JP3671601B2 - How to unwind glass roving - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to glass roving used for filament winding molding (hereinafter referred to as FW molding), pultrusion molding, and the like, which are molding methods of fiber reinforced plastic (FRP).
[0002]
[Prior art]
FRP is manufactured by impregnating a reinforcing fiber such as glass fiber with a liquid thermosetting resin and then curing the resin, and has been widely used as a pipe, a bar, and the like.
[0003]
As such FRP molding methods, the FW molding method, the pultrusion molding method, and the like are known. The FW molding method is suitable for producing pipe-shaped and cylindrical molded bodies, and loosens in a mold (mandrel) with tension applied to a reinforcing material such as glass roving impregnated with a liquid thermosetting resin. This is a method in which the resin is cured after being wound in a state without any cracks.
[0004]
The pultrusion method is suitable for producing pipe-shaped, plate-shaped, and non-empty rod-shaped molded bodies, and has a predetermined cross-sectional shape of a reinforcing material such as glass roving impregnated with a liquid thermosetting resin. In this method, the resin is pulled out while passing through a mold and heated during this time to cure the resin.
[0005]
In general, in order to manufacture this type of glass roving, first, a sizing agent is applied to a glass filament having a diameter of 6 to 15 μm, then 50 to 1600 pieces are bundled, and the strand count is changed to a 20 to 735th strand and then a twill is applied. While forming a cake by winding it into an abacus ball shape, it is dried. Next, a method is employed in which a plurality of the dried cakes are prepared, the strands are unwound from the inner layer of each cake, a predetermined number of the cakes are aligned and combined.
[0006]
The glass roving produced in this manner is wound in a cylindrical shape, and is packaged and shipped with a heat shrink film or the like having an opening at one end for removal when the roving is used and unwound.
[0007]
[Problems to be solved by the invention]
When producing a cake as described above, generally glass filaments having the same diameter are bundled and wound into a single strand, or glass filaments having the same diameter are divided into almost the same number and bundled. Then, a method of taking a plurality of strands and then winding them is adopted.
[0008]
In general, glass roving is produced by combining a plurality of strands having substantially the same count, and then wound into a cylindrical shape. To obtain a certain cylindrical shape, glass roving is configured. It is necessary to control the tension of the entire strand bundle. In the case of strands unraveled from the same type of cake in this way, the total tension of the tension applied by the unraveling tension and the bartender, which is the simplest tensioning device, becomes almost uniform in each strand. Is wound into a cylindrical shape with almost no slack.
[0009]
Therefore, even if the glass roving is unwound from such a wound body layer of the glass roving and impregnated into the resin by FW molding or pultrusion molding, the strand bundle is difficult to spread and impregnation failure tends to occur.
[0010]
Especially in the case of pultrusion molding, the glass fibers are oriented almost in one direction, so there is almost no reinforcing effect in the direction perpendicular to the glass fibers, and the molded product may be broken only by a slight impact such as dropping. .
[0011]
In order to prevent such breakage of the molded product, glass strands were deposited in a spiral shape, then the strands were bonded, and a continuous strand mat or glass strand made into a sheet shape was cut into 10 to 100 mm and deposited non-oriented. After that, the strands are bonded and the chopped strand mat formed into a sheet is used together with the roving, and in this case, the continuous strand mat or the chopped strand mat is expensive, or these are formed at the time of molding. There are problems such as easy tearing.
[0012]
The present invention has been made in view of the above circumstances, and since strand bundles are likely to spread when unwound, impregnation failure is unlikely to occur in FW molding or pultrusion molding, and glass has a reinforcing effect in a direction perpendicular to glass fibers. An object is to provide a method for solving roving.
[0013]
[Means for Solving the Problems]
As a result of repeating various experiments to achieve the above object, the present inventors have used a plurality of two types of strands having different counts in order to easily spread the strand bundle constituting the glass roving. It has been found that the unwinding direction from the inner layer of the cake of all or part of the strands may be reversed from the unwinding direction from the wound inner layer when using glass roving.
[0014]
In other words, when glass roving is composed of two types of strands with different counts, the strands with smaller counts are less rigid than the strands with larger counts. The strand bundle is easy to spread.
[0015]
Usually, since the strands are unwound from the inner layer of the cake when the yarns are combined, all the unwound strands are twisted in the direction opposite to the unwinding direction. For example, when a strand is unwound from the inner layer of the cake, if it is unwound clockwise, the strand is counterclockwise twisted (Z-twisted), and conversely, when the strand is unwound from the inner layer of the cake, When unwound clockwise, the strands are subjected to clockwise twist (S twist).
[0016]
Therefore, for example, a strand unwound clockwise from a plurality of cake inner layers is wound and wound to produce a glass roving wound body, and the glass roving is unwound clockwise again from the wound inner layer of the glass roving. Then, the strands constituting the glass roving are subjected to counterclockwise unwinding and twisting twice at the time of combining and unwinding, and the strand bundle becomes difficult to spread. The strand twist was unraveled when using the unraveling.
[0017]
In other words, the glass roving unwinding method according to the present invention is such that one to a plurality of first strands and a plurality of second strands having a smaller count than the first strand are combined and wound in a cylindrical shape. in wound by glass roving comprising the unwinding direction from the rotating winding body layer when using a glass roving this, the first strand of half or more and / or the second strand in the production of this glass roving The unwinding direction from more than half of the cake inner layer is the reverse direction.
[0018]
Further, the glass roving unwinding method of the present invention is preferably characterized in that the first strand and the second strand have a count difference of 400 or more, and the glass filaments constituting the first strand are single. The fiber diameter is 16 μm or more, and the single filament diameter of the glass filament constituting the second strand is 15 μm or less.
[0019]
[Action]
Since the first strand in the present invention has a larger strand count than the second strand, the first strand is more rigid than the second strand. Therefore, when the first strand is combined with the second strand, the tension when the first strand is combined is larger than that of the second strand due to its rigidity, so that the second strand is the second strand. The yarn is combined in a slightly slack state around one strand. As a result, the strand bundle constituting the glass roving in which these yarns are combined easily spreads.
[0020]
Further, in the present invention, the unwinding direction from the wound inner layer when using the glass roving, and more than half of the first strand and / or more than half of the second strand when manufacturing the glass roving. Since the unwinding direction from the cake inner layer is reversed, when using glass roving, the strands of some or all of the strands are unraveled and easily spread.
[0021]
Furthermore, in the present invention, when the unwinding direction from the cake inner layer of the first strand and the unwinding direction from the cake inner layer of the second strand in manufacturing the glass roving are reversed, the unraveling of the glass roving is performed. Since a strand (strand A) that is sometimes untwisted and a strand (strand B) that is further twisted coexist, it is more preferable.
[0022]
That is, when a strand unwound clockwise and a strand untwisted counterclockwise are combined, they are unwound and twisted in opposite directions. When using the glass roving thus produced, one strand (strand A) is untwisted during unwinding from the wound inner layer, and the other strand (strand B) is further twisted. become.
[0023]
As a result, the strands A and B, which are almost equal in length when they are combined, are unwound from the roving wound body, so that the apparent yarn length of the strand A becomes long, and the apparent yarn of the strand B The length is shortened. As a result, the strand A becomes loosely positioned around the strand B, and the strand bundle is likely to spread.
[0024]
When the glass roving thus produced is used for FW molding or pultrusion molding, it has a reinforcing effect in a direction perpendicular to the glass fiber, and impregnation defects in the molded product are reduced, and the yield rate is improved.
[0025]
Such effects depend on the impregnation apparatus, mandrel, and mold of the molding equipment for performing FW molding and pultrusion molding, but usually the unwinding direction from the wound inner layer of the glass roving and the glass roving are produced. If the unwinding direction from the cake inner layer of more than half of the first strand or the second strand of the second strand is in the reverse direction, the unwinding direction from the glass roving wound body layer, The effect is great when the unwinding direction from the cake inner layer of more than half of the two strands is reversed. Furthermore, the unwinding direction from the wound inner layer of the glass roving and the unwinding direction from all cake inner layers of the first strand, or the unwinding direction from all cake inner layers of the second strand are reversed. The effect is more remarkable. By the way, more than half here is based on the count.
[0026]
In the present invention, if the difference in the number of the first strand and the number of the second strand is 400 or more, the looseness of the second strand is further increased, and the single filament diameter of the glass filament constituting the first strand is 16 μm. As described above, when the single filament diameter of the glass filament constituting the second strand is 15 μm or less, the glass filament constituting the first strand itself is more rigid than the glass filament constituting the second strand, and the first strand is , More rigid than the second strand. As a result, the difference in yarn length between the two becomes large, the slackness of the strand becomes larger, and the strand bundle is more easily spread, which is preferable.
[0027]
【Example】
Hereinafter, the glass roving unwinding method of the present invention will be described in detail based on examples and comparative examples.
