CZ20012004A3 - Method of mixing fibrous components, weighing feeding device and control device for controlling feeding rate of material supply - Google Patents

Abstract

The invention relates to a method and a device for mixing fibrous constituents using weight feeding according to which the fibrous material to be dosed is removed, each time, from fibrous balls and is delivered into a weighing container via a device provided for supplying material. A prefilling chamber is connected upstream from said weighing container. The weighing container is separated from the prefilling container by a controllable flap and, after weighing, the material is discharged from the weighing container and released onto a mixing strip. A desired specified weight curve is given to the weighing device for each fibrous component (I, II, III). In order to fill the weighing container (10), the device for supplying the material is controlled according to said specified weight curve by a corresponding variation of the delivery rate. The course of the weighing cycle is fixed by the corresponding percentile delivery rate over the percentile time of the weighing cycle (unit curve). The capacity of the prefilling chamber (8) corresponds to the capacity of the weighing container (10).

Description

(57)

The fiber material to be dispensed is removed from the fiber packs and fed to a weighing container (10) by a feeding device, upstream of the pre-filling space (8), the weighing container (10) being separated from the pre-filling space (8) by a controllable flap (9). ) and after weighing the material from the weighing container (10) is dropped onto the mixing belt (12). The weighing device is set for each fiber component (I, II, III) the desired nominal weight curve, according to which the material feeding device (4) is controlled to fill the weighing container (10) corresponding to the change in feed rate. The course of the weighing cycle is determined by the respective percentage administered relative to the percentage of the weighing cycle. The capacity of the pre-filling space (8) corresponds to the capacity of the weighing container 10). A control device (40) is associated with the material supply device (4), which controls the feed rate of the material supply device (4) according to a given nominal weight curve.

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A method of mixing fiber components, a weighing feeder and a control device for controlling the feed rate of the material feed

Technical field

BACKGROUND OF THE INVENTION The present invention relates to a method and apparatus for mixing fiber components by weighed feed, which is provided with a weighing container and a pre-filling space, wherein the weighing container is separated from the pre-filling space by a controllable flap.

The invention further relates to a feed rate control device for a material feed device of a weighing feed device for mixing fiber components, in which the feed material is conveyed by the material feed device to a weighing container.

BACKGROUND OF THE INVENTION

To mix the fiber components, a weighing feeder is used to dispense the individual fiber components in which the fiber packages are fed through the feed table and the adjoining feed belt to the upward point belt from which the fibrous material is disassembled and conveyed up against the return roll. A follow-up pickup roller feeds the loose material to the weighing container.

The weighing of the fibers in this known discontinuous manner generally proceeds in such a way that the weighing container is supplied with two different feed rates, the feed power being determined by the speed of the spike belt. First, coarse dosing is carried out at a high speed of the spike belt to fill the weighing container as quickly as possible. At this high speed, however, only the inaccurately required weight can be achieved. Therefore, this rapid filling takes place only to a certain degree of filling. Once this coarse fill limit is reached, the tip band is switched to a low speed, and at this low speed a fine dispensing is carried out until the desired precise weight is reached. When this second limit value is reached, the tip band stops. The weight is then determined: :: ·· ·33233θ · Φ · · «· φ φφ · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · For accurate weighing, it is essential that the balance is at rest, that is to say no more oscillations due to filling. This may take 2 to 3 seconds. Then the weighing container is emptied onto the so-called mixing belt and tared, i.e. the weighing device is set exactly to zero 5. In this way, the weighing device is ready for the next weighing and the point belt is switched on again to first carry out a coarse filling for the next weighing at high speed.

Despite the precise adjustment of the weighing device and the immediate stop of the spike belt, the fibers fall into the weighing container even after reaching the second limit value, so that the desired weight value is exceeded, sometimes not even 10. This is particularly the case when the fibrous material has little fluff. To compensate for this inaccuracy, this weight value shall be determined and shall be taken into account by weight for subsequent weighings. In addition, flaps are formed above the weighing container, which close immediately upon reaching the final weight to prevent further entry of the fibrous material into the weighing container.

In order to accelerate the weighing cycle, it is desirable to quickly fill the weighing container, but high tip speed results in high performance, but due to poor fluff of the fibrous material, the weighing accuracy is low because of material entrainment and the like. Although the low speed of the spike belt 20 leads to better fluff, the performance and hence the filling speed of the weighing container is low. The aim is therefore to achieve the highest possible performance while still providing good fluff and high weighing accuracy.

