Patent Application
20120137638
The invention relates to a packaged tow structurally characterized that a carbon fiber precursor tow having a large degree of fineness and a flattened shape in cross section is thrown into a packaging container through a tow supply shoot and layered therein, and a method and a device for manufacturing the packaged tow, more particularly to a packaged carbon fiber precursor tow applied with a top/bottom surface identification means to identify a first surface and a second surface, the first and second surfaces respectively representing top and bottom surfaces of a front end and a back end in the carbon fiber precursor tow contained in the packaging container, and a method and a device for manufacturing such a packaged tow.
The carbon fibers excel in specific intensity, specific modulus, flame resistance, heat resistance, and durability. Therefore, a range of application of the carbon fibers thus technically advantageous is increasingly expanding. In recent years, thickened carbon fiber precursor tows including 50,000 filaments or more started to be used in order to improve the productivity of carbon fibers for cost reduction. In consequence of the ongoing trend, any packaged tow with such a thickened fiber tow is inevitably enlarged in size. An advantageous way to manufacture the packaged tow thus upsized is to throw the tow into a packaging container. So far were invented and disclosed variously different tow throw-in packaging techniques.
Japanese Patent Application Laid-Open No. 2006-176328 (Patent Document 1) discloses such a packaging technique. According to the packaging method disclosed in the Patent Document 1, a moisture-contained carbon fiber precursor tow having a large degree of fineness of 48,000 dtex to 720,000 dtex and a flame-proofed carbon fiber precursor tow (hereinafter, the carbon fiber precursor tow and the flame-proofed carbon fiber precursor tow are both simply called carbon fiber precursor tow) are thrown into a packaging container through a tow throw-in shoot, and a press plate on standby at a position above an end on the side of a folded end is pressed down when the packaging container reciprocated in a tow-width direction arrives at a folded end on the other side to compress the tows to obtain a packaged tow. The technique of the Document 1 is particularly characterized by setting a storage bulk specific gravity of the carbon fiber precursor tow thus packaged to at least 340 kg/m3.
Japanese Patent Application Laid-Open No. 2008-121147 (Patent Document 2) discloses a packaging technique similar to the method disclosed in the Patent Document 1. According to the packaging method, a tow throw-in shoot is elevated relative to a packaging container as a tow throw-in top in the packaging container rises to a higher level. The method is particularly characterized in that a distance a (mm) between a lowest position on a tow lead-out end and the tow throw-in top, a thickness h (mm) of a press plate, and a minimum distance y (mm) between the press plate and the tow throw-in shoot meet a relationship expressed by the formulas; 10≦a≦400, and (a-h)/y≦3.3, when a total degree of fineness of the tow is at least 48,000 dtex to less than 180,000 dtex.
The carbon fiber precursor tow thus packaged in the packaging container is not infinitely continuous but has a finite length, therefore, it is not possible to directly flame-proof and carbonize different tows in succession. In fact, the flame-proofing and the carbonization processes have to be suspended every time when these processes for the tow in one packaging container are over. The technical disadvantage resulted in the development of a piecing work to obtain a string of continuous tow by connecting front and back ends of tows. With this technique, the tow can be continuously flame-proofed and carbonized.
A long and continuous tow obtained by the piecing work still possibly undergoes a problem; thread breakage at joined parts of the tows due to heat accumulation particularly in the flame proofing process which generates heat. This sometimes interrupts the flame-proofing and carbonization processes desirably continuously performed. As disclosed in Japanese Patent Application Laid-Open No. 2008-150733 (Patent Document 3), for example, a thread breakage preventing technique performed prior to the piecing work was developed, wherein ends of the tows, at which the tows are joined with each other, are flame-proofed in advance.
It is disclosed in, for example, Japanese Patent Publication 47-51979 (Patent Document 4) that when a yarn continuously supplied, such as synthetic-fiber filament yarn, spanned yarn, or textured yarn, is introduced in a housing container, a front end thereof is led out of the container, ends of the yarn at its front and back are fixed to an outer surface of the housing container, and the front end of the yarn is joined with a back end of a yarn introduced in another housing container.
It is disclosed in the Patent Document 5 (Japanese Patent Application Laid-Open No. 2002-138326) that a fiber tow is cut as soon as a corrugated board box or a can is fully filled with fiber, and the cut end is knotted to prevent unraveling of the tow, or a clip-like member is applied to the tow end to prevent unraveling of the tow end.
When the ends of a plurality of packaged carbon fiber precursor tows are thus flame-proofed and then joined with each other by the piecing work to obtain a string of continuous tow, thread breakage still possibly happens during the flame proofing process due to heat accumulation. There has been a strong call for a breakthrough to solve the problem.
An immediate object of the invention is to solve the technical problems described above. Other objects will be construed from the description given below.
Faced with these technical problems, the inventors of the invention studied the technical problems through discussions and carried out various tests. Then, they finally found out that the conventional piecing work was not particularly designed not to incorrectly identify top and bottom surfaces of tows when the tows were joined with each other, therefore, the tows joined with their top and bottom surfaces the other way around were naturally twisted, and the twisted parts often underwent thread breakage due to heat accumulation. Based on this finding, the inventors of the invention reached the conclusion; a carbon fiber precursor tow can be prevented from twisting when a front end and a back end of the carbon fiber precursor tow are each applied with a top/bottom surface identification means configured to identify a first surface and a second surface respectively representing tow top and bottom surfaces. Then, they finally succeeded in accomplishing the invention.
