and the property measurement. Material waste can also be reduced.

Furthermore, the properties of the fiber yarn layer are preferably measured before the fiber yarn layer is processed in a subsequent process step and the structure of the yarn layer is thus changed. Particularly preferably, the collecting region is arranged in the production direction upstream of the reprocessing device, preferably upstream of the first nonwoven fleece layer or the first stiffening device. Certain properties of the nonwoven semifinished product, such as the fibre orientation or the fibre opening, can be better collected in the raw fibre yarn layer. The properties of the nonwoven semifinished product to be collected may also change during the further processing. By such an advantageous arrangement of the collecting areas, characteristic deviations can easily be mapped to possible causes in the fiber production process or in the yarn layer formation process.

The monitoring method is used for monitoring the production process and the product quality. Depending on the application, high quality requirements can be placed on the nonwoven. In the framework of quality assurance, nonwoven manufacturers are interested in monitoring the production process. It is particularly advantageous to store or document the properties of the collected nonwoven semifinished product. The cause of the quality deviation of the nonwoven fabric can be determined better.

Particularly preferred is an embodiment of a monitoring method for the automated control of a nonwoven preproduction installation.

The monitoring device can be part of a nonwoven preproduction plant, which is designed in particular for carrying out the monitoring method. It is particularly advantageous to arrange the monitoring device in a production plant with a central plant controller. The monitoring device can have a servo mechanism specifically designed for setting and/or adjusting the nonwoven preproduction apparatus. The servomechanism may have an actuator with which the fiber preparation device or the veil layer forming device may be physically adjusted.

Another important aspect of the present disclosure is the monitoring of the moisture and/or charge of the fiber or nonwoven semi-finished product. This aspect of the disclosure has independent inventive significance.

According to the disclosed monitoring technique, changing environmental conditions or fluctuating fiber characteristics do not negatively impact product quality. Mass deviations can be prevented or reduced. Waste can be reduced by this monitoring technique.

Friction may cause materials or components to become electrostatically charged. In the field of the nonwoven fabric industry, it may be undesirable for fibers to scatter or for fibers to adhere to components due to an electrostatic field.

The charged fibres can easily adhere to machine parts, such as conveyor belts, and disturb the production process. Especially for materials that are not or only weakly conductive (e.g. plastics), the fibre material may be electrostatically charged.

By monitoring the charge, an electrical breakdown that accompanies the formation of a spark can be prevented.

The generation of the electrostatic field is closely related to the moisture content of the fibrous material and the ambient air. Above a certain humidity, the charge of the fibre material can be reduced or even prevented. Both the humidity of the fibre itself and the humidity of the ambient air have a significant influence on the quality of the production process.

In addition to the electrostatic effect, humidity can have a negative effect on machine parts. For example, if the humidity is too high, corrosion may occur on the machine components. Too high a fibre moisture can lead to undesirable properties (for example caking) in the nonwoven semifinished product or the finished nonwoven product. Whereas too low a humidity tends to cause electrostatic fields.

It is therefore advantageous to monitor the moisture and/or the charge of the fiber and/or nonwoven semifinished product with regard to the quality of the product and the durability of the apparatus. The humidity will advantageously be kept within an optimum range. Preferably, the relevant air humidity is taken into account depending on the ambient temperature.

The climatic environmental conditions of the equipment may vary greatly depending on the place of use and the season. Seasonal, climatic and weather-related differences in environmental conditions at a production site can be mitigated by monitoring techniques. The air humidity and the ambient temperature can be adjusted independently of the external ambient conditions. Undesired scattering of fibers or adhesion of fibers can be prevented over the entire field.

In particular in the case of fiber mixtures from different fiber types and sources, the properties of the fiber flows can be monitored separately. As a raw material, the fibers are usually supplied in the form of pressed bales. Depending on the storage and transport conditions, the fibers introduced into the apparatus may have different characteristics (e.g. moisture). The automatic monitoring of the properties of the fiber or nonwoven semifinished product can compensate for external influencing factors.

The humidity and/or the charge of the fiber or non-woven fabric semi-finished product are collected by a collecting device. The acquisition device may include one or more sensors. Preferably an infrared sensor is used. The collecting device is arranged in the nonwoven production plant as follows: i.e. the properties are acquired in a suitable acquisition area.

In order to achieve automated monitoring, the acquisition results are processed in an electronic data processing device. The acquisition results represent an important data source. In the sense of digital production (industrial 4.0), the acquisition results can be analyzed for different purposes. For example, the data may be used to regulate or control the device. Alternatively or additionally, the acquisition results may be used for process documentation and quality assurance. The data may be processed in real time and/or stored permanently.

Depending on the humidity or charge collected, suitable servo interventions can be automatically carried out on the device. Generating servo instructions for a servo of a device, machine or component. The servo command is an electronic signal. The servo commands can be exchanged between data processing units (e.g. acquisition devices and device controllers), in particular via a bus system.

Preferably, the environmental conditions in a specific climate-controlled region of the nonwoven-fabric production plant can be regulated by means of an air-conditioning plant. Preferably, the air conditioning apparatus is designed to heat or cool ambient air. Furthermore, the air may also be humidified and/or dried. Preferably, the moisture can be applied directly (e.g. by spraying, painting or wetting) on the fibrous material. Alternatively or additionally, moisture may be added or removed indirectly via ambient air. Preferably, the air conditioning apparatus may dry the fibers or the air.

