JPH0660035B2 - Deformed glass fiber and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial field of application" The present invention relates to glass fiber particularly suitable for use as a reinforcing material mixed in thermosetting resin, thermoplastic resin and the like, and a method for producing the same.

"Prior Art" In general, glass fiber uses a bushing having a circular shaped orifice plate with a large number of orifices on the bottom surface, and the molten glass in the bush is discharged through the orifices to form filaments. It is manufactured by bundling filaments such as the above into one or several strands and winding them. Each filament of glass fiber produced in this way has a cross-sectional shape close to a perfect circle and has a uniform thickness in the longitudinal direction.When used as a reinforcing material, a treatment agent is generally attached to the surface of glass and resin. Provides interfacial adhesion.

"Problems to be solved by the invention" In recent years, it has been strongly desired to improve the strength of a composite material of a resin and glass fiber and the tear strength of a paper made of glass fiber. Since the manufactured glass fiber has a smooth cross-sectional shape that is close to a perfect circle in the longitudinal direction, when used as a reinforcing material, the entanglement between the fibers is weak and the above requirements cannot be sufficiently satisfied.

In order to solve this problem, glass in which the particles of the refractory having a diameter of several times the diameter of the glass fiber in the longitudinal direction of the glass fiber are arranged at appropriate intervals and the surface of the glass fiber is made uneven so that the fibers can easily become entangled Fiber and its manufacturing method
It is proposed in Japanese Patent No. 42259. However, the glass fiber described in this publication is extremely complicated in structure and is troublesome to manufacture. Therefore, the present invention provides a glass fiber having a simple structure and easy production, and a method for producing the same, in addition to the fact that the entanglement of fibers is strong and the reinforcing effect can be enhanced when used as a reinforcing material of a composite material. It is intended.

"Means for Solving Problems" The glass fiber of the present invention which achieves the above object is characterized in that it is composed of only homogeneous glass and that the cross-sectional shape and cross-sectional area thereof periodically change in the longitudinal direction.

Further, the method of the present invention for producing the above glass fibers uses an orifice plate consisting of a plurality of orifice groups, each of which is a plurality of orifices closely arranged in a symmetric relationship, and one filament is spun for each group. The spinning condition is adjusted so that the orifice that spins the filament sequentially and repeatedly moves from one orifice in the group to another orifice that is adjacent to the orifice.

When a group of two orifices is formed, it is preferable to form a conical recess on the bottom surface of the orifice plate so that the outlets of the orifices of the two orifices open symmetrically with each other. In this case, the filament is composed of two orifices. Move back and forth between.

1 if one group consists of three or more orifices
The orifices of the group may be arranged at equal intervals on the circumference, and the outlets of these orifices may be opened to form a conical convex portion having an apex coinciding with the center of point symmetry of the outlet on the lower surface of the orifice plate. Preferably, in this case, the filaments circulate circumferentially in succession to the next adjacent orifice in the group.

"Action" Since the glass fiber of the present invention has a cross-sectional shape and a cross-sectional area which are periodically changed in the longitudinal direction, and a bulge-like bulge formed at appropriate intervals in the longitudinal direction prevents slippage between the fibers. The entanglement can be strengthened.

Further, the migration of filaments in the method for producing glass fiber of the present invention is accompanied by the fact that the molten glass flowing out to the orifice of the orifice forming the filament is joined together when the molten glass flowing out to the outlet of the adjacent orifice becomes large. Each time the transition occurs, the filament entrains the merged molten glass and changes the cross-sectional shape and cross-sectional area.

"Example" FIG. 1 shows an example of the modified glass fiber of the present invention. The filament 1 basically has an ordinary circular cross section as shown in FIG. 2A, but is spaced apart in the longitudinal direction. 2B
As shown in the figure, a hump 2 having a "eggplant" -shaped cross section is formed. The glass fiber of the present invention can be manufactured in various shapes according to the manufacturing method described later, not limited to the shape shown in FIG. 1, but is characterized in that the cross-sectional shape and the cross-sectional area are cyclically changed, The area ratio of the maximum cross-sectional area portion and the minimum cross-sectional area portion is preferably within the range of 2-15. This ratio is 2
When it is smaller, the desired entanglement effect cannot be obtained, and 1
When it is larger than 5, the fibers are often broken during winding or in the post-treatment process.

The glass fiber of the present invention described above can be produced by the method described below. FIG. 3 is a schematic front view showing an operating state of the apparatus for producing glass fiber of the present invention. Molten glass 5 in a bushing 4 having an orifice plate 3 at the bottom flows out through a large number of orifices 6 and a large number of filaments 1
After being spun into a strand and coated with a sizing agent by the applicator 7, the sizing unit 8 bundles the strands into one strand 9. The strand 9 is traversed by a traverse device 10 and wound on a winding tube 11.