The specific material properties also play an important role in the weighing of fibers, for which reason all speed and limit values must be set. The filling of the filling space 25 in front of the spike belt also has an influence on the parameters to be adjusted.

Fiber blending plants are generally operated with several weighing tanks and various raw materials. The slowest weighing determines the performance of the entire production facility. In order to achieve the 30 required accuracy and performance in the weighing methods described, it is necessary that the equipment is adjusted by operating personnel with good knowledge of procedure and experience. The setting values must be determined empirically for each fiber type, which is expensive.

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Although electronically controlled weighing devices are already known which greatly facilitate the operation and control of such mixing devices, it is nevertheless necessary to enter and store in the control device the relevant data and empirical values for the materials to be processed and all intended for processing. 5 materials and mixtures required to ensure a control program. This is time consuming and requires experienced professional staff. In addition, there is always a risk of incorrect settings. For new mixtures and materials, empirical values must first be tested and found.

From DE 34 12 920 there is known a device for dispensing filling material for 10 filling of a container. The weighing container is filled in two stages with coarse dosing and fine dosing. For coarse metering, the material is fed into the pre-chamber through the first inlet, which is provided with a shut-off device relative to the weighing container, the volume metering of the filling material in the pre-chamber being provided. When the specified volume is reached, the pre-chamber filling is terminated and its contents are emptied into the weighing container. After closing the closure between the pre-chamber and the weighing container, a fine dosing is carried out by a second feeding path. During this time, the pre-chamber can already be refilled with the first feed path so that the feed rate to the weighing container is shortened. A disadvantage of this known device is the need for two separate filling paths for fine filling and for 20 pre-filling, so that for each filling path only the corresponding damper control and the corresponding supply device are required. This device is therefore relatively expensive.

Further, a method for continuously determining the weight of a granular, fibrous or sheet material, in particular tobacco, is known, in which the material in a continuous stream is transferred by the first feed means to the second feed means 25 and fed therefrom to the following treatment operations (DE 28 41 494). ). The feed rate of the first feed means is controlled depending on the weight of the material delivered to the second feed means. The problem of achieving non-continuous weighing for mixing fiber components yet continuous material feeding and fluffing does not exist in this known apparatus. This known method and its intended device also fails to assemble the various fiber components according to the specified weight fractions for further processing.

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Finally, an electronic control program is known from US-PS 4,766,966 for filling the weighing container from the pre-filling space in the shortest possible time, but avoiding overloading due to rapid filling. The supply of goods to be weighed into the weighing container is therefore controlled by the different opening width of the 5 outlet flaps from the pre-container. Nothing can be learned about the mixing of the fiber components and the feeding of material into the pre-filling space. By controlling the opening size of the discharge flaps, there is a risk that the fibrous material will adhere to incompletely opened flaps, causing irregularities and incomplete filling of the weighing container.

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the indicated drawbacks and to provide a method and a weighing device for substantially simplifying the setting and dosing of individual components. It is a further object of the invention to achieve a high production capacity while still providing good fluff and high weighing accuracy. These objects are solved by the features of claims 1, 15 and 17 in combination or separately.

Overview of the drawings

Further details of the invention will be described in more detail with reference to the drawings, in which FIG. 1 shows a weighing container in a schematic representation; FIG. 2 shows a mixing device with three weighing containers; FIGS. 3, 4 and 5 show different curves. 6 shows a comparison of the conveyed quantity with and without interruption of feeding; and FIG. 7 shows a weighing container with an enlarged pre-filling space.

DETAILED DESCRIPTION OF THE INVENTION

Giant. 1 schematically shows the construction of a weighing container. The bale Γ, 12, 1 přes' are fed through the feed table 2 and its feed belt 3 to the tine strip 4, which releases the parts from the fed packages and transports them upwardly against the return roller 30 5. The return roller 5 is positioned at an adjustable distance from the tip. of the belt 4 and rotates in the opposite direction to the feeding direction of the tip belt 4. Excessive amounts

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The fibers which are carried by the tip belt 4 are not released by this distance of the return roll 5, but are retained by this distance of the return roll 5. As a rule, the feed belt 3 of the feed table 2 and the spike belt 4 are in drive relationship with each other. A continuously variable drive 41 is provided for the tip belt 4 so that the tip belt 4 can run at any feed speed that is specified by the control device 41. The tip belt 4 is followed by a high speed orbiting pickup roller 6 which releases fibrous material from the tip belt 4. its fluffy. Fluffy fibers or flakes of fibers are fed by the pickup roller 6 to the pre-filling space 8, which is closed by the flaps 9 and can be closed to the weighing container 10. The fan 7 provides dust extraction. Below the weighing container 10 is a longitudinally extending mixing belt 12 onto which the fibers weighed in the weighing container 10 are dropped. At the end of the mixing belt a compression roller 11 is provided to densify the fibrous material into a homogeneous web.