It is particularly preferred to combine direct humidification with indirect air conditioning. For example, the liquid may be sprayed onto the fibres by a wetting device. The fibers can have their static charge reduced by increasing the moisture content. Additionally, the humidity in the (e.g. corrosion-prone) air-conditioning area may be maintained at an optimal level by dry ambient air. In particular in process sections in which undesired scattering of fibers may occur, it may be advantageous to moisten the fibers in a targeted manner.

Preferably, the air conditioning zone of the nonwoven production plant is locally defined. A separate air conditioning zone can increase the energy efficiency of the plant, in particular compared to the air conditioning of the entire plant.

The servo instructions preferably comprise an executed value for the liquid quantity, the temperature indicator or the humidity indicator. Alternatively or additionally, the servo instructions may comprise execution values for the mechanical servo (e.g. rotational speed of the drive, angle of the guiding mechanism, position of the adjustment area, motion index).

The components of the device have suitable interfaces for receiving and/or sending servo commands.

Preferably, multiple pickups or servos may be used for separate fiber streams (fiber sources). Differences between the characteristics of the different fiber streams may be identified and compensated for.

The acquisition regions can be arranged at different locations in the nonwoven production plant. Preferably, the collecting region is arranged at the outlet of a veil-forming device (e.g. a bur fleece machine, an airlaid (Airlay), a nonwoven fleece-forming device (spinnvlies einrichtung)) or a fiber-producing device (e.g. a bale breaker, a fiber opener, a metering device, a fiber mixing device). A plurality of acquisition regions, in particular with a plurality of acquisition devices, can be provided along the production process. For example, the collecting area may be arranged in the bale breaker, after the fiber mixing device and/or at the outlet of the flake feeder.

In a first embodiment, monitoring techniques may be used for quality assurance purposes. The collected characteristics of the semi-finished nonwoven are processed in a data processing device. The acquisition results may include raw measurement data or pre-processed characteristic data. Data preparation algorithms can be used in processing the acquisition results, by which measurement data with temporal and spatial information is enriched. Furthermore, a temporal or spatial dependent pattern in the course of the acquisition results can be determined. The acquisition results can be stored both in a memory, in particular in a suitable database for quality assurance purposes, and also displayed on a suitable display means, for example a central device terminal. This treatment is advantageous because undesirable properties can already be identified in the nonwoven semifinished product at an early stage of the production process.

Preferably, the transverse and/or longitudinal profile of the property is generated from the acquisition. The longitudinal profile may in particular comprise a temporal and/or positional course of the property along the production direction. The transverse profile comprises a course of properties with respect to the width of the nonwoven semifinished product and/or the fibre flow. Preferably, location information and/or time information is stored for the collected characteristics. For example, the measured position of a running meter (e.g., a meter running since the beginning of production) relative to a reference position may be stored. Production time (e.g., date and time) may also be associated with the collected characteristics. Correlating the acquired characteristics with the acquisition position is particularly advantageous for precise control or adjustment of the characteristics.

In a further embodiment, the monitoring technique can be used for the adjustment of the nonwoven-fabric pre-production system, in particular for adjustment purposes. The collected characteristics may be compared to target characteristics to determine characteristic deviations. By means of suitable decision rules, servo commands for adjusting the nonwoven preproduction installation are generated. In the generation of the servo commands, both the captured characteristics and the target characteristics as well as the determined characteristic deviations and/or other process parameters can be taken into account.

In particular for generating servo commands for adjusting the fiber preparation device and/or the yarn layer forming device. In particular, the properties of the nonwoven semifinished product can be adjusted by adjusting the nonwoven preproduction apparatus. More information, for example from other sensors of the device, may also be taken into account during the adjustment process. For example, the fibre opening may be measured and adjusted by adjustment of one or more opening devices. Suitable servo instructions are generated and transmitted either to the machine controller, directly to the fiber preparation device or the yarn layer forming device, or to a suitable servo.

In accordance with the servo instructions, the actuators of the nonwoven fabric pre-production apparatus can alter the fiber preparation process or the yarn layer formation process to cause the acquired properties to vary in a desired direction. For example, servo instructions for a servo mechanism may be transmitted to a feedwell of a flake feeder. The width of the feedwell is adjusted by means of an actuator, e.g. an electric motor, according to the servo instructions.

In order to adjust the properties of the nonwoven semifinished product by adjusting the nonwoven preproduction installation, a suitable adjustment algorithm is used. Either a simple linear regulator or a complex non-linear regulator may be used to generate the servo commands. In particular, a trained artificial neural network or fuzzy regulator may be used to process the acquisition results and generate appropriate servo instructions.

Drawings

The invention is illustrated and schematically shown in the drawings. Wherein:

fig. 1 shows a schematic representation of a nonwoven fabric preproduction plant (10) with a monitoring device (40), a central plant controller (11) and an air conditioning plant (12);

FIG. 2 shows a schematic representation of a nonwoven preproduction plant (10) with a feeder (31), a fleece machine (32) and a servo (50);

FIG. 3 shows a schematic representation of a nonwoven production plant (15) with a nonwoven preproduction plant (10) and a nonwoven laying machine (91) and a nonwoven stiffening device (92);

fig. 4 shows a schematic top view of the nonwoven semifinished product (3) between the yarn layer forming device (30) and the further processing device (90);

fig. 5 shows a schematic representation of a nonwoven preproduction plant (10) with an air-conditioned fleece former (30) and a plurality of moistening devices (24).

