Patent Application
20150034755
The present invention relates to a manufacturing method and a manufacturing device for a bundle product, which performs manufacturing while adjusting the amount of threads wound so that a predetermined amount or more of the bundle product obtained by collectively winding threads continuously running in the longitudinal direction can be finally obtained.
Threads typified by fibers and hollow fiber membranes, and the like (hereinafter, also simply referred to as threads) have been used and actively utilized in various fields and applications from the past in the form of a thread product formed only by the threads, or a final product manufactured using the threads as a main component element. In particular, in many cases, a bundle of threads obtained by bundling plural threads can significantly improve performances as a product in comparison with a case of a single thread. Thus, bundled products formed by the bundle of threads or final products manufactured by using the bundle product as a main component element have been increasingly widely used.
Here, threads attracting attentions as those forming high functional bundle products include carbon fibers exhibiting high strength and reduced weight, optical fibers supporting the information society, and hollow fiber membranes used in various filters. As described above, these threads usually exhibit significantly excellent performances when used as a bundled product rather than when used as a single thread. Thus, their performances should be guaranteed as the entire bundled product having plural threads converged therein, rather than as the single thread. For this reason, extra care should be taken to manufacture and manage these bundle products.
A description will be given more specifically by giving an example of a hollow fiber membrane filter (hereinafter, also referred to as a “module”) used in water treatment such as wastewater reclamation and desalination of sea water. In general, the hollow fiber membrane filter has a resin or metallic container, called a case, accommodating a bundle of hollow fiber membranes. This filter is designed so as to cause raw water to flow into this container and pass from the outside (or the inside) of the hollow fiber membranes to the inside (or the outside) to achieve filtration effect on the raw water, and to separate the filtered water from which impurities have been removed and the concentrated water having impurities concentrated therein, and let them flow out of the case.
Although there are various kinds of factors that determine the filtration performance of this module, the following two factors are particularly important: the amount of hollow fiber membrane bundle, and the existence or absence of any defective hollow fiber membrane (hereinafter, also simply referred to as a “defective fiber”) contained in the filter.
In general, as for the amount of hollow fiber membrane bundle, at least one physical quantity is selected from the following plural physical quantities according to performances required by customers or applications of the module, which is the final product. In other words, the physical quantities include, for example, the number of, the outside diameter of, the surface area of, and the weight of all the hollow fiber membranes contained in the module (hereinafter, part or all of these are also referred to as “managed quantities”). If these managed quantities fall below a predetermined value, the module cannot fully exert its filtration performance.
On the other hand, the defective hollow fiber membrane includes one having, for example, a scratch, a defect, a foreign substance, a dent, swelling, or a large hole formed on the surface thereof, and one having, for example, an excessively thick shape (thin membrane), an excessively thin shape (thick membrane), a crushed/flattened shape, a twisted shape, or a clogged shape (hereinafter, part or all of these are also collectively referred to as “defect”). If the hollow fiber membrane bundle, constituting the module, contains such a defective hollow fiber membrane, the module does not fully exert its performance. Furthermore, only the small number of defective hollow fiber membranes contained may lead to a reduction in the product lifetime of the entire module (for example, if the defective portion breaks when the module is being used, the raw water enters the filtered water).
Here, the hollow fiber membrane bundle is generally manufactured by forming a raw material into a hollow-shaped thread through an outlet port, applying various processes, winding the thread using, for example, a rotating reel, and cutting all the wound threads at a predetermined position. Further, in order to reduce manufacturing costs, plural hollow fiber membranes are usually formed in a single line at the same time, and wound up with the same single rotating reel. Thus, efficiency of the manufacturing processes improves with increase in the number of threads that can be manufactured at the same time in a single line (note that the method of collecting the hollow fiber membrane bundle is not limited to winding using the rotating reel).
It should be noted that the amount of winding of the rotating reel is generally set such that the hollow fiber membranes can exert a predetermined filtration performance when finally assembled in the module on the assumption that each of the hollow fiber membranes is in an ideal state in which the outside diameter, the surface area, and the weight of each of the hollow fiber membranes are always equal to design values, and no defect exists in each of the hollow fiber membranes. This is because, under conditions changing every moment during manufacturing, it is difficult to anticipate how the outside diameter, the surface area, and the weight of the hollow fiber membranes change, and it is not possible to anticipate where defects occur in the hollow fiber membranes. As a result, there is no other choice but to set the ideal states as temporary targets.
However, in reality, the outside diameter, the surface area, and the weight of the hollow fiber membranes vary and defects possibly occur during the processes of manufacturing the hollow fiber membrane bundle.
For these reasons, with the conventional method of manufacturing a hollow fiber membrane bundle, a special worker adjusts the amount of the hollow fiber membrane bundle, before the hollow fiber membrane bundle obtained by activating the rotating reel for a set number of rotations based on the ideal state is assembled into the case. More specifically, the worker first checks whether the hollow fiber membrane bundle contains any defective hollow fiber membrane, and removes the defective hollow fiber membrane from the hollow fiber membrane bundle if found. Then, the worker randomly selects several threads from the hollow fiber membranes remaining in the hollow fiber membrane bundle, measures the outside diameter or surface area or weight of part of the selected hollow fiber membrane, and averages the results. After this, standard values for the managed quantities set in order to ensure quality of the module serving as the final product are checked, and hollow fiber membranes, of which managed quantities are already measured and in which it is already known that no defect is contained, are replenished to the bundle until the managed quantities exceed these standard values.
With the process of manufacturing the hollow fiber membrane bundle as described above, a bottleneck obviously occurs in the process in which the worker adjusts the amount of hollow fiber membranes. Thus, many workers need to be employed to efficiently manufacture the hollow fiber membrane bundle, which leads to a significant increase in manufacturing costs. Further, in reality, it is not possible to manually measure the managed quantities for all the hollow fiber membranes contained in one hollow fiber membrane bundle (usually containing several hundreds of hollow fiber membranes). Thus, adjustment of the amount of hollow fiber membranes has to be made only on the basis of measured values (representative values) obtained through sampling of hollow fiber membranes. However, with the method as described above, the actual performance of the hollow fiber membrane bundle after adjustment may be not adequate.
As for measures for solving the problems as described above, configurations of Patent Documents 1, 2, and 3 are proposed.