Giant. 7 illustrates a weighing feed device with enlarged pre-filling space. The components of this device with the same function are also marked as in Fig. 1, so that the description of the device according to Fig. 1 also applies to Fig. 7. A large pre-filling space 80 is provided above the weighing container 10 having up to approximately 80% 10. This enlarged pre-filling space serves to receive material during the time of calming the weight and dropping the contents of the weighing container 10 onto the feed belt 12 so that the tip belt 4 can feed the fibrous material without stopping. In order to monitor the filling level of the pre-filling space 80, measuring devices 13 are provided on both sides. These measuring devices are preferably in the form of light barriers.

Giant. 2 shows a device with three weighing dosing devices I, II and III, each of which throws one component on the mixing belt 12. Dropping from the weighing containers 10 is carried out in such a way that the components to be mixed are arranged in layers one above the other and at the same time come to the mixing spreader 13. This means that they first discard a proportion of their component weighing the metering device III and the belt 12 transfers this layer to the weighing metering device II. There the other component is deposited from the weighing container 10 on the layer from the weighing dosing device III and both are then transported further to the weighing dosing device I, which then places the third component on both layers. At the end of the feed belt 12, all three layers then pass under the presser 44 99 44: 4 4 44:

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44 44 44 44 44 by the roller 11 and fed to the mixing spreader 13, which continuously mixes the deposited layers and passes through the conduit 14 to the mixing chamber.

The supply of the weighing container 10 is carried out in one known apparatus such that in the first stage the material is transported quickly without weight control, i.e. the flaps 9 are closed and the material is collected in the pre-filling space 8. During this time, dropping the last weighed amount closes the floor flap of the weighing container 10 and when the floor flap is closed, taring occurs. In the second phase the material is still transported quickly and without weight control, but the flap 9 opens and throws the collected material into the weighing container 10, whose floor flap is closed. In the third phase, the material container 10 will now be filled with rapid material transport until a certain amount is filled which is less than the nominal quantity to trigger a signal to switch the material feed to a low speed at which the material is added to the target material weight. . When the target weight is reached, the material feed is disconnected and the flaps 9 are closed. This is followed by about two seconds of rest to measure the resulting weight. Finally, with the material feeding still closed and the flaps 9 closed, the floor flap is opened and the weighed amount is dropped onto the mixing belt 12.

The pre-filling serves to increase production capacity by reducing material feed-back times, since with the flap 9 closed in both first phases, the material feed can start again. However, the prefill function according to the known method cannot be used when the material feed rate is subject to severe fluctuations.

The method of the invention removes these disadvantages. Although the material feed takes place at different speeds, it is continuous, so that no downtime occurs. This has the great advantage that by splitting the material feed over a longer time, which is otherwise occupied by downtime, it is possible to work at lower material feed rates, which leads to significantly better fluff and more accurate dosing. As a further object of the invention it becomes superfluous to adjust the individual parameters because the individual feed and feed rates, including the times within the weighing cycle, are optimized by themselves while being adjusted to different materials. The method of operation according to the invention is as follows:

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First, the desired cycle of the weighing cycle is indicated in the so-called universal curve. This cycle resulted from the sum of many empirical values and expresses the material feed as a percentage of the weighing cycle as a percentage. Since the tip band speed of the weighing feeder is approximately 5 proportional to the amount of material being conveyed, this universal curve in percent represents approximately the course of the tip band speed, and hence the feeding of the material or the conveyed amount per unit of time. Surprisingly, it has been found that the optimum material flow behavior is approximately the same in all cases, so that this curve can be readily transferred to all 10 specific values as a percentage. This has the great advantage that the weighing cycle and thus one essential parameter are assigned to the control device 40 by means of a universal curve, so that only the weighing time and the target nominal weight to be observed are left to be specified for each particular case. Of course, the computer embedded in the control device 40 can also detect both of these values directly from the desired production power.