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

The nonwoven production plant (15) can be configured with a different number of machines depending on the nonwoven to be produced. The nonwoven production plant (15) comprises a nonwoven preproduction plant (10) for producing a nonwoven semifinished product (3) and one or more further processing devices (90) for processing the nonwoven semifinished product (3) into a finished nonwoven (7). Different transport mechanisms can be used to transport the fiber or fiber yarn layers between the various machines.

Fig. 1 shows a nonwoven production plant (15) with a nonwoven preproduction plant (10) and a reprocessing device (90). The non-woven fabric pre-production device (10) comprises a fiber preparation device (20), a yarn layer forming device (30) and a monitoring device (40). Preferably, the nonwoven-fabric production plant (15) also has a plant controller (11).

In a nonwoven fabric preproduction plant (10), fibers (1) are prepared in one or more fiber preparation devices (20). The prepared fibers (2) are subsequently formed into a nonwoven semifinished product (3) in one or more yarn layer forming devices (30). The non-woven fabric semi-finished product (3) is composed of a fiber yarn layer which is not processed yet.

The monitoring device (40) has a detection device (41) having one or more sensors (410) for detecting properties of the nonwoven semi-finished product (3). The properties of the nonwoven semifinished product (3), in particular its moisture content, charge, weight distribution, fiber orientation, fiber mix ratio and/or fiber opening, are detected in a detection region (5).

It is particularly advantageous to arrange the collecting region (5) in the vicinity of the outlet of the nonwoven semifinished product (3) from the yarn-layer forming device (30). The collecting device (41) and/or the collecting area (5) can be located inside or outside the yarn layer forming device (30).

One or more further processing devices (90) are connected downstream of the collection area (5) in the production direction (4). The further processing device (90) is used to further process the nonwoven semifinished product (3) into a finished nonwoven (7) in one or more processing steps. The structure of the fiber yarn layer is changed during the reprocessing. In particular, several yarn layers can be laid one above the other in a nonwoven fleece layer laying machine (91) in order to increase the thickness of the yarn layers. During the reprocessing, in particular the fibre orientation can be changed. Other properties can also be changed by reprocessing after the acquisition region (5).

Preferably, the air conditioning is carried out in several sections of the nonwoven-fabric preproduction plant (10). In particular in regions with humid climates, this embodiment is advantageous for influencing the moisture and/or temperature of the semifinished fibre or nonwoven product (3). The nonwoven-fabric production plant (15) can have one or more air-conditioning plants (12). Preferably, the treatment zones inside the fiber preparation device (20) and/or the nonwoven forming device (30) are air-conditioned. Alternatively, the entire production plant can be air-conditioned by means of an air conditioning system (12). In this preferred embodiment, the air conditioning system (12) can be adjusted using the system controller (11). Alternatively, the air conditioning system (12) can also receive the servo commands (45) directly from the monitoring device (40).

The collecting device (41) measures the nonwoven semifinished product in the collecting region (5). One or more sensors (410) can be moved over the nonwoven semi-finished product (3). The movement of the sensor (410) can be carried out along or transversely to the transport direction of the nonwoven semifinished product (3). The movement of the sensor (410) can be controlled as a function of the speed of conveyance of the nonwoven semifinished product (3) in the collecting region (5). This is particularly advantageous for the acquisition result to be easily adapted to the relevant part of the running semi-finished nonwoven (3). The individual or all sensors (410) can also be arranged in a stationary manner. The stationary arrangement is particularly advantageous for locally measuring the moisture content of, for example, a nonwoven semifinished product (3). The sensors (410) can be arranged above and below the semi-finished nonwoven. In an alternative embodiment, the collecting region (5) can also be located inside the thread layer forming device (30), in particular the fleece machine.

The measurements made using the sensor (410) are contactless. Preferably an infrared sensor is used. Other contactless measuring methods with a camera or other active radiation sources, for example for X-rays, are also possible. For this purpose, the collecting device (40) is designed to arrange a suitable sensor (410) on the semi-finished nonwoven fabric product (3) in such a way that the properties of the semi-finished nonwoven fabric product can be reliably collected.

The monitoring device (40) also has a data processing unit (42). The data processing unit (42) may include a digital memory having a data processing program and a processor. The data processing unit (42) is designed for processing the acquisition results of the acquisition unit (41), in particular for performing the processing steps of the claimed monitoring method. The data processing unit (42) can also be designed as an embedded system of the acquisition device (410) or as part of the device controller (11). A monitoring device (40) having a data processing unit (42) is designed to carry out the claimed monitoring method.

The monitoring device (40) is designed in particular to generate servo commands (45) for adjusting the nonwoven fabric preproduction installation (10). Preferably, the monitoring device (40) adjusts the properties of the nonwoven semi-finished product (3). The servo commands (45) may be generated according to an adjustment algorithm. The servo command (45) preferably contains an execution variable for closing the control loop. The controller is preferably implemented in a monitoring unit (40), in particular in a data processing unit (42). The production process within the nonwoven fabric pre-production device (10) is adapted according to suitable servo instructions (45) in such a way that the properties of the nonwoven fabric semi-finished product (3) are changed in a desired manner. In another embodiment, the servo command (45) can also be used for an open control loop or for a pilot control (Vorsteuerung).