First, Patent Document 1 describes automatically detecting defects occurring in threads and determining types of the defects while the threads are running in manufacturing processes; cutting and removing length according to the type of the defect while the thread is being running; and joining the cut portions.
Next, Patent Document 2 describes that, if any abnormality in the diameter of thread is automatically detected when the thread is returned from a thread bobbin on the unwind side to a thread cheese on the winding side, length to be cut is calculated on the basis of the degree of the abnormality, and by reversing the rotation of the cheese, the portion to be cut is unwound to cut the target portion.
Next, Patent Document 3 describes that, when a visual inspection worker finds a defective portion and cuts off the defective portion during production (winding) of paper sheets, length that has been cut is automatically detected on the basis of a diameter of the roll before and after the defective portion is cut, and the amount of winding is controlled so as to compensate the portion that has been cut so that the thread with a specified length can be wound.
However, with the methods described in Patent Documents 1 and 2, by automatically performing measurement and inspection during running of the thread, it is possible to eliminate the special worker, and cut off the defective portion. However, these methods are performed on the assumption that a single thread runs in a single line. More specifically, if a defective portion of a certain thread is cut off in the case where two or more threads run in a single line, the length of this thread differs from the lengths of the other threads, so that these threads cannot be wound around the same rotating reel. If these threads are required to be wound around the same reel, when a defective portion is cut off from a certain thread, it may be possible to cut off the same length of a normal portion from threads that do not have any defect and are manufactured at the same time. However, with this method, manufacturing yields reduces. Further, Patent Document 1 or 2 does not propose a method of correcting the final managed quantities for the hollow fiber membrane bundle after the defective portion is cut off.
Patent Document 3 relates to a paper sheet instead of a thread, and obtains a length of a portion to be cut off on the basis of the roll diameter before and after the defective portion is cut off to correct the amount of winding so that the length of the paper sheet contained in the final product meets the requirements. However, as in Patent Documents 1 and 2, it is difficult to apply this method in the case where plural products are manufactured in a single line at the same time. Further, in Patent Document 3, a length of the paper sheet is the only managed quantity. However, in the case where high-functional final product such as the hollow fiber membrane bundle are manufactured, it is essential to manage other values such as an outside diameter, a surface area, and a weight as described above.
An object of the present invention is to provide a manufacturing method and a manufacturing device for a bundle product, which improve inspection quality and manufacturing efficiency in the case where a desired amount of two or more threads continuously running in parallel are collected while being inspected.
In order to solve the problem described above, the manufacturing method for a bundle product according to the present invention includes any of the following configurations (1) to (9) described below.
(1) A manufacturing method for a bundle product, including the steps of: inspecting two or more threads continuously running in parallel in a longitudinal direction; collecting the threads; and cutting all the threads collected at a predetermined position after completion of collecting, to obtain a bundle product having a plurality of threads converged into a bundle, in which
an amount of collection in the collecting step is adjusted on the basis of inspection results obtained in the inspecting step so that at least one managed quantity for a plurality of threads selected from a group including a total number, a total weight, a representative weight, a total outside diameter value, a representative outside diameter value, a total surface area, and a representative surface area of the plurality of threads constituting the bundle product exceeds a predetermined value.
(2) The manufacturing method for a bundle product according to (1) described above, in which the collecting step is a winding and collecting step of collecting the threads during rotation.
(3) The manufacturing method according to (1) described above, in which the collecting step is a cutting and collecting step of collecting the threads while cutting the threads to a certain length.
(4) The manufacturing method according to (1) described above, in which the collecting step is a turn-around collecting step of collecting the threads while turning around the threads at a certain length.
(5) The manufacturing method for a bundle product according to any of (1) to (4) described above, in which the threads are hollow fiber membranes.
(6) The manufacturing method for a bundle product according to any of (1) to (5) described above, in which the managed quantity for the plurality of threads is the total surface area of the plurality of threads constituting the bundle product.
(7) The manufacturing method for a bundle product according to any of (1) to (5) described above, in which the managed quantity for the plurality of threads is the representative surface area of the plurality of threads constituting the bundle product.
(8) The manufacturing method for a bundle product according to (6) or (7) described above, in which, in the inspecting step, outside diameters of the threads are measured, and surface areas of the threads are calculated on the basis of the obtained measured values of the outside diameters.
(9) The manufacturing method for a bundle product according to any of (1) to (8) described above, further including the step of:
removing a thread determined to contain a defect in the inspecting step from the bundle of the plurality of threads, in which
an amount of collection in the collecting step is adjusted so that at least one managed quantity for a plurality of threads selected from a group including a total number, a total weight, a representative weight, a total outside diameter value, a representative outside diameter value, a total surface area, and a representative surface area of the plurality of threads constituting a bundle product after the thread containing the defect is removed in the removing step exceeds a predetermined value.
Further, a device for manufacturing a bundle product according to the present invention includes any of the following configurations (10) to (13).
(10) A manufacturing device for a bundle product including an inspecting unit that inspects two or more threads continuously running in parallel in a longitudinal direction, a collecting unit that collects the threads, and a cutting unit that, after completion of collecting, cuts all the collected threads at a predetermined position, to obtain a bundle product having a plurality of threads converged into a bundle, in which
the manufacturing device further includes a collection-amount adjusting unit that can adjust an amount of collection by the collecting unit on the basis of inspection results obtained by the inspecting unit so that at least one managed quantity for a plurality of threads selected from a group including a total number, a total weight, a representative weight, a total outside diameter value, a representative outside diameter value, a total surface area, and a representative surface area of the plurality of threads constituting the bundle product exceeds a predetermined value.
(11) The manufacturing device for manufacturing a bundle product according to (10) described above, in which the threads are hollow fiber membranes.
(12) The manufacturing device for manufacturing a bundle product according to (10) or (11) described above, in which the inspecting unit includes means for calculating surface areas of the threads on the basis of a measured value of an outside diameter obtained by the inspecting unit that measures outside diameters of the threads.