Describing a basic technical characteristic of a packaged carbon fiber precursor tow according to the invention, a packaged tow wherein a carbon fiber precursor tow having a flattened shape in cross section and having a first surface and a second surface opposite to the first surface is layered and packaged in a packaging container in untwisted state, a front end and a back end of the carbon fiber precursor tow thus packaged are located near a top surface of the carbon fiber precursor tow fully layered including the packaging container, and there is no twist in a part of the carbon fiber precursor tow from a bottom part of the packaged carbon fiber precursor tow to a front end of the carbon fiber precursor tow on the top surface thereof.
Preferably, top/bottom surface identification means configured to identify the first surface and the second surface of the carbon fiber precursor tow are respectively provided at the front end and the back end of the tow. The top/bottom surface identification means configured to identify the first surface and the second surface is preferably a means configured to fix the end of the carbon fiber precursor tow to a top surface indicator. A width dimension of the carbon fiber precursor tow flattened in cross section is preferably at least 15 times larger than a thickness dimension thereof, and a total degree of fineness of the carbon fiber precursor tow is preferably 48,000 dtex to 720,000 dtex.
Preferably, at least one of the ends of the carbon fiber precursor tow is flame-proofed. More preferably, the front end and the back end of the carbon fiber precursor tow are respectively housed in storage bags. The top surface indicator is preferably wound around the front end and/or the back end of the carbon fiber precursor tow in a length of 2 to 10 m.
Describing a basic technical characteristic of a method for manufacturing a packaged tow according to the invention, a method for manufacturing a packaged tow wherein a carbon fiber precursor tow having a first surface and a second surface opposite to the first surface and a flattened shape in cross section and also having a large degree of fineness in total from 48,000 dtex to 720,000 dtex is supplied into a packaging container through a tow supply shoot and layered therein, the method including: leading out a front end in a predefined length of the carbon fiber precursor tow supplied through the tow supply shoot from the packaging container in untwisted state and holding the lead-out front end before starting to supply the tow into the packaging container; moving a tow lead-out port of the tow supply shoot with the carbon fiber precursor tow downward to a throw-in start position on a bottom section of the packaging container while still holding the lead-out front end before starting to supply the tow into the packaging container; and starting to supply the tow into the packaging container after the tow lead-out port arrives at the tow throw-in start position.
Most preferably, the holding the lead-out front end of the carbon fiber precursor tow outside of the packaging container includes retaining a part of the tow from the front end of the tow to the lead-out port in untwisted state. While holding the lead-out front end of the carbon fiber precursor tow, the front end of the tow can be held by an air sucker. Thus, the front end of the tow is preferably retained in untwisted state by a tow front end holding means. While holding the lead-out front end of the carbon fiber precursor tow, it is desirable that the carbon fiber precursor tow be temporarily fixed at a tow passing position provided on an upper opening of the packaging container by a temporary fixing means.
While holding the lead-out front end of the carbon fiber precursor tow outside of the packaging container, the tow lead-out port of the tow supply shoot may be located outside of the packaging container and moved to an opening position immediately above the supply start position on the bottom section of the packaging container after the front end is led out and held, or the tow lead-out port may be temporarily immovably located at the opening position immediately above the supply start position on the bottom section of the packaging container until the tow lead-out port of the tow throw-in shoot starts to move downward after the holding the lead-out front end of the carbon fiber precursor tow outside of the packaging container starts.
More preferably, the method further includes: applying a top/bottom surface identification means configured to identify the first surface and the second surface to the front end of the tow during the holding of the lead-out front end of the carbon fiber precursor tow before completing the layer stacking of the carbon fiber precursor tow in the packaging container; and applying a top/bottom surface identification means configured to identify the first surface and the second surface to a surface of the back end of the tow on the same side as the front end of the tow when the layer stacking of the carbon fiber precursor tow in the packaging container is completed. Before applying the top/bottom surface identification means to the front end and/or the back end of the carbon fiber precursor tow, the front end and/or the back end of the tow are preferably flame-proofed.
The top/bottom surface identification means preferably has a top/bottom surface indicator configured to identify the first surface and the second surface of the carbon fiber precursor tow. The top/bottom surface identification means is a temporary fixing means for fixing same ones of the first surfaces or the second surfaces on the ends of the tow which are the front end and the back end of the carbon fiber precursor tow to the top/bottom surface indicator such that the same surfaces are directed in a direction. The method preferably further includes winding at least the front end in the ends of the tow in a length of 2 to 10 m from the front end of the tow around the top/bottom surface indicator in untwisted state. The method may further include: housing the front end and the back end of the tow temporarily fixed to the top/bottom surface indicator respectively in storage bags when the layer stacking of the carbon fiber precursor tow in the packaging container is completed; and locating the front end and the back end of the tow housed in the storage bags near the top of the multilayered tow including the packaging container.
Describing a basic technical characteristic of a device for manufacturing a packaged tow according to the invention, a device for manufacturing a packaged tow wherein a carbon fiber precursor tow having a first surface and a second surface and a flattened shape in cross section and also having a large degree of fineness in total from 48,000 dtex to 720,000 dtex is supplied into a packaging container through a tow supply shoot in untwisted state and layered therein, and a tow lead-out port of the tow supply shoot can be moved from a predefined standby position near an upper opening of the packaging container before the supply of the tow into the packaging container starts to a tow throw-in start position preset on a bottom section of the packaging container when the supply of the tow into the packaging container starts, the device including: a tow front end nipping means configured to nip a front end of the carbon fiber precursor tow supplied through the tow throw-out port before the tow starts to be throw in; and a tow front end holding means configured to temporarily nip or hold a front end of the tow in a predefined length drooping in a loop-like shape between the tow front end nipping means and the tow lead-out port in untwisted state.