In this preferred embodiment, the servo command (45) is sent to the device controller (11). The system controller (11) can be used to control and monitor the entire nonwoven production system (15) as a whole. The controller is designed in particular to process servo commands (45) for monitoring, in particular for adjusting, properties of the nonwoven semi-finished product (3). The device controller (11) may particularly comprise a drive stage (Treiberstufen) to convert a signal current of the servo command (45) into a power current. Alternatively, the drive stage can also be arranged on another part of the nonwoven fabric preproduction apparatus (10), in particular on the fiber production device (20) or the yarn layer forming device (30). The central device controller (11) can communicate with the individual parts of the nonwoven fabric preproduction device (10), in particular with the monitoring device (40), in particular via a bus network.

In order to generate suitable servo commands (45), the monitoring device (40) can additionally process information of the nonwoven production installation (10) in addition to the detection results of the detection device (41). In particular, target properties of the nonwoven semifinished product (3) can be obtained or input by the user. The monitoring device (40) is designed to determine a deviation between the acquired characteristic of the nonwoven semi-finished product (3) and a target characteristic. The target characteristic may exist in the form of a fixed or variable value or range of values. For example, a target moisture of the nonwoven semifinished product can be predefined, which has a value range between a minimum moisture and a maximum moisture. The collected characteristics and the target characteristics may exist as determined values and/or as statistical values. The properties of the nonwoven semifinished product (3) can also be present as a spatial and/or temporal distribution.

The adjustment of the properties of the nonwoven semifinished product (3) to predetermined target properties is particularly advantageous for achieving a high-quality finished nonwoven (7). A high-quality nonwoven semifinished product (3) is advantageous for further processing. Certain properties of the yarn layer, in particular the fibre opening or fibre orientation, are determined at an early stage of the production process, in particular by the fibre preparation device (20) and the yarn layer forming device (30). The earlier acquisition of these properties along the production direction (4) can improve the adjustment possibilities. Furthermore, it is also possible to better acquire certain properties before the first reworking of the changing yarn layer structure. In particular, the measurement method for measuring radiation passing through a yarn layer may provide better information regarding the properties of a thin and unreinforced yarn layer. It is therefore advantageous to arrange the collecting region (5) in the production direction (4) upstream of the first nonwoven fleece layer (91) and/or the needling machine. Furthermore, a short running time of the yarn layer between the yarn layer formation and the collection area (5) also leads to better regulation dynamics.

The economy of the system can also be improved by automatically adjusting the nonwoven preproduction plant (10) as a function of the detection result of the monitoring device (40). The commissioning time can be shortened and the number of rejects reduced.

Fig. 2 shows a further embodiment of a nonwoven preproducer (10). The monitoring device (40) generates and transmits servo commands (45) directly to the fiber production device (20) and/or the yarn layer forming device (30). Preferably, the yarn layer forming device (30) comprises a raising machine (32) and a feeder (31). The feeder (31) supplies the prepared fibres (2) to a fleece forming machine (32). In the feeder (31), a continuous fiber flow is formed, in particular from the prepared fibers (2), which is processed in a fleece machine to form a yarn layer. The feeder (31) has a guide and transport mechanism for the fibers, by means of which the fiber flow can be influenced. For example, the cross-section of the feedwell in the feeder (31) may be varied. The servo mechanism (50) adjusts the fiber guide mechanism in accordance with the servo command (45).

The servo mechanism (50) may comprise a drive stage and an actuator, in particular an electric motor. The servo mechanism (50) is preferably arranged on the fiber preparation device (20) or on the yarn layer forming device (30). The servo (50) may have a uniform interface for receiving servo commands (45). The interface may be compatible with and may communicate via a bus system of the veil layer forming apparatus (10). The servomechanism (50) can also have a dedicated machine interface, instead of its own actuator, by means of which the actuator of the nonwoven-fabric pre-production device can be actuated. The servomechanism (50) may serve as a unified interface for servo commands (45) for different actuators. This is particularly advantageous in the case of nonwoven preproduction plants consisting of machines from different manufacturers.

The monitoring technology can be provided as an add-on component of existing nonwoven production equipment. In this case, the use of a uniform interface on the servomechanism (50) for transmitting the servo commands (45) is particularly advantageous, since the servomechanism only needs to be adapted to the existing machine.

Fig. 3 shows a nonwoven fabric preproduction plant (10) with a special fiber preparation device (20). In the device, different fiber types (1) are processed into yarn layers. The fiber preparation device (20) comprises a fiber mixing device (22) in which different fiber types (1) are mixed.

The fiber mixing device (22) is preferably designed to be adjustable by means of servo commands (45). This is particularly advantageous and makes it possible to vary or adjust the fibre mixing ratio of the collected semifinished nonwoven fabric product (3).

The fibre (1) is usually supplied to the apparatus in the form of pressed bales. The embodiment shown has a bale breaker (21), in which the fibers are released from the bale. The fiber mass is opened in one or more steps. The fiber production device (20) can have one or more bale crushers (21) and/or fiber opening devices (23). The fibers (1) are produced by the fiber production device (20) in such a way that they can form a yarn layer in a yarn layer forming device (30), in particular in a mechanical or pneumatic napper (32). The yarn layer forming device (30) may also comprise (additional) opening devices, in particular fine opening machines for a multi-stage opening process.