(13) The manufacturing device for manufacturing a bundle product according to any of (10) to (12) described above, in which
on the assumption that a thread determined to contain a defect by the inspecting unit is removed from the bundle of the plurality of threads before the product is shipped, the collection-amount adjusting unit adjusts an amount of collection by the collecting unit so that at least one managed quantity for a plurality of threads selected from a group including a total number, a total weight, a representative weight, a total outside diameter value, a representative outside diameter value, a total surface area, and a representative surface area of the plurality of threads constituting a bundle product after the thread containing a defect is removed exceeds a predetermined value.
With the manufacturing method for a bundle product according to the present invention, it is possible to measure all the managed quantities for all the plural threads during running from the start of collection to the end. This makes it possible to control the amount of winding in a collecting step so that each of the managed quantities exceeds standard values, and to reliably ensure the quality of the bundle product finally obtained. Thus, it is possible to eliminate the need for a worker to measure the managed quantities after the bundle product is obtained and replenish normal threads to the bundle product. Further, since all the managed quantities can be measured for all the plural threads, which is impossible for the worker to do, it is possible to minimize the risk that actual performance of the bundle product finally obtained is insufficient.
Further, with the present invention, it is possible to inspect all the plural threads during running as to whether any defect exists, and further, it is possible to control the amount of winding in a collecting step while considering that, if any defect is found, this defective portion is removed later from the bundle of threads. Thus, it is possible to eliminate the need for the worker to inspect the bundle of threads after the bundle product is obtained and replenish normal threads to the bundle product.
Yet further, according to the present invention, it is assumed that the defective portion is removed once after the bundle of threads is obtained. Thus, if the number of defects occurring increases, there is no need to stop the line, and hence, manufacturing efficiency does not deteriorate.
The manufacturing device for a bundle product according to the present invention is one that can preferably implement the manufacturing method for a bundle product according to the present invention described above, and is one that can ensure the quality of threads constituting the bundle product and improve manufacturing efficiency in the case where two or more threads are caused to continuously run in parallel.
a) and 1(b) are schematic views each illustrating an example of an embodiment (winding and collecting step) of a manufacturing device according to the present invention, in which
a) and 3(b) are schematic views exemplarily illustrating images each including hollow fiber membranes with various outside diameters.
a) to 4(d) are schematic views exemplarily illustrating images each including hollow fiber membranes which are defective fibers.
a) and 7 (b) are schematic views each illustrating an example of another embodiment (cutting and collecting step) of the manufacturing device according to the present invention, in which
a) and 8(b) are schematic views each illustrating an example of another embodiment (turn-around collecting step) of the manufacturing device according to the present invention, in which
a) and 9(b) are schematic views each illustrating an example of an embodiment (a marker is provided in the winding and collecting step) of the manufacturing device according to the present invention, in which
A manufacturing device for a bundle product according to an embodiment of the present invention includes at least an inspecting unit, a collecting unit, a cutting unit and a collection-amount adjusting unit for bundle products. Of these units, the collecting unit and the cutting unit may be configured as units independent from each other, or configured as a cutting and collecting unit having both of a collecting function and a cutting function. Further, the manufacturing device for a bundle product may further include a marker unit.
The inspecting unit includes measuring and inspecting means and an inspection controlling mechanism, and is one that performs measurements and inspection on two or more threads continuously running in parallel in the longitudinal direction, as to managed quantities selected from the total amounts (total number, total weight, total outside diameter, total surface area) and representative amounts (representative weight, representative outside diameter, representative surface area). Further, the inspecting unit can inspect the threads as to whether any defect exists in the threads. The marker unit includes a marker head and a marker controlling mechanism, and puts a mark on a thread determined to be abnormal in collaboration with the inspecting unit.
The collecting unit unites plural threads, which continuously run, while collecting the threads, and can adjust the amount of collection per bundle product in collaboration with the inspecting unit and the collection-amount adjusting unit. Examples of the independent collecting unit include a winding and collecting device that collects the threads while rotating, and a turn-around collecting device that collects the threads while turning around the threads at a predetermined length. The cutting unit cuts all the threads collected by the collecting unit at a predetermined position.
Further, the cutting and collecting unit has a function of collecting plural threads, a function of adjusting the amount of collection, and a cutting function. An example of the cutting and collecting unit includes a cutting and collecting device that collects the threads while cutting the threads to a certain length.
The collection-amount adjusting unit is a controlling unit that adjusts the amount of collection in the collecting unit so that the managed quantities for the plural threads measured by the inspecting unit exceed a predetermined value in the bundle product, and further, adjusts the amount of collection of the threads in the collecting unit so as to compensate for the managed quantities corresponding to the threads determined to be abnormal by the inspecting unit and removed from the bundle product.
A manufacturing method for a bundle product according to an embodiment of the present invention includes at least an inspecting step, a collecting step, and a cutting step. Of these steps, the collecting step and the cutting step may be configured as steps independent from each other, or configured as a cutting and collecting step that performs both of the operations.
In the inspecting step, measurement and inspection are performed on two or more threads continuously running in parallel in the longitudinal direction, as to managed quantities selected from the total amounts (total number, total weight, total outside diameter, and total surface area) and representative amounts (representative weight, representative outside diameter, and representative surface area).
In the collecting step, plural threads continuously running are collected while being united. On the basis of the managed quantities measured in the inspecting step, it is possible to determine whether standard values set for the bundle product are exceeded, and adjust the amount of collection of the threads. Further, if it is detected in the inspection step that an abnormal thread (defective fiber) exists, it is possible to further adjust the amount of collection of the threads so as to compensate for the managed quantities corresponding to the defective fiber removed from the bundle product.
In the cutting step, all the threads collected in the collecting step are cut at a predetermined position. Further, in the cutting and collecting step, plural threads are collected and cut in one step.
With the manufacturing method for a bundle product according to the present invention, it is possible to stably manufacture high-quality bundle products by using the manufacturing device for a bundle product described above.
An example of the bundle product may include a hollow fiber membrane bundle used as an ultrafiltration membrane, a microfiltration membrane, a gas separation membrane, a pervaporation membrane, and a dialysis membrane. The hollow fiber membrane bundle is used, for example, in water treatment, artificial kidney, or concentration of valuables in various industrial processes. Note that the bundle product is not limited to the hollow fiber membranes as described above, and any bundle product may be possible, provided that the bundle product is a thread product such as fiber for clothing, carbon fiber, optical fiber, steel wire, and medical catheter, which has a structure in which plural threads can be substantially manufactured in parallel at the same time.