Since the filling capacity of the weighing container 10 is entered, the computer calculates the necessary number of weighing cycles and their time span as well as the nominal weight to be assigned to each weighing cycle. Based on the nominal weight entered, the computer calculates a nominal weight curve (FIG. 4) using a universal curve (FIG. 3), according to which the filling of the weighing container 10 20 compares the corresponding changes in the fiber supply to the weighing container 10. The speed of the spike belt is always controlled by the drive 41 so that the spike belt 4 does not stop at all or only in exceptional cases, so that the feeding of material takes place throughout the weighing cycle. This is made possible by the largest dimensioning of the pre-filling space 80 (FIG. 7), which is at least half the size of the pre-weighing container 10, preferably two-thirds to the same, and can therefore receive a continuous supply of material, dropping the target weight from the weighing container 10. Only the fine refill quantity need not accept the pre-filling space, as it falls directly into the weighing container 10 with the flaps 9 open. This not only achieves substantially 30 faster loading and thus greater weighing machine performance. thereby allowing a lower filling speed also improved fiber retention and more accurate filling. Naturally, the savings in downtime of the material feed can also be used to shorten the weighing cycle time and thereby increase performance without compromising the quality of the fluttering.

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The weighing cycle is basically divided into three phases, namely (Fig. 6) into pre-filling (zone A), main filling (zone B) and fine filling (zone C). There is also a dwell time (zone D). With the corresponding size of the pre-filling space 8 resp. 80 can be completely dispensed with without the main filling, so the weighing cycle is divided into only 5 pre-filling (zone A + B + C) and fine filling (zone D). The pre-filling is carried out with the flaps 9 closed into the pre-filling area 8 or 8, respectively. 80. During this so-called pre-filling, the balance will stand still and measure the final weight as well as opening and dropping the final weight onto the mixing belt 12, including any necessary taring of the balance. The fine filling is always carried out after emptying the pre-filling space 10 and with the flaps 9 open to bring the balance to the target weight. In this way, 2 to 3 seconds can be saved, which in a typical weighing cycle of 12 to 14 seconds means a reduction in the feed rate or an increase in power of 15 to 25%.

Giant. 3 shows a universal curve for a weighing cycle without delay in material feed. As is apparent from FIG. 3, the conveyed amount at the beginning of the 15 cycle is approximately 100%. This transported quantity is maintained for approximately 60% of the weighing cycle time. Thereafter, the transported quantity is reduced to approximately 20% and for the remaining 20-25% of the weighing cycle time, fine delivery to the target weight is performed as the transported quantity decreases. The area under the universal curve represents the total conveying quantity to be achieved and 20 to be dropped as a target weight on the mixing belt 12. By integrating this universal curve, a nominal weight curve is obtained (Fig. 5). The universal curve is then used for each of the mixed components I, II, III, 100% being the transported quantity necessary to achieve the nominal weight of the component during the weighing cycle.

Since all three components have the same time for the weighing cycle, the required nominal speed curve is governed by the nominal weight to be achieved. Therefore, component I has the highest rated speed, in our example 60 m per minute, component J 30 m per minute and component III about 10 m per minute. This corresponds approximately to the mixing ratio of the components 60: 30: 10.

However, the control of the mixing process via the nominal weight curve derived from the universal curve can also be carried out on a conventional weighing cycle with the material being stopped. Giant. 6, however, comparatively illustrates the enormous benefits of eliminating downtime in favor of a continuous supply: · ´ · Ρ6 $ 248ο |

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9999 material. The heavily pulled universal curve represents a weighing cycle with the usual downtime. Zone A indicates the usual pre-fill time, Zone B the main fill, while Zone C indicates the feed-down time. The percentage numbers give an example of the usual course of the weighing cycle. It is immaterial whether the weighing cycle lasts 12 seconds or 16 seconds. In this case, the example was taken from a weighing cycle of 14.5 seconds. As shown in FIG. 6, the downtime is 25 to nearly 30%. By eliminating this downtime for material feed, the feed rate can be reduced to approximately 60% with a reasonably large pre-fill space 80, or a 25% reduction in the weighing cycle can be achieved with the full feed rate. Since the areas under the respective curves represent an amount corresponding to the nominal weight, it is clear what advantages the method according to the invention brings.

