JP5215080B2 - Cross lay web manufacturing method - Google Patents

Description

  The present invention relates to a method for producing a cross lay web. By the method of the present invention, a cross lay web having a substantially uniform basis weight in the width direction can be produced.

2. Description of the Related Art Conventionally, a technique capable of manufacturing a cross lay web having a substantially uniform thickness in the width direction is known. For example, in Patent Document 1 (Japanese Patent Laid-Open No. 8-284955),
In a method for producing a cross lay web, comprising supplying a web fed from a card machine to a web transport means, and feeding the web from a web delivery section of the web transport means to a cross lay web transport section of a web lamination transport means. The basis weight of the web sent from the card machine is periodically increased or decreased by periodically changing the web sending speed for sending the web from the card machine, and the web sending unit of the card machine and the web transport The accumulating means is arranged between the web receiving part of the means or in the middle of the web conveying means, and the web sending speed from the card machine is correlated with the periodic change of the web sending speed from the card machine. The web transport distance in the accumulator is increased as the period periodically increases, and the web delivery speed from the card machine is periodically decreased. By changing the web transport distance in the accumulator means to be short according to the above, the web delivery speed sent from the accumulator means is made substantially constant, and the web delivery part of the web transport means is made substantially constant speed by the carriage means. And the reciprocating motion by the carriage means so that the web portion with a small basis weight is laminated on both ends of the cross lay web, The web is fed from the web delivery section of the web transport means to the cross lay web transport section of the web stack transport means at a substantially constant speed, and the cross lay of the web stack transport means is The production speed of the cross lay web is characterized in that the conveyance speed of the web conveyance section is set to a substantially constant speed. Way. "(Claim 1)
Is disclosed. However, although there is disclosure of periodically increasing / decreasing the basis weight of the web sent from the card machine by changing the web sending speed at which the card is sent from the card machine, the specific pattern of periodic increase / decrease is disclosed. The degree of uniformity in the width direction of the cross lay web is not disclosed.

Regarding periodically increasing or decreasing the basis weight of the web delivered from the card machine, for example, in Patent Document 2 (Japanese Patent Laid-Open No. 6-168853), “the periodic change in the basis weight of the web material is the above-mentioned cross It is preferable to follow a sinusoid that is synchronized with the reciprocating movement of the wrapper carriage, and it is also possible to superimpose higher harmonics on the sinusoid ”(paragraph [0007]).
Is described.

In view of this, the present inventor attempted to follow the basis weight of a web (hereinafter sometimes referred to as a card web) sent from a card machine according to a sine curve synchronized with the reciprocation of the carriage means in Patent Document 1. . The result is shown in FIG. The A curve shows the distribution of the weight per unit area in the width direction of the cross lay web when the card web per unit area is not subjected to periodic changes. I understand. The curve B shows the case where the basis weight of the card web is cyclically changed according to the sine curve. The basis weight of the central portion of the cross lay web rises and the basis weight is higher than that of the curve A. It can be seen that a maximal point is formed in the center of the uniformized one. The C curve shows the case where a cyclic change according to a sine curve with a large amplitude is given to the basis weight of the card web, and the maximum point where the basis weight is larger than both ends at the center of the cross lay web. You can see that it is made.
As described above, it is found that when the card web weight is periodically changed according to a sine curve, a distribution of W-shaped weight is generated in the width direction of the cross lay web. There has been a demand for further improvement in the uniformity of the basis weight of the resin.

JP-A-8-284055 Japanese Unexamined Patent Publication No. 6-116853

  Accordingly, an object of the present invention is to solve the problems of the prior art and provide a method for producing a cross lay web having a substantially uniform basis weight in the width direction.

According to the present invention, the problem is that the web fed from the card machine is supplied to the web conveying means, and is supplied from the web sending portion of the web conveying means to the cross lay web conveying portion of the web stack conveying means. In the production method of the cross lay web,
By periodically changing the web delivery speed at which the web is sent from the card machine, the basis weight of the web delivered from the card machine is periodically increased and decreased, and the web delivery unit of the web transport means is configured as a carriage means. The periodic change in the web delivery speed from the card machine so that the reciprocating motion at a substantially constant speed is performed and the web portion with a small basis weight is laminated on both ends of the cross lay web. Correlating to follow a sinusoid synchronized to the reciprocating motion of the carriage means;
The sine curve includes a sine curve A having a short cycle corresponding to a portion where the delivery speed is faster than the average speed, and a sine curve B corresponding to a portion where the delivery speed is slower than the average speed, and having a long cycle and a small amplitude. Is a curve synthesized by alternately arranging,
A web is supplied at a substantially constant speed from the web delivery section of the web transport means to the cross lay web transport section of the web stack transport means, and the cross lay web transport section of the web stack transport means The conveyance speed is set to a substantially constant speed.
This can be solved by the above-described method for producing a cross lay web.

According to the preferred embodiment of the manufacturing method of the present invention, the following relationship is established between the sine curve A represented by Equation 1 and the sine curve B represented by Equation 2.
y _A = sin bx (Formula 1)
y _B = a sin (b / (2b-1)) x (Expression 2)
a = c / (2b-1) (Formula 3)
0 <a <1 (Formula 4a)
1 <b (Formula 5a)
0.8 ≦ c ≦ 1.2 (Formula 6a)

According to a further preferable aspect of the manufacturing method of the present invention, the following relationship is established between the sine curve A represented by Equation 1 and the sine curve B represented by Equation 2.
y _A = sin bx (Formula 1)
y _B = a sin (b / (2b-1)) x (Expression 2)
a = c / (2b-1) (Formula 3)
0.33 <a <1 (Formula 4b)
1 <b <2 (Formula 5b)
0.9 ≦ c ≦ 1.1 (Formula 6b)

  According to another preferred aspect of the manufacturing method of the present invention, an accumulating means is arranged between the web sending part of the card machine and the web receiving part of the web conveying means or in the middle of the web conveying means, and the card machine In relation to the periodic change in the web delivery speed from the card machine, the web transport distance in the accumulating means is increased as the web delivery speed from the card machine periodically increases, and the web delivery speed from the card machine is increased. By changing the web transport distance in the accumulator means to be shorter as the speed of the web is periodically delayed, the web sending speed sent from the accumulator means is made substantially constant.

  The present invention solves the problems of the prior art and can produce a cross lay web having a substantially uniform basis weight in the width direction.

Hereinafter, the present invention will be described with reference to the accompanying drawings.
The card machine used in the present invention is an apparatus for generating a web by opening raw material fibers. For example, the card machine 1 shown in FIG. 6 that has been conventionally used can be used as it is. In the card machine 1, first, raw fibers are carded by a plurality of workers (not shown) and strippers (not shown) on a main cylinder (not shown) to form a web in which the fiber directions are aligned. To do. This web is sent to the doffer 14, peeled off from the doffer by the stripping roll 15, passed between the fled roll 16a and the smooth roll 16b, sent out from the web sending section 6, and the next web conveying means, or , And supplied to the accumulating means as required.

  In the present invention, the supply amount of raw material fibers per unit time to the card machine is kept constant, and the web feed speed sent from the card machine is periodically increased or decreased according to a sine curve described in detail below. To increase or decrease the basis weight of the web periodically. That is, when the web delivery speed of the card machine is decreased, the basis weight of the web to be sent out increases, and when the web delivery speed of the card machine is increased, the basis weight of the web to be sent out decreases. In the present invention, the web delivery speed of the card machine correlates with the periodic increase / decrease in the basis weight of the web delivered from the card machine. The web delivery speed from the card machine, and hence the basis weight increase / decrease can be increased or decreased by a known method, for example, the doffer 14 or stripping roll 15 shown in FIG. 6, the compact roll 17 shown in FIG. 7, or FIGS. It can be controlled by changing the rotational speed of the drafter 18 shown in FIG.

  As shown in FIG. 6, for example, as shown in FIG. 6, the web transport means 2 used in the present invention has a climbing apron 23 to which the support rolls at both ends are fixed, and a fixed support roll at one end as a fulcrum. And a fall apron 24 that can be reciprocated by the supporting roll. The web transport means 2 moves the web sent from the card machine 1 at a substantially constant speed and supplies it to the cross lay web transport unit 4. For the climbing apron 23 and the fall apron 24, a conventionally known means such as a belt conveyor can be used. As shown in FIG. 6, the climbing apron 23 is not limited to a mode of transporting the web slightly upward, and may be a mode of transporting the web substantially in the horizontal direction or slightly downward. Further, as shown in FIG. 6, the fall apron 24 preferably has a cross-ray web center line as a midpoint of the reciprocating motion, but is not limited to this mode. The position may be shifted from the center line of the web. Although a vertical type apparatus has been described here as the web conveying means 2, a conventionally known horizontal type apparatus can also be used.