Embodiments according to the present invention will be described below with reference to the drawings by taking a hollow fiber membrane bundle as an example. Note that these embodiments do not limit the present invention.
The first embodiment of the manufacturing device for a bundle product according to the present invention includes an inspecting unit, a winding and collecting unit, a cutting unit, and a collection-amount adjusting unit.
In
Note that
Furthermore, in
The hollow fiber membrane to be manufactured in the present invention is basically collected in the form of a united-thread hollow fiber membrane 11 obtained by uniting single threads 10 of the hollow fiber membranes as illustrated in
Here, the material for the hollow fiber membrane includes, for example, organic polymers such as polycarbonate, polyolefin, polyamide, polyimide, cellulose, polysulfone, polyethersulfone, polymethacrylic acid, polyacrylonitrile, polyvinylidene fluoride, and polyetherketone, and ceramics such as alumina, zirconia, titania, and silicon carbide.
As illustrated in
Here, the winding and collection controlling mechanism 24 controls start and stop of rotation of the winding and collecting device 22, the rotational speed, movement of the reel 23 in the same direction as that of the rotational axis, movement of the reel position after the completion of winding, the number of rotations of the reel, 23 and other operations. Furthermore, the number of rotations of the reel 23 is controlled so that the predetermined amount of the united-thread hollow fiber membrane bundle 12 can be obtained. Then, after the predetermined amount thereof is obtained, a completion operation such as stop of the reel or automatic movement to the next reel position is controlled.
Furthermore, the inspecting unit according to an embodiment of the present invention includes the measuring and inspecting head 20 that monitors the single thread of the hollow fiber membrane, and the measurement and inspection controlling mechanism 21 that processes information obtained by the measuring and inspecting head 20 to actually measure the outside diameter of the thread or check existence of defect. The measurement and inspection controlling mechanism 21 and the winding and collection controlling mechanism 24 are configured so that information can be communicated to each other. Note that, for the measuring and inspecting head 20, it may be possible to employ, for example, a general-purpose digital camera, an analog camera, a lens for general-purpose cameras, or a shape measurement sensor using an LED illumination or laser light. Further, as for the measurement and inspection controlling mechanism 21, it may be possible to employ a system configured by installing, for example, an image capturing board, a signal processing board, a communication board, signal processing software, and system controlling software to a general-purpose PC, or a commercially available image inspection system. Further, it may be possible to integrally form the winding and collection controlling mechanism 24 and the measurement and inspection controlling mechanism 21. Operations of parts associated with these control signals will be described in detail later.
After the reel 23 finishes winding the predetermined amount of the united-thread hollow fiber membrane bundle 12, the united-thread hollow fiber membrane bundle 12 is cut at a portion joined with the united-thread hollow fiber membrane 11, and conveyed to the next step together with the reel 23. Note that, after this, in the case where the united-thread hollow fiber membrane 11 is continuously conveyed from the upstream side, a new empty reel 23 is immediately set, and winding of the united-thread hollow fiber membrane 11 is started, thereby continuing manufacturing.
Next, the cutting step will be described with reference to
These are basic descriptions of the manufacturing method of the hollow fiber membrane bundle 13. Next, a method of controlling the collecting step will be described.
As described above, the managed quantities for the hollow fiber membrane bundle 13 are specified on the basis of applications of a module, which is a final product, or performance required by customers for the module. The managed quantities include, for example, the total number, the total weight, the representative weight, the total outside diameter value, the representative outside diameter value, the total surface area, and the representative surface area concerning all the hollow fiber membranes contained in the hollow fiber membrane bundle 13, which is to be assembled in the module sometime in the future.
If the hollow fiber membranes are manufactured in an ideal state where the shapes or weights of the hollow fiber membrane do not vary, and no defective fiber exists therein, the amount of collection in the collecting step can be determined on the basis of quality standard values, and correction during manufacturing is not required. However, actually, variation in manufacturing occurs, and if a defective fiber exists due to external disturbances occurring during manufacturing processes, this defective fiber has to be removed from the hollow fiber membrane bundle 13. Thus, the present invention is characterized in that, on the assumption that variation in manufacturing occurs or a defective fiber exists, the collecting step is preferably controlled during manufacturing so that the hollow fiber membrane bundle 13 exceeds predetermined standard values after the collecting step and the removing step. Note that it is necessary that the managed quantities for the hollow fiber membrane bundle 13 at least exceed the standard values. However, it is more preferable to perform control so as to end the collection step at a time when these managed quantities exceed the standard values because such control eliminates wasteful manufacturing.
Variations in manufacturing of the hollow fiber membranes and the existence of the defective fiber are monitored by the measuring and inspecting head 20 and the measurement and inspection controlling mechanism 21 as illustrated in
The digital camera serving as the measuring and inspecting head 20 repeatedly captures, at temporal intervals, images of the plural single threads 10 of the hollow fiber membranes conveyed in parallel without failing to capture images of even a part of the hollow fiber membranes, and sends the captured images to the measurement and inspection controlling mechanism 21.
In
In
Note that, in these images, it is assumed that the captured image resolution in the width direction (XD direction) of the hollow fiber membrane in the image is X μm/pix, and the captured image resolution in the longitudinal direction (YD direction=direction in which a hollow fiber membrane is conveyed) of the hollow fiber membrane is Y μm/pix. The captured image resolution is defined as an amount indicating the actual size in the three-dimensional world to which each pixel (pix) constituting the image corresponds, and a unit thereof is defined as the size (μm/pix) per pixel (pix).
