JPS6323304B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION a.Object of the present invention The present invention relates to a method for producing hard processed cotton made from various synthetic fibers. We have succeeded in producing extremely strong hard processed cotton that is superior in performance, particularly in terms of peel strength and tensile strength, which is more than double that of conventional products. This makes it possible to provide hard processed cotton that can exhibit extremely diverse performance when used for various purposes as described below.

b. Prior art and its drawbacks (1) The conventional method for manufacturing this type of hard processed cotton is to use various high heat resistant synthetic fibers or their waste or a mixture thereof (hereinafter abbreviated as high heat resistant fiber). In addition, 20 to 30% of various synthetic fibers with low heat melting properties, scraps thereof, or mixtures thereof (hereinafter abbreviated as low heat melting fibers), which can be melted and bonded at relatively low temperatures of around 130 to 160°C, are added. The mixed cotton is rolled out using a cotton machine to make it into a rolled cotton shape.The rolled cotton is then needle punched using a needle machine to make it into a plate shape.
After being heat treated at temperatures of 130 to 160 degrees Celsius, the fibers are combined in an entangled state due to the melt adhesion of the low heat melting fibers in the mixed fibers, and then pressed to the required thickness. This process produces hard processed cotton.

The hard processed cotton obtained above has a thickness x
The weight and hardness per m ² can vary depending on the purpose, such as the mixing ratio of the materials and the strength of the press work, and according to the JIS-L3201 standard, the peel strength (Kg / 50 mm) is 5 to 10. Tensile strength (Kg/cm ² ) is between 10 and 25, and elastic fatigue is between 8 and 10%.

(2) The above conventional manufacturing method is currently a commonly used advanced manufacturing method in the industry, although there may be slight fluctuations in its numerical values. The disadvantage of the hard processed cotton obtained by this process is, in particular, its peel strength, that is, the hard processed cotton formed into a plate shape as shown in the first figure.
Lack of durability against peeling force in the stacking direction, and lack of tensile strength, that is, durability against the force of pulling hard processed cotton formed into a plate from side to side to break it, as shown in the second diagram. It lies in the lack.

The reason for this is as follows.

In other words, high heat-resistant fibers are the main components that form hard processed cotton, but these fibers and mixed low-heat melting fibers become entangled with each other during the rolling process using a cotton mill, but they are still hardly spread. The fibers appear to be aligned in the direction of the cotton, and the strong intertwining effect is achieved by punching with the main needle machine, but this is only in the vicinity where the needle passes.

Then, heat treatment is performed in this state to melt the low heat melting fibers and bond the fibers that are in contact with each other around the fibers.

However, the high heat resistant fibers are only passively bonded by the low heat fusibility fibers and do not change themselves at all, and therefore do not contribute to the entanglement adhesive action at all.

From the above, it can be seen that the part that exhibits peel strength is mainly the needle punched part where entanglement adhesion is well performed, other parts are not so effective, and
Since the tensile strength is only the adhesive force of the low heat melting fibers that bond the high heat resistant fibers together, this is also not very strong.

c. Solving the above-mentioned problems by the present invention Therefore, the present invention solves the above-mentioned drawbacks of the conventional manufacturing method due to high heat-resistant fibers, i.e., fibers that are mainly made of hard processed cotton (low heat-fusible fibers melt).
It was discovered that the process does not cause any changes and is always passive and does not play any active role in the manufacturing process. High-temperature fibers also undergo some kind of change during the manufacturing process (not changing the essence of the fiber, but causing a change in the external shape), which particularly contributes to increasing the intertwining density of the fibers, and
The processability is improved, and in a good entangled state and easy-to-process state, the melt adhesion effect of the low heat melting fibers is fully demonstrated, and the fibers are extremely strongly intertwined and bonded together. With the aim of developing hard processed cotton with outstanding strength and tensile strength, various researches revealed that a mixture of the above two types of fibers could be produced at extremely high temperatures during the heat treatment process, which was unimaginable with conventional technology. This purpose was achieved through heat treatment.

In other words, in the conventional technology, no matter what kind of synthetic fiber it is, as long as it is a synthetic fiber, it is weak against high heat and will inevitably melt under high heat, so heat treatment processing for synthetic fibers is carried out at the lowest possible temperature. It is common technical knowledge to avoid damaging the properties of the fibers by doing so.
In the above method for manufacturing hard processed cotton, heat treatment is performed at 130 to 160°C in order to melt and bond the low-heat-melting fibers, but if higher heat is applied, there is a risk that the high-heat-resistant fibers will also melt. Furthermore, there was no doubt that the melting temperature of the above-mentioned low heat-fusible fiber was set as the maximum temperature limit for heat treatment, since even if it does not melt, there will always be an adverse effect.

However, as a result of repeated experiments and research without being bound by the conventional technical common sense, the inventor of the present application found that the limit temperature at which the high heat-resistant fibers such as the polyester fibers melt is around 260 to 270 degrees Celsius. The high heat resistant fiber is very close to the melting limit temperature.
160~ by heat treatment to around 260℃
When heated at temperatures around 200 degrees Celsius, the fibers undergo a strong contraction and crimping phenomenon, automatically intertwining each other strongly and densely, and at temperatures around 260 degrees Celsius they become extremely flexible, making the entire structure It becomes soft and elastic like freshly pounded mochi or marshmallow, and if pressed in this state, it can be processed freely with excellent workability. ), when the temperature is lowered to room temperature, the processed shape is maintained, the extremely flexible state disappears, and the fiber returns to its original properties, and the shrinkage and crimping state, that is, the high-density entangled state, remains the same. With this technical result, we succeeded in producing hard processed cotton with extremely excellent properties. It is something.

d Manufacturing method according to the present invention The method for manufacturing the hard processed cotton of the present invention will be explained below. Various types of high heat-resistant fibers such as polyester fibers, polyacrylic fibers, polyamide fibers, etc. that do not melt even at high temperatures around 250 ° C. Melt scraps or a mixture thereof (high heat-resistant fibers) with relatively low heat at around 130 to 160℃, such as polyethylene fibers, specially processed polypropylene fibers, specially processed polyester fibers, propylene fibers, and vinyl chloride fibers. Depending on the type of fiber, various types of low heat melting fibers or their scraps or a mixture thereof (low heat melting fibers) to be bonded are used.
Depending on the type of fiber, for example, 20-30% for polyethylene fiber, 30-40% for polypropylene special processed fiber or polyester special processed fiber, 30-40% for propylene fiber or vinyl chloride fiber. The high heat resistant fibers mixed with low heat melting fibers are mixed with 40 to 60% of the inside and outside, and are rolled into a cotton-like shape using a cotton mill. Needle punch processing is performed to make a plate-shaped body, and this plate-shaped body is
First, the low heat-fusibility fibers are heat-treated at temperatures between 130 and 160 degrees Celsius by passing them through a heat treatment machine that heats them to 280 degrees Celsius at a conveyor feeding speed of 2 to 2.5 meters per minute. Melt and bond the high heat resistant fibers at around 160 to 200 degrees Celsius to shrink and crumple them to increase the degree of entanglement between the fibers and increase the density, and then heat the high heat resistant fibers at around 260 degrees Celsius until just before melting to form a plate. The entire product is made into an extremely soft and plump state, similar to freshly pounded mochi, to improve workability, and this flexible and plump product is sent out from a heat treatment processing machine and then continuously passed through a roll press machine. It is then pressed to the required thickness, hardness, and standard between the plates of a flat plate heat press machine (the press itself is heated to around 100℃). After that, the temperature is appropriately lowered to room temperature, and the low heat melting fibers are once completely melted, and the high heat resistant fibers are solidified at room temperature with the bonded state maintained, and the high heat resistant fibers are bonded together. The fiber retains its densely entangled state due to shrinkage and crimping caused by high heat, but it also loses its extremely flexible state caused by high heat and loses its original nature (fiber's original essence). (There is no damage or change at all.) If (thickness) 220 to 300 g per 1 mm x ^m2 , ・Hardness is 40 to 60 inside and outside ・Peeling strength (Kg/50 mm) 10 to 25 inside and outside - Manufactures hard processed cotton with properties such as tensile strength (Kg/ ^cm2 ) of 30 to 60, elastic fatigue of 2 to 4%, and moisture content of 4% or less (according to JIS-L3201 standard). It was designed to do so.

In the above manufacturing method, the size, weight (weight per square ^meter of constant thickness), hardness, etc. of the hard processed cotton plate are determined by the type and mixing ratio of the amphoteric fibers, and especially by adjusting the press processing. can be freely produced by

(1) For example, as a result of manufacturing a low heat melting fiber containing 20% polyethylene fiber by the above manufacturing method, it has a weight of 220 g per 1 mm x m ² (thickness), a hardness of about 40,
Peeling strength (Kg/50mm) around 10, tensile strength (Kg/ ^cm2 ) around 30, elastic fatigue around 4%, moisture content 4% or less (according to JIS-L3201 standard). A hard processed cotton was obtained. In addition, in place of the above 20% polyethylene fiber, when manufactured with a mixture of around 25% for special processed polypropylene fibers and special processed polyester fibers, and around 40% for propylene fibers and vinyl chloride fibers, Hard processed cotton with equivalent properties was obtained. Note that "specially processed fibers" refer to fibers whose single fibers have a composite structure of a material with low heat meltability and a material with high heat resistance.

(2) For example, as a result of manufacturing a low heat-fusible fiber containing 30% polyethylene fiber by the above manufacturing method, it has a hardness of around 60, a thickness of 300 g per 1 mm x ^m2 , and a hardness of around 60.
Peeling strength (Kg/50mm) around 25, tensile strength (Kg/cm ² ) around 60, elastic fatigue around 2%, moisture content 4% or less (according to JIS-L3201 standard). A hard processed cotton was obtained. In addition, instead of the above 30% or less polyethylene fiber, it may be manufactured using 35 to 40% or more in the case of specially processed polypropylene fibers and specially processed polyester fibers, or 60% or less in the case of propylene fibers and vinyl chloride fibers. , hard processed cotton with almost equivalent properties was obtained.

Therefore, the numerical values indicating the properties of the hard processed cotton produced by the method of the present invention are all higher than those of the hard processed cotton produced by the conventional manufacturing method,
This shows the superiority of the present invention, especially in terms of peel strength and tensile strength, which are more than twice as strong.

In addition, in the production method of the present invention, there are subtle changes in the state of the fibers due to changes in heating conditions.
At first, the molten state of the fiber melts and sticks to other fibers around it, but when the temperature reaches 160°C or higher to 200°C or higher, it completely melts and becomes paste-like or syrup-like. The shape disappears, and it becomes sticky and entangled with the entangled high heat resistant fibers, and after processing, it solidifies as it is and plays the role of maintaining the entangled state of the high heat resistant fibers.

(2) Heat treatment at 260°C is carried out by passing the plate through the processing machine at a speed of about 2 to 2.5 m/min, but at 280°C to
When heated at 290°C at a speed of 3 meters per minute, the entire surface of the plate was burnt, and when the temperature was increased even further, the entire plate burst into flames in an instant.

As a result of various experiments, it was found that the maximum heating temperature is about 260 to 270°C.

(3) High heat-resistant fibers shrink and crumple into a dusty or twirly state at temperatures of 160 to 200 degrees Celsius, although they can be formed even at lower temperatures. , the degree of entanglement and density of the fibers are greatly improved, and the completely melted low heat melting fibers like starch syrup are fused to the entangled fibers, which then solidify as they are. The high-density entangled state caused by shrinkage and crimping is maintained as it is, and as a result, the peel strength and tensile strength are significantly improved.

(4) After heat treatment at 260℃, the plate-shaped body becomes as shown above.
The overall texture will be extremely soft and fluffy, like freshly pounded mochi or marshmallows. Therefore, if a material in this state is pressed, there is an advantage that even a bulky material or a hard material with extremely high density by pressing strongly can be freely processed.

As mentioned above, when the fiber returns to room temperature, this special flexibility disappears and it returns to its original properties, without losing its essence as a fiber. Moreover, the shrinkage and crimping state described above does not recover even when the temperature returns to room temperature.
This is similar to when applying a heat permanent to human hair, the shape remains deformed but the essence of the hair remains unchanged.

e.Characteristics and applications of the hard processed cotton of the present invention (a) As mentioned above, the hard processed cotton has a high density in which the mixed synthetic fibers are completely melted by high heat treatment at around 260°C and the ones on the verge of melting. Because it is entangled and integrated into a press-formed material, it has excellent properties, especially in terms of peel strength and tensile strength. Even if it is hit or repeatedly bent, it has strong peeling characteristics, so unlike conventional products, it will not fatigue and peel off like a laminate, and it can withstand even rough use over a long period of time. .

(b) Since the entire plate is integrally constructed with completely uniform density, for example, even if a plate with a thickness of 5 mm is sliced into five thin plates each with a thickness of 1 mm, Each thin plate-like product has the same properties and has excellent peeling strength, and also, for example,
Even if you slice a single plate into a curved or curved shape so that thick and thin parts are formed, the strength of peeling in each part is uniformly strong, so there is a risk of partial peeling. A strong deformed plate-like body can be obtained. This is ideal, for example, as a core material for baseball gloves that may need to be thick or thin depending on the location.

C. As mentioned above, the tensile strength is particularly strong, so as the core material for each part of the kendo gi, fabrics made by machine sewing on both sides are particularly effective in combination with the peeling strength. Durable for long-term use.

(2) As a sole material for slippers, athletic shoes, non-slip shoes for rock fishing, etc., the properties of the product of the present invention can be exhibited in the same manner as above, and in particular, due to its strong peeling strength, sewing by sewing machine is not required during production. It can be manufactured simply by bonding with a strong adhesive, and is durable enough for use, thus reducing production costs.

It can also be used as an insole material for these shoes.

E. As a building material for soundproofing and cold protection, it has a particularly high entanglement density and can be produced with a thickness of 10 to 30 mm.
The products made in this way can be made at a very low price, so you can get the best product.

F) Due to the above properties, in addition to the above-mentioned uses, it can be used as a seat upholstery material for automobile seats, beds, sofas, chairs, etc., which is extremely strong and durable, and is especially inexpensive when using scrap fibers. It can be provided as a practical product.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of peel strength in a plate-shaped hard processed cotton, and FIG. 2 is an explanatory diagram of tensile strength.

Claims (1)

[Scope of Claims] 1. Various high heat resistant synthetic fibers, such as polyester fibers, that are difficult to melt even at high temperatures of around 250°C, their scraps, or mixtures thereof (hereinafter abbreviated as high heat resistant fibers) In addition, various types of synthetic fibers with low heat melting properties such as polyethylene fibers that can be melted and bonded at temperatures around 130 to 160℃, their scraps, or mixtures thereof (hereinafter abbreviated as low heat meltability fibers) are used as fibers. Depending on the type, 20 to 60% of the inside and outside are mixed, and the cotton is rolled out using a cotton machine to make a rolled cotton-like material.The rolled cotton-like material is then needle punched using a needle machine to make a board. This plate-shaped body is heated to 260℃.
Heat treatment is performed using internal and external heat to melt and bond the low heat melting fibers at around 130 to 160℃, and the high heat resistant fibers are shrunk and crimped at around 160 to 200℃ to reduce the degree of entanglement between the fibers. The high heat-resistant fibers are heated at around 260°C to just before melting to make the entire plate-like object extremely flexible and plump, improving workability. This flexible and plump material is then processed through a heat treatment process. At the same time as taking it out, it is pressed to the required thickness, and then the temperature is appropriately lowered to room temperature, and the low heat-melting fibers are completely melted and the high heat-resistant fibers are solidified while being bonded to each other. In addition to maintaining the bonded state, the high heat resistant fiber maintains the high density entanglement state caused by shrinkage and crimping caused by high heat, while also retaining the extremely flexible state caused by high heat. If the fiber is lost and restored to its original nature (the original essence of the fiber does not change at all), if the weight is 220 to 300 g per 1 mm x ^m2 (thickness), the hardness will be between 40 and 60. Peeling strength ( Kg/50mm) 10 to 25 or more, Tensile strength (Kg/ ^cm2 ) 30 to 60 or more, Elastic fatigue 2 to 4% or more, Moisture content 4% or less (according to JIS-L3201 standard). A method for producing hard processed cotton that maintains the properties of hard processed cotton.