JPH0333830B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a fiber opening mechanism for scattering fibers from a separator onto a collection mesh belt to form a uniform random web in a nonwoven fabric manufacturing apparatus using a spunbond method. Prior art As a method for manufacturing non-woven fabric, spun-bond method involves scattering spun filaments from a separator to form a random web on a collection mesh belt running downward, and then melting and bonding this with a hot roller to obtain non-woven fabric. It has been known. The uniformity of the product obtained by this method is greatly influenced by the process of opening and dispersing the fibers and distributing and depositing them on the collection surface. It was hot. That is, a method is used in which fibers are opened and dispersed from a separator and then directly scattered onto the collection surface of a collection mesh belt, a reflection plate is provided on the downstream side of the separator,
These include a method of regulating the position of the fibers falling onto the collection surface, a method of providing a rocking device under the separator, and rocking the fiber group at right angles to the traveling direction of the mesh belt or at a certain angle. Problems with the Prior Art However, each of these conventional methods has the following drawbacks. In other words, in the first method, the occurrence of thread clumps is small, but uniformity in the dispersion width of each fiber group is required, so if there is variation in the dispersion width, a vertical striped pattern will appear thick and thin, and each fiber will become uneven. If there is variation in wind speed among groups, adjacent groups of fibers tend to be attracted toward the direction of higher speed.In the second method, when the dispersed fibers fall onto the collection surface, It vibrates and tends to cause fine streaks on the product in parallel to the direction in which the reflectors are arranged. Furthermore, in the third method, it is necessary to increase the number of oscillations of the oscillating device according to the traveling speed of the collection mesh belt, but the oscillating device has a limited strength and is therefore unsuitable for high-speed molding. Moreover, mutual interference between the fiber groups occurs during rocking, resulting in thread clumps on the collection surface, which impairs the appearance. Means for Solving the Problem As a result of various studies to eliminate these drawbacks of the prior art, the inventor of the present invention has discovered that by providing a pair of reflective dispersion plates curved in an arc between the separator and the collecting mesh belt, the separator It has been found that the fibers opened and dispersed in the above are reopened and dispersed when passing through the reflective dispersion plate, and a uniform nonwoven fabric can be obtained. The present invention was made based on this knowledge,
In a spunbond nonwoven fabric manufacturing device that spreads and disperses spun fibers through a separator to form a random web on a collection mesh belt running below, the intermediate part between the separator and the mesh belt is narrowed to narrow the gap. A pair of reflective dispersion plates curved in an arc shape with widening gaps on the upstream and downstream sides are arranged, and both dispersion plates have a curved degree and an opening angle of
At least one of them is adjustable. To explain this with the help of drawings, Figure 1 is a schematic diagram of the present device, in which a pair of arcuate reflective dispersion plates are located between a separator 1 that blows out spun fibers and spreads and disperses them, and a mesh belt 2. 3 and 3' are arranged facing each other, and the gap between them is widened on the upstream and downstream sides as shown in the figure, and narrowed in the middle part, and the fibers scattered from the separator 1 are reflected. Dispersion plate 3, 3'
The fibers are refiber-dispersed through the gaps and deposited in a folded state on the collecting mesh belt 2 running in the direction of the arrow to form a random web 5. The random web 5 is then thermally fused using a heat roller 7 to produce a nonwoven fabric 6. The dispersion plates 3, 3' are made of a flexible elastic body such as a leaf spring so that the degree of curvature can be adjusted, or the opening angle can be changed so that the gap on the inlet side or the outlet side can be adjusted. However, preferably both the degree of curvature and the opening angle can be adjusted. FIG. 2 shows an example of this, in which supports 10 and 10' are rotatably supported by shafts 9 and 9' on brackets (not shown), and the supports 10 and 10' are connected to bolts 12 at appropriate positions in elongated holes 11 at their upper ends. The supports 10 and 10' are connected to the shafts 9 and 9 by loosening the bolt 12 and moving the link 13 with the bolt 12 fitted in the elongated hole. ′ as a fulcrum and rotates in the direction of the arrow to adjust the opening angle of the upper side. A pair of clamps 15, 15' are also attached to the supports 10, 10' at the lower end and the other 15' at the upper side with bolts 16, 16', respectively.
The bolt 16' on the upper side is slidably fitted into the elongated hole 17, so that its vertical position can be adjusted. The upper and lower ends of the flexible reflective dispersion plates 3 and 3' are fixed to each clamp 15, respectively. The degree of curvature of the reflection dispersion plates 3, 3' can be adjusted by vertically adjusting the positions of the upper clamps 15, 15', and by loosening the bolts 12 and moving the links 13 laterally. The upstream opening angle is adjusted. According to this device, the position and shape of the reflection dispersion plate can be optimally adjusted according to various manufacturing conditions such as the type of fiber used and the manufacturing speed of the nonwoven fabric. Example Curvature 800mm and height 500mm on the downstream side of the separator
A pair of reflective dispersion plates A are arranged with gaps of 120 mm on the fiber inlet side, 60 mm on the middle part, and 120 mm on the outlet side, and polypropylene fibers spun from a nozzle with 100 holes are spun at high speed with an inner diameter of 10 mm at the outlet. After being indexed at a speed of 3000 m/min using an airflow indexing device (ejector and guide tube), the fibers are defibrated and dispersed using a separator, and then passed between the reflective dispersion plates to be re-dispersed, and placed on a collecting mesh conveyor. A web was produced by depositing. Comparative Examples 1 and 2 A pair of straight reflective dispersion plates B with a height of 500 mm were placed on the downstream side of the separator with a gap of 120 mm on the inlet side and 80 mm on the outlet side. A web was produced by passing the dispersed fibers and depositing them on a guiding mesh conveyor. Further, under the same conditions as in the example, the fibers were directly spread from the separator onto the collecting mesh conveyor and deposited to produce a web. The following table shows the rate of variation in basis weight (weight per unit area) of the webs obtained in the above Examples and Comparative Examples 1 and 2.