Most preferably, the device further includes a top/bottom surface identification means configured to identify the first surface and the second surface on supply-side front and back ends of the carbon fiber precursor tow. The top/bottom surface identification means has a top/bottom surface indicator configured to identify the first surface and the second surface of the carbon fiber precursor tow. As described earlier, same ones of the first surfaces or the second surfaces on the ends of the tow which are the front end and the back end of the carbon fiber precursor tow are temporarily fixed to the top/bottom surface indicator such that the same surfaces are directed in a direction.
Preferably, the tow front end nipping means configured to grip the front end of the tow is an air sucker, and the tow front end holding means configured to hold the front end of the tow has a pair of nipping members or a holding member, wherein at least one of the pair of nipping members can move toward and away from the other one of the pair of nipping members, and the nipping members nip a front end of the tow drooping in a loop-like shape between the tow front end nipping means and the tow lead-out port when the nipping members are in proximity to each other. When the single holding member is provided as the tow front end holding means, the holding member can move in an arc shape between immediately below the tow lead-out port of the tow supply shoot and the tow front end nipping means to catch and nip the tow drooping in a loop-like shape between the tow throw-out port and the tow front end nipping means and retains the loop-like shape. The nipping members and the holding member, though not particularly limited, desirably include a plate member having a smoothened surface or a rod member having an arbitrary sectional surface. Desirably further provided is a temporary fixing means configured to temporarily fix in untwisted state a part of the tow between the tow lead-out port and the tow holding means holding or nipping the drooping loop-like tow using the pair of nipping members.
According to the invention, when tows respectively having first and second surfaces are joined with each other in a carbon fiber precursor tow piecing work, the tows can be reliably joined with same-side surfaces of the joined ends being directed in a direction. This prevents such a trouble as the occurrence of thread breakage in a flame-proofing process due to any twist generated in the tows during the piecing work. If top and bottom surfaces are misjudged when tows are joined particularly in a tow in which a few small tows are combined, thread guides cross with each other, which may result in irregular fuzz due to friction or thread breakage due to heat accumulation in the twisted parts. The invention can successfully prevent this possible trouble from happening.
According to the packaged tow provided by the invention, the top/bottom surface indicator which is a structural element of the top/bottom surface identification means is wound around by the front end and/or back end in a predefined length of the carbon fiber precursor tow applied with the top/bottom surface identification means which helps to identify the first surface or the second surface, and the tow-wound parts are wrapped in the storage bags and placed on the top surface of the packaged multilayered tow. Then, directions of the surfaces on the front and back ends can be reliably determined in the tow piecing work by simply unwinding the front and back ends of the tow on the tow-wound parts. Moreover, required lengths of the front and back ends are thereby reliably obtained, and the ends of the tow can be easily and effectively joined with each other.
When the packaging technique disclosed in the Patent Document 1 is applied to a part of the technical characteristics of the method and the device according to the invention, the tow thrown into the packaging container and layered therein can be consistently prevented from twisting during a time period when oscillation of the tow throw-in shoot starts and ceases. Therefore, when the front end of the tow is led out of the packaging container which is a part of the technical characteristics of the invention, a part of the tow from the drooping front end of the tow held like loop by the temporary fixing means to the tow lead-out port is temporarily held in untwisted state while the front end of the tow is being led out of the packaging container and then held. This ensures that untwisted state between the front end of the tow and the throw-in start position on the bottom section of the packaging container is retained. As a result of the synergistic effect of these technical advantages, the first and second surfaces are unfailingly discriminated from each other, and there is no twist starting at the jointed parts. As a result, such a disadvantage as thread breakage due to heat accumulation in any twisted part during the flame proofing process no longer occurs.
Hereinafter, an exemplary embodiment of the invention is described in detail referring the accompanying drawings.
A typical example of the “tow supply shoot” according to the invention is a “tow throw-in shoot” disclosed in the Patent Document 1. The tow throw-in shoot is oscillated when a tow is packaged in the packaging container. As a result of the oscillation, a first surface of the tow is directed upward and a second surface of the tow is then directed upward so that the tow is layered in untwisted state. There is a tow supply shoot configured differently to the tow throw-in shoot. The tow supply shoot is configured to spirally supply the tow into the packaging container while rotating a cylindrical packaging container in one direction and also rotating the shoot per se around a rotational axis set at a position displaced from a rotational center of the packaging container. The tow supply shoot can provide a packaged tow multilayered in untwisted state similarly to the tow-throw-in shoot.
The “tow throw-in shoot” used in the entire description hereinafter given is the “tow supply shoot”, however, other shoots differently configured may be used.
A packaged tow according to the invention is a packaged tow wherein a carbon fiber precursor tow having a flattened shape in cross section and having a first surface and a second surface opposite to the first surface, and a front end and a back end of the carbon fiber precursor tow are each applied with a tow top/bottom surface identification means. Hereinafter, technical terms used in this specification are described.