If the quality of the hollow fiber membrane is managed during manufacturing, it can be considered that there are following two types of managed quantities for the hollow fiber membrane used as indexes: the total amount (total number, total weight, total outside diameter, and total surface area) and the representative amount (representative weight, representative outside diameter, and representative surface area). The former type is one for adjusting the amount of collection of the hollow fiber membrane bundle while considering all pieces of information on the managed quantities for the hollow fiber membrane being manufactured, and is ideal from the viewpoint of the quality management. However, the measurement and inspection controlling mechanism 21 has to carry a huge burden, which results in disadvantages in equipment such as the necessity to use a high-speed expensive calculator, or the necessity for plural calculators to share the system. On the other hand, the latter type is one in which the measurement and inspection controlling mechanism 21 measures, once or plural times, a specific portion of the hollow fiber membrane being manufactured in accordance with predetermined conditions, and adjusts the amount of collection using, as indexes, the representative amounts calculated on the basis of the measurement results, and this type can be configured with simple equipment. However, in order to realize sufficient quality management, it is required that variation in quality of the hollow fiber membrane to be manufactured should be sufficiently small. In other words, it is preferable to adopt the former type in the case where variation in quality of the hollow fiber membrane to be manufactured is expected to be large, and adopt the latter type in the case where the variation is expected to be small.
On the basis of the facts described above, with reference to a process flow in
Where the collecting step starts, first in Step 11, a program in the measurement and inspection controlling mechanism 21 is initialized. At this time, types and the standard values of the managed quantities, which are preset to be used in the quality management, are read into the program. Next, in Step 12, the measurement and inspection controlling mechanism 21 instructs the winding and collection controlling mechanism 24 to rotate the reel 23, and the reel 23 starts to rotate. Then, in Step 13, while the reel 23 rotates one turn, the managed-quantity sum total value for each of the plural single threads 10 of the hollow fiber membranes conveyed in parallel is calculated, and then, the managed-quantity sum total value is corrected on the basis of the judgment results for the defective fiber (details thereof will be described later). Then, in Step 14, the managed-quantity sum total values are added up until the current turn, thereby obtaining the total amount of the managed quantities. Then, in Step 15, it is determined whether the total amount of the managed quantities exceeds a standard value. If the total amount of the managed quantities does not exceed the standard value, the process returns to Step 12, whereas, if the total amount exceeds the standard value, the process moves to Step 16 (if the total amount exceeds the standard value, it means that a predetermined winding of the united-thread hollow fiber membrane bundle 12 is completed at this reel position). Next, in Step 16, it is determined whether winding of the hollow fiber membrane is moved to another reel position. If the winding is moved to another reel position, the winding and collecting device 22 is operated to move the hollow fiber membrane to the next reel position, and the process returns to Step 11. If the winding is not moved, the process proceeds to Step 17. Next, in Step 17, the reel is stopped, and winding of a predetermined united-thread hollow fiber membrane bundle 12 for all of the reel positions is completed.
Details of Step 13 will be described. First, in Step 13a, images 50 of the plural single threads 10 of the hollow fiber membranes conveyed in parallel are captured with a digital camera at time intervals, and the images 50 are sent to a signal processing unit of a digital-camera-type image inspection system. The timing at which images of the single threads 10 of the hollow fiber membranes are captured at time intervals is determined so as to capture all the images of the hollow fiber membranes conveyed without failing to capture images of even a part thereof. For example, the timing for capturing the images may be determined by considering, for example, the width of the image that one shot of image-capturing covers and the speed at which the hollow fiber membranes are conveyed.
Next, in Step 13b, the signal processing unit individually recognizes the images 51 to 67 of the plural single thread hollow fiber membranes in the images 50. Note that, also in the case where cutting of the thread occurs, the occurrence of the cutting 68 of the thread is recognized by checking the portion of the hollow fiber membrane where an image is supposed to be captured. Next, in Step 13c, the managed quantities are calculated for each of the single threads 10 of the hollow fiber membranes. Note that, although the method of calculating the managed quantities will be described later, all the managed quantities are calculated as 0 (zero) for the cutting of the thread.
Next, in Step 13d, all the managed quantities measured until the present time on the basis of the images sent at time intervals are added up to obtain the managed-quantity sum total value for each of the single threads 10 of the hollow fiber membranes. Note that the managed quantities in Step 13d are added up on the assumption that images for one turn of the reel are captured separately plural times, and hence, this does not apply to a case where one image for one turn of the reel is captured only once.
Next, in Step 13e, it is checked whether any of defective hollow fiber membranes 57 to 67 exists in the image. If none of defective hollow fiber membrane 57 to 67 exists, the process proceeds directly to next Step 13h. On the other hand, if any of defective hollow fiber membranes 57 to 67 exists, the process proceeds to next Step 13f. In Step 13f, a removing flag is generated in information on the defective fiber. Usage of the removing flag will be described later. Next, in Step 13g, the managed-quantity sum total value calculated in Step 13d is corrected. More specifically, the defective fiber in which a defect has been found is removed in the removing step, and hence, this managed quantity needs to be excluded from the managed-quantity sum total value during this turn of the reel. Next, in Step 13h, it is determined whether the reel has completed rotating one turn. For this determination, it is only necessary to receive a completion signal from the winding and collection controlling mechanism 24. If the reel has not yet completed rotating one turn, the process returns to Step 13a, whereas, if completed rotating one turn, the process proceeds to Step 14.
Next, with reference to a process flow in
When the collecting step starts, a program in the measurement and inspection controlling mechanism 21 is first initialized in Step 21. At this time, preset types and standard values of managed quantities used for the quality management are read into the program, and a temporary value of the number of rotations of the reel 23 is set. Then, in Step 22, the measurement and inspection controlling mechanism 21 instructs the winding and collection controlling mechanism 24 to rotate the reel 23, and the reel 23 starts to rotate. Then, in Step 23, the managed-quantity sum total value is calculated for each of the plural single threads 10 of the hollow fiber membranes conveyed in parallel, the target number of rotations is determined in accordance with conditions for obtaining the representative amounts, and then, the target number of rotations is corrected on the basis of the determination results on the defective fiber (details thereof will be described later). Then, in Step 24, when the reel 23 rotates one turn, the actual number of rotations is incremented by one. Next, in Step 25, it is determined whether the actual number of rotations exceeds the target number of rotations. If the actual number of rotations does not exceed the target number of rotations, the process returns to Step 22, whereas, if it exceeds the target number of rotations, the process proceeds to Step 26 (if it exceeds the target number of rotations, this means that a predetermined winding of the united-thread hollow fiber membrane bundle 12 is completed at this reel position). Next, in Step 26, it is determined whether winding of the hollow fiber membrane is moved to another reel position. If the winding is moved, the winding and collecting device 22 is operated to move the hollow fiber membrane to the next reel position, and the process returns to Step 21, and if the winding is not moved, the process proceeds to Step 27. Next, in Step 27, the reel is stopped, and winding of a predetermined united-thread hollow fiber membrane bundle 12 for all of the reel positions is completed.