  Below the web sending section 22 of the fall apron 24, the floor conveyor 4 serving as a cross lay web transport section runs in a direction perpendicular to the paper surface of FIG. 6 at a substantially constant transport speed. The web sending part 22 which is the tip part of the fall apron 24 reciprocates at a substantially constant speed in the direction of arrow A by the carriage means 3, so that the cross ray web is moved from the web sending part 22 of the fall apron 24. The web 9 can be supplied to the transport unit 4. At this time, the web 9 passes through the web sending portion 22 of the fall apron 24 at a substantially constant speed. The supplied web 9 is alternately and obliquely folded and laminated on the floor conveyor 4 to generate a cross lay web.

  As shown in FIG. 1, when the basis weight of the web sent out from the card machine is periodically changed according to a sine curve synchronized with the reciprocating operation of the carriage means, the weight of the W-type basis weight is increased in the width direction of the cross lay web. However, as a solution to this problem, the time of the part corresponding to the part where the sending speed of the card web corresponding to both ends of the cross lay web is faster than the average speed is shortened. Consider increasing the time of the part corresponding to the part where the sending speed of the card web corresponding to the part is slower than the average speed and making the speed a little closer to the average speed, so that the weight per unit area in the width direction of the cross lay web is uniform. We found that sex can be achieved.

  2 and FIG. 3, FIG. 2 shows that the web delivery speed F (m / min) from the card machine is the average speed, the variation ratio from the average speed is the vertical axis, and the carriage means Shows the change in the web delivery speed (change in the basis weight of the web) when the time axis when moving from right to left is set to the horizontal axis. According to this figure, the portion corresponding to the portion where the sending speed of the card web corresponding to both ends of the cross lay web is faster than the average speed is represented by a sine curve A, and the card web corresponding to the center portion of the cross lay web is shown. The portion corresponding to the portion where the delivery speed is slower than the average speed is represented by a sine curve B.

The period of the sine curve A is shorter than that of the sine curve O. This means that the point that intersects the horizontal axis of the average speed F (m / min) moves to the left of π / 2 and becomes π / 2b. Means. Then, as can be seen from FIG. 3, the point where the sine curve B intersects with the horizontal axis of the average speed F (m / min) moves to the right side of π / 2 and becomes ((2b-1) / b) π. . From these facts, it can be seen that the sine curve A and the sine curve B are expressed by the following equations, respectively.
y _A = sin bx (Formula 1)
y _B = a sin (b / (2b-1)) x (Expression 2)
here,
0 <a <1 (Formula 4a)
1 <b (Formula 5a)
And preferably
0.33 <a <1 (Formula 4b)
1 <b <2 (Formula 5b)
It is.

In the present invention, the area surrounded by the sine curve A and the horizontal axis of the average speed (SA = SA ₁ + SA ₂ ) and the area surrounded by the sine curve B and the horizontal axis of the average speed (SB) are substantially the same. It is preferable to become. Here, SA corresponds to the amount of web slack that occurs between the card machine and carriage means, and SB corresponds to the web deficiency (tensile amount) that occurs between the card machine and carriage means. In order to adjust the sagging and tension and always feed the web to the carriage means at a constant speed, it is preferable to use the accumulating means described in Patent Document 1 between the card machine and the carriage means.

By making the values of SA and SB the same, the equation a = 1 / (2b−1) is established. This equation can be obtained by definite integration of Equation 1 of the sine curve A and Equation 2 of the sine curve B.
In actual production, the values of SA and SB described above are not the same, and even if there are some fluctuations, the web itself may be covered by the expansion and contraction of the web itself.
a = c / (2b-1) (Formula 3)
here,
0.8 ≦ c ≦ 1.2 (Formula 6a)
And preferably
0.9 ≦ c ≦ 1.1 (Formula 6b)
It is.

  As an example, the distribution of the basis weight in the width direction of the web when Expression 3 is satisfied (provided that c = 1) is shown in FIG. 4 as a D curve. As can be seen from FIG. 4, according to the present invention, it is possible to manufacture a cross lay web having a substantially uniform basis weight in the width direction of the web.

  According to the accumulating means that can be used in the preferred embodiment of the present invention, the accumulating means is disposed at an arbitrary position between the web sending section 6 of the card machine 1 and the web sending section 22 of the web conveying means 2; In correlation with the periodic increase / decrease in the web delivery speed from the card machine 1, the web transport distance in the accumulating means is increased as the web delivery speed from the card machine 1 is periodically increased, and the card machine By changing the web transport distance in the accumulating means to be shorter as the web sending speed from 1 is periodically reduced, the web sending speed sent from the accumulating means can be made substantially constant. The accumulating means can be arranged, for example, between the web sending part 6 of the carding machine 1 and the web receiving part 21 of the web conveying means 2 or in the middle of the web conveying means 2, preferably the card It is disposed in the middle of the web conveying means 2 near the web sending part 6 of the machine 1, more preferably between the web sending part 6 of the card machine 1 and the web receiving part 21 of the web conveying means 2.