According to the invention, a carbon fiber precursor tow is a tow formed from a bundle of a larger number of continuous mono filaments, wherein carbon fiber is obtained when heat treatments such as flame proofing and carbonizing processes are applied thereto. The carbon fiber precursor tow includes a generally called flame-proofed fiber precursor tow. The tow may be a straight tow or a crimpled tow. Such a tow is likely to undergo such troubles, for example, thread breakage when later subjected to the flame proofing processes. The invention provides a novel solution for avoiding such a trouble.
The invention is applied to a tow having a flattened shape in cross section, wherein the tow has a first surface and a second surface. The “flattened shape” used in this specification is a shape of the tow having a width dimension representing at least 4 when a thickness dimension of the tow represents 1. In the tow thus flattened in cross section, the first surface and the second surface, which are respectively a top surface and a bottom surface, can be identified because of the structure unlike a tow having a circular shape in cross section. The top and bottom surfaces of the tow cannot be discriminated from each other from their external appearances which appears to be the same, therefore, the invention calls the top and bottom surfaces the first surface and the second surface, respectively. More specifically describing the flattened shape in cross section, the tow desirably has a width dimension representing at least 15 when the thickness thereof represents 1, more specifically, the width dimension of the tow is desirably 15 times larger or more desirably 30 times larger than the thickness of the tow. For example, a ratio between tow thickness and tow width ranges from 1:35 to 1:70. In the case where the width dimension of the tow is not as large as 15 times of the thickness dimension, such a trouble as thread breakage due to heat accumulation more likely to occur if the tow is twisted. In any shapes where the width dimension is at least 15 times larger than the thickness dimension, the first surface and the second surface can be easily identified based on the top/bottom surface identification means, and thread breakage can be more effectively prevented from happening.
Though a total degree of fineness of the tow is not particularly limited, a large degree of fineness which is advantageous for a tow throw-in packaging method, for example, 48,000 dtex to 720,000 dtex, is preferable. The thread breakage preventing effect according to the invention is more evidently confirmed in such a tow having a larger degree of fineness.
At least one of a front end and a back end of the tow is preferably flame-proofed in advance to avoid the occurrence of thread breakage due to heat accumulation. More preferably, the front and back ends of the tows both are flame-proofed in advance. The flame-proofing can be performed to the front and back ends in, for example, 0.3 to 1.0 m from the respective ends.
The top/bottom surface identification means according to the invention is applied to the front and back ends of the tow. The top/bottom surface identification means is only required to identify the first surface and the second surface (hereinafter, called top surface and bottom surface) from their external appearances. The top/bottom surface identification means may include physically arresting the ends of the tow, preventing reversal of the top and bottom surfaces using a physical force though not necessarily arresting the ends of the tow, and adhering an object to one surface of the tow, more specifically includes indication by coloring one surface of the tow, indication by bonding an adhesive tape to one or both surfaces of the tow, indication by securely nipping the tow using a tool like a clothespin, indication by securing the tow to a top/bottom surface indicator having a rectangular or other shapes, and indication by housing the tow in a bag-like member which helps to identify the top and bottom surfaces of the tow. The top/bottom surface identification means is not necessarily limited to any one of these indications, and these indications may be arbitrarily combined.
Preferably, the tow is fixed to a plate-shape member by an adhesive tape. A specific example of the plate-shape piece is a corrugated board piece which is inexpensive and less likely to damage the carbon fiber precursor tow. The tow is attached and fixed to the corrugated board piece by an adhesive tape. When the ends of the tow are thus secured, the ends of the tow are not unraveled or damaged. The top/bottom surface identification means is applied to the front and back ends of the tow both, for example, the top/bottom surface identification means is applied to the front and back ends in approximately 10 m at most from the ends of the tow. For example, the top/bottom surface identification means according to the invention can be applied in 50 cm from the ends of the tow.
The top/bottom surface indicator wound around by the tow 1 is not necessarily limited to the plate-shape member 2. The member may have a circular shape in cross section or a bar-shape member having an elliptical shape in cross section, or a cylindrical member may be used. As illustrated in
Though the shape of the packaging container 4 in which the tow 1 is housed is not particularly limited, an example of the packaging container is a rectangular container having inner dimensions; longitudinal dimension in the range of 500 to 1,500 cm, lateral dimension in the range of 500 to 1,500 cm, and depth dimension in the range of 800 to 1,500 cm.
Though a material of the packaging container 4 in which the tow 1 is housed is not particularly limited, a corrugated board, for example, may be used. A preferable example is a packaging container body formed from a corrugated board, and a non-moisture permeable interior member provided inside of the packaging container body, the interior member having a shape substantially equal to that of an inner shape of the packaging container body and a thickness equal to or smaller than 0.1 mm (for example, polyethylene sheet having a large tensile force). Such an interior member preferably prevents the corrugated board from absorbing any moisture from the tow 1 whenever the moisture-contained tow 1 is thrown into the packaging container, and also prevents the tow 1 from undergoing any damage such as abrasion and scratches caused by the corrugated board.
The packaged tow is typically manufactured by throwing the tow 1 into the packaging container 4. Preferably, a front end 1a is led out of the packaging container 4 so that there is a predefined distance between the front end 1a of the tow 1 and a tow feeding port 6a of a tow throw-in shoot 6 before starting to throw-in of the tow 1. Accordingly, untwisted state is retained between the front end 1a and the feeding port 6a to hold the front end in a predefined length. The tow 1 starts to be fed into the packaging container with untwisted state being retained to manufacture the packaged tow. Then, the tow 1 can be packaged in the packaging container 4 with the front end 1a being left out of the packaging container 4. This manufacturing method is advantageous in that the piecing work for joining the top with the back end 1b of the packaged tow 1 that follows can be easily performed with untwisted state being retained.
