JP3204563B2 - Aramid sheet and honeycomb structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an aramid sheet and a honeycomb structure. That is, an aramid sheet, which is a nonwoven paper obtained by processing aramid fibers into a sheet, and
The present invention relates to a honeycomb structure formed using this as a base material.

[0002]

2. Description of the Related Art Such an aramid sheet is mainly made of finely cut aramid chop fiber, mixed with a binder such as aramid pulp, and made into a nonwoven paper sheet. The aramid chop fiber, which is the main component, has conventionally been linear. In other words, conventionally, continuous aramid fibers are simply cut into small pieces as they are to form straight aramid chop fibers, and an aramid sheet is manufactured using such aramid chop fibers as a main component. A honeycomb structure or the like is formed using such an aramid sheet as a base material.

[0003]

The following problems have been pointed out in such a conventional example. First
Meanwhile, in the conventional aramid sheet, the aramid chop fiber, which is the main component, has been linear. Thus, although rigidity is high, it has been pointed out that when a tensile load or a compressive load is applied in the sheet surface direction, its own elasticity and deformability are poor, and the impact strength is low. Accordingly, a problem has been pointed out that the honeycomb structure formed using such an aramid sheet also has a low impact strength.

[0004] Second, in the conventional aramid sheet, the aramid chop fiber, which is the main component thereof, has a straight shape and is relatively short. In other words, since the conventional aramid chop fiber has a linear shape as described above, if a long size is used, it is not bulky and evenly distributed in the sheeting process, so that the production of the aramid sheet is not easy and the quality is high. Becomes unstable. Therefore, in the conventional aramid sheet, a short one having an indispensable aramid chop fiber as its main component has been used.

Thirdly, however, it has been pointed out that such a short aramid chop fiber requires chopping to cut it very finely and shortly, and that the production of the aramid sheet is troublesome and troublesome. Fourthly, it has been pointed out that a fourth problem is that since the aramid chop fiber as a main component is short, general rigidity and strength of the aramid sheet are uneasy. It should be noted that a similar problem has been pointed out for a honeycomb structure formed using such an aramid sheet.

The present invention has been made in view of the above circumstances, and has been made to solve the above-mentioned problems of the prior art. First, the present invention employs a curd-shaped aramid chop fiber having a curvature. Secondly, the impact strength is improved, secondly, it is easy to make a sheet and it is easy to manufacture and mold, and the quality is stable.
The chop processing is also easy, and it is easy to manufacture and mold from this aspect. Fourth, it is excellent in general rigidity and strength.
An object is to propose an aramid sheet and a honeycomb structure.

[0007]

The technical means of the present invention for achieving this object is as follows. First, claim 1
Is as follows. That is, this aramid sheet is cut into fine pieces having a length of about 3 mm to about 30 mm, has a curvature radius of about 3 mm to about 100 mm, and is made of aramid chop fiber that is processed into a curl shape instead of a linear shape. And Aramid pulp, which is a binder, is mixed and compounded to form a sheet. Next, claim 2 is as follows. That is, the honeycomb structure is a planar aggregate of hollow columnar cells, and the aramid sheet according to claim 1 is used as a base material of a cell wall forming the cells. I do.

[0008]

The present invention comprises the above-mentioned means, and operates as follows. This aramid sheet mainly contains a predetermined aramid chop fiber. That is, an aramid chop fiber which has a curvature radius of about 3 mm to about 100 mm, has a curl shape, and is cut to a length of about 3 mm to about 30 mm is used as a main component. The honeycomb structure is formed using such an aramid sheet as a base material. Therefore, first, the aramid chop fiber, which is the main component, does not have a linear shape but a curl shape, and has a substantially spring-like structure. Therefore, in the aramid sheet and the honeycomb structure, when a tensile load or a compressive load is applied along the sheet surface or the cell wall direction, the stress is relaxed by the elasticity and deformability of the aramid chop fiber itself. The impact strength is improved as compared with this type of conventional example. Secondly, the aramid chop fiber, which is the main component, has a curl shape instead of a straight shape, and functions as a sliding surface. Therefore, the aramid sheet has a multilayer structure having a curled sliding surface, and the aramid chop fibers are uniformly distributed without being bulky as in this type of conventional example in the sheeting process, so that the long aramid chop is long. Even if fibers are used, sheeting becomes easy. in this way,
Since the aramid sheet and the honeycomb structure are linear as in the conventional example of this type, it is not necessary to use very fine and short aramid chop fibers. That is, since it is a curled shape having a curvature, even if an aramid chop fiber having a relatively long length of about 3 mm to 30 mm is used, manufacture and molding are easy and the quality is stable. Third, since a long aramid chop fiber can be used as the main component, chopping is simple and labor is reduced. That is, the aramid sheet and the honeycomb structure do not require the chop processing for cutting very finely and shortly as in the conventional example of this type, and the chop processing is simple.
Easy to mold. Fourth, similarly, since aramid chop fibers having a large size can be used as the main component, the aramid sheet and the honeycomb structure are excellent in general rigidity and strength.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings. The drawings show an embodiment of the invention,
FIG. 1A is an overall perspective view of an aramid sheet,
FIG. 2B is an enlarged plan view of the portion A, and FIG. 3C is an enlarged front view of the portion B. FIG. 2 is an enlarged front view showing a mode in which the aramid fiber is curled, and FIG.
FIG. 2 (2) shows a load, and FIG. 3 (3) shows a case where friction is applied. In the perspective view of FIG. 3, (1) shows the step of obtaining an aramid sheet by heating and pressing, (2) FIG. 3 shows the step of applying an adhesive to the aramid sheet and stacking it, (3)
The figure shows the step of bonding by heating and pressing. FIG. 4 shows a honeycomb structure.