  According to the preferred embodiment of the present invention, although the web delivery speed of the card machine periodically increases and decreases, the web is finally transferred to the web delivery unit 22 of the cross lay web transport unit 2 by providing the accumulating means. It can be supplied at a substantially constant rate. Further, by providing the accumulating means, the tension applied to the web can be kept constant, and the wrinkle of the web can be prevented.

Hereinafter, specific embodiments of the accumulating means that can be used in the present invention will be described with reference to FIGS.
FIG. 10 shows that a belt conveyor 51 is provided between a web delivery unit 6 of the card machine 1 and a web receiving unit 21 of the web transport means 2 and includes a pair of movable rolls 52a and 52b and four fixed rolls 53a, 53b and 53c. , 53d, an accumulating means 5 having a structure for rotating a trajectory is shown.

  The four fixed rolls 53a, 53b, 53c, 53d and the pair of movable rolls 52a, 52b are arranged so that the axial directions thereof are parallel to each other, and the four fixed rolls 53a, 53b, 53c, 53d are arranged. Is arranged at each vertex of a rectangle (including a square) when viewed from the axial direction. The fixed roll 53 a is provided in the vicinity of the web sending unit 6 of the card machine 1, and the fixed roll 53 b is provided in the vicinity of the web receiving unit 21 of the web conveying means 2. The pair of movable rolls 52a and 52b maintains a substantially midpoint of the side between the fixed rolls 53a and 53b and a substantially midpoint of the side between the fixed rolls 53c and 53d while keeping the distance between the two rolls constant. It is possible to move in the direction of arrow D on the connecting straight line. The pair of movable rolls 52a and 52b is held movably within a predetermined range by appropriate holding means (not shown).

  The belt conveyor 51 passes outside the four fixed rolls 53a, 53b, 53c, and 53d and passes inside the two movable rolls 52a and 52b, respectively. Of the trajectory of the belt conveyor 51 formed in this way, the range from the surface where the belt conveyor 51 comes into contact with the fixed roll 53a, through the surface which comes into contact with the movable roll 52a, to the surface which comes into contact with the fixed roll 53b becomes the web conveyance unit 54. The web 9 sent from the web sending unit 6 of the card machine 1 is received and sent to the web receiving unit 21 of the web transport means 2.

  Since the pair of movable rolls 52a and 52b move in the direction D connecting the respective axes of the movable rolls, the trajectory of the belt conveyor 51 changes as the movable rolls 52a and 52b move. The moving range of the pair of movable rolls 52a and 52b does not exceed the range of the rectangular side formed by the belt conveyor passing through the four fixed rolls 53a, 53b, 53c and 53d, and the inner side of the movable rolls 52a and 52b does not pass. It is preferable to be within the range.

  As shown by a solid line in FIG. 10, when the movable rolls 52a and 52b are lowered to a position where the surface where the movable roll 52a contacts the belt conveyor 51 substantially coincides with the side between the fixed rolls 53c and 53d, the belt conveyor 51 is shown as a solid line. And the distance of the web transport unit 54 in the accumulating means is maximized. On the other hand, when the movable rolls 52a and 52b are moved up to the position indicated by the broken line, the belt conveyor 51 takes a locus indicated by the broken line, and the distance of the web conveyance unit 54 in the accumulating means is minimized. By moving the pair of movable rolls 52a and 52b continuously, the distance of the web transport section 54 in the accumulating means can be continuously changed between the maximum distance and the minimum distance. FIG. 10 shows only the transport path of the web 9 when the distance of the web transport section 54 in the accumulating means is substantially maximum, and in other cases (for example, when the web transport distance in the accumulating means is minimum). The conveyance path of the web 9 is omitted.

  When the sending speed of the web 9 sent from the web sending unit 6 of the card machine 1 is periodically increased or decreased, the positions of the pair of movable rolls 52a and 52b are changed by appropriate control means (not shown) in correlation with the speed. Then, the distance of the web conveyance unit 54 in the accumulating means is changed. Thereby, the web delivery speed of the accumulator means, that is, the supply speed to the web transport means 2 can be made substantially constant.

  FIG. 11 shows another embodiment of the accumulating means 5 in which an accumulating means 5 in which a movable guide roll 55 and a fixed roll 56 are arranged between the web sending section 6 of the card machine 1 and the web receiving section 21 of the web conveying means 2. Is shown. The fixing roll 56 is preferably fixedly installed on the web receiving unit 21 of the web conveying means 2 and provided on a substantially same horizontal plane as the web sending unit 6 of the card machine 1. On the other hand, the movable guide roll 55 capable of translating in the direction of arrow E about the intermediate point between the web delivery unit 6 of the card machine 1 and the fixed roll 56 is the same as the web delivery unit 6 of the card machine 1 and the fixed roll. 56. The movable guide roll 55 is held movably within a predetermined range by an appropriate holding means (not shown).

  The web 9 delivered from the web delivery unit 6 of the card machine 1 passes under the movable guide roll 55, passes between the fixed roll 56 and the web receiving unit 21 of the web delivery means 2, and passes through the web delivery means. Sent to 2. As shown by the solid line in FIG. 11, when the movable guide roll 55 is lowered, the web 9 to be conveyed passes along the locus indicated by the solid line, and the web conveyance distance in the accumulating means (in this embodiment, the web delivery of the card machine 1). The distance from the portion 6 to the fixed roll 56) is maximized.

  On the other hand, when the movable guide roll 55 rises to the position indicated by the broken line, the web 9 to be conveyed passes along the locus indicated by the broken line, and the web conveyance distance in the accumulating means becomes the minimum. By continuously moving the movable guide roll 55, the web conveyance distance in the accumulating means can be continuously changed between the maximum distance and the minimum distance.

  When the delivery speed of the web 9 delivered from the web delivery unit 6 of the card machine 1 is periodically increased or decreased, the position of the movable guide roll 55 is changed in correlation with the appropriate control means (not shown), thereby accumulating. The web conveyance distance in the means is changed. Thereby, the web delivery speed of the accumulator means, that is, the supply speed to the web transport means 2 can be made substantially constant. The embodiment shown in FIG. 11 can be easily used when the difference between the maximum distance and the minimum distance of the web transport distance is about 25 cm or less, despite the simple structure. Further, it is preferably used when the web fibers are strongly entangled. In FIG. 11, the conveyance path of the web 9 when the web conveyance distance in the accumulating means is maximized is indicated by a solid line, and the case where the web conveyance distance in the accumulating means is minimized is indicated by a broken line. The conveyance path is omitted.

FIG. 12 shows another embodiment of the accumulating means, a pair of rotatable parts having a fixed end and a free end between the web sending part 6 of the card machine 1 and the web receiving part 21 of the web conveying means 2. An accumulating means 5 having conveying means (for example, a belt conveyor), that is, a web receiving side conveying means (for example, a receiving side belt conveyor 63) and a web sending side conveying means (for example, a sending side belt conveyor 66) is shown.
The receiving side belt conveyor 63 is held at a fixed distance by a fulcrum roller 61 and a free end roller 62 that are fixedly installed in the vicinity of the web sending unit 6 of the card machine 1, and the sending side belt conveyor 66 is It is held at a constant distance by a fulcrum roller 64 and a free end roller 65 which are fixedly installed in the vicinity of the web receiving portion 21 of the web conveying means 2. The receiving-side belt conveyor 63 can rotate in the direction indicated by G from the lower limit indicated by the solid line to the upper limit indicated by the broken line in FIG. On the other hand, the delivery-side belt conveyor 66 can also rotate in the direction indicated by H within the range from the lower limit indicated by the solid line to the upper limit indicated by the broken line, with the fulcrum roller 64 as the center.

  When the receiving side belt conveyor 63 and the sending side belt conveyor 66 are at the lower limit positions indicated by solid lines, the web 9 sent from the web sending unit 6 of the card machine 1 is conveyed on the receiving side belt conveyor 63, and then It is conveyed on the delivery side belt conveyor 66 and supplied to the web receiving unit 21 of the web conveying means 2. In this case, the web conveyance distance in the accumulator means is substantially the maximum corresponding to the sum of the total length of the receiving side belt conveyor 63 and the total length of the sending side belt conveyor 66.

  On the other hand, when the receiving side belt conveyor 63 and the sending side belt conveyor 66 are at the upper limit positions indicated by broken lines, the web 9 sent from the web sending unit 6 of the card machine 1 is conveyed on the receiving side belt conveyor 63, Next, it is conveyed on the sending side belt conveyor 66 and supplied to the web receiving unit 21 of the web conveying means 2. In this case, a part of the receiving side belt conveyor 63 and a part of the sending side belt conveyor 66 are overlapped. Therefore, the web conveyance distance in the accumulator means is substantially equivalent to the distance between the fulcrum roller 61 and the delivery-side fulcrum roller 64 and is minimized.