A part of the tow led out of the packaging container 4 through the feeding port 6a of the tow throw-in shoot 6 before starting to feed the tow 1 has to be retained untwisted. To this end, the following two methods for leading out and holding the tow are available depending on a standby position of the tow throw-in shoot 6 before the tow 1 starts to be fed through the tow throw-in shoot 6. A length of the tow end to be held is 2 to 10 m in view of operability of the piecing work performed later.
First and second methods are described in detail referring to different operation steps illustrated in
According to the first method, before the tow 1 starts to be fed, the tow throw-in shoot 6 provided in an upper direction of the packaging container 4 is oscillated from a regular throw-in position illustrated in
According to the present exemplary embodiment, an air sucker 11, which is one of structural elements of the tow front end nipping means according to the invention, is provided at a lateral position adjacent to the tow feeding port 6a to nip the front end of the tow 1 falling downward while retaining untwisted state. Other examples of the tow front end nipping means according to the invention are a wind-up roll configured to wind up the front end of the tow 1 in a predefined length, and a tow supply gear roll configured to suspend rotation as soon as the feed of the front end of the tow 1 in a predefined length is finished. The air sucker is preferably used in view of operability, safety, and structural simplicity.
Moreover, a tow front end holding means 12 according to the invention is provided at a position in an upper direction of a suction port 11a of the air sucker 11 and the packaging container 4 and below a part not interfering with the tow feeding port 6a during the oscillation. The tow front end holding means 12 has first and second nipping members 12a and 12b. The first nipping member 12a, which is one of the nipping members, is immovably located substantially immediately below the suction port 11a of the air sucker 11. The second nipping member 12b, which is the other nipping member constituting the tow front end holding means 12, is provided reciprocatably in a horizontal direction in a part near the upper opening of the packaging container 4 and not interfering with the tow feeding port 6a of the tow throw-in shoot 6 during the oscillation. According to the present exemplary embodiment, the first and second nipping members 12a and 12b are formed from round bar members having equal dimensions and horizontally provided orthogonal to an oscillation plane of the tow throw-in shoot 6 as illustrated in
Steps for holding the front end of the tow 1 according to the first method are described in detail referring to
The tow throw-in shoot 6 configured to oscillate on an oscillation center in an upper central part of the empty packaging container 4 in a direction where the tow 1 is fed in is provided. A gear roll 13 for supplying the tow is provided on an upstream side of the tow throw-in shoot 6. Before starting to feed the tow 1 by oscillating the tow throw-in shoot 6, the tow throw-in shoot 6 is perpendicularly positioned. To temporarily securely hold the front end in a predefined length of the tow 1 supplied through the tow feeding port 6a of the tow throw-in shoot 6, the tow feeding port 6 is oscillated in one direction as far as the maximum oscillation width, and then halted at the position as illustrated in
After the front end of the tow 1 is thus suctioned, the tow 1 is continuously supplied through the tow feeding port 6a of the tow throw-in shoot 6. The tow 1 thus continuously supplied then starts to droop in a loop-like shape between the first nipping member 12a and the second nipping member 12b located at positions distant from each other as illustrated in
When the upper end is thus nipped and held, the tow throw-in shoot 6 halted at the position oscillates to a predefined position of the packaging container 4 as illustrated in
Then, the tow throw-in shoot 6 is oscillated to start a normal throw-in operation and the oscillation continues until the packaging container 4 is fully filled with the tow 1. Then, the tow 1 throw-in operation ends. When the tow 1 throw-in operation ends, a cut end of the tow 1 nipped by the air sucker 11 (front end 1a of the tow) and the back end 1b of the tow 1 when the throw-in operation ends are respectively applied with the top/bottom surface identification means. Describing the application of top/bottom surface identification means then, as described earlier referring to
The tow front end and the tow back end housed in the storage bags 5 and 9 are placed on the top surface of the multilayered tow in which the fed tow is stacked in folded layers, and the upper opening of the packaging container 4 is sealed with the cap 10 as illustrated in
Though the tow 1 is directly fed into the packaging container 4 according to the drawings, the invention may provide a container having an inner shape similar to that of the packaging container 4, which is not being illustrated in the drawings, in the packaging container 4 beforehand as described earlier, wherein the tow 1 may be thrown into the wrapping member and then packaged.
So far is described in detail the first method of holding the tow front end according to the invention. The second method is described below referring to
The second method is largely different to the first method in that the tow throw-in shoot 6 before the tow 1 starts to be fed keeps a posture illustrated in
To solve the problem, the present exemplary embodiment provides tow front end holding means 12 immediately above the tow throw-in start position and below the suction port 11a of the air sucker 11 which is an example of the tow front end nipping means similarly to the first method. Similarly to the first method, the second method may employ, other than the air sucker, a wind-up roll configured to wind up the front end of the tow 1 in a predefined length, and a tow supply gear roll configured to suspend rotation as soon as the feed of front end of the tow 1 in a predefined length is finished.
