JPH0684792B2 - Waste cotton molding air tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention is an air permeable tube made of a molded product of collected waste cotton. Since the air-permeable pipe has excellent air permeability, water permeability and hardness, it is used as a drainage air-permeable pipe for underground use for agriculture, or an underwater use air-permeable pipe for fishing, or an air-permeable pipe for indoor air conditioning. Or as an air permeable tube for other purposes.

Among the above-mentioned uses, the use as a drainage permeable pipe for underground burial for agriculture is a use that has not been conceived at all until now, and is the use developed for the first time with the advent of the permeable pipe of the present invention.

(B) Conventional technology and its problems Up to now, no air-permeable tube has been constructed that allows a large amount of gas to permeate through the entire surface of the layer forming the tube and has excellent hardness. That is, it has been conventionally known that a sheet-shaped fiber molded product made of fibers and resin and having a high fiber ratio has good air permeability, and for example, a non-woven fabric is given as an example. However, these fibrous sheet-shaped molded products generally have a small amount of the raw material used per unit volume, in other words, only a soft one having a small density is produced because the raw material fibers are relatively expensive. From these soft sheet-shaped moldings, hard and tubular moldings having a high density like the present invention cannot be produced. For the above reasons, the tubular fiber molding having excellent air permeability and hardness as in the present invention has not been produced so far, and no research has been conducted on the manufacturing technology and application development of the molding. The present invention provides a hard air-permeable tube that is practical and cost-effective for the first time by using a large amount of recovered waste cotton with a low raw material cost and adopting optimum molded product manufacturing conditions. Was developed.

(C) Means for Solving the Problems The present invention relates to a fiber mat obtained by applying a resin binder to recovered waste cotton in an amount of 0.1 to 0.7 by weight of the resin / fiber, and the resin binder is melted to produce waste cotton. Heat-pressed into a tube under conditions that are difficult to melt, density 0.2 to 1.0 g /
cm ³ , air permeability 0.1 to 10 sec, water permeability 3 × 10 ^-3 to 1 × 10 ^-6 m / sec, flexural modulus 10 to 200 kg / mm ² ,
It is a waste cotton molded air-permeable tube that has air permeability in all parts of the tube wall.

The air-permeable tube of the present invention has excellent air permeability, water permeability, and hardness as the above-mentioned physical property values, and since it has the ability to permeate air from all parts of the tube wall, it is of course suitable for conventional air-permeable tube applications. The following will also develop new uses as agricultural air-permeable tubes.

For use in agriculture, the air permeable pipe of the present invention is buried in the soil of a field and air is sent into the pipe by an air compressor.
The air in the pipe permeates all parts of the pipe wall and diffuses into the soil in contact with the pipe to give air to the soil, promoting the growth and development of crops. Therefore, it is not necessary to cultivate the fields sufficiently to introduce air into the soil as before. Further, the air permeable pipe of the present invention can be used not only as a gas permeable pipe but also as a drain pipe for collecting excess water in the soil through the pipe wall and collecting it in the pipe in a field where drainage is poor.

The present invention uses, as a raw material, a recovered fiber waste composed of one or more kinds of cloth waste, yarn waste, and single fiber waste generated in the spinning process, the nonwoven fabric manufacturing process, the dyeing process, and the sewing process. The collected fiber wastes are synthetic fibers such as polyester fiber, nylon fiber, acrylic fiber, vinylon fiber, polypropylene fiber, polyurethane fiber, polyvinyl chloride fiber, artificial fiber such as acetate fiber and rayon fiber, and cotton, wool, silk, hemp, etc. The above natural fibers or a mixture of two or more kinds thereof may be used.

The recovered fiber waste is collected by opening the fibers to form recovered cotton waste, but an unopened fiber bundle having a thickness of 20 to 1500 denier is contained in the opened waste cotton as compared with the waste cotton that is opened in a uniform cotton shape. Alternatively, a light opening with 5 to 60% by weight of thread waste or a mixture of both is good. That is, by mixing these fiber bundles and thread wastes in the waste cotton, physical properties such as air permeability, water permeability, hardness (flexural modulus), and tensile strength of the final molded product are improved.
These fiber bundles and lint are the cause of the improvement of physical properties.
By playing the role of water conduit and aggregate. As described above, it is preferable to lightly open the recovered fiber waste, and the processing cost can be reduced.