The pre-filling is carried out at the material feed rate, which is set so that the existing pre-filling space 8 and the pre-filling space 8, respectively. 80 is in the specified resp. available at the present time well utilized and optimally filled. If the size of the pre-filling space 80 (FIG. 7) is approximately 60 to 80% of the weighing container 10, the pre-filling time will be substantially filled at this time. When the flaps 9 are opened, this pre-filled quantity enters the weighing container 10 and only a fine filling at a low feeding speed is then required to achieve the desired target weight.

Feeding of the material begins with the feed rate (Fig. 4), which is determined by the nominal weight curve (Fig. 5). By comparing the nominal and actual values with the entered nominal weight curve, the amount remaining to reach the target weight is determined. If the difference amount is very large, the feed rate of the material can also be increased once again to 100% and only reduced to fine feed for the last 10 or 20%. The aim, however, is to perform the filling as uniformly as possible at the feed rate so that the feed rate in the subsequent cycle is already adapted to this pre-filling time.

As soon as the target weight is reached, the flaps 9 close and cut off the additional material feed. However, the feeding of material does not stop, but immediately begins to refill the pre-filling space 8 resp. 80 while the balance is in its idle state, weighing and dropping the weighed material.

For optimum utilization of the pre-fill space 8 or 80, it is necessary to determine the correct feed rate during this pre-filling period, since «• · · · · · · · · · · · · · · · · · · · · · · · · ·

this may deviate from the nominal speed (Fig. 4) derived from the nominal weight curve due to the specificity of the material. Although this can in principle also be done manually and by entering empirically determined values, it is also possible that the weighing device itself optimizes here. This happens as follows:

Depending on the default setting, for the first weighing cycle, material feed begins with a feed rate of approximately 50%. Depending on the size of the pre-filling space 8 or 80, after the weighing time of approximately 60% of the weighing cycle, the amount of material at the flat pre-filling speed into the pre-filling space 8 or 80 is then checked. this measurement is automatically taken into account because the actual amount is measured in dependence on the feed rate during this pre-filling.

This check can be done in different ways. One method is, for example, by opening the flaps 9 into the weighing container 10 to dispense the amount delivered by the pre-filling until the time 15 so that it can detect the intermediate weight which is entered into a computer which compares it to the nominal weight. If this actual value is lower than the nominal value, it means that the 50% rate of filling is too low and must be increased according to the difference between the actual value and the nominal value. Already for the next weighing cycle, the computer enters the correct feed rate 20 so that the pre-filling space 8 or 80 is optimally used. If the pre-filling amount is too high, the speed will be reduced accordingly. This eliminates the need for conventional adjustment measures. This procedure can also be repeated to make it more precise.

Another method of optimizing the pre-filling rate is to equip the pre-filling space 8 with a filling level measuring device (measuring probe, photocell, etc.). The pre-filling space 8 is filled until the measuring device reacts and advises the filling of the space, thereby opening the flaps 9. At the same time, the time consumed is determined and the computer calculates and sets the optimum filling rate by increasing or decreasing the basic setting. With this method, the pre-filled amount can then be adjusted to the target weight and used as the first weighing.

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In order to prevent overfilling of the pre-filling space 8 by optimizing the feed speed expediently from such a low feeder with certainty, full filling of the pre-filling space will not yet be achieved. Typically, this is achieved at about 50% of the feed rate. In the first weighing cycle, the optimum starting speed of the spike belt 4 or the feed rate, as described above, is then determined after approximately 25 to 70% of the weighing cycle time by comparing the actual weight to the nominal weight.

Of course, it can also be provided that the once determined feed rates for certain materials and component assemblies are stored and recalled when the same case is repeated, without having to perform the appropriate optimization again. However, auto-optimization is generally preferable as misalignment is avoided and staff do not have to worry about adjusting the correct pre-filling rate at all.

For the following weighing cycles, the optimum feed rate is determined after optimization. As soon as the pre-filling is reached, the control switches to the nominal filling curve with the specified filling speed. The regulating member which expediently affects the feed rate of the tip band 4 controls the speed along this curve, so that the feed rate is also reduced correspondingly to perform fine dosing while reaching the final weight. Once this target weight has been reached, the cycle for material feeding is completed and the feed belt speed 4 switches to optimized feed speed after closing the flaps 9, starting the pre-filling process and thus a new weighing cycle. Thus, while the pre-filling space 8 or 80 is already filled with material, the weighing device remains with the weighing container 10 at rest, and after the expiration of the opening of the weighing container 10 the weighed material drops onto the mixing belt 12.

Of course, even with this weighing method, at the end of the weighing cycle, the deviation of the actual weight from the nominal weight is determined and taken into account in subsequent weighing cycles. This can be done as usual by weight, but the feed rate can also be influenced to optimize the course. This is done by keeping the course of the weighing cycle the same according to the universal curve, but the corrected rate of correction is set to 100% of the conveyed quantity and thus corrected. • 0 00 00 • · · · 0 • 0000 00 • 0 0 0 0 00 • 0 0 0 00

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00 000 nominal weight curve input and nominal speed curve derived therefrom. In this way, very accurate weighing is achieved.

As shown in FIG. 2, a number of components have to be assembled and mixed in most cases for the mixture. One weighing device I, Π or III is provided for each component. Thus, in this case, three components can be mixed. Because the proportions of the individual components are of different sizes, the loading of the weighing containers 10 takes a different time for conventional known filling methods, so that the component having the largest proportion also needs the longest time so that the two remaining weighing containers terminate their weighing operation sooner. the quantity must wait for the weighing container with the largest quantity. According to the invention, the three weighing containers are matched to each other so that all three weighings are completed at the same time. By determining the nominal weight curve from the universal curve and entering the respective weighing dosing device for each component, the velocity curve for the filling rate is reduced accordingly. The pre-filling is slower, but it is possible to maintain the filling to the target weight independently of the pre-filling speed so that the same time space as the largest component is filled. Since the nominal nominal curve is derived from the universal curve, the weighing cycle takes place here in the same way as for the largest component. Special settings are not required. The universal curve is entered in each control unit or in the control unit of the entire plant. It is therefore sufficient to enter only the required production capacity or weighing cycle and the required target weights of the individual components. Everything else, including process optimization, is performed by the computer control.

In order to achieve the same mixture at the beginning and at the end of the mixing batch, the control can also be programmed such that the dropping of the weighed amounts of fibers from the weighing dosing devices starts and ends one after the other so that completely mixed layers are formed. Thus, in the example of FIG. 2, the weighing dosing device III drops its last weighed amount onto the mixing belt 12 and then ceases its operation. The last dropped quantity then reaches the weighing metering device II, which drops its component onto the last weighed amount of the weighing metering device III and then terminates its operation. Only when this blend package passes the last weighing metering device 1 does the mixing device disconnect. The same is the case during start-up, starting with the IH weighing device and then connecting the weighing devices II and I.

In the example described, the process control has been described by entering the desired nominal weight curve, in which the feeding of material to the weighing container 5 10 is controlled. This nominal weight curve can also be determined empirically, but it is advantageous to do so according to the invention using a universal curve.

Optimization of the feed rate, especially for pre-filling, is of importance not only in relation to the larger pre-filling space 80, which can accommodate virtually the entire filling quantity except for the remaining filling for fine dosing. 10 The expanded pre-filling space can also be used successfully with traditional known weighing methods, thus significantly shortening the process or reducing the required feeding speed.

As can be seen from the full heavily drawn curve in Figure 6, it is possible to enter the universal curve even for the traditional delayed weighing process (section D) and control the cycle accordingly.

Consequently, these parts of the invention have a separate meaning, however, the optimum is achieved by using all of the described parts together. The described embodiments are given by way of example only and can be varied or combined in other ways without departing from the spirit of the invention.

Claims (24)