The tow front end holding means 12 has third and fourth nipping members 12c and 12d. The third and fourth nipping members 12c and 12d are positioned substantially immediately below the suction port 11a of the air sucker 11 before holding the front end of the tow. The third and fourth nipping members 12c and 12d are formed from long plate members having equal dimensions. As illustrated in
To temporarily securely hold the front end in a predefined length of the tow 1 fed through the tow feeding port 6a of the tow throw-in shoot 6, the tow throw-in shoot 6 in an upright position is oscillated in one direction toward the halt position and then halted at a position illustrated in
After the front end of the tow 1 is thus suctioned, the tow 1 still continues to be fed through the tow feeding port 6a of the tow throw-in shoot 6. The tow 1 thus continuously supplied starts to droop in a loop-like shape between the third nipping member 12c and the fourth nipping member 12d located at positions distant from each other as illustrated in
At the time, the tow 1 still continues to be fed through the tow feeding port 6a of the tow throw-in shoot 6, and the tow 1 thus supplied through the tow feeding port 6a passes over an upper edge of the packaging container 4 and then falls toward the bottom section of the packaging container. According to the present exemplary embodiment, after confirming that there is no twist in a part of the tow from the nipped part in the front end of the loop-like tow to the bottom section of the container, the tow 1 and the upper edge of the packaging container 4 that the tow 1 passed over are temporarily nipped and held by a clip 15. The clip 15 is an example of the temporary fixing means according to the invention. After the feed of the tow 1 starts, the clip 15 may be removed whenever appropriate.
When the tow 1 is successfully nipped and held, the tow throw-in shoot 6 at rest then starts to move downward straight to the tow throw-in start position in the packaging container 4 as illustrated in
Then, the tow throw-in shoot 6 is oscillated to start the normal throw-in operation and the oscillation continues until the packaging container 4 is fully filled with the tow 1, and the tow 1 throw-in operation ends. Before the feed of the tow 1 starts, the fourth nipping member 12d already returned to the original retract position. When the feed of the tow 1 is finished, a cut end of the tow 1 nipped by the air sucker 11 (front end 1a of the tow) and the back end 1b of the tow 1 when the throw-in operation ends are respectively applied with the top/bottom surface identification means. The front end and the back end of the tow thus applied with the top/bottom surface identification means in a manner similar to the first method are housed in the storage bags 5 and 9. The front end and the back end of the tow thus applied with the means are placed on the top surface of the package tow in which the tow is folded and layered as illustrated in
The air sucker 11 is not necessarily immovably located at the predefined position as described in the present exemplary embodiment. The air sucker 11 may be configured to move horizontally toward and away from the tow feeding port 6a with the suction port 11a thereof being directed toward the tow feeding port 6a. The air sucker 11 thus configured moves away from the tow feeding port 6a with the front end 1a of the tow being nipped by the air sucker 11 which is an example of the tow front end nipping means in accordance with or regardless of an amount of the tow 1 fed through the tow feeding port 6a of the tow throw-in shoot 6. Therefore, it becomes unnecessary to provide the first to fourth nipping means 12a to 12d used as the tow nipping means to hold the front end of the tow in the first and second methods. A distance between the moved air sucker 11 and the tow feeding port 6a is 2 to 10 m which is the length of the front end of the tow. When the moving distance of the air sucker 11 is limited to the numeral range, the suctioning is halted at the same time as the movement of the air sucker 11, or the movement of the air sucker 11 alone is halted. When the movement of the air sucker 11 alone is halted, the tow 1 is cut near the suction port 11a at the same time as the halt, and the top/bottom surface identification means is applied thereto then.
However, there are problems in moving the air sucker 11 by the given distance; it is difficult to retain the posture of the tow and the package manufacturing device requires a large space because the tow 1 having a length of 2 to 10 m is suspended in a space between the halt position of the air sucker 11 and the tow feeding port 6a, it is necessary to provide a more sophisticated device to move the air sucker 11, and such a device complicates the programs housed in the controller.
To avoid these problems, the invention can solve any problems caused by moving the air sucker 11 in a long distance by securely holding the front end of the tow in a predefined length until the packaging is completed.
According to the technical characteristics, the suction port 11a of the air sucker 11 is located near the tow feeding port 6a during a standby period before the front end of the tow starts to be nipped by the air sucker 11, and the air sucker 11 starts to move as soon as the front end of the tow 1 is suctioned and nipped by the air sucker 11. At the time, the guide rollers 14 are horizontally aligned on the same plane off the travelling path of the air sucker 11. Then, the guide rollers 14 do not block the movements of the air sucker 11 and the tow 1. After the air sucker 11 moved in the required short distance, adjacent ones of the aligned guide rollers 14 are moved upward and/or downward such that the plurality of guide rollers 14 are arranged in the zigzag manner. Accordingly, the tow 1 linearly moving is guided in the zigzag manner as the plurality of guide rollers 14 move upward and downward in the zigzag manner. As a result, a required length of the front end is obtained. The guide rollers 14 may be conventional guider rollers. Other examples of the guide rollers 14 are Nelson rollers and dancer rollers.
Referring to the drawing, a holding member 12e is used in place of the third and fourth nipping members 12c and 12d which are the structural elements of the tow front end holding means 12 as illustrated in
As illustrated in
Referring to
After that, the tow 1 still continues to be fed. The tow 1 thus continuously fed advances to between the suction port 11a and the second horizontal shaft 12e-3 and droops in a loop-like shape as illustrated in
Unless the part is twisted, the tow may be temporarily fixed directly to the packaging container 4 or fixed to other sections in place of the packaging container 4. To directly fix the tow to the packaging container 4, the tow and the upper end of the packaging container may be nipped with a clip, or an outer surface of the packaging container 4 may be wound around by a rubber band to interpose the tow therebetween. When the tow is fixed to other sections in place the packaging container 4, the tow may be fixed by a stationary clip outside or a magnet in a bar shape or a plate shape.
To directly fix the tow 1 to the packaging container 4, the tow 1 may be nipped with a clip 15 along the upper opening edge of the packaging container 4 as illustrated in
During the normal throw-in operation, the tow can be prevented from twisting by the throw-in methods disclosed in the Patent Document 1 (Japanese Patent Application Laid-Open No. 2006-176328) and the Patent Document 2 (Japanese Patent Application Laid-Open No. 2008-121147). Because the back end can be easily picked up to discriminate the top and bottom surfaces from each other to know whether the tow is twisted, it is not so complicated to process the back end of the tow as to process the front end. Therefore, the end part may be knotted, however, a part of the tow is wasted as disclosed in the Patent Document 5 (Japanese Patent Application Laid-Open No. 2002-138326). To avoid such a waste, the method disclosed in the Patent Document 5 may be employed, or the tow may be bonded to the plate-shape member 2 with the top surface thereof directed upward as described earlier.
The tow 1 is discharged into the packaging container 4 through the tow throw-in shoot 6 and packaged. Referring to
The packaging container 4 where the front and back ends of the tow are housed is transferred to a carbon fiber manufacturing process and subjected to the flame-proofing process in which the tow ends are flame-proofed beforehand. The front and back ends of the tow are unwound from the plate-shape member and then set in, for example, a flame-proofing device disclosed in the Patent Document 3. The unwinding work unwinds the whole tow confirming that the tow is not twisted while unfolding the tow in the same direction of the tow throw-in direction on the top surface of the tow thrown into the packaging container and slightly shifting the unfolded tow in the tow-width direction. As far as the adhesive tape constituting the top/bottom surface indicating means is directed upward when the whole tow is unwound, it is confirmed that there is no twist in the tow between the packaging container and the plate-shape member. When the whole tow is unwound, the tow is set in the flame-proofing device such that the surface with the adhesive tape attached thereto is directed upward, and the plate-shape member is removed therefrom. Then, the tow is flame-proofed.
The flame-proofed front and back ends of the tow are bonded to the plate-shape member such that the surface with the adhesive tape is directed upward. The whole unwound tow is wound again around in untwisted state and housed in the storage bags, and then placed on an upper part of the packaging container.
The packaging container 4 in which the flame-proofed front and back ends of the tow are housed is transferred to a predefined position of the carbon fiber manufacturing process. At the position, the front end of the tow is taken out of the packaging container with the plate-shape member being attached to it, but the plate-shape member is removed from the back end of the tow. Then, the carbon fiber manufacturing process starts. The front and back ends of the tow in a next packaging container to be subjected to the piecing work are similarly flame-proofed, and the packaging container is then transferred to a position adjacent to the packaging container transferred earlier. Similarly, the unwinding work unwinds the whole front end of tow confirming that the tow is not twisted while unfolding the tow of the preceding packaging container in the same direction of the tow throw-in direction on the top surface of the tow thrown into the next packaging container and slightly shifting the unfolded tow in the tow-width direction. The front end of the tow in the preceding packaging container and the back end of the tow in the next packaging container are put together facing each other such that the tape-attached surfaces are directed upward, and the plate-shape member is then removed. Then, the tows are joined.
A tow having the total degree of fineness of 180,000 dtex, width of 60 mm, and thickness of 2 mm was bonded to a corrugated board piece in the size of 300 mm×150 mm by a vinyl cloth tape (product name: Vinyl Cloth, No. 750, width: 75 mm supplied by SEKISUI CHEMICAL CO., LTD.) such that a top surface of a throw-in front end of the tow was directed upward. Then, the tow was wound in approximately 5 m around a corrugated board piece such that the tow was not twisted and housed in a plastic bag. The tow wound around the corrugated board piece was kept outside of a packaging container, and the tow started to be thrown into the packaging container. After the throw-in operation was completed, a back end of the tow was bonded to a corrugated board piece with a surface thereof on the same side as the front end was housed in the plastic bag. Then, plastic bags in which the front and back end of the tow were housed were housed in the packaging container. The packaging container was a corrugated board container having the size of 720 mm in longitudinal dimension, 720 mm in lateral dimension, and 1,000 mm in height dimension whose interior was finished with a square-bottomed interior material made of polyethylene having the thickness of 0.05 mm.
The packaging container was transferred to the carbon fiber manufacturing process. The front and back ends of the tow were respectively unwound from the corrugated board pieces and set in a flame proofing device with tape-attached surfaces thereof being directed upward. Then, the tow was removed from the corrugated board pieces, and the tow ends in the length of 700 mm from the ends of the tow were flame-proofed in the atmosphere of 250° C. at the wind velocity of 3 m/min for 120 minutes.
The flame-proofed front and back ends of the tow were bonded again to the corrugated board pieces with their same-side surfaces being directed upward and then wound around the corrugated board pieces. The tow-wound corrugated board pieces were housed in plastic bags and then housed in the packaging container.
The packaging container in which the flame-proofed front and back ends of the tow are housed was transferred to a predefined position of the carbon fiber manufacturing process. The back end of the tow was removed from the plate-shape member formed from the corrugated board piece, while the front end of the tow was left wound around the plate-shape member formed from the corrugated board piece, and the tow was then taken out of the packaging container. Then, manufacturing of a carbon fiber started with the back end of the tow. The front and back end of the tow in a next packaging container subjected to the piecing work were similarly flame-proofed, and the next packaging container was transferred to a position adjacent to the preceding packaging container. The front end of the tow in the preceding packaging container and the back end of the tow in the next packaging container were put together facing each other such that the tape-attached surfaces were directed upward and joined with each other by air interlacing at five positions spaced at intervals of 50 mm under the air pressure of 500 kPa.
Because the same-side surfaces of the tows were joined with each other, there was no twist in the obtained tow, enabling a stable and continuous operation without such a trouble as thread breakage during the flame proofing.
An operation similar to that of the Example 1 was performed except that used tows had the total degree of fineness of 201,000 dtex, width dimension of 100 mm, and thickness dimension of 2 mm. The tows were joined on the same-side surfaces thereof. Therefore, there was no twist in the obtained tow, which led to a stable and continuous operation without such a trouble as thread breakage during the flame proofing.
An operation similar to that of the Example 1 was performed except that used tows had the total degree of fineness of 127,000 dtex, width dimension of 50 mm, and thickness dimension of 2 mm in which two small tows including 50,000 filaments and having the monofilament degree of fineness of 1.27 dtex were combined. The tows were joined on the same-side surfaces thereof. Therefore, there was no twist in the obtained tow, which led to a stable and continuous operation without such a trouble as thread breakage during the flame proofing.
A tow similar to that of the Example 1 was located with a throw-in front end of the tow being directed upward, and the upward surface was colored in red. The tow was wound in approximately 5 m around a commercially available cardboard tube (length: 33 cm, inner diameter: 51 mm, thickness: 1.5 mm) in untwisted state and put in a plastic bag. The tow wound around the cardboard tube was held outside of a packaging container, and the tow started to be thrown into the packaging container. After the feed of the tow ended, a surface of a back end of the tow on the same side as the front end was directed upward and colored in red, and then bonded to a cardboard tube and put in a plastic bag. The plastic bags in which the front end and the back end of the tow were housed was placed in the packaging container. The packaging container was a corrugated board container having the size of 720 mm in longitudinal dimension, 720 mm in lateral dimension, and 1,000 mm in height dimension whose interior was finished with a square-bottomed interior material made of polyethylene having the thickness of 0.05 mm.
The packaging container was transferred to the carbon fiber manufacturing process. The front and back ends of the tow were respectively unwound from the cardboard tubes and set in a flame proofing device with red-colored surfaces thereof being directed upward to be flame-proofed in the atmosphere of 250° C. at the wind velocity of 3 m/min for 120 minutes.
The flame-proofed front and back ends of the tow were wound again around the cardboard tubes with their surfaces colored in red being directed upward. The tow-wound cardboard tubes were housed in plastic bags and then placed in the packaging container.
The packaging container in which the flame-proofed front and back ends of the tow are housed was transferred to a predefined position of the carbon fiber manufacturing process. The back end of the tow was removed from the plate-shape member formed from the cardboard tube, while the front end of the tow was left wound around the plate-shape member formed from the cardboard tube, and the tow was then taken out of the packaging container. Then, manufacturing of a carbon fiber started with the back end of the tow. The front and back ends of the tow in a next packaging container subjected to the piecing work were similarly flame-proofed, and the next packaging container was transferred to a position adjacent to the preceding packaging container. The front end of the tow in the preceding packaging container and the back end of the tow in the next packaging container were put together facing each other such that the red-colored surfaces were directed upward and joined with each other by air interlacing at five positions spaced at intervals of 50 mm under the air pressure of 500 kPa.
The tows were joined on the same-side surfaces thereof. Therefore, there was no twist in the obtained tow, which led to a stable and continuous operation without such a trouble as thread breakage during the flame proofing.
A tow was not applied with the top/bottom surface identification means, and front and back ends of the tow were not processed. Such a tow was housed in a packaging container similarly to the Example 1.
The packaging container was transferred to the carbon fiber manufacturing process. The tow was set in a flame proofing device regardless of top and bottoms surfaces on the front and back ends of the tow. Then, the ends of the tow in the length of 700 mm from the ends of the tow were flame-proofed in the atmosphere of 250° C. at the wind velocity of 3 m/min for 120 minutes.
The packaging container in which the flame-proofed front and back ends of the tow are housed was transferred to a predefined position of the carbon fiber manufacturing process. Then, manufacturing of a carbon fiber started with the back end of the tow. The front and back ends of the tow in a next packaging container subjected to the piecing work were similarly flame-proofed, and the next packaging container was transferred to a position adjacent to the preceding packaging container. The front end of the tow in the preceding packaging container and the back end of the tow in the next packaging container were put together and joined by air interlacing at five positions spaced at intervals of 50 mm under the air pressure of 500 kPa.
Because the tows were joined regardless of the top and bottom surfaces thereof, the tow was twisted unless the same-side surfaces were accidentally joined without any twist, and heat accumulation in the twisted parts during the flame-proofing process generated smoke and breakage, failing to perform a stable and continuous operation.
A tow was not applied with the top/bottom surface identification means, and front and back ends of the tow were not processed. Such a tow was housed in a packaging container similarly to the Example 3. Because the tows were joined regardless of the top and bottom surfaces thereof, the tow was twisted unless the same-side surfaces were accidentally joined without any twist, and heat accumulation in the twisted parts during the flame-proofing process generated smoke and breakage, failing to perform a stable and continuous operation.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2009-186418 | Aug 2009 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP10/63408 | 8/6/2010 | WO | 00 | 2/9/2012 |
