JPS58220721A - Moldig mat and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a molding mat which is good in flexibility, dispersion uniformity, and deep drawing moldability by a method in which a thermosetting resin is dispersed on wooden pulps and dried, the wooden pulps are mixed with a specific natural vegetable fiber and synthetic fiber to form a bulky mat, and the mat is needle-punched. CONSTITUTION:Wooden chips (wooden pulps steamed and beaten at 130 deg.C or higher) are mixed with a thermosetting resin 12 and dried by a dryer until a moisture content of 10-30% is reached. Then, 55-110pts.wt. the wooden pulp is further mixed with mixed fibers consisting of 10-30pts. natural vegatable fibers 14 having a fiber length of 10mm. or more and a denier of 10 or less and 5- 10pts.wt. chemical synthetic fibers having a fiber length of 3mm. or more and a denier of 5 or less in a mixer 36. The mixture thus obtained is molded into a bulky mat through a mat former 38 and then subjected to a needle punching 40 in such a way that fibers are combined with one another and thrusting of needle from at least one side through the mat is avoided. Thus, an objective mat 20 is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dry molding mat suitable for deep drawing molding and a method for producing the same.

Dry molding pine 1~, which is made from wood pulp as the main raw material, is conventionally known, and is used, for example, as interior material for automobiles, cases for audio equipment,
It is also used in the manufacture of other items such as furniture. IIT requirements for this type of mat include being inexpensive, having good moldability and handling before molding, having the desired mechanical strength, and having little variation in quality. It is.

Wood pulp is cheap and lightweight, so we want to mix it in as much as possible as the main raw material, but pIaI
A felt-like mat is made by mixing a large amount (more than 50%) of short (mostly 5' mm or less) grade wood pulp.
JA construction has been considered difficult in terms of uniform dispersion, strength characteristics, and mat handling properties.

Therefore, 20% or more adhesive (usually thermosetting resin)
Generally, the mixture was mixed at around 50% and precured, but mixing and covering a large amount of resin in this way not only increases the mat cost, but also deteriorates the flexibility of the mat. However, it is difficult to control the process such as hot stones and time for preliminary curing, and there are drawbacks such as the progress of curing of the resin, which adversely affects the properties of the molded product, and the uniformity of the quality of the molded product. “In addition, in order to reduce the amount of thermosetting resin blended, various P
Addition of A-thread material is also practiced, but depending on the method of addition, thin fibers may turn into neps and pill).
There was also a drawback that each component raw material was not uniformly dispersed in the mat, which resulted in a deterioration of the mat performance.

'The present invention has been made in view of the actual state of the prior art, and its purpose is to provide a material with good dispersion uniformity and mat handling properties, flexible properties, and good fit and moldability in deep drawing dies. The object of the present invention is to provide a molding mat that is good and can exhibit sufficient mechanical strength after molding, and to provide a method for efficiently manufacturing such a molding mat. .

The present invention will be explained in more detail below.

The mat for molding according to the present invention contains 50 to 100 parts of wood pulp obtained by steaming and defibrating wood chips, and a fiber length of 10 parts.
Natural plant fibers with a thickness of 10 denier or more with a diameter of 1 mm or more
0 to 30 parts by weight, the fiber length is 311 m or more, and the thickness is 5
A felt-like mat in which 15 to 10 parts of chemically synthesized tJA having a denier or less and 5 to 20 parts by weight of a thermosetting resin are uniformly dispersed and mixed, and at least one surface thereof is made of a needle punch. This structure has been subjected to fiber-to-fiber bonding treatment.

In the present invention, wood pulp obtained by steaming and defibrating wood chips is used. Traditionally, the wood pulp used for this type of molding mat was mainly paper pulp, so
The pulp itself had no adhesive effect, and a large amount of auxiliary adhesive was required.

In contrast, in the present invention, the wood pulp as described above is used, and since it contains natural resins (hemicellulose and lignin), it can be sufficiently effective as an adhesive if there is an appropriate amount of moisture and heat. In particular, high-temperature steamed wood pulp has a resin layer (on the defibrated side) that contains the main fibers (
As the hemicellulose and lignin) are softened and defibrated, wood fibers with more exposed resin layers than normal crushed ice pulp are obtained, which allows for a wider bonding area during subsequent hot-press molding. The effect is good, and the amount of synthetic resin added as an auxiliary agent is small and flows easily. Furthermore, in the present invention,
Wood pulp is manufactured from wood chips, and unlike the conventional method of using waste paper or waste wool, the quality is stable and the supply amount is also stable. The reason why we set the amount of wood pulp to be 50 to 100 parts is because we want to mix as much wood pulp as possible in terms of the price per pine tree and weight reduction, but if it is too much, the mat strength will be insufficient. However, if it is too small, there will be a shortage of fleshy material.

The natural vegetable fiber has a length of 1Q mm or more and a thickness of 10 denier or more, and is blended in an amount of 10 to 30 parts by weight. This natural vegetable fiber is intended to provide strength as a main skeleton material, and is preferably a thick and long fiber, and from this point of view, those having the above numerical values are used. Specifically, hemp,
Dicote hemp is especially good.