The binder resin used in the present invention may be a commercially available thermosetting resin or thermoplastic resin which is usually used. Examples of thermosetting resins include phenol formalin resin, urea formalin resin, and melamine formalin resin,
Examples of the thermoplastic resin include polyethylene resin, pre-propylene resin, polyester resin, nylon resin, polyurethane resin, polyvinyl chloride resin, epoxy resin,
There are polystyrene resin, SBR, NBR, etc. In selecting a resin, it is important to select a resin having a melting point lower than that of the waste cotton, which is the main component, and to select a resin having a performance that matches the required quality of the final molded product. The resin binder may be used in the form of powder, small lumps (diameter 3 to 10 mm), fibrous, net, or liquid dissolved or dispersed in a solvent. The method of use depends on the shape of the resin binder, and there is a method of sprinkling it on a cotton or cotton layer, a method of spraying, a method of applying, a method of dipping, or a method of inserting into a fiber mat. When the waste cotton is a mixture of two or more kinds of cotton having different melting points, the low melting cotton can be used as a binder resin or as a part thereof.

The resin / fiber weight ratio employed in the present invention is 0.1 to 0.7. The final molded product having a ratio of 0.7 is, for example, a flexural modulus of 200 kg / mm ^{2, which} is very hard and is sufficiently practical as a hard molded product. As the ratio becomes smaller than 0.7, the hardness decreases and the softness increases, and at the same time, the air permeability and water permeability, which are the features of the fiber molded product, increase, so it can be applied to the final molded product that takes advantage of this feature. Even if the resin amount exceeds 0.7, the effect of increasing the hardness of the final green mold is small, but on the contrary, the characteristics such as air permeability and water permeability are lost and the cost is high, so the recovered fiber waste is used. The benefits of are reduced. On the other hand, when the ratio is less than 0.1, the amount of resin is small and the adhesive force between the fibers due to the resin is weakened, and the physical properties such as tensile strength and bendability decrease.

The waste cotton with the resin binder is made into a fiber mat using a simple card or weber. The fiber mat is preferably a non-homogeneous fiber mat in which the unopened fiber bundles in the waste cotton or the yarn waste or a mixture of both are present in almost intact form.

Next, preferable heating and pressing molding conditions in the present invention will be described. Molding is performed using a press molding machine. It is necessary to adopt a temperature condition in which the binder resin melts and the main waste cotton does not melt, and therefore the heating temperature is determined by the melting point of the resin binder used and the main waste cotton. Generally, it is desirable to employ a temperature 10 ° C lower than the resin melting point or 60 ° C higher than the resin melting point.

Regarding the pressing force, the larger the pressure, the stronger the pressure and the higher the density and hardness. Generally, the applied pressure is in the range of 0.1 to 100 kg / cm ² , but in the case of molded products requiring high hardness,
20 to 70 kg / cm ² is preferred.

The time required for heating and pressing is at least the time required for the resin binder to melt, and generally 10 to 30
Appropriately select and employ a suitable time within the range of 0 seconds. When the melting takes a considerable time, a method of heating and pressurizing after the preheat treatment is also advantageous.

For molding, select the optimum one from the above range and simply
Although it is possible to obtain the target tubular product with only one molding step, in the case of a tubular molded product with a complicated shape such as an air-permeable tube, first use weak conditions and prepare the first stage preliminary. Form a flat sheet with tensile strength that is more than the shape can be retained by molding, cut it into a belt shape, and then spiral that belt around the iron core of the convex mold as in the ordinary paper tube manufacturing method. After wrapping it in the shape of a circle, use a tubular concave mold to
It is preferable to perform the tubular main molding of the step. As another method of forming the tubular molded product, the flat sheet after the first-stage preforming is cut into an area slightly larger than the surface area of the tube, and the tubular convex mold is used in the same manner as in the ordinary paper tube manufacturing method. It is also possible to carry out the second stage tubular main molding under strong conditions using a tubular concave mold after flatly winding the iron core on the above.

If the shape example of the waste cotton molded air-permeable tube of the present invention is shown by the drawings,
It is as follows. 1 to 7 are perspective views of tubes formed into air permeable tubes. FIG. 1 shows a straight pipe with a flange (9). 2 shows a tapered tube (2), FIG. 3 shows a right cylindrical tube (3), and FIG. 4 shows an elbow tube (4).
5 and 6 show a ribbed straight pipe (7), FIG. 5 has a ring-shaped rib (5), and FIG. 6 has a spiral-shaped rib (6). Moreover, FIG. 7 shows a cheese tube (8). Reference numeral (10) in the above figure showing these examples
Indicates an unopened fiber bundle or thread waste, and since a large number of unopened fiber bundles or thread waste (10) are scattered, they serve as a conduit, a water conduit, and a reinforcing material. It improves the air permeability, water permeability and hardness of the air permeable tube.

(D) Action The manufacturing cost of a fiber molded product that uses a regular raw material and undergoes complicated processes such as spinning, web production, molding processing is high. Therefore, the molded product has conventionally been mainly made of a flexible product having a small amount of fibers and a small density, and a hard product having a large density has hardly been produced. The present invention is an air-permeable tube of a fiber molded product having excellent fiber performance such as air permeability and water permeability, and having the same hardness and tensile strength as the fiber reinforced plastic, but such a molded product is inexpensively recovered. This can be achieved for the first time by using a large amount of waste cotton to increase the density, and further by using the above-mentioned optimum conditions of the fiber mat manufacturing technology and the heat and pressure molding technology. The product development of the above-mentioned fiber molded air permeable pipe, which has not hitherto existed in the world, has also led to the application development of the agricultural air permeable and water permeable pipe of the present invention.

Next, the features of the fiber mat manufacturing technology and the heat and pressure molding technology for manufacturing the air-permeable tube of the present invention are as follows. Firstly, in order to improve the fiber performance such as air permeability and water permeability, especially unopened fiber bundles or yarn waste or The use of waste cotton mixed with a mixture of the two is to make a fiber mat that exists as it is. The second feature is that in order to improve the above-mentioned fiber performance, a resin matte having a large fiber ratio is produced by mixing a small amount of a resin binder into the waste cotton in the fiber mat manufacturing process. Next, since the shape of the fiber mat is so unstable that the fiber mat loses its shape when held by hand, even if the fiber mat is suddenly subjected to heat and pressure molding, uneven molding density occurs and a molded article having a good shape cannot be obtained.
The third feature is to solve this problem by first making a flat sheet-like fiber sheet with tensile strength that is more than the shape can be retained in the first stage preforming, and then in the second stage main forming It is to adopt a two-stage molding method that creates a tubular molded product that is true to the above. As described above, the target waste cotton molded air-permeable tube can be obtained by the manufacturing method of the present invention.

The air permeability is measured by JI as described in Examples and Comparative Examples below.
SP-8117, water permeability was measured according to JIS-A-1218, and flexural modulus was measured according to JIS-K-7203.

Example 1 Polyester 70% polypropylene generated in the sewing process
45% by weight of unopened fiber bundles and yarn waste distributed in the range of 50 to 1200 denier in the cotton swab, by gently opening the recovered fiber waste consisting of 30% mixed cotton cloth waste and system waste by opening it. I made a waste cotton. Phenol formalin resin powder is mixed with the waste cotton in an amount such that the resin / fiber weight ratio becomes 0.25, and then the mixture is placed in a car under mild conditions to form an inhomogeneous fiber mat in which the unopened fiber bundle and the thread waste are mixed in the same shape. I made it.
The fiber mat had a thickness of 60 mm and a density of 0.02 g / cm ³ and was in a state in which the morphology was likely to collapse. Next, add 17
Clearance of 15m using a flat plate press machine heated to 5 ℃
It was pressed for 20 seconds at m and a pressure of 10 kg / cm ² . The obtained flat fiber sheet is 15 mm thick and has a density of 0.09 g / cm without losing its shape.
The flexible sheet of ³ was the best as a molding material.

Next, the fibrous sheet molding was heated and pressure-molded to produce a tubular fiber molding having an inner diameter of 80 mm and a length of 1 m. First, the fiber sheet is cut into an area slightly larger than the surface area of the pipe to be manufactured, and this is attached to the cut portion of the iron core convex mold having an inner diameter of 70 mm, flatly wound, and the overlapping portions of the ends are temporarily adhered. , 210 in advance
With a concave die press machine heated to ℃, clearance is 3.0mm, press force is 60kg / cm ² for 60 seconds, inner diameter is 80mm, thickness is 3.0mm.
A lightweight tubular molded product having a density of 0.45 g / cm ³ was obtained. The molded product was a fiber molded air-permeable tube which had a flexural modulus as hard as 98.6 kg / mm ² and an excellent air permeability of 0.1 seconds and a water permeability coefficient of 0.5 × 10 ⁻³ m / sec. In the molded product, polypropylene cotton in the blended cotton was also melted to serve as a binder.

Application Example The air-permeable tube of Example 1 was buried in the center of the ridge in the field at a depth of about 40 cm from the soil surface, and the ridge was sown and grown with Chinese cabbage seeds. Air from the compressor was passed through the air permeable tube at a frequency of 4 to 5 times a month after germination, and the air was passed through the tube wall to provide the sky in the field soil. After 3 months, I was able to harvest large Chinese cabbage.

On the other hand, the Chinese cabbage prepared by the usual method without sending air from the air tube was poor in growth and inferior to the above Chinese cabbage.

Example 2 Recovered fiber waste consisting of cloth waste and thread waste mixed with polyester polyester produced in the sewing process and the dyeing process is lightly opened by a fiber-opening machine and 50 to 800 denier unopened fiber bundle and yarn are contained in the waste cotton. A waste cotton containing 35% by weight of residual waste was produced. A polyethylene resin powder was mixed with the waste cotton in an amount such that the resin / fiber weight ratio was 0.4, and then the mixture was put on a simple card to form a fiber mat. The fiber mat had a thickness of 72 mm and a density of 0.021 g / cm ³ , and was a non-homogeneous mat in which the above-mentioned unopened fiber bundle and yarn waste cotton were present as they were. Next, the fiber mat is preliminarily
It was pressed for 20 seconds with a clearance of 6 mm and a pressure of 20 kg / cm ² using a flat plate press machine heated to 5 ° C. The resulting flat fiber sheet has a thickness of 6 mm and is densely bonded with a binder resin.
It was a relatively strong sheet with a tensile strength of 0.25 g / cm ³ .

Next, the fibrous sheet-shaped molding material was heated and pressure-molded to produce a tubular fiber molding. First, the fiber sheet cut into a belt shape with a width of 100 mm is spirally wound around an iron core concave mold having an outer diameter of 70 mm, and then a clearance of 2.5 mm is obtained with a concave mold press machine preheated to 145 ° C. , At a pressure of 60 kg / cm ² 1
Pressed for 50 seconds, inner diameter 70mm, thickness 2.5mm, density 0.60g / c
A lightweight tubular molding of m ³ was obtained. The molded product has a bending elastic modulus of 125.6 kg / mm ^{2 which} is hard due to the effect of scattering of unopened fiber bundles, has an excellent air permeability of 0.3 seconds, and has a water permeability coefficient of 0.1 × 10 ⁻³ m / sec. It was a gas pipe.

(E) Effect of the Invention The air-permeable tube of the present invention is a completely novel fiber molding that has not existed in the world so far, and it uses a large amount of inexpensive recovered waste cotton to increase the density, and the fiber mat manufacturing technique of the present invention. ,
This can only be done by using the heat and pressure molding technology. The air-permeable tube of the present invention has excellent air permeability, water permeability, and hardness, and also has the ability to permeate air from all parts of the tube wall. It can also be used for new applications of agricultural air-permeable pipes that are buried in the soil to feed air and permeate the pipe wall to supply air to the soil.

[Brief description of drawings]

1 to 7 are perspective views each showing an example of the waste cotton molded air permeable tube of the present invention. (1) …… Flanged straight tube, (2) …… Tapered tube (3) …… Cylindrical tube, (4) …… Elbow tube (5) …… Ring-shaped rib, (6) …… Spiral Ribs (10) ... Unopened fiber bundles or thread waste

Claims (3)

[Claims] 1. A fiber mat obtained by applying a resin binder to a recovered waste cotton in an amount of 0.1 to 0.7 by weight of resin / fiber, and the resin binder is melted to form a tubular shape under the condition that the waste cotton is difficult to melt. Heat-press molded, density 0.2 to 1.0
g / cm ³ , air permeability 0.1 to 10 sec, water permeability coefficient 3 × 10 ^-3 to 1 × 10 ^-6 m / sec, flexural modulus 10 to 200 kg / mm ² , air permeability to all parts of pipe wall Waste cotton molded air tube. 2. A non-homogeneous fiber mat made of recovered waste cotton mixed with 3 to 60% by weight of unopened fiber bundles or yarn waste having a thickness distributed in the range of 20 to 1500 denier. The waste cotton molded air-permeable tube described in the item. 3. A function that air sent to a pipe buried in the soil of a field penetrates the pipe wall and diffuses into the soil to give air to the soil.
The waste cotton molding air-permeable pipe according to claim 1, which is used as an underground pipe for agricultural use, which has a function of collecting excess water in the soil of a field through the pipe wall and collecting it into the pipe.