JPH10212648A - Oil absorbent felt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a felt capable of suitably supplying an oil to a wriggling part of a mechanical product, excellent in oiling properties and oil retention. SOLUTION: This oil absorbent felt comprises 10wt.% to 50wt.% of ultrafine single fiber having >=70% porosity, 0.01g/cm<3> to 0.80g/cm<3> density and <0.8 denier thickness and 90wt.%-50wt.% of single yarn having >0.8 denier thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a felt capable of suitably supplying oil to a wrigging portion of a machine product and having excellent oil absorbency and oil absorbency.

[0002]

2. Description of the Related Art In a machine product having a wriggling part, such as a printer, a felt is used to continuously supply a certain amount of oil to the wrigging part. Naturally, such a felt having a large oil absorption is preferable. In order to increase the oil absorption of the felt, there is a method of reducing the density of the felt and increasing the porosity per unit volume. However, when the porosity is increased, the oil absorption increases, but on the contrary, the oil absorption retention decreases, and the oil is scattered due to vibration or the like, and the oil absorption decreases.

On the other hand, Japanese Patent Application Laid-Open No. 52-94234 describes a felt-like material having excellent water absorbency and less dripping of ink, which can be suitably used as an ink reservoir. This is a felt in which fibers having crimps and fibers which are liable to fibrillation are mixed. The amount of ink stored is increased by crimping, and the fibrillated fibers serve as a binder. However, such a felt improves the ink drop by only randomizing the fiber direction of the crimped fiber, so that even if the ink can be held in a free state, it cannot be held when a certain centrifugal force is applied. There is a point.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to supply oil to a wrigging portion in a suitable manner and to supply a felt excellent in oil absorbency and oil absorbency at low cost.

[0005]

Means for Solving the Problems The present inventors have studied the preparation of the material constituting the felt and the manufacturing method, and have completed the present invention. That is, the felt of the present invention has a porosity of 7
0% or more, and the density is 0.01 g / cm ^{3 to} 0.80 g /
cm ³ and 10 to 50% by weight of ultrafine short fibers having a thickness of less than 0.8 denier, and 90 to 50% by weight of short fibers having a thickness of more than 0.8 denier. It is a refueling felt characterized by the above-mentioned.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Matrix fibers having a thickness of 0.8 denier or more used in the present invention include thermoplastic synthetic fibers, semi-synthetic fibers such as rayon, and natural fibers such as cotton. Not done. When thermoplastic synthetic fibers are used, for example, polyolefins such as polypropylene and polyethylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon 6 and nylon 66, and copolymers thereof. Can be used. Further, a mixture of two or more of these fibers may be used.

[0007] The felt of the present invention is characterized by using both the matrix fibers and the ultrafine short fibers. It is necessary that the fiber diameter of the ultrafine short fibers used by mixing with the matrix fiber is less than 0.8 denier, preferably less than 0.6 denier. By mixing such ultrafine fibers having a density of less than 0.8 denier, the retention of oil is increased by capillary action, and a felt excellent in both oil absorption and oil retention can be obtained. If the fiber diameter exceeds 0.8 denier, the effect due to the capillary phenomenon is reduced, and the oil absorption retention is reduced. The term "oil absorption retention" as used herein refers to an oil absorption performance when a certain centrifugal force is applied to the felt.

It is necessary that the proportion of the ultrafine short fibers having a density of less than 0.8 denier is 10 to 50% by weight, preferably 15 to 40% by weight, based on the whole felt. If the content is less than 10% by weight, the effect of oil retentivity due to capillary action of the ultrafine fibers is insufficient. However, when the content exceeds 50% by weight, needle breakage frequently occurs during the production of felt, which is not preferable.

The ultrafine short fibers having a density of less than 0.8 denier used in the present invention are not particularly limited.
Alternatively, a composite fiber split by a chemical method is preferable.

[0010] The fiber to be split by a physical method is not particularly limited, and a commercially available known fiber can be suitably used. However, the effects of the present invention such as lubricating property and lubricating retention property are more preferable. In order to achieve the above, it is preferable that the conjugate fiber is a composite fiber using an olefin component such as polyethylene as at least one component. For example, a fiber in which polyethylene and polyethylene terephthalate are compounded into a star-shaped portion and a foot portion thereof is commercially available (Kanebo Synthetic Co., Ltd., trade name: Kanebo polyester type E91, etc.). Such a composite fiber is naturally divided into seven if the number of stars is six. Therefore, if the denier of the composite fiber is 2 deniers, the average denier of the split fibers is 0.57 denier. Further, the fiber to be chemically split is not particularly limited, and a commercially available known fiber can be suitably used. For example, a composite fiber composed of two components, ordinary PET and special PET that is easily dissolved by alkali treatment, is commercially available (Kanebo Synthetic Fiber Co., Ltd., trade name MX103, etc.).

The fibers split by the above physical method are split by a carding process or a needle punching process. Ideally, it is preferable not to divide in the carding process but to divide in the needle punching process. The above Kanebo polyester (trade name) type E91 is also excellent in this respect.

It is also possible to blend binder fibers to obtain a suitable formability of the felt. Binder
The fibers are softened or melted by heating to a temperature lower than the softening point of the matrix fibers and the ultrafine fibers to express the fusibility. The fusion temperature varies depending on the type of the matrix fiber and the ultrafine fiber used.For example, when a regular polyester fiber is used as the matrix fiber and a polyethylene-polyester split fiber is used as the split fiber, the fusion temperature may be 130 ° C or less. preferable.

As the binder fiber, a copolymer or a blend polymer, for example, a copolymer whose melting point is lowered by a copolymer component such as isophthalic acid, or a heat-sealing polymer such as a blend polyester is preferably used. Is done. The heat treatment is performed at a temperature lower than the softening point temperature of the matrix fiber and at a temperature higher than the temperature at which the binder fiber exhibits the fusibility. However, the heat treatment may be performed as a single step or in conjunction with the heat molding step. By such heat treatment, the constituent fibers intersecting with the binder fibers adhere at the intersections to impart morphological stability to the nonwoven fabric substrate, and the binder fibers cooperate with the support function of the matrix fibers to give the nonwoven fabric substrate an appropriate rigidity. give. Furthermore, the use of the binder fiber makes it possible to absorb the uneven shape attached to the surface of the nonwoven fabric or to intentionally impart unevenness to the surface of the nonwoven fabric.

The binder fiber may be a single-component fiber made of the above-mentioned heat-fusible polymer, but is a sheath-core type conjugate having a homopolymer as a core component and a heat-fusible copolymer as a sheath component. The use of fiber is more preferable because the heat fusion function can be achieved while maintaining the function of supporting the core component. Examples of such binder fibers include, but are not limited to, Bellcombi of Kanebo Synthetic Co., Ltd. having a normal polyester polymer as a core component and a low-melting copolyester polymer as a sheath component.

When a binder fiber is added, its content is usually at least 5% by weight, preferably at least 10% by weight, more preferably at least 20% by weight. When the content of the binder is less than 5% by weight, sufficient rigidity or molding stability cannot be maintained, and even forming may be difficult.
In addition, there is a possibility that the fibers may fall off.

When the content of the binder fiber is 20% by weight or more, the composite binder fiber forms a network,
Felt moldability is maintained well. In addition, the adhesive strength is increased, and the fibers and the like can be prevented from falling off.

The length of these short fibers greatly depends on the method and equipment for producing the felt of the present invention, but when producing felt through a card, the fiber length is preferably 50 mm or more.

The porosity of the felt of the present invention must be 70% or more. If the porosity is less than 70%, the oil absorbing property is reduced, so that the object of the present invention cannot be sufficiently achieved. The porosity here indicates the ratio of the volume occupied by the space per unit volume of felt. Specifically, the unit volume per 1 m ² is obtained from the thickness at the time of molding of the felt, and the ratio of the space occupied per unit volume is calculated from the weight of the short fibers used and the polymer density of the short fibers, This is defined as the porosity. In addition, the oil absorption here means
Fig. 3 shows the absorption performance of oil when the felt is in a no-load state.

The felt has a density of 0.01 g / cm ^3.
０．８0.80 g / cm ³ . 0.0
If it is less than 1 g / cm ³ , the strength of the felt is insufficient and shape stability cannot be obtained. Conversely, if it exceeds 0.80 g / cm ³ , needle breakage will frequently occur during the production of felt, and there is a possibility that problems such as an increase in cost due to an increase in the amount of fibers used may occur.

The felt made of the fibers can be produced by a usual method. That is, specifically, there is a method in which the raw material cotton is opened and mixed, then a web is made through a card, and a needle is punched to produce a felt.

When the binder fiber is used, the felt of the present invention can be molded by heating at 70 to 260 ° C. for several minutes and pressing. As a result, the low melting point sheath portion of the binder fiber is melt-bonded to other fibers, thereby maintaining the moldability. Here, the heating temperature is 70
If the temperature is lower than 0 ° C., molding cannot be performed even if the heating time is prolonged. Conversely, if the temperature exceeds 260 ° C., the entire felt melts and the molding cannot be performed similarly.

The heating method performed here is not particularly limited. It can be appropriately selected depending on the application and cost.

The thickness of the felt of the present invention after forming is 1
mm or more is preferable. If it is less than 1 mm, the density increases even if the basis weight is reduced, so that the unit porosity may be reduced and the oil absorption may be insufficient.

[0024]

The present invention is a felt which supplies oil to the wrigging part and has excellent oil absorbency and oil absorbency, and can be easily formed at a low cost.

[0025]

【Example】

(Measurement method of lubrication amount per unit volume) 1c sample
mx 2 cm, which was immersed sufficiently in Shell Oil Co., Ltd. Terrace Oil T-37, allowed to stand on a 40-mesh wire net, and weighed after the oil did not fall off. The amount of oil absorption per 1 cm × 2 cm was determined.

(Method of measuring oil absorption per unit volume) 1 cm × 2 cm whose oil absorption was measured by the wire mesh method described above.
Sample was attached to a centrifugal dehydrator as it was, and after centrifugal dehydration was performed for 3 minutes, the weight was measured, and its 1 cm × 2 cm
The remaining oil absorption per unit was defined as the oil absorption retention. The centrifugal force at this time was set at 500 rpm.

EXAMPLE 40% by weight of 51 mm of split ultrafine fiber "E91" 2 denier (7 split after passing through a card), binder fiber "408"
0 "40% by weight of 2 denier, 51 mm, and 20% by weight of 2 denier, 51 mm of regular polyester fiber were mixed and subjected to carding, cross laying and needle punching in the usual felt manufacturing process. A felt having a thickness of 20 mm and a basis weight of 1070 g / m ² was obtained. This one more
Forming was performed by heating press at 30 ° C for 90 seconds, thickness 2.88 mm, basis weight 960 g / m ² , density 0.37 g
/ Cm ³ and a porosity of 72.4% were obtained.

The lubricating felt of the present invention thus manufactured is 1 c in width.
m, and cut to a length of 2 cm to produce a test body. The oil absorption of this test specimen was 0.438 cc, and the oil absorption retention was 0.312.
cc and good. In addition, these test pieces had good mold holding properties, and the fibers did not fall off the cut surface of the felt.

COMPARATIVE EXAMPLE 100% wool (4 denier) was subjected to carding, cross-laying and needle punching in the usual felt manufacturing process to obtain a refueling felt having a thickness of 2.87 mm and a basis weight of 1421 g / m ² .

The lubricating felt of the present invention thus manufactured is made to have a width of 1c.
m, and cut to a length of 2 cm to produce a test body. The oil absorption of this test specimen was 0.379 cc, and the oil retention was 0.279.
cc.

[0031]

[Table 1]

[0032]

[Table 2]

Claims (1)

[Claims] A porosity of 70% or more and a density of 0.01
g / cm ³ is a ~0.80g / cm ^3, and the thickness 0.
10% by weight to 50% by weight of ultrafine short fibers of less than 8 deniers,
90% by weight of short fibers having a thickness of more than 0.8 denier
A refueling felt containing 50% by weight.