By continuously moving the receiving side belt conveyor 63 and the sending side belt conveyor 66, the web conveyance distance in the accumulating means can be continuously changed between the maximum distance and the minimum distance. In FIG. 12, as in FIG. 11, the transport path of the web 9 when the web transport distance in the accumulating means is maximized is shown by a solid line, and the case where the web transport distance in the accumulator means is minimized is shown by a broken line. However, the conveyance path in other cases is omitted.
Corresponding to the periodic increase / decrease of the delivery speed of the web 9 delivered from the web delivery unit 6 of the card machine 1, the receiving side belt conveyor 63 and the delivery side belt conveyor are correlated by appropriate control means (not shown). The position of 66 is changed, and the web conveyance distance in the accumulating means is changed. Thereby, the web delivery speed of the accumulator means, that is, the supply speed to the web transport means 2 can be made substantially constant.

FIG. 13 shows another embodiment of the accumulating means 5 as a web receiving side conveying means (for example, a receiving side belt) fixed between the web sending section 6 of the card machine 1 and the web receiving section 21 of the web conveying means 2. An accumulating means 5 having a conveyor 73) and a rotatable web delivery side conveying means (eg delivery side belt conveyor 76) having a fixed end and a free end is shown.
The receiving side belt conveyor 73 is held at a fixed distance by a fixed roller a71 and a fixed roller b72 fixedly installed in the vicinity of the web delivery unit 6 of the card machine 1, and the sending side belt conveyor 76 is A fulcrum roller 74 fixedly installed in the vicinity of the web receiving portion 21 of the conveying means 2 and a free end roller 75 are held at a fixed distance, and the fulcrum roller 74 is the center, and the lower limit shown by a solid line in FIG. It can be rotated in the direction indicated by J within the upper limit range.

When the sending side belt conveyor 76 is at the lower limit position indicated by the solid line, the web 9 sent from the web sending unit 6 of the card machine 1 is conveyed on the receiving side belt conveyor 73 and then on the sending side belt conveyor 76. Is supplied to the web receiving portion 21 of the web conveying means 2. In this case, the web transport distance in the accumulator means is substantially the maximum corresponding to the sum of the total length of the receiving side belt conveyor 73 and the total length of the sending side belt conveyor 76.
On the other hand, when the delivery side belt conveyor 76 is at the upper limit position indicated by the broken line, the web 9 delivered from the web delivery unit 6 of the card machine 1 is directly sent to the delivery side without passing through the reception side belt conveyor 73. It is sent to the belt conveyor 76, conveyed on the delivery side belt conveyor 76, and supplied to the web receiving unit 21 of the web conveying means 2. In this case, the web conveyance distance in the accumulating means substantially corresponds to the distance between the receiving side fixed roller a71 and the sending side fulcrum roller 74, and is minimized.

  By continuously moving the delivery-side belt conveyor 76, the web conveyance distance in the accumulating means can be continuously changed between the maximum distance and the minimum distance. In FIG. 13, as in FIG. 11, the transport path of the web 9 when the web transport distance in the accumulating means is maximized is shown by a solid line, and the case where the web transport distance in the accumulator means is minimized is shown by a broken line. However, the conveyance path in other cases is omitted.

  Corresponding to the periodic increase / decrease of the delivery speed of the web 9 delivered from the web delivery section 6 of the card machine 1, the position of the delivery-side belt conveyor 76 is changed by an appropriate control means (not shown). The web conveyance distance in the accumulating means is changed. Thereby, the web delivery speed of the accumulator means, that is, the supply speed to the web transport means 2 can be made substantially constant.

  In the embodiment shown in FIG. 13, the belt conveyor on the web receiving side is a fixed type and the belt conveyor on the web sending side is a rotatable type, but the belt conveyor on the sending side is fixed and the belt conveyor on the receiving side is fixed. The belt conveyor can also be made rotatable.

  As a special aspect of the accumulating means, when the web itself has sufficient strength, a sufficient distance is provided between the web sending part of the card machine and the web receiving part of the web conveying means. The conveyance distance may be adjusted by the slack of the web. That is, an interval at which the web passing between the web sending part of the card machine and the web receiving part of the web transport means can be lowered in the direction of gravity by the weight of the web itself is set to the web sending part of the card machine and the web transport means. It may be provided between the web receiving portion. In this case, when the web delivery speed from the card machine is periodically increased, the sag of the web at the interval increases, and when the web delivery speed from the card machine is periodically decreased, the sag of the web at the interval decreases. . When the interval is provided between the web sending part of the card machine and the web receiving part of the web conveying means, the distance is lowered in the direction of gravity between the web sending part of the card machine and the web receiving part of the web conveying means. It is preferable to provide means (for example, a pressing roll provided in combination with a belt conveyor of the web conveying means) for pulling up the slack portion of the web formed on the web receiving portion of the web conveying means.

  EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but these do not limit the scope of the present invention.

Example 1
Polyester fibers (fineness: 2 dtex, fiber length: 64 mm) were pre-opened and then put into a card machine, where the average speed of the web delivered from the doffer was 38 m / min. Further, assuming that the maximum speed is 43.3 m / min, which is 14% higher than the average speed, and in equations 1 to 6, a = 0.54, b = 1.43, and c = 1, as shown in FIG. The web delivery speed was set according to a composite curve in which the curve A and the sine curve B were combined.

Thereafter, the web delivered from the carding machine was supplied to the web transport means, and the cross lay web was formed by feeding the web from the web delivery section of the web transport means to the cross lay web transport section of the web lamination transport means.
As described above, by periodically changing the web delivery speed at which the web is sent from the card machine, the basis weight of the web delivered from the card machine is periodically increased and decreased, and the web of the card machine is increased. An accumulating means is arranged between the sending section and the web receiving section of the web conveying means, and the web sending speed from the card machine is periodically correlated with the periodic change in the web sending speed from the card machine. The web transport distance in the accumulating means is increased as the speed increases, and the web transport distance in the accumulating means is changed to be shorter as the web sending speed from the card machine periodically decreases. The web delivery speed of the web transport means is substantially constant, and the web delivery portion of the web transport means is substantially constant speed by the carriage means. In addition to causing reciprocal movement, a periodic change in the web feed speed from the card machine and the reciprocating movement by the carriage means so that web portions with a small basis weight are stacked on both ends of the cross lay web. The web is fed at a substantially constant speed from the web delivery section of the web transport means to the cross lay web transport section of the web stack transport means, and the cross lay web of the web stack transport means The conveying speed of the conveying unit was made substantially constant.

The distribution of the basis weight in the width direction of the obtained cross lay web is shown in the D curve of FIG. The average value of the basis weight is 40 g / m ² , the distribution from this average value is shown on the vertical axis, and the average value is 0%. As is apparent from FIG. 5, a cross lay web having a substantially uniform basis weight in the width direction could be obtained.

<< Comparative Example 1 >>
A cross lay web was formed in the same manner as in Example 1 except that the speed of the web delivered from the doffer was a constant value of 38 m / min.
The distribution of the basis weight in the width direction of the obtained cross lay web is shown as a curve A in FIG. The average weight per unit area is 40 g / m ² . As is apparent from FIG. 5, the basis weight of the cross lay web was not uniform in the width direction.

<< Comparative Example 2 >>
The speed of the web delivered from the doffer was 38 m / min. Further, the maximum speed was increased by 12% of the average speed to 42.6 m / min, and the web delivery speed was set according to the sine curve O as shown in FIG.
The distribution of the basis weight in the width direction of the obtained cross lay web is shown in the B curve of FIG. The average weight per unit area is 40 g / m ² . As is apparent from FIG. 5, the basis weight of the cross lay web was not uniform in the width direction.

  The present invention can be used for the production of a cross lay web.