[Table] Here, the weight fluctuation rate for various parts of the web is as follows. 2×√(X-X) ² /N/X×100 X: Weight per unit area of each location (g/cm ² ): Average value of weight at each location N: Total number of measurement locations The uniformity of the basis weight is improved by using a reflective dispersion plate whose middle part is narrowed and curved in an arc. Effects of the Invention As described above, according to the device of the present invention, the simple structure of arranging the reflective dispersion cloth curved in an arc shape on the downstream side of the separator suppresses the occurrence of thick and thin unevenness in the yarn cluster streak pattern of the nonwoven fabric, and creates a balanced pattern. In addition, the degree of curvature and/or opening angle of the reflection dispersion plate can be optimally adjusted according to various manufacturing conditions such as the type of fiber used and the manufacturing speed of the nonwoven fabric.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the manufacturing apparatus according to the present invention, and FIG.
The figure is a schematic diagram showing the mounting structure of the reflection dispersion plate. 1...Separator, 2...Mesh belt, 3,
3'...Reflection dispersion plate, 5...Random web, 6...Nonwoven fabric, 7...Heat roller, 10,10'...Support,
13...link, 15,15'...clamp.

Claims (1)

[Claims] 1. A pair of reflective dispersion plates curved in an arc shape with a narrow gap in the intermediate portion and wide gaps on the upstream and downstream sides are disposed downstream of the separator, and the spun fibers are opened by the separator. In a spunbond nonwoven fabric production device that disperses fibers, passes them between reflective dispersion plates to redistribute them, and forms a random web on a collection mesh belt running downstream of the fibers, the reflective dispersion plates A nonwoven fabric manufacturing device in which at least one of the opening angles is adjustable. 2. The nonwoven fabric manufacturing apparatus according to claim 1, wherein the reflective dispersion plate has an upper end and a lower end attached to an attached support, and one of the upper ends is adjustable in position. 3. The nonwoven fabric manufacturing apparatus according to claim 1, wherein the reflection dispersion plate is rotatably supported on a shaft and its upper and lower ends are attached to a support whose opening angle is adjustable. 4. The nonwoven fabric manufacturing apparatus according to claim 1, wherein the separators are arranged at regular intervals.