4 is a plan view showing a part of the lower surface of an embodiment of the orifice plate 3 used in the apparatus of FIG. 3 for producing the glass fiber of FIG. 1 by the method of the present invention. The orifice plate 3 has an array of circular orifices 6 in pairs of two, and two orifice outlets of each pair of these orifices 6 are formed on the lower surface of the orifice plate 3 by cutting as shown in FIG. Conical recess formed 1
They are symmetrically located in 2 and face each other to open. This orifice plate has been developed to automatically regenerate a sliced orifice, which is disclosed in Japanese Patent Application No. 60-149849 (Japanese Patent Publication No.
However, the present invention adjusts the spinning temperature to a lower temperature than in the case of the automatic regeneration of the prior application and the spinning filament described below. As you can see, adjust the winding speed, orifice size, orifice spacing, and other factors.

That is, under the spinning conditions according to the present invention, as shown in FIG. 6, the filament 1 is formed only of the molten glass flowing out to the left orifice, for example, of the pair of orifices 6, 6, and the molten glass droplet 13 is formed at the outlet of the right orifice. It is only formed. As shown in FIG. 7, when the glass droplet 13 at the right orifice outlet reaches a certain size, the molten glass at both orifice outlets merges and one filament 1 is spun from both as shown in FIG. Become. Since the amount of the molten glass joined to this one filament flows out from the orifice on the right side immediately after the merging, the molten glass cone is offset toward the orifice on the right side. In the present invention, the filament spun from the molten glass cone having such a shape is not separated into two filaments and moves to the orifice on the right side away from the orifice on the left side as shown in FIG. At this point, droplets are formed by the molten glass flowing out, and the left and right orifices in FIG. 6 are just replaced. Next, when the droplets formed at the left orifice exit become larger, the molten glass at the orifice exit on the right merges and the filament moves to the left again, and thus the filament reciprocates between the left and right orifices at a certain time interval. The molten glass merged with is taken in to form a hump as shown by 2 in FIG. 1 at an appropriate interval in the longitudinal direction. The interval between these humps is determined by the transition period of the filament between the left and right orifices, and the transition period depends on the spinning temperature, the winding speed,
Orifice size, (major and minor diameters for oblong, diameter for circular) orifice spacing. First
Fig. 0 is a photograph showing a cross section of a strand in which a large number of filaments spun by using the orifice plate of Fig. 4 are gathered, and is formed into a filament having a circular cross section.
It can be seen that the hump portion of the profile cross section is mixed.

FIG. 11 shows an orifice array of another embodiment of the orifice plate used in the method of the present invention, showing a group of eight orifices 6a, 6b, 6c, 6d, 6e, 6
f, 6g, and 6h are arranged at equal intervals on the circumference, and these are point-symmetrically opened around the apex of the conical convex portion 14 projecting on the lower surface of the orifice plate as shown in FIG. In this embodiment, for example, filaments formed on the orifice 6a are aligned at small time intervals on the orifices 6b and 6c.
Then, it moves to the adjacent orifices one after another, and the molten glass that merges each time is transferred to form a hump.

In Table 1, as shown in FIG. 13, two orifices 6 ', 6'opening in the conical recess 12' are grouped into one group as in the orifice plate of FIG. 4, but the orifice 6 ',
The results of a glass fiber manufacturing experiment by the method of the present invention using an orifice having a cross-sectional shape of 6'deformed into an oval are shown.

The glass fibers obtained by this experiment had humps having the shape shown in FIG. 1 at intervals shown in Table 1. The confluence time in this table is the time from the transition of filaments until the confluence occurs and the next transition occurs.The interval of the humps is determined by the confluence time and the winding speed. The filament is fairly long, but one strand is quite short. For example, an 800-hole orifice plate forms one strand of 800 filaments, and each filament has a hump interval of 7
If it is m, the strand will contain one hump with an average spacing of 0.9 cm. The tensile strength of FRP using this strand as a reinforcing material is 10 to 15 compared to conventional FRP.
% Improved.

When the method of the present invention was tested using the orifice plate shown in FIG. 4 having an orifice and the dimensions shown in Table 2, the results shown in Table 2 were obtained.

When the method of the present invention was tested using the orifice plates shown in FIGS. 11 and 12 having 8 orifices having the dimensions and shapes shown in Table 3 and 1 protrusion as a group, Table 3 shows the results. I got the result.

Table 3 shows that the embodiment having 8 orifices per group in FIGS. 11 and 12 is compared with the embodiment having 2 orifices per group shown in FIG. 4 and FIG. 5 or FIG. It is shown that filaments with a relatively short hump interval can be obtained.

Although the embodiment described above shows a preferred embodiment, it is possible to use an orifice plate having a flat lower surface without forming a concave portion or a convex portion on the lower surface of the orifice plate.
It has been found that the present invention can be practiced by using an orifice plate in which one or three or more orifices are formed as a group.