Based on the prior art (combination of Patent Document 1 and Patent Document 2), when the basis weight of the web sent from the card machine is periodically changed so as to follow a sine curve synchronized with the reciprocating operation of the carriage means It is a graph which shows distribution of the fabric weight of the width direction. It is a graph which shows the sine curve (Sine curve A and Sine curve B) which can be used by this invention compared with the sine curve (Sine curve O) used by a prior art. 3 is a graph showing a part of the shapes of a sine curve A, a sine curve B, and a sine curve O shown in FIG. It is a graph which shows distribution of the fabric weight of the cross direction of the cross lay web (D curve) obtained by the manufacturing method of this invention. The graph which shows the distribution of the fabric weight of the width direction about the cross lay web (D curve) manufactured by the manufacturing method of this invention manufactured in the Example, and the cross lay web (A curve and B curve) manufactured as a comparative example. It is. It is explanatory drawing which shows typically the manufacturing apparatus of the cross lay web by the conventional method. It is explanatory drawing which shows typically another one embodiment of the web sending part of the card machine which can be used for this invention. It is explanatory drawing which shows typically another one embodiment of the web sending part of the card machine which can be used for this invention. It is explanatory drawing which shows typically another one embodiment of the web sending part of the card machine which can be used for this invention. It is explanatory drawing which shows typically one embodiment of the accumulating means which can be used for this invention. It is explanatory drawing which shows typically another embodiment of the accumulating means which can be used for this invention. It is explanatory drawing which shows typically another one embodiment of the accumulating means which can be used for this invention. It is explanatory drawing which shows typically another one embodiment of the accumulating means which can be used for this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Card machine; 2 ... Web conveyance means; 3 ... Carriage means;
4 ... floor conveyor; 5 ... accumulating means; 6 ... card machine web sending section;
7 ... Cross layer device; 8 ... Web stacking and conveying means; 9 ... Web (card web);
10 ... cross lay web; 14 ... doffer; 15 ... stripping roll;
16a ... Fluted roll; 16b ... Smooth roll;
17 ... compact roll; 18 ... drafter;
21: Web conveying means web receiving part; 22 ... Web conveying means web sending part;
23 ... Climbing apron; 24 ... Fall apron;
25 ... Climbing apron web sending part;
26 ... Fall apron web receiving part;
51 ... belt conveyor; 52a ... movable roll a; 52b ... movable roll b;
53a to d ... fixed roll; 54 ... web transport unit;
55 ... movable guide roll; 56 ... holding roll;
61 ... fulcrum roller; 62 ... free end roller;
63 ... receiving side belt conveyor; 64 ... fulcrum roller;
65 ... Free end roller; 66 ... Delivery side belt conveyor;
71 ... fixed roller a; 72 ... fixed roller b;
73 ... receiving side belt conveyor; 74 ... fulcrum roller;
75 ... Free end roller; 76 ... Delivery side belt conveyor

Claims (3)

In the method for producing a cross lay web, the web sent from the card machine is supplied to the web transport means, and is supplied from the web delivery section of the web transport means to the cross lay web transport section of the web stack transport means.
By periodically changing the web delivery speed at which the web is sent from the card machine, the basis weight of the web delivered from the card machine is periodically increased and decreased, and the web delivery unit of the web transport means is configured as a carriage means. The periodic change in the web delivery speed from the card machine so that the reciprocating motion at a substantially constant speed is performed and the web portion with a small basis weight is laminated on both ends of the cross lay web. Correlating to follow a sinusoid synchronized to the reciprocating motion of the carriage means;
The sine curve includes a sine curve A having a short cycle corresponding to a portion where the delivery speed is faster than the average speed, and a sine curve B corresponding to a portion where the delivery speed is slower than the average speed, and having a long cycle and a small amplitude. Is a curve synthesized by alternately arranging,
A web is supplied at a substantially constant speed from the web delivery section of the web transport means to the cross lay web transport section of the web stack transport means, and the cross lay web transport section of the web stack transport means substantially a constant speed transport speed,
The above-described cross-lay web manufacturing method is characterized in that the following relationship is established between the sine curve A represented by Equation 1 and the sine curve B represented by Equation 2 .
y _A = sin bx (Formula 1)
y _B = a sin (b / (2b-1)) x (Expression 2)
a = c / (2b-1) (Formula 3)
0 <a <1 (Formula 4a)
1 <b (Formula 5a)
0.8 ≦ c ≦ 1.2 (Formula 6a) Between the sine curve A and the sine curve B, and wherein the following relationship is satisfied, cross-lay web method as claimed in claim 1.
y _A = sin bx (Formula 1)
y _B = a sin (b / (2b-1)) x (Expression 2)
a = c / (2b-1) (Formula 3)
0.33 <a <1 (Formula 4b)
1 <b <2 (Formula 5b)
0.9 ≦ c ≦ 1.1 (Formula 6b) An accumulating means is arranged between the web sending part of the card machine and the web receiving part of the web conveying means or in the middle of the web conveying means, and is correlated with the periodic change of the web sending speed from the card machine. The web conveyance distance in the accumulator means is increased as the web delivery speed from the card machine periodically increases, and the web conveyance in the accumulator means is increased as the web delivery speed from the card machine periodically decreases. By changing the distance short, the web delivery speed delivered from the accumulator means is made substantially constant.
The method for producing a cross lay web according to claim 1 or 2 , characterized by the above.

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