Details of Step 23 will be described. First, in Step 23a, images 50 of the plural single threads 10 of the hollow fiber membranes conveyed in parallel are captured with a digital camera, and the images 50 are sent to a signal processing unit of a digital-camera-type image inspection system. Next, in Step 23b, the signal processing unit individually recognizes the images 51 to 67 of the plural single thread hollow fiber membranes in the images 50. Note that, also in the case where cutting of the thread occurs, the occurrence of the cutting 68 of the thread is recognized by checking the portion of the hollow fiber membrane where an image is supposed to be captured. Next, in Step 23c, it is checked whether the target number of rotations is determined. If it is determined, the process moves to Step 23g. If it is not determined, the process proceeds to Step 23d. Next, in Step 23d, the managed quantities are calculated for each of the single threads 10 of the hollow fiber membranes, and the calculated value is stored in a numerical buffer. Note that, although the method of calculating the managed quantities will be described later, all the managed quantities are calculated as 0 (zero) for the cutting of, the thread. Next, in Step 23e, it is checked whether data on the managed quantities necessary to calculate the representative amounts are available. If the data are available, the process proceeds to Step 23f, whereas, if the data are not yet available, the process moves to Step 23g. Next, in Step 23f, the data on the managed quantities are processed and calculated in accordance with conditions for calculating the representative amounts and the standard values to determine the target number of rotations, and the temporary number of rotations is rewritten with the target number of rotations. Next, in Step 23g, it is checked whether any of the defective hollow fiber membranes 57 to 67 exists in the image. If it does not exists, the process proceeds directly to next Step 23j. On the other hand, if it exists, the process proceeds to next Step 23h. In Step 23h, a removing flag is generated in information on the defective fiber. Usage of the removing flag will be described later. Next, in Step 23i, the target number of rotations calculated in Step 23f is corrected. More specifically, the defective fiber in which a defect has been found is removed in the removing step, and hence, with the current target number of rotations, there is a possibility that it is not possible to satisfy the standard values at the end. In such a case, the target number of rotations needs to be increased. Next, in Step 23j, it is determined whether the reel has completed rotating one turn. For this determination, it is only necessary to receive a completion signal from the winding and collection controlling mechanism 24. If the reel has not yet completed rotating one turn, the process returns to Step 23a, whereas, if the reel has already completed rotating one turn, the process proceeds to Step 24.
Here, a supplementary description will be given of Step 23f. The conditions for calculating the representative amounts used in Step 23 should be appropriately set according to the degree of variations occurring during manufacturing processes, the degree of the quality management for product types to be manufactured, or quality requirements from customers. For example, it is preferable to use, an average value of all the managed quantities for all the plural threads for the first turn of the reel 23, or an average value of specific single threads, or an average value of these values for plural turns. However, the way of determining the conditions for calculating the representative amounts is not limited to those described above.
As for common items between the two methods, which are the total amount and the representative amounts used as indexes of the managed quantities for the hollow fiber membrane, the first common item is a characteristic as to the way of obtaining the managed quantities. More specifically, the managed quantity is basically obtained in a fine performance with the maximum captured-image resolution (X μm/pix, Y μm/pix) described above (primary managed quantity). However, it may be possible to make correction using a general image processing method in order to remove external disturbance factors from data, and obtain a secondary managed quantity on the basis of plural primary managed quantities. The general image processing method includes averaging, normalizing and other methods.
The second common item is a method of detecting a defect in the hollow fiber membrane. More specifically, it may be possible to apply a general image processing technique for inspection of the defective hollow fiber membrane. For example, it is only necessary to register, in advance, images 51 to 56 of normal hollow fiber membranes in
Here, a more specific description will be given of a method of obtaining the managed quantities (number, weight, outside diameter value, and surface area).
First, as for the number, the number serving as the managed quantity is only treated as the total amount, and is calculated in Step 13 in
Next, as for the weight, the weight serving as the managed quantity is treated as both the total amount and the representative amount. Note that, during the process of manufacturing the hollow fiber membrane, a raw material for the hollow fiber membrane is generally supplied accurately. More specifically, the outside diameter value may be larger or smaller than the design value due to variations in formation of the raw material into the shape of the hollow fiber membrane. In this case, the thickness is small in the former case, and the thickness is large in the latter case. However, the amount of the raw material per unit length of the hollow fiber membrane is constant. Thus, the weight W (unit: mg) of one hollow fiber membrane contained in the hollow fiber membrane bundle 13 can be accurately calculated by Equation 1 on the basis of the weight Wm (unit: mg/mm) of the raw material used per unit length, and the length L mm of the hollow fiber membrane bundle 13.
W=Wm×L Equation 1
Next, as for the outside diameter, the outside diameter R μm is calculated using Equation 2 described below on the basis of the number Xn pix of pixels in the XD direction of an image of the hollow fiber membrane and the captured-image resolution X μm/pix in the XD direction, within the minimum unit of measurement (=area of one pixel in the YD direction) in the direction in which the hollow fiber membrane is conveyed.
R=X×Xn Equation 2
The outside diameter R dam obtained through Equation 2 described above and serving as the managed quantity is obtained in Step 13c or Step 23d in the process flow. Naturally, plural outside diameters R μm can be obtained from one image, and can be obtained also for each turn of the reel.
Next, as for the surface area, the present invention assumes that the surface area is obtained by adding up, in the minimum unit of measurement, the circumference of a hollow fiber membrane in the direction in which the hollow fiber membrane is conveyed. Thus, in the minimum unit of measurement, by using the general formula for substantially obtaining the circumference, the surface area S μm2 is calculated using Equation 3 described below on the basis of the outside diameter R μm and pi π.
S=π×R Equation 3
The surface area S μm2 obtained through Equation 3 described above and serving as the managed quantity is obtained in Step 13c or Step 23d in the process flow as the circumference in the minimum unit of measurement. Naturally, plural surface areas S μm2 can be obtained from one image, and can be obtained also for each turn of the reel. Further, the value obtained by adding up information in the conveying direction has a meaning of the surface area.