Further, in the embodiment shown in FIGS. 4 and 5, each of the two orifices of one group is replaced by three and four adjacent small orifices as shown in FIG.
The molten glass flowing out of the four orifice sets is always united and spun into a filament of triangular section, and the molten glass flowing out of the other four orifice groups is always united and spun into a filament of square section. Further, by appropriately adjusting the filament so as to reciprocate between the two orifice sets, a filament having a hump having an alternating cross-sectional shape of a triangle and a quadrangle and an increased cross-sectional area at the transition point is manufactured. It is possible.

Also, in the embodiment shown in FIGS. 4 and 5, 2 in 1 group
As shown in FIG. 15, the individual orifices have different diameters, and when the spinning filament is reciprocated between these two orifices, the diameters alternately change to a larger diameter and a smaller diameter, and each change point. It is possible to produce filaments with humps having a further increased cross-section.

[Advantages of the Invention] As described above, according to the present invention, a glass fiber which is composed of only homogeneous glass and whose cross-sectional shape and cross-sectional area periodically change in the longitudinal direction can be obtained, so that the entanglement of the fibers becomes stronger When used as a reinforcing material for a material, the strength of the composite material is significantly improved as compared with the conventional composite material using glass fiber as a reinforcing material, and the manufacturing method thereof is relatively simple.

[Brief description of drawings]

FIG. 1 is a diagram showing the appearance of an example of the modified glass fiber of the present invention. 2A and 2B are respectively AA of FIG.
It is sectional drawing and BB sectional drawing. FIG. 3 is a front view showing the outline of the operating state of the apparatus for carrying out the present invention. Fourth
FIG. 5 is a plan view showing a part of the lower surface of an embodiment of the orifice plate used in the method of the present invention, and FIG.
It is a -V sectional view. 6 to 9 are cross-sectional views for explaining the transition state of filament when the glass fiber of the present invention is manufactured using the orifice plate of FIG. FIG. 10 is an enlarged photograph showing a cross section of a strand formed by bundling a large number of filaments spun using the orifice plate of FIG. 4, that is, the shape of the fiber.
FIG. 11 is a plan view showing an orifice array of an orifice group of another embodiment of the orifice plate used in the method of the present invention, and FIG. 12 is a sectional view taken along line XII-XII of FIG. FIG. 13 is a plan view showing a modified example in which the circular orifice of the orifice plate of FIG. 4 is changed to an elliptic orifice. FIG. 14 shows an embodiment in which each of the pair of orifices of each group of FIG. 4 is composed of three and four small diameter orifice groups, respectively, to form glass fibers whose cross-sectional shapes change alternately into triangles and squares. It is a top view which shows an example. FIG. 15 is a plan view showing an embodiment in which the diameters of the pair of orifices in each group in FIG. 4 are made different so as to form glass fibers whose diameters alternate. 1 ... Glass fiber (filament), 2 ... hump, 3 ... Olihus plate, 6,6 ', 6a-6h ... Olihus, 12,12' ... recess, 14 ... convex,

Claims (9)

[Claims] 1. A glass fiber which is composed of only homogeneous glass and whose cross-sectional shape and cross-sectional area change periodically in the longitudinal direction. 2. The glass fiber according to claim 1, characterized in that the cross-sectional shape thereof changes periodically into a "shaped" shape and a circular shape. 3. The ratio of the maximum cross-sectional area to the minimum cross-sectional area is 2-15.
The glass fiber according to claim (1) or (2), which is within the range. 4. A method for producing a glass fiber using an orifice plate comprising a plurality of orifice groups, each of which has a plurality of orifices arranged close to each other in a symmetric relationship, and one filament is spun in each group. The spinning temperature, the winding, so that the orifice through which the filament is spun is repeatedly and sequentially transitioned from one orifice in the group to another adjacent orifice, and at the same time, the droplets of the molten glass flowing out from the other adjacent orifice are joined together. A method for producing a glass fiber, wherein a cross-sectional shape and a cross-sectional area periodically change in the longitudinal direction, characterized by adjusting a speed, an orifice size, and an orifice interval. 5. The spinning temperature is 1140 ° C. to 1240 ° C.
The winding speed is adjusted to 216 m / min to 691 m / min, the orifice size is adjusted to 1.1 mm to 2.5 mm, and the orifice interval is adjusted to 0.3 mm to 0.8 mm. The method for producing glass fiber according to the item (4). 6. The method for producing a glass fiber according to claim 4, wherein each group includes two orifices, and the filament reciprocates between the two orifices. 7. The orifice plate according to claim 6, wherein the orifice plate has a conical recess on the lower surface of which the outlets of the two orifices of each group open symmetrically with respect to each other. A method for producing the glass fiber described. 8. A group according to claim 1, wherein each group includes three or more orifices arranged at equal intervals on the circumference, and the filaments are successively moved in the circumferential direction to the adjacent orifices. The method for producing glass fiber according to the item 4). 9. The orifice plate is characterized in that the outlets of three or more orifices of each group are opened, and a conical convex portion having an apex coinciding with the center of point symmetry of the outlets is provided on the lower surface. The method for producing glass fiber according to claim (8).