PATENT CLAIMS A method of blending fiber components by weighed feed, wherein the metered fiber material is removed from the fiber packages and is conveyed by a feeding device to a weighing container before a pre-filling space is preceded, wherein the weighing container is separated from the pre-filling space by a controllable flap The material from the weighing container is dropped onto a mixing belt, characterized in that for each fiber component (I, II, III) a desired nominal weight curve is set according to which the feed of the weighing container (10) is controlled by adjusting the feed rate. Method according to claim 1, characterized in that the course of the weighing cycle is determined by the respective percentage administered to the percentage of the weighing cycle (universal curve). Method according to one of claims 1 or 2, characterized in that the nominal weight curve (Fig. 5) for each component (I, II, III) is determined from the universal curve (Fig. 3), based on the nominal weight of the component (I, II, III) to be achieved in the weighing cycle. Method according to one or more of the preceding claims, characterized in that the same weighing cycle duration is assigned for the individual components (I, II, III) (Fig. 5). Method according to one or more of the preceding claims, characterized in that the weighing cycle is divided into a pre-filling stage (Fig. 6), during which the feed material is placed in the pre-filling space (8; 80), and into a fine filling stage (8). 6), during which the conveyed material reaches the weighing container (10) immediately through the pre-filling space. Method according to one or more of the preceding claims, characterized in that the treatment of the material supply is carried out by varying the feeding speed of the spike strip (4). Method according to one or more of the preceding claims, characterized in that the adjustment of the actual weight to the respective nominal weight curve of the specified nominal weight is carried out by a control member. ································· Method according to claim 7, characterized in that the control member influences the actual feed speed of the tip strip (4). Method according to one or more of the preceding claims, characterized in that the duration of the weighing cycle is determined by the speed of the mixing belt. Method according to one or more of the preceding claims, characterized in that the weighting of the weighed amounts of fibers onto the mixing belt (12) from the weighing dosing devices starts and ends one after the other so that completely mixed layers are produced. Method according to one or more of the preceding claims, characterized in that, in order to determine the optimum feed rate, the feed rate of the material feed (4) for the first weighing cycle is set according to an empirical value and after 25 to 70% of the weighing cycle time the actual weight is compared to the nominal weight and the difference thus determined is used to correct the feed rate of the material feed (4). The method of claim 11, wherein the empirical value for optimizing the delivery rate is about 50%. Method according to one or more of the preceding claims, characterized in that the feed rate for the fine dosing remains unchanged irrespective of the change in the feed rate for the material feed during the pre-filling and / or the main filling. Method according to one or more of the preceding claims, characterized in that at the end of the weighing cycle the deviation of the actual weight from the nominal drop weight is detected and that the difference is taken into account for correcting the feed rate. A method of blending fiber components by weighed feed, wherein the metered fiber material is removed from the fiber packages and is conveyed by a feed device to a weighing container before the pre-filling space is preceded, wherein the weighing container is separated from the pre-filling space by a controllable flap and The material from the weighing container is dropped onto a mixing belt, characterized in that the material supply (4) feeds the fibrous material throughout the weighing cycle, while the material supply to the weighing container is discontinuous. Method according to claim 15, characterized in that the feed rate of the material feed (4) approaches zero at the end of the fine dosing, but once again it reaches the full value after closing the flaps (Figs. 3, 4 and 6). A weighing feeder in which the metered material is fed by a material feeding device into a weighing container, upstream of the pre-filling space, wherein the weighing container is separated from the upstream pre-filling space by a controllable flap, characterized in that the material supply is assigned to a control device (40) which controls the feed rate of the material supply device (4) according to a given nominal value curve (FIG. 5). Apparatus according to claim 17, characterized in that the material supply device comprises a spike strip (4) which releases fibrous material from the feed package and is provided with a continuously controllable drive (41). Device according to one of claims 17 or 18, characterized in that the capacity of the pre-filling space (8; 80) corresponds to the capacity of the weighing container (10). Device according to one or more of the preceding claims, characterized in that the capacity of the pre-filling space (8; 80) corresponds to approximately 80% of the capacity of the weighing container (10). Device according to one or more of the preceding claims, characterized in that the capacity of the pre-filling space (8; 80) corresponds at least to the capacity of the weighing container (10) reduced by the amount of precision filling. A control device for controlling the feed rate of a material feed device (4) of a weighing feed device for mixing fiber components, wherein the feed material is fed to a weighing container (10) by the material feed device (4), characterized in that the control device (4) 40) for the dispensed fibrous material, a desired nominal value curve (Fig. 5) is assigned, according to which the control device (40) controls the feed of material (4) for filling the weighing container by adjusting the feed rate. Control device according to claim 22, characterized in that the control device (40) is given a weighing cycle run by the respective percentage of the delivered quantity by means of the weighting cycle percentage (universal curve - Fig. 3) from which the nominal weight curve can be determined. 5) for each component (I, II, • 999) Ρ ^ 32 ^ 8φ • · · · · III), based on the nominal weight of the component (I, II, III) to be achieved in the weighing cycle. Control device according to claims 22 and 23 for controlling the feed rate of the material supply device (4) of the weighing feeder device according to one of the claims 1 or 16.