First, as shown in FIG. 1, an aramid sheet 1 is made of an aramid chop fiber 2 having a predetermined curvature and length.
In other words, the aramid chop fiber 2 having a radius of curvature of about 3 mm to about 100 mm, being curled, and being cut to have a length of about 3 mm to about 30 mm is mixed with aramid pulp 3 as a binder to form a sheet. A description will be given of such an aramid sheet 1 along its manufacturing process. As shown in FIG. 2, as the aramid fiber 4 which is a nylon fiber, a meta-type or para-type is used. Aramid fiber 4 is processed into a curl with curvature. That is, before the aramid chop fiber 2 is chopped, a curvature residual stress is generated in the continuous aramid fiber 4 in advance, and various methods can be considered as the method. For example, a method of applying heat H to the aramid fiber 4 as shown in FIG. 2A, and a load P using a roller 5 or the like to the aramid fiber 4 as shown in FIG. 2B. Method, Figure 2
As shown in FIG. 3C, a method of adding friction R to the aramid fiber 4 by using a friction material 6 or the like, a method of using these in combination, and the like can be considered. Further, in the polymerization molding step of the aramid fiber 4 itself, a curvature residual stress can be generated in advance.

Next, the aramid fiber 4 in which the curvature residual stress has been generated is once stretched against the curvature residual stress, and subjected to chopping for fine cutting using a cutter. Fiber 2 is obtained. Then, after the fact, the aramid chop fiber 2 immediately returns to the curl shape having the curvature based on the curvature residual stress. In this way, for example, the aramid chop fiber 2 having a radius of curvature of about 3 mm to 100 mm and a length of about 3 mm to 30 mm is prepared. Aramid pulp 3 as a binder
The aramid pulp 3 is formed of a pulp-like pulp in which the aramid fiber 4 is finely chopped and then subjected to a chemical treatment with a sulfuric acid solution or the like to make it easily entangled. Then, the above-mentioned aramid chop fiber 2 is reduced from 10% to 8%.
Aramid pulp 3 is used by mixing at about 0% by weight, and aramid pulp 3 is mixed and mixed with the mixture, and as shown in FIG. The aramid sheet 1 having the aramid chop fiber 2 as a main component is manufactured, which functions as a link.

Aramid sheet 1 thus manufactured
As shown in FIG. 1, curled aramid chop fiber 2 which is finely cut and has a curvature is used as a main component, and aramid pulp 3 as a binder is mixed and compounded as a nonwoven paper. It is in the form of a sheet made of paper. That is, the aramid chop fiber 2 of this aramid sheet 1
Is curled with a curvature radius of about 3 mm to about 100 mm, and is cut to a length of about 3 mm to about 30 mm. Then, using such an aramid sheet 1 as a base material, as shown in FIG.
The honeycomb structure 9 which is a planar assembly of the above is formed.

A description will be given of such a honeycomb structure 9 along a forming process thereof. First, as shown in FIG. 3 (2), the adhesive 10 was applied to such an aramid sheet 1 in the form of striations, then cut at predetermined lengths, and applied in the form of striations. The adhesives 10 are vertically stacked in a positional relationship shifted by a half pitch. Then, as shown in FIG. 3 (3), the adhesive 10 applied by hot pressing is used.
Is heated and pressurized and melt-hardened, thereby bonding the stacked aramid sheets 1 together. Then, the honeycomb structure 9 shown in FIG. 4 is formed by extending in the stacking direction. In addition, the honeycomb structure 9 shown in FIG. 4 is formed by a so-called corrugated method, in which the aramid sheet 1 is made of a flat plate material and a corrugated plate material, and these are joined and laminated in a predetermined positional relationship after cutting. You may make it shape | mold.

The honeycomb structure 9 formed in this manner is made up of a planar assembly of hollow columnar cells 8, and the aramid sheet described above is used as a base material sheet for the cell walls 11 forming the cells 8. 1 is used. That is, the honeycomb structure 9 is provided with such an aramid sheet 1.
The cell walls 11 are divided into independent spaces,
For example, as shown in the figure, in addition to a regular hexagon, a triangular shape, a trapezoidal shape, and other various shapes are formed as a planar assembly of a large number of hollow column-shaped cells 8. In general, it is excellent in weight ratio strength, has high rigidity and strength as well as light weight, and also has excellent rectification effect, flatness accuracy, heat insulation, sound insulation, etc., large surface area per unit volume and molding It is known for its easy and easy characteristics and is widely used for various purposes.

The present invention is configured as described above. Then, it becomes as follows. That is, the aramid sheet 1 is mainly composed of a curled aramid chop fiber 2 having a curvature (see FIG. 1), and the honeycomb structure 9 is formed using the aramid sheet 1 as a base material (see FIG. 1). See FIG. 4 etc.). Therefore, the aramid sheet 1 and the honeycomb structure 9 are formed in the following first, second, third,
It becomes the fourth.

First, the aramid chop fiber 2 as the main component has a curl shape, not a straight shape, and has a substantially spring-like structure (see FIG. 1). Therefore, the aramid sheet 1 and the honeycomb structure 9 have such aramid chop fibers 2 when a tensile load or a compressive load is applied along the sheet surface or the cell wall 11 surface direction.
The stress is relaxed by its own elasticity and deformability, and the impact strength is improved as compared with the above-described conventional example of this type.

Second, the aramid chop fiber 2, which is the main component, forms a curl instead of a straight line, and functions as a sliding surface (see FIG. 1). Therefore, aramid sheet 1
Since the aramid chop fiber 2 has a multilayer structure having a curled sliding surface, the aramid chop fiber 2 is not bulky and uniformly distributed as in the above-described conventional example in the sheet forming process, so that the long aramid chop fiber 2 has a long size. Even if you use
Sheeting becomes easy. As described above, the aramid sheet 1 and the honeycomb structure 9 are easy to manufacture and mold and have stable quality even when the long aramid chop fiber 2 is used.

Third, since the long aramid chop fiber 2 can be used as the main component, chopping is simple and labor is reduced. That is, the aramid sheet 1 and the honeycomb structure 9 do not require the chop processing for cutting very finely and shortly as in the above-described conventional example, and the chop processing is simple. Is easy.

Fourth, similarly, since aramid chop fiber 2 as a main component can be used having a long size,
The aramid sheet 1 and the honeycomb structure 9 are also excellent in general rigidity and strength.

[0020]

As described above, the aramid sheet and the honeycomb structure according to the present invention employ curled aramid chop fibers having a curvature as described above.
The following effects are exhibited.

First, the impact strength when a tensile load or a compressive load is applied is improved. Secondly, since the aramid chop fibers are uniformly distributed without being bulky in the sheeting process, even if long aramid chop fibers are used, manufacture and molding are easy and the quality is stable. Third
In addition, since long aramid chop fiber can be used, chopping is easy and labor is reduced, and it is easy to manufacture and mold from this aspect, and fourth, it is excellent in general rigidity and strength. ing. As described above, the effects exhibited by the present invention are remarkably large, for example, the problems existing in this type of conventional example are eliminated.

[Brief description of the drawings]

FIG. 1 shows an embodiment of an aramid sheet according to the present invention,
(1) is an overall perspective view, (2) is an enlarged plan view of a portion A, and (3) is an enlarged front view of a portion B.

FIG. 2 is an enlarged front view showing a mode in which aramid fibers are curled in the same embodiment, where (1) shows a case where heat is applied, (2) shows a case where a load is applied, and (3) shows a case where friction is applied. Show the case.

FIG. 3 is a perspective view for explaining the embodiment, and (1)
The figure shows the process of heating and pressing to obtain an aramid sheet,
FIG. 2 (2) shows a step of applying an adhesive to the aramid sheet and stacking the sheets, and FIG. 3 (3) shows a step of bonding by applying heat and pressure.

FIG. 4 is a perspective view showing an embodiment of a honeycomb structure according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Aramid sheet 2 Aramid chop fiber 3 Aramid pulp 4 Aramid fiber 5 Roller 6 Friction material 7 Heat roller 8 Cell 9 Honeycomb structure 10 Adhesive 11 Cell wall H Heat P force R Friction

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI // B29K 105: 12

Claims (2)

(57) [Claims] An aramid chop fiber, which is cut into a length of about 3 mm to about 30 mm, has a curvature radius of about 3 mm to about 100 mm, and is processed not in a linear shape but in a curl shape as a main component. Aramid pulp as a binder is mixed and formed into a sheet. 2. A honeycomb structure comprising a planar aggregate of hollow columnar cells, wherein the aramid sheet according to claim 1 is used as a base material of a cell wall forming the cells. body.