[0028]
(Example 1)
First, a sizing agent was applied to a glass filament having a single fiber diameter of 18.7 μm, and then 1600 of these were bundled and wound into an abacus ball shape while applying a twill after forming 1150th strand (first strand), and dried. As a result, a cake (first cake) having a loss on ignition of 0.4% by weight was prepared.
[0029]
In addition, after applying a sizing agent to a glass filament with a single fiber diameter of 13.3 μm, these 800 pieces are bundled to form a 290th strand (second strand) and wound into an abacus ball shape while applying a twill and dried. As a result, a cake (second cake) having a loss on ignition of 0.4% by weight was produced.
[0030]
As the sizing agent, 7.0% by weight of vinyl acetate emulsion (manufactured by Nippon SC Co., Ltd .: Yodosol LD-1010) as a binder, and γ-methacryloxypropyl trimethoxysilane (Nihon Unicar Co., Ltd.) as a silane coupling agent. Company: A-174) 0.2% by weight, a cationic surfactant 0.03% by weight as the lubricant, and the balance water was used.
[0031]
Next, the first strand is unwound clockwise from the inner layers of the two first cakes, and the second strand is unwound clockwise from the inner layers of the second cake 24, and the strands are combined. Then, a 9260-th glass roving wound body was produced by winding it into a cylindrical shape.
[0032]
Then, three glass roving rolls were prepared, the roving was unwound counterclockwise from these inner layers, and impregnated with unsaturated polyester resin in a nip roll type impregnation tank, at a speed of 0.5 m / min. The pultrusion molding was carried out to produce an empty rod-shaped pultrusion molded product having a diameter of 6 mm. In addition, loosening of the strand bundle was observed during the pultrusion molding.
[0033]
When the cross section of the FRP molded product thus obtained was observed with the naked eye, the impregnation state of the unsaturated polyester resin into the strand was good.
[0034]
(Example 2)
Two pieces of the first cake of Example 1 were prepared, and a glass roving wound body was produced under the same conditions as in Example 1 except that the first strand was unwound counterclockwise from the inner layer. Prepare three glass roving rolls, unwind glass roving counterclockwise from these inner layers, impregnate with unsaturated polyester resin in nip roll type impregnation tank, and pull out at a speed of 0.5 m / min. Molding was carried out to produce an empty rod-like pultruded product having a diameter of 6 mm. As a result of the pultrusion molding, the strand bundle was loosened.
[0035]
When the cross section of the FRP molded product thus obtained was observed visually, the impregnation state of the unsaturated polyester resin into the strand was good.
[0036]
(Comparative example)
In the same manner as in Example 1, after applying a sizing agent to a 13.3 μm glass filament, 800 of these bunches are bundled, wound into a abacus ball shape while being twilled and then dried, and then strongly dried. A cake having a heat loss of 0.4% by weight was prepared.
[0037]
And the strand was unwound counterclockwise from the inner layer of 32 pieces of these cakes, and these were combined, and then wound into a cylindrical shape to produce a 9280-th glass roving winding.
[0038]
Next, three glass roving windings were prepared, the glass roving was unwound counterclockwise from these inner layers, and an empty rod-like pultruded product having a diameter of 6 mm was produced in the same manner as in Example 1. No slack in the strand bundle was observed during pultrusion.
[0039]
When the cross section of the FRP molded product thus obtained was observed with the naked eye, there was a defect in the impregnation state of the unsaturated polyester resin into the strand, and an unimpregnated strand was observed.
[0040]
【The invention's effect】
As described above, when the glass roving unwinding method of the present invention is used for FW molding or pultrusion molding, strand bundles are easily spread during molding, resin impregnation into the strands is improved, and impregnation defects in the molded product are reduced. As a result, the yield rate is improved. Further, a pultruded product having a reinforcing effect also in a direction perpendicular to the glass fiber can be obtained.

Claims (3)

One or more of the first strands and a plurality of second strands having a smaller count than the first strands are combined and wound in a cylindrical shape. The unwinding direction from the wound inner layer in use is opposite to the unwinding direction from the cake inner layer of more than half of the first strand and / or more than half of the second strand when manufacturing the glass roving. A method for unraveling a glass roving characterized by being oriented. The glass roving unwinding method according to claim 1, wherein the first strand and the second strand have a count difference of 400 count or more. The glass according to claim 1 or 2, wherein the glass filament constituting the first strand has a single fiber diameter of 16 µm or more, and the glass filament constituting the second strand has a single fiber diameter of 15 µm or less. How to solve roving.