Both the bale breaker (21) and the opening device (23) are adjustable. The fiber preparation process can be adjusted according to the servo instructions (45). This is particularly advantageous for adjusting the fiber opening of the collected nonwoven semifinished product (3).

The fiber preparation device (20) may also include a moistening device (24) (also referred to as a "wet out station

"). The fibers may be treated with various chemical agents in a wetting station, particularly by wetting or spreading with a liquid. For example, an antistatic agent may be sprayed onto the fibers there to prevent or reduce their static charge. Other chemical treatments are also possible. The humidifying device is also adjustable. In particular, the moisture content of the fibers can be influenced by adjusting the humidifying device.

Fig. 4 shows a plan view of the nonwoven semifinished product (3) between the yarn layer forming device (30) and the further processing device (90). The properties of the nonwoven semifinished product (3) in the acquisition zone (5) are acquired by means of a monitoring device (40). This figure shows a preferred embodiment of an acquisition device (41) with a movable sensor (410). An embodiment with a sensor beam (411) extending over the width of the nonwoven semi-finished product is also shown.

The semifinished nonwoven fabric product (3) is continuously conveyed in the production direction (4). Due to the transport movement of the veil-layer web (3) and the movement of the sensor (410), the collecting area (5) also moves on the veil-layer web (3). A trajectory (5) of the positions at which the properties of the nonwoven semi-finished product are acquired is thus obtained. Over time, the measurement is made in a zigzag or wave shape, in particular over the entire width of the veil layer web (3).

According to the detected properties, a profile (6) of the properties can be determined, in particular along the width of the nonwoven semifinished product (3) transverse to the production direction (4). The profile describes the distribution of the properties of the nonwoven semifinished product.

The characteristics acquired at the acquisition location (5i) are preferably provided with location information and/or time information.

By detecting the properties and/or the spatial or planar distribution of the properties, an automatic adjustment can be carried out on an actuator (50) of a thread layer forming device (30), for example a fleece or a feed well, or of a fiber production device (20).

Preferably, the adjustment is carried out on actuators (50) which are designed to locally influence the properties of the nonwoven semifinished product (3). In the embodiment shown, the feeder well of the feeder (31) is adjusted. The feeder well preferably has an actuator which is designed to regulate the fiber flow over the entire width and/or at various points along the width of the nonwoven semifinished product. By adjusting the feed well, the weight per unit area of the nonwoven semifinished product can be controlled or adjusted locally and/or planarly and/or globally.

Alternatively or additionally, other actuators (50) on the fiber production plant (20) or on the yarn layer forming device (30), such as, for example, bale breakers, card clothing of the fleece machine (32), metering devices or fiber openers, can be automatically adjusted.

Preferably, the collecting area (5) is arranged next to the first fleece machine (32). In another embodiment, the collecting region (5) is arranged in the production direction (4) downstream of the second, third or further fleece machine (32) or further yarn layer forming device (30). In some applications, the nonwoven semi-finished product (3) can be laid between a plurality of yarn layer forming steps (for example, nappers). In this embodiment, the nonwoven semifinished product (3) in the collecting region (5) is a laid and unreinforced fiber yarn layer. The further processing of the modified structure may relate to one or more properties of the semifinished nonwoven.

Preferably, the collecting area (5) is arranged after the last fleece machine (32) in the production direction (4). Preferably, the acquisition zone (4) is arranged before the first reinforcement means. During the strengthening, the cohesion between the fibers of the semi-finished nonwoven is increased.

The nonwoven semifinished product may consist of a single or multiple fibre yarn layers. The fiber yarns may in particular be placed in a stack during the formation of the yarn layer. Whereby the thickness of the fibre yarn layer can be increased.

Fig. 5 shows a schematic view of a nonwoven preproduction apparatus (10) with various embodiments of monitoring techniques, particularly for moisture and/or charge.

Fig. 5 shows a schematic representation of a nonwoven preproduction plant (10) with different embodiments of monitoring technology, in particular for moisture and/or charge.

The figure shows a possible embodiment of a climate controlled zone (13). A yarn layer forming device (30), such as a napper (32), includes an air conditioning apparatus (12). The air conditioning system (12) is designed to regulate environmental conditions, in particular absolute or relative air humidity and/or temperature, in a climate-controlled region (13). In this advantageous embodiment, the climate control region is integrated in the fleece forming machine (32). The housing of the fleece machine is substantially climate-isolated from the surroundings.

The nonwoven-fabric production plant can comprise one or more climate control zones (13) or air-conditioning units (12). Climate zones (13) may also be built around the machine (e.g. for retrofitting).

The nonwoven fabric pre-production installation (10) can comprise one or more moistening devices (24). The wetting apparatus (also referred to as a "wet station") is configured for applying a liquid or grease to the fibers. The humidifying device (24) may comprise, in particular, a nozzle or other humidifying means. Preferably, distilled water is sprayed. Mist can also be formed. Alternatively or additionally, chemicals, additives or lubricants may be applied in the humidifying station (24). The humidifying device (24) may be integrated with an air conditioning apparatus (12). Preferably, the humidifying device comprises one or more liquid tanks and/or a controllable pump. Alternatively or additionally, the air conditioning apparatus (12) may include a drying mechanism (e.g., an infrared lamp, blower or heater).

The moistening device (24) can be integrated in the machine, in particular in the fiber production device (20) or in the yarn layer forming device (30).

The air conditioning system (12) and/or the humidifying device (24) comprise a servo mechanism (50). The servo mechanism (50) is designed to receive a servo command (45). The servomechanism (50) is also designed to regulate humidification (for example by metering a liquid) and/or dehumidification (for example by regulating temperature or radiation).

The figure shows various arrangement options of the acquisition region (5) or acquisition device (41). In particular, the properties of the fiber stream can be collected after, in or on the bale breaker (21), after, in or on the fiber mixing device (22), or at a further fiber preparation device (20). Preferably, the characteristics are acquired in an acquisition area (5) which is arranged after the servomechanism (50) in the production direction (4). By such an arrangement, these characteristics can be advantageously regulated in a regulation loop ("feedback control"). Alternatively or additionally, these characteristics may also be controlled.

The properties of the collected nonwoven semifinished product can also be used for other purposes, for example for predictive maintenance and/or damage detection. In a preferred embodiment, the collected characteristics are automatically analyzed. The frequency state of the characteristic is preferably analyzed. In particular, a fourier transform may be applied to the acquired characteristics. The frequency of the acquired characteristic may be compared to the frequency of the periodic movement (e.g., the rotational speed of the rotating or oscillating part) or to a previously known machine parameter. In a preferred embodiment, damage to the component is identified by a frequency model in the acquired characteristics. Automatic alerts may be generated regarding apparent frequency conditions. In particular, a warning may be generated regarding damage or the need for maintenance on a particular part.

The nonwoven semifinished product is a layer of flat and/or web-shaped fiber yarns. The width of the nonwoven semifinished product is preferably lm to 4 m.

The monitoring means preferably comprises an infrared sensor. Alternatively or additionally, a radioactive emission sensor or an X-ray sensor may be used. In particular, isotope backscatter sensors are also suitable. The radioactive emission of krypton isotopes is particularly suitable for collecting the characteristics of semi-finished non-woven fabrics.

The use of radioactive radiation requires special radiation protection measures. After the half-life has expired, the sensor or radiation source must typically be replaced. The advantage of an infrared sensor is that it can also collect humidity. Furthermore, the maintenance of the infrared sensor is also less complicated. Preferably, different sensors can be determined depending on the type of nonwoven product. Preferably, the particular acquisition region and application of the acquisition results are combined with different sensor types.

In a preferred embodiment, the monitoring device (40) is designed with an acquisition device (41) and its own data processing device (42). The advantages of this embodiment are: the monitoring method can be used on existing equipment by adding a monitoring device (40). Thus, the product quality can be improved on the existing equipment.

In another embodiment, the monitoring device (40) may be configured as a distributed system. In particular, the detection device (41), the data processing device (42) and the servomechanism (50) can each be designed in a separate hardware unit. The data processing unit may be implemented in particular in a device controller.

The present invention can be modified in various ways. In particular, features shown, described or claimed for the individual embodiments can be combined with one another, substituted for one another, supplemented or omitted in any desired manner.

As an independent aspect that may be used alone or in combination with the aspects addressed by the independent claims, the present disclosure includes monitoring techniques having the following features.

A monitoring method for a production process for producing a nonwoven (7) from fibers (1, 2) in a nonwoven production plant (15), characterized in that the moisture and/or the charge of the fibers (1, 2) or of a nonwoven semifinished product (3) is detected in a detection region (5) by means of a detection device (41) and the detection result is processed in a data processing unit (42), wherein a servo command (45) for at least one servo mechanism (50) of the nonwoven production plant (15) is generated, wherein the servo mechanism (50) is designed to adjust the moisture of the fibers (1, 2) and/or the moisture of the nonwoven semifinished product (3) and/or an environmental condition in at least one part of the nonwoven preproduction plant (10).

According to the monitoring method, the fibers (1, 2) are wetted by means of an adjustable wetting device (24), in particular by applying a liquid.

According to the monitoring method, a humidifying device (24) is arranged in the production direction (4) before a yarn layer forming device (30), in particular a fleece machine (32).

According to the monitoring method, a humidifying device (24) for humidifying the fibers (1, 2) is integrated in the fiber preparation device (20), in particular in the bale breaker (21), the fiber opening device (23) or the fiber mixing device (22).

According to the monitoring method, a humidifying device (24) for humidifying the fibers (1, 2) is integrated in the yarn layer forming device (20).

According to the monitoring method, the nonwoven fabric preproduction installation (10) comprises at least one adjustable air conditioning installation (12).

According to the monitoring method, the ambient conditions, in particular the air humidity and/or the temperature, can be set in the fiber production device (20) and/or in the yarn layer forming device (30) by means of an air conditioning device (12).

According to the monitoring method, the nonwoven fabric pre-production installation (10) comprises at least one climate control zone (13) which is substantially separated from the surroundings.

According to the monitoring method, the climate control region (13) is spatially limited to the fiber production device (20) or the yarn layer forming device (30), in particular to the fleece machine (32).

According to the monitoring method, the nonwoven fabric preproduction installation (10) comprises an air conditioning installation (12) or a humidifying installation (24), which air conditioning installation (12) or humidifying installation (24) can be actuated by means of servo commands (45).

According to the monitoring method, the moisture and/or the charge of the fibers (1, 2) or the nonwoven fabric blank (3) is/are regulated.

According to the monitoring method, the humidity of a part of the fibers (1, 2) or the humidity of a local area of the non-woven semi-finished product (3) is adjustable.

According to the monitoring method, the nonwoven fabric preproduction installation (10) comprises a moistening device (24) which is designed to apply a liquid in an adjustable servo region (46).

According to the monitoring method, the servo area (46) extends only over a part of the fibre.

A monitoring device (40) for a nonwoven production plant (15), having a collecting device (41) for collecting moisture and/or electrostatic charges of fibers (1) or nonwoven semi-finished products (3), wherein the monitoring device (40) is designed for carrying out a monitoring method according to one of the preceding claims.

A nonwoven-fabric pre-production plant (10) with a monitoring device, wherein the nonwoven-fabric pre-production plant (10) is designed for carrying out a monitoring method according to one of the preceding claims.

List of reference numerals

1 fiber

2 (prepared) fiber

3 semi-finished product of non-woven fabric

4 production direction

5 acquisition area

5i local acquisition position

6 characteristic Profile

7 nonwoven fabric

10 non-woven fabric pre-production equipment

11 device controller

12 air-conditioning equipment

13 climate regulated zone

15 non-woven fabric production equipment

20 fiber preparation device

21 bale breaker

22 fiber mixing device

23 fiber opening device

24 humidifying device

30-yarn layer forming device

31 feeder

32 raising machine

40 monitoring device

41 acquisition device

410 sensor

411 sensor beam

42 data processing unit

45 servo command

46 servo region

50 servo mechanism

90 reprocessing device

91 non-woven fabric laying machine

92 nonwoven fabric reinforcing means.

Claims

1. A monitoring method for a production process of a nonwoven semifinished product, characterized in that properties of the nonwoven semifinished product (3), in particular weight per unit area, fiber orientation, fiber mixture ratio and/or fiber opening, are acquired in an acquisition region (5) by an acquisition device (41) and the acquisition results are processed in a data processing unit (42), wherein the nonwoven semifinished product (3) in the acquisition region (5) is a layer of fiber yarn which has not yet been processed and the properties of the nonwoven semifinished product (3) are acquired over a width of the nonwoven semifinished product (3) transverse to the production direction (4).

2. Monitoring method according to claim 1, characterized in that the collecting region (5) is located directly at or near the outlet of the semifinished nonwoven fabric product (3) from a yarn layer forming device (30), in particular a fleece machine, a carding machine, an airlaid machine, a nonwoven fleece machine.

3. Monitoring method according to claim 1 or 2, characterized in that the collecting area (5) is located in the production direction (4) before a rework device (90) changing the yarn layer structure, in particular a nonwoven fleece layer laying machine (91) or a stiffening device (92).

4. Monitoring method according to any one of the preceding claims, characterized in that the non-woven semi-finished product (3) is non-laid and/or non-reinforced.

5. Monitoring method according to any one of the preceding claims, characterized in that the non-woven semi-finished product (3) is a single-layer or multi-layer fibre yarn layer.

6. Monitoring method according to any one of the preceding claims, characterized in that a spatial distribution of the properties of the non-woven semi-finished product (3) along and/or transverse to the production direction (4) is acquired, in particular with a movable sensor (410) or a fixed sensor beam (411).

7. Monitoring method according to any one of the preceding claims, characterized in that local properties of the nonwoven semi-finished product (3) are acquired at least one local acquisition location (5i), in particular using location information.

8. Monitoring method according to any of the preceding claims, wherein the acquisition results are stored in a memory of the data processing unit (42) and/or displayed on a display means.

9. Monitoring method according to any of the preceding claims, characterized in that the acquisition results are frequency analyzed, in particular on the basis of a fourier transform.

10. Monitoring method according to claim 9, characterized in that, on the basis of the frequency analysis, a damage or maintenance requirement on a component of the nonwoven fabric pre-production plant (10) is determined, in particular by comparison of the periodic movement of the component with the frequency analysis of the acquisition results.

11. Monitoring method according to any one of the preceding claims, characterized in that the acquisition result is compared with a target property of the non-woven semi-finished product (3) and a property deviation is determined.

12. Monitoring method according to one of the preceding claims, characterized in that servo commands (45) for the nonwoven preproduction device (10), in particular a fiber preparation device (20) and/or a yarn layer forming device (30), are generated.

13. Monitoring method according to one of the preceding claims, characterized in that servo commands (45) are generated which are designed for locally influencing and/or setting and/or adjusting the properties of the nonwoven semifinished product (3) in a servo region (46), in particular in a partial region of the width of the nonwoven semifinished product (3) transverse to the production direction.

14. Monitoring method according to any one of the preceding claims, characterized in that the spatial and/or planar distribution of properties, in particular local properties or cross-directional and/or properties along the production direction (4), of the non-woven fabric semi-finished product (3) is adjusted or controlled.

15. A monitoring method according to any one of the preceding claims, characterised in that the servo instructions (45) are transmitted to a central device controller (11), a servo (50), a fibre preparation device (20) or a yarn layer forming device (30).

16. Monitoring method according to one of the preceding claims, characterized in that process parameters relating to the nonwoven preproduction device (10), in particular the fiber preparation device (20) and/or the yarn layer forming device (30), in particular the fiber volume flow, the speed of the fiber conveying mechanism, the position of the fiber guide (Faserleitterk), or air conditioning are changed.

17. Monitoring method according to one of the preceding claims, characterized in that the properties of the collected nonwoven semifinished product (3) are specifically influenced, in particular a compensation of property deviations, by changing process parameters.

18. Monitoring method according to any one of the preceding claims, characterized in that the weight per unit area of the nonwoven semi-finished product (3), in particular the distribution of the weight per unit area over the width of the nonwoven semi-finished product (3), is collected.

19. Monitoring method according to one of the preceding claims, characterized in that the weight per unit area of the nonwoven semifinished product (3), in particular the spatial and/or planar distribution along and/or transverse to the production direction (4), is influenced in a targeted manner by adjusting the fiber feed rate of the nonwoven preproduction apparatus (10), the feed properties of a feeder (31) or the input of a yarn layer forming device (30).

20. Monitoring method according to one of the preceding claims, characterized in that the fiber orientation in the semifinished nonwoven fabric product (3) is influenced in a targeted manner by adjusting a yarn layer forming device (30), in particular a carding machine or a pneumatic fleece machine (air fleece machine).

21. Monitoring method according to one of the preceding claims, characterized in that the mixing ratio of the fiber components in the nonwoven semifinished product (3) is specifically adjusted by adjusting a bale breaker (21), a metering device, a fiber opening device (23) or a fiber mixing device (22).

22. Monitoring method according to one of the preceding claims, characterized in that the opening of the fibers in the semifinished nonwoven (3) is influenced in a targeted manner by adjusting a fiber opening device (41) or a yarn layer forming device (30).

23. Monitoring method according to one of the preceding claims, characterized in that the temperature in the semifinished nonwoven fabric product (3) is influenced in a targeted manner by adjusting a nonwoven fabric preproduction device (10), in particular a nonwoven fabric fleece forming device or an air conditioning device.

24. A monitoring device (40) for a nonwoven production plant, characterized in that the monitoring device (40) has an acquisition device (41) for acquiring properties of a nonwoven semifinished product (3) in an acquisition region (5) and a data processing unit (42), wherein the acquisition device (41) comprises one or more sensors (410), in particular infrared sensors, radioactive emission sensors and/or X-ray sensors, wherein the acquisition device (41) is designed for acquiring properties of an untreated nonwoven semifinished product (3) over a width of the nonwoven semifinished product (3) transverse to a production direction (4).

25. The monitoring device (40) according to claim 24, characterised in that the monitoring device (40) is designed for detecting properties of a non-woven semi-finished product (3), in particular of a loose and/or non-laid and/or non-reinforced fibre yarn layer.

26. Monitoring device (40) according to claim 24 or 25, characterized in that the monitoring device (40) is configured to collect a yarn layer property directly in an outlet of the nonwoven semi-finished product (3) from a yarn layer forming device (30), in particular a mechanical or pneumatic fleece machine, or in a collecting region (5) in the vicinity of the outlet.

27. Monitoring device (40) according to one of the preceding claims, characterized in that the monitoring device (40) is configured to acquire the properties of the non-woven semi-finished product (3) in an acquisition region (5) inside or on a yarn layer forming device (30), in particular a fleece machine (32).

28. Monitoring device (40) according to one of the preceding claims, characterized in that the monitoring device (40) is configured to acquire a yarn layer property in an acquisition zone (5) along the production direction (4) before a first reprocessing device (90) changing the yarn layer structure along the production process, in particular a first nonwoven laying machine (91) and/or a first strengthening machine (92).

29. Monitoring device (40) according to any one of the preceding claims, wherein the sensor (410) of the collecting device (41) is movable over the non-woven semi-finished product (3) along and/or transverse to the production direction (4).

30. The monitoring device (40) according to any one of the preceding claims, characterised in that the monitoring device (40) is configured for carrying out a monitoring method according to any one of the preceding claims.

31. Monitoring device (40) according to one of the preceding claims, characterized in that the monitoring device (40) is configured for generating servo commands (45) for a nonwoven preproduction plant (10), in particular a fiber production device (20) and/or a yarn layer forming device (30).

32. A nonwoven fabric pre-production plant (10) having a fiber preparation device (20) and a yarn layer forming device (30) for forming a nonwoven fabric semi-finished product (3), characterized in that the nonwoven fabric pre-production plant (20) comprises a monitoring device (40) according to any one of the preceding claims and is configured for carrying out a monitoring method according to any one of the preceding claims.

33. The nonwoven preproduction plant (10) according to claim 32, characterized in that the fiber preparation device (20) and/or the yarn layer forming device (30) can be adjusted by the monitoring device (40) in order to specifically influence, in particular adjust, the properties of the nonwoven semifinished product (3).

34. A nonwoven production plant (15) for producing a nonwoven (7), characterized in that the nonwoven production plant (15) has a nonwoven preproduction plant (10) according to one of the preceding claims and one or more further processing devices (90) which change the structure of the yarn layer, in particular a nonwoven laying machine (91) and/or a nonwoven stiffening device (92), wherein the collecting region (5) of the monitoring device (40) is between the yarn layer forming device (30) and the further processing device (90) of the nonwoven preproduction plant (10).