In the present invention, by using the methods as described above, the predetermined managed quantities (number, weight, outside diameter value, and surface area) are obtained in accordance with the manufacturing conditions or conditions for quality management, and the manufacturing processes are automatically controlled on the basis of the total amount (=flow in
It should be noted that, in the description above, an example is given in which a general-purpose digital-camera-type image inspection system is used for the measuring and inspecting head 20 and the measurement and inspection controlling mechanism 21. However, any device or unit may be used, provided that similar effects can be obtained with the device or unit. In particular, in order to optimize specifications of a device, it is preferable to select, according to manufacturing ability of the manufacturing processes, each unit that realizes the measuring and inspecting head 20 and the measurement and inspection controlling mechanism 21, and uniquely build up a system.
The second embodiment of the manufacturing device for a bundle product according to the present invention includes the inspecting unit, the cutting and collecting unit, and the collection-amount adjusting unit.
As illustrated in
Here, the cut and collection controlling mechanism 32 controls the number of cuts with the cutter 31, in addition to starting and stopping of operation of the cutting and collecting device 27, the speed at which the clips move, cutting operations, and the like. The number of cuts is controlled so that a predetermined amount of the united-thread hollow fiber membrane bundle 12′ can be obtained. After the predetermined amount is obtained, the cut and collection controlling mechanism 32 performs completion operations such as stopping cutting and clip, or replacing the collection tray 28 with an empty collection tray which is not illustrated.
Furthermore, as in embodiment 1, also in embodiment 2, the measurement and inspection controlling mechanism 21 and the cut and collection controlling mechanism 32 are configured so that information can be communicated between them.
After the predetermined amount of the united-thread hollow fiber membrane bundles 12′ is collected on the collection tray 28, the united-thread hollow fiber membrane bundle 12′ is bound into a bundle at one end portion thereof with a binding unit which is not illustrated, is hung with a crane, and is carried out toward the removing step. Thus, in the case where cutting and collecting are employed as the collecting means, a step of cutting the hollow fiber membrane bundle is not required in the cutting step.
It should be noted that configurations other than those described above may be similar to those of embodiment 1.
The third embodiment of the manufacturing device for a bundle product according to the present invention includes the inspecting unit, a turn-around collecting unit, the cutting unit, and the collection-amount adjusting unit.
As illustrated in
Here, the turn-around collection controlling mechanism 36 controls the number of turns of the turn-around gear 34, in addition to starting and stopping of operation of the turn-around collecting device 33, the speed at which the moving guide moves, the rotational speed of the turn-around gear, and the like. After the predetermined amount is obtained, the turn-around collection controlling mechanism 36 performs completion operations, such as stopping the turn-around operation and gear-rotating operation, or replacing the turn-around gear 34 with an empty turn-around gear which is not illustrated.
Further, also in embodiment 3, as in embodiment 1 and embodiment 2, the measurement and inspection controlling mechanism 21 and the turn-around collection controlling mechanism 36 are configured so that information can be communicated between them.
After the predetermined amount of the united-thread hollow fiber membrane bundles 12″ is collected on the turn-around gear 34, the united-thread hollow fiber membrane bundle 12″ is bound at one end portion thereof with a binding unit, not illustrated, is cut at both ends thereof with a cutting tool, not illustrated, is hung with a crane in this state, and is carried out toward the removing step.
It should be noted that configurations other than those described above may be similar to those of embodiment 1.
The fourth embodiment of the manufacturing device for a bundle product according to the present invention includes the inspecting unit, the marker unit, the winding and collecting unit, and the collection-amount adjusting unit.
As illustrated in
It should be noted that configurations other than those described above may be similar to those of embodiment 1. Furthermore, also in the collecting steps of embodiments 2 and 3, it may be possible to apply the marking as in this embodiment.
With the configurations illustrated in
As for conditions for manufacturing the hollow fiber membranes, a design value of the outside diameter was set to 1425 μm. More specifically, a design value of the circumference was 0.0044745 m, and a design value of the surface area per hollow fiber membrane of one turn of the reel was 0.0062643 m2. Note that this hollow fiber membrane bundle was finally incorporated into a module for water treatment, which is a final product. In order to ensure the performance of the module, it is necessary for this hollow fiber membrane bundle to have a standard value of 4.02 m2 for the total surface area. If the hollow fiber membrane bundle is formed by 642 single threads, the total surface area is 4.0216806 m2 on the assumption that the hollow fiber membrane is manufactured ideally in accordance with the design values, and satisfies the standard value. In other words, it is only necessary to rotate the reel by 214 turns under the conditions for manufacturing three united threads. Note that the managed width in connection with the abnormality of the outside diameter of a single hollow fiber membrane is set in the range of 1350 to 1500 μm in order to avoid causing inconveniences to customers during the time when the module is being used, which has been already described.
Under the conditions as described above, the hollow fiber membrane bundle was manufactured. As a result, depending on the manufacturing states of a certain lot, the outside diameter of the hollow fiber membrane tended to be smaller than the design value (a median value was approximately 1370 μm), and at the time when the reel rotated 214 turns, the total surface area was 3.87 m2, and had not reached the standard value of 4.02 m2. Thus, the collection-amount adjusting unit continued to perform collection while controlling the collecting unit. Then, at the time when the reel rotated 223 turns, the total surface are of the hollow fiber membrane reached 4.03 m2, and satisfied the standard value (note that the number of hollow fiber membranes was 669). On the contrary, in the manufacturing state of another lot, the outside diameter of the hollow fiber membrane tended to be larger than the design value (a median value was approximately 1488 μm), and at the time when the reel rotated 205 turns, the total surface area of the hollow fiber membrane was 4.023 m2, which satisfied the standard value (note that the number of the hollow fiber membranes was 615).
Furthermore, in the manufacturing state of another lot, the hollow fiber membrane was manufactured with the outside diameter of the hollow fiber being almost the design value (a median value was approximately 1422 μm). However, immediately after the reel rotated 186 turns, one of the three single threads was cut. Thus, after that, only two single threads were collected. At the time when the reel rotated 229 turns, the total surface area of the hollow fiber membrane was 4.026 m2, which satisfied the standard value (note that the number of the hollow fiber membranes was 644).
The hollow fiber membranes manufactured in the above-described cases were each assembled in a module, and final inspection before shipping of the modules was performed on these modules. As a result, these modules exhibited sufficient filtration performance.
For a certain type of the hollow fiber membrane bundle, it is known that the manufacturing state is sufficiently stable, and the initial state continues. Thus, the surface area serving as the managed quantity was managed using representative amounts. Conditions for calculating the representative amount were set such that the reel rotated up to 3 turns; the outside diameter was measured once for each of three single threads; and the number of rotations of the reel was obtained on the basis of the average value of nine pieces of outside diameter data. Under these conditions, manufacturing was performed (note that conditions other than those described above were similar to those in Example 1).
As a result, the following outside diameter data were obtained: for the first single thread, 1452 μm (first turn), 1454 μm (second turn), and 1452 μm (third turn); for the second single thread, 1451 μm (first turn), 1450 μm (second turn), and 1452 μm (third turn); and for the third single thread, 1454 μm (first turn), 1455 μm (second turn), and 1453 μm (third turn). Further, by averaging these data, the average outside diameter of 1452.56 μm was obtained. On the basis of this outside diameter, in order to satisfy the standard value of 4.02 m2 for the surface area, the hollow fiber membrane bundle was configured by setting the number of rotations of the reel to 210 turns, and setting the number of single threads to 630. This hollow fiber membrane bundle was assembled in a module, and final inspection before the shipment of the module was performed on the module. As a result, the module exhibited sufficient filtration performance.
Furthermore, in this Example, the managed quantity did not have to be always monitored. Thus, it was possible to significantly reduce the amount of processing load that the general-purpose PC used as the inspecting unit has to carry. This makes it possible to, for example, view the past inspection information, organize data, create documents, and duplicate various electronic data to an external medium while manufacturing the hollow fiber membrane bundle. As a result, it is possible to improve efficiency of the entire operations.
A hollow fiber membrane bundle was manufactured using the configuration in
As a result, during the time when the hollow fiber membrane bundle was manufactured, the measuring and inspecting unit detected 6 defective hollow fiber membranes (scratch), 17 defective hollow fiber membranes (foreign substance), and 8 defective hollow fiber membranes (swelling), each of which is to be contained in the hollow fiber membrane bundle to be finally obtained in the cutting step. On the basis of these results, the collection-amount adjusting unit increased the number of rotations of the reel by 11 turns to 221 turns from 210 turns, which is the number of rotations in the case where no defective hollow fiber membrane exists.
Further, at the time when the hollow fiber membrane bundle was obtained in the cutting step, the marker applied markings to these defective hollow fiber membranes through firing with emission of laser from a distance in a range of 100 to 250 mm by setting the position of the binding unit to the reference.
At the time when manufacturing was completed, this hollow fiber membrane bundle contained 663 single threads. However, an operator checked the markings in the removing step, and removed 31 defective hollow fiber membranes, which were determined to be the defective by the measuring and inspecting unit. Finally, the number of the hollow fiber membranes was 632. This hollow fiber membrane bundle was assembled in a module, and final inspection before the shipment of the module was performed on the module. As a result, the module exhibited sufficient filtration performance. Furthermore, since the defective hollow fiber membranes were accurately removed, no abnormality was found in the module also during the time when the module was used by a customer.
A hollow fiber membrane bundle was manufactured using the configuration illustrated in
As described in Example 1, the design value of the outside diameter of the hollow fiber membrane was 1425 μm. In order to ensure the performance of the module having the hollow fiber membrane bundle finally assembled therein, the standard value of the total outside diameter of this hollow fiber membrane bundle is 1.28 m. If the hollow fiber membrane bundle is formed by 642 singles threads, the total outside diameter was 1.28079 m on the assumption that the hollow fiber membrane was manufactured ideally in accordance with the design values, and it is possible to satisfy the standard value. In other words, it is only necessary to rotate the reel by 214 turns under the manufacturing conditions for three united threads.
Under these conditions, the hollow fiber membrane bundle was manufactured. As a result, depending on the manufacturing states of a certain lot, the outside diameter of the hollow fiber member tended to be larger than the design value (a median value was approximately 1467 μm), and at the time when the reel rotated 208 turns, the total outside diameter of the hollow fiber membrane was 1.282 m, and satisfied the standard value (the number of the hollow fiber membranes was 624). This hollow fiber membrane bundle was assembled in a module, and final inspection before the shipment of the module was performed on the module. As a result, the module exhibited sufficient filtration performance.
The hollow fiber membranes were collected and cut at the same time, which realized reduction in time required for the entire processes for manufacturing the hollow fiber membrane bundle.
On the other hand, in a manufacturing state similar to that in Example 1, a hollow fiber membrane bundle was manufactured without adjusting the amount of collection of the hollow fiber membranes and the effect of the present invention was confirmed. As a result, regardless of the manufacturing states of the hollow fiber membrane, the reel stopped rotating at 214 turns on the basis of the design value, and hence, in the case where the outside diameter of the hollow fiber membrane was smaller than the design value, the total surface area of the hollow fiber membrane bundle did not satisfy the standard value. Thus, the module did not sufficiently exhibit the filtration performance in the final inspection before the module is shipped, and was discarded as a defective product. On the other hand, in the case where the outside diameter of the hollow fiber membrane is larger than the design value, the total surface area of the hollow fiber membrane bundle satisfied the standard value, while the volume of the hollow fiber membrane bundle was larger than necessary, and the hollow fiber membrane bundle was not able to be inserted into a module. Thus, single threads had to be removed from the hollow fiber membrane bundle until the hollow fiber membrane bundle was able to be inserted into the module.
Further, in the case where cutting of threads occurred during manufacturing, the number of hollow fiber membranes that are short of the design value had to be counted after collection was completed, and the necessary number of hollow fiber membranes had to be added, which was the troublesome labor and time.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-043208 | Feb 2012 | JP | national |
This is the U.S. National Phase application of PCT/JP2013/051850, filed Jan. 29, 2013, which claims priority to Japanese Patent Application No. 2012-043208, filed Feb. 29, 2012, the disclosures of each of these applications being incorporated herein by reference in their entireties for all purposes.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2013/051850 | 1/29/2013 | WO | 00 |
