JP3216557B2 - Method for manufacturing compressed tissue paper products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing tissue paper. More specifically, a two-ply compressed tissue paper that reduces the bulk of tissue paper products and improves the convenience of carrying and storing by consumers, and is soft and comfortable, and has low bulk but excellent water absorption. It relates to the product and the method of manufacturing it.

[0002]

2. Description of the Related Art As is well known, it is considered that tissue paper is preferably soft, comfortable to the touch, strong, bulky and water-absorbent. In the conventional tissue paper manufacturing technology, it is mainstream to make bulky paper, and various proposals have been devised and disclosed for that purpose. Commercially produced are through-air drying methods, and are disclosed in U.S. Pat. Nos. 3,301,746 and 3,882,106.
No. 8, etc. There are many proposals as a method of producing bulky paper other than the through-drying method, but the main purpose of these production methods is, like the through-drying method, soft, soft, strong, bulky, and bulky and water-absorbing tissue paper. Is to provide.

On the other hand, from the viewpoint of economy, bulky paper means that the volume per unit weight is large, and it is obviously expensive in terms of packaging costs, transportation costs and storage costs for tissue products. Also, bulky tissue products are inconvenient to handle in terms of convenience such as carrying by consumers and storage space at home. Regarding the manufacturing technology for providing compressed tissue paper products, Japanese Utility Model Application Laid-Open No. 63-172394 has been proposed, but folded tissue paper is pressed with a press machine.
It can be performed experimentally only by describing that it is compressed to about half the bulk, but it does not consider the return due to the compressive elasticity of the tissue paper, and there is still a problem to be solved for industrial use. ing.

[0004]

SUMMARY OF THE INVENTION In view of the foregoing, the present invention reduces the bulk of tissue paper products to improve the convenience of carrying and storing by consumers, and is soft, comfortable and low in bulk. The purpose of the present invention is to develop a technique for producing a two-ply tissue paper having excellent water absorbency.

[0005]

The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems. As a result, the present inventors have found that the papermaking moisture of the Yankee dryer is kept at a certain level or more, and that the calendering treatment is performed immediately after the Yankee dryer. It has been found that a compressed tissue paper having low bulk, excellent in softness and touch can be manufactured by simultaneously performing strengthening and adjusting the pressure on the tissue paper folded and laminated by the processing machine.

(1) The present invention relates to a two-layer Yankee paper machine using lignocellulosic fiber as a raw material .
Hardwood fiber on the dryer side in the thickness direction of the web, anti-dryer side
The paper moisture with softwood fibers and papermaking 5 wt% to 9 wt% of <br/> Te I shoe web, then by calendering by on-machine calendering and / or ply machine in Yankee paper machine, in total 2 stacks or more
By performing soft calendering at a linear pressure of 4 to 10 kg / cm and then processing with a folded plate processing machine, the bulk density based on the product paper box volume (product tissue paper weight /
Paper box within the volume, that) forms a compressed tissue paper bundle is 0.12 g / cm ³ or more, a method of manufacturing a compressed tissue paper product of 2-ply, characterized by packing.

( 2 ) The present invention provides a method for producing a two-ply compressed tissue paper product as described in (1 ) above, wherein the papermaking moisture of the Yankee paper machine is 5% by weight or more. About.

( 3 ) The present invention is characterized in that the soft calendering process is a one-stack process on-machine and a two-stack process on a ply machine. The present invention relates to a paper product manufacturing method. (4) The present invention is an elastic roll of a soft calender is the Shore D Hardness 8 0-95 degrees, above, wherein the urethane rubber or is made Po rear <br/> bromide resin (1) or The present invention relates to a method for producing a two-ply compressed tissue paper product according to ( 3 ).

( 5 ) The present invention is characterized in that, among the pair of elastic rolls and metal rolls in the on-machine soft calender, the metal roll is a crown control roll (swimming roll: Custer). ( 3 )
Or a method for producing a two-ply compressed tissue paper product according to ( 4 ). ( 6 ) The present invention is to reduce the height of the tissue bundle when the upper surface of the tissue bundle of the product immediately after processing by the folding plate processing machine is pressed at 0.12 kg / cm ² to 65 to 75% of the height of the paper box. The two-layer pressure according to the above (1), which is controlled.
The present invention relates to a method for producing a reduced tissue paper product.

[0010]7)SaidThe present inventionAs an invention related to
Are (1) to (6) Product box made by the method
The bulk density based on the product is 0.12 g / cm^ThreeThat is more than
Characterized by two stacked paper boxescompressionMade of tissue paper
GoodsInvention. (8)SaidThe present inventionAs an invention related toIs two sheets
Is made of two layers, one side is hardwood fiber,
Features that the opposite side is formed from paper layer of softwood fiber
The above (72) Compressed tissue paper described in 2)
Par productsInvention. (9)SaidThe present inventionAs an invention related toIs a double stack
TishwebDenseDegree 0.26g / cm^Three~ 0.34g /
cm^ThreeWherein the (7) Or (8)
Two-ply compressed tissue paper product as describedInvention
To.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION As the lignocellulosic fiber used in the present invention, a chemical pulp obtained by cooking softwood or hardwood with an alkaline cooking chemical is used. Recovered paper pulp has high strength due to advanced beating, but is not desirable in terms of softness and touch.

As a paper machine for compressing tissue paper, a commercially common Yankee paper machine in which a Yankee dryer is combined with a paper machine such as a round net, a long net or a twin wire can be used. As a matter of course, it is not preferable to use a paper machine or a paper making method that produces bulky paper such as a through-air drying method. The most suitable paper machine for the present invention is a two-layer Yankee paper machine.

In the Yankee paper machine, unbeaten (600 to 660 ml, CSF) which is soft and has excellent touch to the Yankee dryer side in the thickness direction of the tissue web.
[C. S. F. : Canadian Standard Freeness, JISP81
21 pulp layer mainly composed of hardwood, and the anti-dryer side is subjected to beating as necessary as tissue paper (650-730 ml, CSF). Is formed.

In general, at the exit of a Yankee dryer to which dry crepe has been applied, the dry side has a good feel in the thickness direction of the tissue web, and the anti-dryer side has a rough crepe crest. Because the texture is also bad, in the ply machine, when a two-ply tissue is formed, a layer mainly composed of softwood faces the inside of the two tissues, and a layer mainly composed of hardwood is arranged outside the tissue. A product with a constant strength and a good touch can be obtained as a price. This is an important factor in the production of a comfortable compressed tissue paper. Hereinafter, the two-ply tissue (two-ply) compressed tissue paper is simply referred to as a compressed tissue paper.

In the present invention, it is desirable that the tissue moisture at the outlet of the Yankee dryer is high. The water must be at least 5% by weight or more, preferably 6.5% by weight or more and 9% by weight or less. If the content exceeds 9% by weight, the moisture profile is deteriorated, and the difference from the equilibrium moisture in the normal state of the tissue web is increased, so that not only the thickness control in the calendering process becomes difficult, but also a problem such as a dimensional change is caused. Occurs. When the water content is less than 5% by weight, even if the tissue bundle is compressed by applying a predetermined pressure by a folding plate type processing machine, the tissue bundle inside the product paper box returns to the bulk due to the compression recovery force with time and the top surface of the paper box. Is likely to be pushed up. In this state, when the consumer takes out the tissue from the outlet on the top of the carton, the tissue to be taken out is pressed against the top of the carton and the tissue bundle at the bottom, so smooth removal cannot be expected. The case where the tissue is broken easily occurs.

As is well known, the boxed tissues are alternately folded so that one set can be continuously taken out of the box. This folding method is called an inter-hold, and the tissue is folded about half with the machine direction as the axis.If the moisture of the tissue is too low, the compression processing of this fold will be insufficient, and for the above-mentioned reason, it will be necessary to take out the product tissue. This will cause problems.

The density of the compressed tissue paper product is 0.2
The optimum value is 6 to 0.34 g / cm ³ (however, the paper thickness is measured on two sheets which are the actual product). Density 0.26 g / cm ³
If less than this, a large pressurization is required by a folding plate type processing machine, and not only does the tissue bundle easily collapse and hinders the operation, but also the bulk of the tissue bundle returns due to the compression elasticity of the tissue bundle, as described above. Tends to push up the top of the paper box, which causes a problem in taking out the tissue.
If the density exceeds 0.34 g / cm ³ , the tissue becomes paper-like, and not only loses the softness and quality of the tissue paper, but also deteriorates the water absorption.

As a method of controlling the density of the tissue web by combining a general Yankee paper machine and a ply machine, there are a method of controlling the crepe applied to the tissue web at the outlet of the Yankee dryer and a method of controlling the paper thickness by calendering. There is a way to do that. Of these methods, the method of reducing the thickness of the paper by reducing the amount of crepe applied deviates from the original purpose of tissue paper, which is the production of soft crepe paper, and is not a preferable method.

On the other hand, the method of controlling the paper thickness by the calendering process is as follows.
For a stack of tissue webs, use one or two stacks of a pair of fully polished chilled rolls and metal rolls, one each for the top and bottom, to improve the smoothness of the tissue surface and reduce the paper thickness. method of controlling the sheet thickness in the width direction and the flow direction of the ply machine direction towards lowering is common. However, if the linear pressure is increased to reduce the paper thickness with this calender, the calender action on the tissue web tends to be too sharp due to the narrow actual nip width between the metal rolls, and the paper layer breaks and the paper becomes rigid. In addition, there is a drawback that thickness control in the width direction is extremely difficult, and wrinkles are increased in winding, and satisfactory results cannot be obtained.

According to the present invention, a multi-stage soft calender is used as a method of controlling the optimum paper thickness over the entire width of the winding when the ply machine is applied to the folding plate processing machine after the ply machine and maintaining excellent properties as tissue paper. Processing has been selected. The soft calender is usually composed of one metal roll and the other one is made of an elastic roll.

As the metal roll, for example, a chill roll, an alloy chill roll, a steel roll, or a metal roll having a hard chromium-plated roll surface is appropriately selected and used. As the elastic roll, for example, natural rubber, styrene rubber, nitrile Various plastic resins such as rubber, chloroprene rubber, chlorosulfonated ethylene rubber, butyl rubber, polysulfide rubber, silicon rubber, fluoro rubber, urethane rubber, aromatic polyamide resin, polyimide resin, polyether resin, polyester resin, polycarbonate resin, and cotton An elastic roll made of paper, wool, tetron, nylon, or a mixture thereof is appropriately selected and used.

The elastic roll has a hardness of 80 to 95 degrees, preferably 85 to 92 degrees in Shore D hardness (ASTM standard, D-2240). Among them, an elastic roll using a urethane rubber and an aromatic polyamide resin is easy to handle, has a long life, and is most preferable for obtaining the desired effects of the present invention.

As described above, the number of stacks in the calendar processing is as described above. In the facial tissue, one or two stacks of chilled calendar processing are usually performed by a ply machine. In the present invention, at least two stacks are required in the soft calendar processing. Considering the paper thickness of the product and the tissue quality in total, it is desirable to use 3 to 4 stack processing.

The most suitable calendering method for the present invention is a soft calender three-stack process in which an on-machine soft calender one-stack process is combined with a two-stack soft calender process in a ply machine.
kg / cm is preferred. More effective calendering can be performed by calendering the tissue web stored for a certain period of time with the ply machine, as well as calendering immediately after creping at the outlet of the Yankee dryer.

In the Yankee dryer, the tissue web is dried from about 50% to about 5% moisture by the medium pressure steam sensible heat inside the dryer and the hot air from the dryer hood. ° C
The web is cooled somewhat while the tissue web travels a few meters to the on-machine calendering device. However, since the web temperature is close to 70 ° C, the on-machine calendering becomes hot calendering and the ply machine calendering. In comparison, the paper thickness of the tissue web is further reduced at the same linear pressure, and the feel of the tissue is further improved.

The conventional concept of tissue paper making is as follows.
The emphasis is on bulk, and powerful on-machine calendaring is not generally performed. However, classes in the present invention
Swimming roll is down control roll (Kyusuta
A preferred method is to apply a linear pressure of 4 to 10 kg / cm using the above method. As is well known, swimming rolls are calendaring devices that are widely used in the paper industry for crown adjustment. The roll has a rotating metal shell and a fixed shaft, and adjusts the crown by applying hydraulic pressure between the shell and the shaft to deflect the roll.

The advantage of the swimming roll compared with the commonly used fixed crown roll is that the fixed crown roll changes the roll diameter in the width direction of the roll, so that the peripheral speed of the roll and the speed of the tissue web are different. Cannot be matched in the width direction. On the other hand, swimming rolls have the same roll diameter over the entire width, so the speed of the tissue web and the peripheral speed of the roll are the same, no rubbing occurs due to the speed difference between the paper and the roll, and the tension of the web after calendering is It becomes relatively uniform in the width direction.

Another advantage is that in the case of an on-machine calender, the temperature profile in the width direction of the tissue web coming out of the Yankee dryer is not uniform, and in the case of a fixed crown roll, the non-uniform temperature profile of the tissue web is a metal roll. And the roll undergoes uneven thermal expansion in the width direction. In the case of a swimming roll, since oil at 50 to 60 ° C. higher than room temperature is flowed inside the roll, the temperature profile in the width direction of the roll is less variable than the fixed crown roll, and the uneven thermal expansion of the roll is also small. . For the above two reasons, if a swimming roll is used with an on-machine calendar, the tissue web after papermaking has been subjected to a uniform heat calendering process in the width direction and has less wrinkles during winding, making it ideal for compressed tissue paper. It is.

On-machine soft calender The tissue web that has been subjected to one-stack processing is further adjusted in paper thickness by two-stack soft calender processing in a ply machine to form a small winding slit to a width that is less than twice the width of the finished product. Then, it is put on a folding plate processing machine. As is well known, in a processing machine, a predetermined number of small windings corresponding to a predetermined number of sets of a final product are hung on an unwinder, and the tissue is pulled out in the longitudinal direction and passed through a folding plate. Yuki is engaged, the long strip of tissue bundles predetermined set number of the final unwind stand is formed. This bundle of tissues is cut into a length to fit in a paper box by a cutter, and is packed in a paper box of a predetermined size by a box packing machine (Cartoner).

In the process of processing the compressed tissue paper, it is most important to control the bulk of the tissue bundle immediately after packing. It is desirable that the height of the tissue bundle is 65 to 75% of the height of the paper box in a state where the tissue bundle immediately after packing is drawn out and a pressure of about 0.12 kg / cm ² is applied to the upper surface of the tissue bundle.

As is well known, when a tissue bundle is formed by a stand (folding plate processing machine) , an appropriate number of tissue bundles are installed in accordance with the number of sets of tissue bundles. Is performed by the pull unit. The pull unit is a device that sandwiches the top and bottom of the tissue bundle with a belt and can simultaneously pull and compress the tissue bundle. It is desirable to adjust the degree of pressure applied by the belt according to the result of measuring the height of the tissue bundle. 0.12 kg / cm ^{2 for} tissue
The reason why the bulk is measured by applying a certain level of pressure is that there is a large variation in the measured value of the bulk when no load is applied, and it is difficult to perform an accurate measurement. If the pressure is too strong, the bulk hardly changes.

The pressing height of the tissue bundle is 75% of the height of the paper box.
Is exceeded, the tissue bundle reaches a state in which the upper surface of the paper box is pushed up after about 10 days due to the compression elasticity of the tissue bundle, and as described above, there is a problem that the tissue bundle is easily broken when the tissue is taken out. On the other hand, if it is less than 65%, an excessive gap is generated between the upper surface of the tissue bundle and the upper surface of the paper box even when the bulk of the tissue bundle is returned with time, so that the tissue bundle is wavy inside the paper box due to vibration during product transportation. This causes a problem that the paper breaks when the consumer takes out and uses the tissue.

The final product of the compressed tissue paper manufactured according to the present invention has the same tissue weight per box, can reduce the height of the carton by more than 20%, and has a bulk density of 0 based on the volume of the carton. .12 kg / cm ³ or more.
Surprisingly, the quality of the final product exceeded expectations. That is, the softness and the touch feeling, which are considered to be the most important in the quality of the tissue paper, were greatly improved, and the concerned deterioration of the water absorption was hardly recognized.

[0034]

The present invention will be described in more detail with reference to the following Examples, but it should be understood that the present invention is by no means restricted thereto. Parts and% in Examples and Comparative Examples are parts by weight and% by weight unless otherwise specified. The measurement unit and the measurement method during evaluation of the examples and comparative examples are as follows.

1. Rice tsubo: Unit g / m ² : According to JIS P8124 Thickness: unit mm: according to JIS P8118. However, the thickness of the tissue product was measured with two sheets and divided by two. 3. ^3. Density: unit g / cm ³ : According to JIS P8118 Tensile strength (longitudinal): Unit N: According to JIS P8113. However specimens shall pulling in the longitudinal direction of the paper 2 ply paper width 25 ± 0.1 mm, the distance between grips 100
± 2 mm. 5. Softness (horizontal): unit mN / 10 cm: TAPPI Paper Pulp Test Method No. 34-80, according to the softness test method for sanitary paper. A two-ply tissue paper (100 mm x 100 mm) is inserted into a certain gap (6.
(35 mm) It was measured with a handle ometer (manufactured by Kumagai Riki Kogyo Co., Ltd.), which measures the amount of work required to push in at intervals. The test piece was pushed in by bending it in parallel with the flow direction of the sample. 6. Water absorbency: Unit seconds: Based on the water absorbency of the drop method according to JIS S3104. 7. Touch feeling: Sensory evaluation method: Sensory evaluation of 5 boys and 15 girls was displayed according to the following criteria. Very good: ◎, good: ○, normal: △, poor: × 8. Tissue bundle bulk: unit mm: The product was collected at the outlet of the boxing machine, and within 3 minutes after collection, the bulk (height) of the tissue bundle was measured with a JIS gold scale under a pressure of 0.12 kg / cm ² . 9. Easiness of taking out product tissue: Sensory evaluation method: The product is collected at the exit of the boxing machine, and is packaged in 5-pack film and cardboard. On the 10th to 11th days, a round trip truck transportation of about 700 km was carried out, and the transported products were indicated by the following criteria in sensory evaluations of 5 boys and 15 girls. Very good: ◎, Good: ○, Normal: △, Inferior: ×

Examples 1 to 4 Unbeaten bleached hardwood kraft pulp (LBKP: 630 m)
l. C. S. F. ), And beaten bleached softwood kraft pulp (NBKP:. 690ml.C.S.F) wet strength agent WS-525 to (used after adding Nippon PMC Co., Ltd.) versus 0.10% per pulp Then, in a twin-wire type two-layer papermaking Yankee paper machine, the dryer side: the anti-dryer side = 60: LBKP is on the dryer side and NBKP is on the anti-dryer side in the thickness direction of the tissue web. 40
Paper weight ratio. The combined basis weight of the tissue web was 13.6 g / cm ² . The papermaking moisture was adjusted to 6.8%. Each pair of rolls at all calendar on-machine calendering and ply machine soft calendering is its Shore hardness 92 degrees upper an elastic roll urethane rubber coating, the lower side of the roll is the swimming roll with metal rolls (Kyusuta Was used. Table 1 shows the calendar conditions of Examples 1 to 4.

In the ply machine, the two webs were stacked and calendered so that the non -dryer side of the tissue web faced the inside, and then slit to a width of 199 mm. In a folded plate processing machine (manufactured by PCMC), 200 sets (400 sheets) of tissue bundles were formed while being folded by an inter-hold. In the pull unit, the pressure was adjusted so that the bulk of the tissue bundle immediately after processing in Examples 1 to 4 became 42 to 49 mm. With the cutter, the tissue bundle is cut to a length of 232 mm, and the dimensions are 116 mm, 244 mm,
It was packed in a paper box with a height of 65 mm. Table 2 shows various properties such as paper quality of the product.

Comparative Example 1 The linear pressure of the soft calender was 7 kg / cm to 12 kg / cm.
The tissue paper was manufactured under the same conditions as in Example 1 shown in Table 1 except that the tissue paper was increased to cm. Table 2 shows the evaluation results.
Shown in The tissue bundle was waving in the paper box. Comparative Example 2 60 parts of NBKP and 40 parts of LBKP on the dryer side and 60 parts of NBKP and 40 parts of LBKP on the side of the dryer in the thickness direction of the tissue web in the thickness direction of the tissue web in a two-layer Yankee paper machine at a ratio of 60:40. Tissue paper was manufactured under the same conditions as in Example 2 shown in Table 1 except for the following. Table 2 shows the evaluation results.

Comparative Example 3 Tissue paper was produced under the same conditions as in Example 2 shown in Table 1 except that the papermaking moisture was 4.5%. Table 2 shows the evaluation results. Comparative Example 4 Table 1 except that a chilled roll was used for the upper roll of the calendar of the ply machine and the linear pressure was set to 2.5 kg / cm.
The tissue paper was manufactured under the same conditions as in Example 4 shown in FIG. Table 2 shows the evaluation results. The winding after the ply machine had many wrinkles, and many wrinkles were observed in the product tissue bundle.

Comparative Example 5 Both the upper and lower sides of the on-machine calender were pressed at a linear pressure of 2.5 kg / cm using a chilled fixed crown roll. The winding after papermaking was regarded as broke because the wrinkles became extremely unusable. Comparative Examples 6 to 8 Commercial tissue papers containing 200 sets (400 sheets) of companies A, B and C were purchased and tested. Table 2 shows the evaluation results.

[0041]

[Table 1]

[0042]

[Table 2]

[0043]

As is clear from Tables 1 and 2, in Examples 1 to 4 of the present invention, the bulk density based on the volume of the paper box is made higher than that of the conventional product by performing a soft calendering process for two or more stacks. As a result, the height of the paper box can be reduced by 20% or more as compared with the commercially available products shown in Comparative Examples 6 to 8, and the two-ply tissue web equivalent to the commercially available product has a rice tsubo and a tensile strength. In addition, there is no inferiority in water absorption, touch feeling, and ease of taking out product tissue. Among them, the product of Example 1 not only can reduce the height of the paper box, but also in comparison with Comparative Examples 1 to 4 and Examples 2 to 4, particularly in terms of the feeling of touch and ease of taking out the product tissue. Are better.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-293054 (JP, A) JP-A 63-172394 (JP, U) JP-A 2-38995 (JP, U) (58) Investigation Field (Int.Cl. ⁷ , DB name) A47K 10/16 A47K 7/00 D21H 27/00

Claims (4)

(57) [Claims] 1. A two-layer Yankee paper machine using lignocellulosic fibers as a raw material in a thickness direction of a tissue web.
With hardwood fibers on the dryer side and softwood fibers on the anti-dryer side
Papermaking water to paper 5 wt% to 9 wt% of Te I shoe web, then by calendering by on-machine calendering and / or ply machine in Yankee paper machine, linear pressure 4 or more 2 stacks total of 10 kg
/ Performs soft calender treatment at cm, followed by processing in the folding plate type machine, the bulk density of the product carton volume basis (product tissue paper weight / paper box within the volume, that) is 0.12 g / cm ³ or more Forming a bundle of compressed tissue papers and packing them in a box. 2. The method for producing a two-ply compressed tissue paper product according to claim 1, wherein the soft calendering process is a one-stack process on-machine and a two-stack process on a ply machine. Elastic roll 3. A soft calender is the Shore D Hardness 8 0-95 degrees, according to claim 1 or 2 two-ply compressed tissue paper wherein it is made of urethane rubber or polyamide resin Product manufacturing method. 4. The height of the tissue bundle when the upper surface of the tissue bundle immediately after processing by the folding plate processing machine is pressed at 0.12 kg / cm ² is controlled to 65 to 75% of the height of the paper box. The method for producing a two-ply compressed tissue paper product according to claim 1, wherein: