JPH10237800A - Crepe paper, paper yarn and their production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a flexible crepe paper, etc., having soft touch, causing no change in dimension in the longitudinal direction in a rewinding process and slitting process, not hindering quantitative production control due to not large change in dimension. SOLUTION: A slurry consisting essentially of a pulped plant fiber is made into a wet paper S by a cylinder machine 11. The wet paper S before drying is conducted to a roll 2 brought into contact with a first doctor blade 1, subjected to crepe treatment, pressed against a cylindrical dryer 4 and dried. Then a second doctor blade 7 is brought into contact with a cylindrical face of the dryer 4, the paper subjected to crepe treatment again, peeled and taken up. In the process, the roll 2 brought into contact with the first doctor blade 1, the cylindrical dryer 4 and a taking up speed are set so that an elongation rate at the inflection point of a stress-strain curve by a constant extension rate tensile strength tester by JIS P8113 is made 0.17-0.23 the elongation at break.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crepe paper, a paper thread and a method for producing the same.

[0002]

2. Description of the Related Art Various methods for producing crepe paper have been proposed over the years and have been put to practical use. For example, the following method is known.

(1) A wet paper web is guided on a roll, creped by abutting a doctor blade, and then pressed against a cylindrical drying cylinder to be adhered and dried. (2) After the creping treatment of (1), the crepe is dried without being pressed against the drying tube.

(3) After sticking and drying on a cylindrical drying cylinder without creping, a doctor blade is brought into contact with the surface of the drying cylinder to crepe and wind. (4) Moisturize the dried paper and heat and press the crepe-patterned engraved roll as needed.

(5) The dried paper is pushed into a gap provided with a part having a function of a doctor blade and passed therethrough. As this type of apparatus, a Myrex machine manufactured by Bird Inc. of the United States is known.

[0006]

Among the crepe papers obtained by the above-mentioned methods, the crepe papers obtained by the methods (1), (2) and (4) have a hard tactile sensation and have a longitudinal direction measured by a handle ometer. The value of softness is also large. On the other hand, the crepe paper obtained by the methods (3) and (5) has a soft touch, but causes a dimensional change in the vertical direction in the rewinding process and the slitting process. In addition, characteristics such as weight and elongation and tactile sensation greatly vary, which is inconvenient.

[0007] The present invention solves the above-mentioned problems, has a soft touch, does not cause a dimensional change in the vertical direction in the rewinding process or the slitting process, and does not greatly change the size. It is an object of the present invention to provide a crepe paper, a paper thread, and a method for producing the same, which have no problems.

[0008]

In order to achieve the above-mentioned object, the present invention according to claim 1 mainly comprises a pulped vegetable fiber and has a high elongation by a constant-speed elongation type tensile strength tester of JISP8113. The curve diagram has one inflection point at which the strength changes from convex to concave in the direction of the strength axis, and the ratio of stress to rupture strength at the inflection point is 0.02 to 0.20. The ratio of the tangent gradient to the initial gradient at the inflection point is 0.4 to 0.4.
8 is the crepe paper.

According to a second aspect of the present invention, a wet paper mainly composed of pulped vegetable fibers is guided on a roll in contact with a first doctor blade, subjected to creping, and then pressed against a cylindrical dryer to dry the paper. Then, a second doctor blade is brought into contact with the drying cylinder, creping is performed again, and the crepe paper is peeled off from the drying cylinder and wound up.
The elongation at the inflection point of the strength-elongation curve diagram of the constant-speed elongation type tensile strength tester of No. 8113 is 0.17 to less than the elongation at break.
The gist of the present invention is a method for producing a flexible crepe paper characterized by setting the roll, the cylindrical drying cylinder, and the winding speed, which are in contact with the first doctor blade, so as to increase the ratio by 0.23 times.

According to a third aspect of the invention, there is provided a flexible paper thread characterized by slitting the crepe paper according to the first aspect to a width of 1.0 mm or more. The gist of the invention of claim 4 is a method of manufacturing a flexible paper thread, characterized in that the flexible crepe paper of claim 3 is slit to a width of 1.0 mm or more.

(Pulped Plant Fiber) The plant fiber used as the pulped plant fiber is not particularly limited. It can be selected from wood fiber, wood bast fiber, hemp bast fiber, and leaf fiber. Conifer, hardwood, mitsumata, kozo,
There are cancer, mulberry, flax, ramie, hemp, jute, kenaf, manila hemp, sisal hemp, and the like.

The pulping method includes a kraft method, a sulfite method, a simple alkali method, and the like. The pulping method is described in detail in "Craft Pulp, Non-Wood Pulp" (published by the Japan Association of Paper and Pulp Technology) edited by the Japan Association of Paper and Pulp Technology. Have been.

As other fibers, polyvinyl alcohol fibers to which a small amount of adhesive synthetic fibers can be added, carboxymethyl cellulose fibers having poor water solubility, and chitosan short fibers can be used in an amount of 10% or less, preferably 5% or less. .

Although the crepe paper of the present invention has the most preferable softness, it is necessary that this softness is not lost by simultaneously passing through a slitting step and a rewinding step. In addition, it is necessary that a significant dimensional change does not make it difficult to grasp the weight and the length.

A crepe paper satisfying these necessary items has a "strength / elongation curve diagram by a constant-speed elongation-type tensile strength tester of JISP 8113" which is initially upward, ie, convex in the high-strength direction, and later has a convexity of 1 mm. This is achieved by having the property of exhibiting a shape that passes through a number of inflection points into a concave shape in the direction of high strength.

A crepe paper whose curve diagram is concave or straight in the high-strength direction from the beginning expands due to the tension in the slitting process or the rewinding process, and loses its flexibility if left as it is, Weight is reduced.

The same applies to the case where the convex portion is small and is less than the minimum required tension in the slitting process and the rewinding process. Stress at this inflection point (inflection point stress)
Is 0.02 to 0.20 times the force at break (rupture strength), and the ratio of the gradient of the tangent line at the inflection point to the initial gradient is 0.4 to 0.8. Crepe paper is flexible, and does not significantly change in weight or length in the slitting or rewinding process, and does not change much in flexibility.

More preferably, the stress at the inflection point is 0.04 to 0.10 times the force at break (rupture strength), and these are softness, weight and flexibility. A more excellent crepe paper is obtained by integrating stability and the like. The ratio of the tangent gradient (tangent gradient) at the inflection point to the initial gradient is
0.4 to 0.8 is good.

If the stress ratio at the inflection point (ratio of the stress at the inflection point to the breaking strength) is more than 0.20, the flexibility is insufficient. If the inflection point stress ratio is less than 0.02, dimensional stability is lacking, and it is difficult to grasp the weight and length.

The ratio of the tangent gradient at the inflection point to the initial gradient indicates a smooth and soft tactile sensation and is 0.4
If it is smaller than this, it gives the feeling that the initial hardness is crushed, giving a feeling of lack of flexibility and discomfort to many people. On the other hand, when it is larger than 0.8, a drawback that crepe wrinkles are easily broken is recognized. (Method for producing crepe paper) The flexible crepe paper of the present invention is obtained by converting a slurry mainly composed of pulped vegetable fiber into a circular mesh,
Papermaking is performed using a paper machine using a papermaking machine such as a short net, an inclined wire, a long net, etc., and the wet paper web before drying is guided on a roll in contact with a first doctor blade, subjected to creping, and then formed into a cylindrical shape. Drying is performed by pressing the dryer, and then a second doctor blade is brought into contact with the cylindrical surface of the dryer, creped again, peeled off and wound up.

FIG. 1 shows an example of a case where paper is made by a round paper machine 11. In the figure, the first doctor blade 1
Can be effectively creped by also using the metal roll of the press roll. Thereafter, the creped wet paper web S is pressed against the cylindrical drying cylinder 4 by the touch roll 3 to dry effectively, and the second doctor blade 7 is brought into contact with the cylindrical surface of the cylindrical drying machine 4 to crepe again. Perform processing.

A glue and a release agent are adhered to the surface of the drying cylinder 4 by means of a spray 5 or the like, so that stable drying and smooth creping by the second doctor blade 7 and progress of the separation are maintained. . Reference numeral 8 denotes a take-up roll for winding the formed crepe paper S1, reference numeral 9 denotes a blanket, reference numeral 10 denotes a tension roll, and reference numerals 12 and 13 denote separation rolls for separating the papermaking S and the blanket 9.

In this step, the roll surface speed ratio between the roll 2 contacting the first doctor blade 1 and the drying cylinder 4 is determined by:
Depending on the speed ratio between the surface of the drying cylinder 4 and the winding, the crepe paper S
Many of the properties of the crepe paper, such as those represented by the elongation, softness, and other shapes of the "strength and elongation curve diagram of the constant-speed elongation type tensile strength tester of JISP 8113", are determined. In this case, the respective speed ratios are determined such that the ratio of the elongation at the inflection point to the elongation at break in the strength-elongation curve of the crepe paper obtained by winding is 0.17 to 0.23. Set to.

If the ratio is smaller than this, the flexibility and dimensions of the crepe paper become unstable, and if the ratio is too large, the flexibility is lost. It is not possible to separately determine the effect of the speed ratio between the roll 2 contacting the first doctor blade 1 and the drying cylinder 4 and the effect of the speed ratio between the drying cylinder 4 and the winding (winding roll 8) independently. It doesn't make much sense. The former is the characteristics of pulped plant fiber,
In particular, it changes slightly depending on the state of beating or fibrillation. It also changes depending on the moisture content of the wet paper immediately before being pressed and attached to the drying tube. The latter is the drying cylinder 4 and the second
Slightly changes depending on the adhesive force between the paper and the surface of the drying cylinder 4 at the contact point of the doctor blade 7 and the state of the tip of the doctor blade 7.

The winding speed imparts a slight tension to the paper which has been dried and peeled off by the second doctor blade 7, so that the strength-elongation curve shows a tendency to increase the elongation near zero stress. It is preferable to adjust so as to rise while showing a gradient from near the origin.

The crepe paper formed and wound as described above is usually slit into a paper thread or tape having a width of 1 mm or more by a slitter or a micro slitter equipped with a commercially available tension control mechanism. In this case, it is desirable that the tension control be converted to a unit width and maintain an accuracy that is not inferior to the level and fluctuation rate of the winding tension during papermaking.

(Paper Yarn and Method for Producing the Same) The crepe paper obtained from the crepe paper formed as described above is cut into a tape shape by a slitter such as a micro slitter or the like in the form of a tape, whereby the paper thread is cut. Form. The width of the paper to be cut is preferably 1 mm or more. If it is less than 1.0 mm, it is too thin and disadvantageous as a yarn material. In particular, 1.0 mm to 2
A range of 0 mm is preferable as the thread material, but it may be larger than 20 mm. (Testing Method) Next, means for obtaining a characteristic value from a “strong-elongation curve diagram by a constant-speed elongation-type tensile strength tester of JISP8113” will be described.

Tensile test is performed according to JISP 8113 using a constant-speed elongation type tensile strength tester equipped with a self-recording device to create an elongation / elongation curve. From the obtained strength-elongation curve, the items for each item are determined as follows.

Initial gradient: In general, the strength-elongation curve has a portion (linear portion) a which is regarded as a straight line starting from a point separated from 0 by a length of 0 to 2% of the breaking strength.
A straight line A, which is an extension of the straight line portion a, is drawn, and its gradient is obtained. In Examples and Comparative Examples described later, suffixes 1 and 2 are added to the gradient A of Examples 1 and 2, and the suffixes are added to the gradient A of Comparative Examples 1 to 4.
h1 to h4 are added. In addition, the same suffix is added to each of the following items for identification in the same manner as in the examples and comparative examples.

Inflection point: The strength-elongation curve diagram is obtained by forming a curve convex on the strength axis from the end of the straight line portion a used for obtaining the initial gradient, and then usually forming an approximate straight line b. After that, the curve shifts to a concave curve on the intensity axis. The center of the approximate straight line portion b is treated as an inflection point α.

Inflection point gradient: The gradient of the approximate straight line b is expressed as a tangent gradient at the inflection point. Inflection stress and inflection point elongation: The strength scale value at the inflection point is read to be the inflection point stress. Also, the scale of the inflection point at the inflection point is read to obtain the inflection point elongation rate.

FIG. 1 shows an example of each of the above values. Breaking strength and breaking elongation: Determined according to JISP8113. Flexibility: J. TAPPI, paper pulp test method 34-
It was measured using a handle ometer according to 80 "Test Method for Softness of Sanitary Thin Paper".

[0033]

EXAMPLES Example 1 and Comparative Examples 1 to 3 will be described below. 80 parts of lightly beaten NBKP and Manila hemp pulp
A stock slurry consisting of 20 parts was prepared. Four types of crepe paper having a weight of 26 to 31 g / m ² were obtained by using the slurry in a press roll section of a round paper machine having a Yankee type drying cylinder and a crepe paper manufacturing apparatus in which a doctor blade was in contact with the drying cylinder. Was manufactured.

Example 1 is a crepe paper having a weight of 30 g / m ² and a target elongation at break of 50% manufactured according to the above (manufacturing method). In Table 1, the actual breaking elongation was 47%.

In Comparative Example 1, the creped wet paper web was dried by passing it between a blanket wound around a 3/4 circumference of the drying cylinder and the surface of the drying cylinder without pressing the wet paper web against the drying cylinder. Is a crepe paper having a weight of 26 g / m ² and a target breaking elongation of 30% wound up without using a doctor blade. In Table 1, the actual breaking elongation was 27%.

Comparative Example 2 is a crepe paper having the same production method as Comparative Example 1, except that the target roll elongation was set to 60% by changing the speed ratio between the press roll used for creping and the drying cylinder. . In Table 1, the actual breaking elongation was 64%.

In Comparative Example 3, the wet paper was pressed against the drying tube and dried in the same manner as in Example 1, but the wound weight was 30 g / m ² , and the target breaking elongation was 60% without using the second doctor blade.
Crepe paper. In Table 1, the actual elongation at break is 5
8%.

Measured weight, breaking strength, breaking elongation, stress at inflection point, elongation percentage at inflection point, initial slope, slope at (tangent at) inflection point, and stress and breaking strength at inflection point Table 1 shows the ratio of the inflection point (tangent line at) and the ratio of the gradient to the initial gradient, and the softness in the longitudinal direction (average value of the front and back sides) measured using a handle ometer.

The features of Example 1 were that the ratio of the inflection point gradient to the initial gradient was particularly high, the "softness" exhibited a small value, and the paper tape actually slit to a width of 4 mm was also extremely soft. .

In Comparative Examples 1 and 3, the breaking strength, the inflection point stress, and the elongation curve were larger than those in Example 1, the initial gradient was more than three times that in Example 1, and the softness was higher. , Value 3
The value was nearly doubled, and the touch was quite hard.

In Comparative Example 2, although the breaking strength, the inflection point stress, and the initial gradient of the strength-elongation curve were almost the same as those in Example 1,
The value of the softness was twice or more, and the touch was hard.

In Example 1, it was not found that the dimensional change and the characteristic instability due to the tension in the rewinding and slitting processes would hinder production control and quality control. Example 2 and Comparative Example 4 In Example 2, a pulp slurry of Manila hemp pulp was prepared, and 1% of a polyamideamine epichlorohydrin resin was added as a wet strength agent. Was prepared.

Comparative Example 4 is a crepe paper obtained by omitting only the use of the second doctor blade on the drying cylinder from the paper making process of Example 2. Table 2 shows the measured values of the same items as in Example 1.

In Example 2, the speed ratio between the press roll, the drying cylinder and the winding was set so that the ratio of the elongation at inflection point to the elongation at break was 0.20 as in Example 1. The direction "softness" value was remarkable and a soft crepe paper was obtained.

The inflection stress / rupture strength / ratio of this crepe paper was 0.061, and the inflection point gradient / initial gradient / ratio was 0.64.

Further, changes in dimensions, tactile sensations, and characteristics due to the rewinding process and the slitting process were small, and were within a practically negligible range. 2mm width using micro slitter
To make a paper thread. The paper yarn obtained in Example 2 was significantly more flexible than the paper yarn obtained in Comparative Example 4, and was wound and twisted using a 20th-count cotton yarn as a core yarn to obtain an integrated dense composite yarn. Was done.

[0047]

[Table 1]

[0048]

[Table 2] (Example 3) In the first example, the obtained crepe paper was cut into a tape shape with a micro slitter. The cut paper width was 1 mm, 3 mm, 10 mm, and 20 mm. All of the paper yarns were soft to the touch and pliable.

The present invention is not limited to the above embodiment, but can be arbitrarily changed without departing from the present invention.

[0050]

As described in detail above, according to the first and second aspects of the present invention, the feel is soft, and the dimensional change does not occur in the vertical direction in the rewinding step or the slitting step. The flexible crepe paper does not hinder the quantitative production control because the fluctuation is not large.

According to the third aspect of the invention, a flexible paper thread can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a manufacturing process.

FIG. 2 shows JISP811 of Example 1 and Comparative Examples 1 to 3.
FIG. 3 is a graph showing a strong elongation curve obtained by using a constant-speed elongation type tensile strength tester of FIG.

FIG. 3 is a graph showing strength and elongation curves of JISP8113 of Example 2 and Comparative Example 4 measured by a constant-speed elongation type tensile strength tester.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... 1st doctor blade, 2 ... Roll, 4 ... Cylindrical drying cylinder, 7 ... 2nd doctor blade, S ... Wet paper.

Claims (4)

[Claims] Claims: 1. JISP mainly comprising pulped vegetable fiber
The strength-elongation curve diagram of the constant-speed elongation type tensile strength tester No. 8113 has one inflection point where the strength changes from convex to concave in the direction of the strength axis. 0.02-
Crepe paper wherein the ratio of the tangent slope to the initial slope at the inflection point of the curve is 0.4 to 0.8. 2. A wet paper mainly composed of pulped vegetable fiber is guided on a roll in contact with a first doctor blade, subjected to creping, dried by pressing against a cylindrical dryer, and then dried. In the method for producing crepe paper, in which the doctor blade of No. 2 is brought into contact with the drying cylinder and subjected to creping treatment again and peeled off from the drying cylinder and wound up, a strength and elongation curve diagram obtained by a constant-speed elongation type tensile strength tester of JISP8113 Setting the roll, the cylindrical drying cylinder, and the winding speed in contact with the first doctor blade so that the elongation at the inflection point is 0.17 to 0.23 times the elongation at break. Characteristic method for producing crepe paper. 3. The crepe paper according to claim 1 having a width of 1.0
Flexible paper thread characterized by slitting to mm or more. 4. A method for producing a paper thread, comprising, after producing the crepe paper according to claim 2, slit the crepe paper to a width of 1.0 mm or more.