The chemical synthetic fiber has a fiber length of 3 mm or more and a thickness of 5 denier or less, and is added in an amount of 5 to 10 parts by weight. This chemically synthesized fiber compensates for the inflexibility of natural plant fibers as a strut road material, and also softens when heated and acts as a lubricant during molding, preventing the main frame material and fleshy material from slipping and causing damage. This prevents the mat from breaking, and from this point of view, those having the above numerical values are used. Specifically, a material that does not melt during hot pressure, such as polyester or rayon, is used.

In this case, 5 to 20 parts of thermosetting resin are applied as an adhesive. As mentioned above, since high-temperature steamed wood pulp is used in the present invention, the amount of the resin component to be blended may be relatively small.

Furthermore, the present invention is characterized in that the felt-like mat in which such component materials are uniformly dispersed is subjected to interfiber bonding treatment by impermeable needle punching. This interfiber bonding treatment by needle punching may be performed on only one side of the felt mat, but it is preferably performed on both sides. In either case, it is important to cover the needle of the needle punch so that it does not penetrate the fluted mat. The needle punch method is a method in which a large number of needles with small barbs move up and down to pierce the mat, creating a three-dimensional intertwining of the fibers within the mat and mechanically bonding them. However, in the present invention, unlike the conventional method, the needle does not penetrate into the pine 1 as described above.

In the present invention, when needle punching is performed on only one side, the needle puncture layer should be about 1/3 to 2/3 of the mat thickness, and the needle punching layer should be on both sides. When processing, the mat thickness is 115-21
It is desirable to have needle piercing layers on both sides with a depth of about 5 mm. With this structure, a layer (needle puncture layer) in which I8Iim is three-dimensionally intertwined and bonded is formed on the surface of the mat by needle punching, so the handling properties of the mat are significantly improved.
Therefore, the amount of thermosetting resin added can be kept small, and 1 (ゝ:・ 11 As the mat remains, it exhibits flexibility and fluidity that allows it to fit well into the deep drawing mold during hot-pressure molding, improving moldability.In addition, this type of mat is relatively thick. Although the needle contains hard fibers, it was also found that the occurrence of needle breakage was significantly reduced by the needle punch method, which does not penetrate the needle.

The molding mat having such a structure has sufficiently satisfactory performance, and has a density of 0.05 to 0.200/C.
It is about 12.

Next, a method for manufacturing a molding mat according to the present invention will be described. The method for producing a mat for molding according to the present invention involves spraying and mixing a thermosetting resin onto wood pulp obtained by defibrating wood chips by steaming them at 130°C or higher, passing the dryer through a drying device to attach the thermosetting resin to the wood pulp, and reducing the water content. 10-30%
55 to 110 parts of wood pulp adjusted to
Separately, the fiber length is 1Qmm or more and the thickness is 10mm.
Natural plant tIJA navy blue with 10 to 30 small motherboard over denier! 5 to 10 parts by weight of chemically synthesized fibers with a diameter of 3 mm or more and a thickness of 5 deniers or less are mixed with a mixed fiber prepared by defibrating, mixed in a mixer, and then passed through a mat former to form a bulky mat. This is a method in which needle punching is performed from at least one side of the bulky mat so that the needles do not penetrate the bulky mat, thereby bonding the fibers to each other.

The drawings are step-by-step diagrams of the method. First, the wood chips 10 are defibrated using a steam defibration device 30. Since this steamed wood pulp is produced at about 50% (wet), a drying process is essential in order to form a felt-like mat, and it is also necessary to uniformly dry the fine pulp.

Therefore, the steamed wood pulp is introduced into a drying device 32 equipped with a dispersion mixer, and at the same time, a predetermined amount of thermosetting resin 12, which will serve as a binder, is sprayed in powder or liquid form.

This allows uniform dispersion of fine pulp and mixing and adhesion of thermosetting resin in one step, and by controlling the moisture content of the wood pulp after drying to 10-30%, the thermosetting resin becomes powder. In the case of liquid, the moisture in the pulp evaporates, and in the case of liquid, the solvent evaporates, making the adhesion to the pulp stronger.

Apart from this, natural plants! 14 fibers and 16 synthetic fibers
and are mixed in advance using a regular cotton opening machine No. 34. The reason why these two types of fibers are mixed in advance is to prevent particularly fine chemical synthetic fibers from forming neps (pilling). As a result of experiments, it was found that mixing only thin chemical synthetic fibers would result in a lot of neps, whereas mixing thick and rigid natural vegetable fibers would prevent the fine fibers from becoming neps. It depends. In addition, 1. If the natural plant 4 [14] and the chemically synthesized fiber 16 are mixed in advance, there is an advantage that the mixture with the wood pulp can be made much more uniform than when the three types are mixed at the same time.

In this way, the mixed fibers of natural vegetable fibers and chemically synthesized fibers and the essential pulp to which the thermosetting resin has been attached are sent to the quantitative feed mixer 36 and mixed at a predetermined ratio, and then At the mat 38)-[the sheet is formed into a rut-like bulky mat 18. After that, this bulky mat 18 is
Punch iJ! 40, and when double-sided processing is performed, a first needle punching process is first performed on one side, and then a second needle punching process is performed on the side to be used. As mentioned above, in these treatments, the needle does not penetrate the mat. In addition to the above-mentioned advantages, since the needles are impenetrable, fine particles constituting the pine i~ do not fall off during needle punching.

The needle-punched mat is cut into a predetermined shape by a cutting device 42 to become a molding mat 22. 2. Cutting waste 20 generated during cutting can be used as a reused raw material. In the conventional thermal semi-curing method, the effectiveness of the resin has deteriorated to some extent, and if it were to be recovered as a raw material, it was necessary to re-add the resin corresponding to the deteriorated amount, but with the method of the present invention, Since thermal semi-curing is not performed, it is sufficient to return the cut scraps 20 to the quantitative supply mixer 36 (1-1), and quality control becomes easy.

A comparison between the embodiments of the present invention and the prior art is shown in the following table.

In the table, the raw materials and their blending ratios for product A of the present invention are as follows: Wood pulp...100 parts by weight (dry conversion) Liquid phenol resin (resol type)...20 parts by weight (solid content equivalent) Hemp 5 alt (10 parts by weight) Denier, length 10-20Il1m)
... 20 parts by weight Borini [Stell I navy blue (1.5 denier, length 3-b), and the raw materials and their blending ratios for product B of the present invention are those disclosed by the company. Note that the needle punching depth by the needle punching machine was 1/4 of the mat thickness on both sides.

The comparison amount was made by using the conventional method of thermal semi-curing instead of needle-punch bonding, in which a mixed mat original fabric made with the same raw material composition as Invention Product B was subjected to aeration heat treatment using a hot air transfer machine to form phenol. The fibers are bonded by semi-curing the resin.

As is clear from the above table, the product of the present invention has a tensile strength of 2 times higher as a mat for molding, good moldability, and it can be seen that the mechanical strength of the molded product is considerably improved.

Since the present invention is constructed as described above, it has good dispersion uniformity of raw material components, good matte handling, flexible properties, good fit and moldability in deep drawing dies, and has sufficient mechanical strength after molding. It is possible to obtain a molding mat that can avoid the development of mechanical strength, and also to efficiently produce such a molding mat, which has an excellent effect of φ.

Furthermore, since we use steamed and defibrated pulp from wood chips, we can increase the amount of wood pulp by using the needle punch method, and at the same time, we can reduce the amount of thermosetting resin. Good mat handling performance and product strength equal to or higher than conventional products can be obtained. Since the needle of the needle punch is designed to prevent the needle from penetrating the mat, resin, fine pulp, fibers, etc. do not fall out of the pine during needle punching, and the needle punching does not cause the needle to penetrate the mat. Despite this, a supple mat was formed and the fins had good resistance to deep drawing.
Therefore, the moldability is good, there is almost no breakage of the needle, and there are excellent effects such as the ability to reuse the pine wood scraps produced by cutting as is. Also,
Since natural vegetable fibers and chemically synthesized fibers are premixed, the product has excellent dispersion uniformity and has the effect of improving mat strength.

[Brief explanation of the drawing]

The drawings are explanatory diagrams of the method of the present invention. 10... Wood chip, 12... Thermosetting resin, 14
...Natural plant fiber, 16.Chemical synthetic fiber, 20.
...Molding mat, 30...Steam defibration device, 32...
・Drying device, 371... Cotton opening machine, 3G... Regular stone supply a combined 1 jl, 38... Matsu 1 to former-140
... Needle punch machine, 42... Cutting device. Same as Yunosuke Seriki

Claims (1)

[Claims] 1. Rice pulp obtained by steaming and defibrating water-containing pulp 50 to 10
0 parts by weight, 10 to 30 parts by weight of natural vegetable fibers with an IL length of 10 + nm or more and a thickness of 10 deniers or more, and 5 to 10 parts of chemical synthetic fibers with II fibers of 3 mm or more and a thickness of 5 deniers or less. It is a felt-like mat in which 5 to 20 parts by weight of thermosetting resin are uniformly dispersed and mixed, and at least one side of the mat has been subjected to interfiber bonding treatment by non-penetrating needle punching. A molding mat characterized by: 2. Wood pulp made by steaming wood chips at 130°C or higher (mixed with a thermosetting resin and adhering the thermosetting resin to the wood pulp through a drying device, and adjusting the moisture content to 10 to 30%) 55 to 110 parts by weight of wood pulp and, separately from this, 10 to 30 parts by weight of natural plant Ili fibers with a fiber length of 1 Q mm or more and a thickness of 10 deniers or more, and a fiber length of 3 mm or more and a thickness of 5 deniers or less. A mixed st prepared by mixing and defibrating 5 to 10 layers of chemical synthetic fibers.
After mixing in a mixer, pass through a mat former to form a bulky mat, and perform needle punching from at least one side of the bulky mat so that the needle does not penetrate the bulky mat, and then combine [ft] A method for producing a molding mat, characterized by: