JPS63500188A - Paper finishing method using base layer thermoforming - Google Patents

Abstract

Process for producing gloss and smoothness on the surface of a paper web (1), comprising: A. advancing a web (1) of papermaking fibers through a nip formed by a smooth metal finishing drum (2) and a resilient backing roll (3, 5) providing a nip pressure on the web (1) of at least 13,780 KN/M<2> (2000 psi); and B. heating the drum (2) to a temperature at least high enough to heat a critical substrata portion of the web (1) to a temperature of at least the dynamic Tg of the fibers to provide an unexpected increase in gloss and surface flatness without excessively densifying the entire sheet.

Description

[Detailed description of the invention] Paper finishing method using base layer thermoforming Technical field FIELD OF THE INVENTION This invention relates generally to papermaking, and more particularly to finishing printing paper to improve its properties. Concerning a new method of gerudame.

Background technology High quality printing papers must combine a number of physical properties. the heaviest Two important points are a flat and smooth surface that makes it easy to print on the printing press, and especially after printing. It is with a gloss that brings about a more attractive surface. These properties can be obtained using various methods, e.g. Coating the paper with pigments and binders or finishing the paper with one or more pressure operations You can get it by raising it.

One of the most common finishing operations used in printing paper production is supercalendering. above, where the pressure is very high against the tightly packed rolls, typically 175 KN/M~437.5 KN/M (10110~2500 bond/wire A series of double-sided steel rolls formed by pressed steel rolls with a nip load of Paper passes through the horn. This is generally 13,780 KN/M2 ~ 27.560 A two-tube pressure of KN/M2 (2000-4000 p, s, i, ) is generated.

Older supercalendar stacks are not externally heated. However, in the nip When a small filling roll that has been subjected to high pressure for the first time bends intermittently due to rotation. , heat is generated. The temperature in such supercalenders is generally about 71 reaching levels of 160°F'. Another important that gives good results The element is that the paper has a high moisture content when it passes through the supercalender. be. In general, the moisture content is between 7% and 9%, or more, based on the bone dry fiber mass. Dew.

Supercalenders achieve flatness and smoothness through extreme compression and densification of the sheet. It provides high gloss and high gloss. Densification undesirably results in decreased opacity and This results in a darkening effect on extremely moist areas.

Supercalenders are usually alternately made of steel and elastic to give the desired smoothness and gloss. It consists of a large number of rolls (9 to 14) of solid material. Both sides should be smooth. In order to carry out the need to flip the paper side that hits the steel roll, An even number of rolls with two elastic rolls (referred to as "cushion rolls") running side by side at It is necessary to run a roll of books. However, this measure will smooth both sides. is only incompletely achieved. This is because the first side finished facing the steel is This is because it will be deformed later by hitting the elastic rolls.

Because of this drawback and the inherent mechanical problems associated with the "cushion roll" nip, Nowadays, many super calendars have an odd double number and a "cushion calendar". ``rule'' operates without a nip, resulting in only one side facing the steel and finishing , the gloss values can be adjusted to be similar on both sides, but inevitably one side will be different from the other. The face also becomes noticeably rougher.

Moutz's finishing method is a machine calender finish, in which the pieces are pressed together under high pressure. The paper web is passed between two typically unheated steel rolls. This method improves smoothness However, since there is no shear in the nip, it produces little shine.

Another common finishing operation is gloss calendering, which is a heated finish. Coated paper without using high pressure for supercalender finishing using top roll Or the high gloss finish on coated paperboard causes scratches. Commercial machine nip The pressure is generally about 87.5 to 175 KN/M (500 to iooo pounds) / line inch). This is generally 6,890KN/M2~13.78QK A nip pressure of N/M2 (I QOQ ~ 2000 p, s, i, ) is generated. child The relatively low pressure does not densify the paper too much, resulting in relatively good opacity. On the other hand, this relatively high temperature softens the coating and allows a relatively good gloss increase. Ru. However, this finishing effect is limited to the coating layer or top surface of the web. follow The surface of this sheet has the smoothness and smoothness that can be obtained with a supercalender finish. Generally high-quality paper with flatness is also applied to coated paperboard. came.

As a result, gloss calendered sheets are similar to super calendered sheets. is not printed satisfactorily by the printing machine.

In recent years, cross calender finishing, machine calender finishing, and super calendering - Numerous changes have been made to the finishing work. The super calendar consists mainly of temperature heated to improve uniformity and control. In general, heating super The render reaches a tip temperature of approximately 82°C (1806F). Allows pressure reduction Machine calendars or screens made in an attempt to produce the same result - The temperature of the parcalender was further increased. In this way, the super calendar style Despite changing the top to a gloss calendar finish, two basic effects remain. It was different.

The bar bar fy l,' 7-dar finish uniformly compresses the entire sheet to a high degree. It flattens the surface fibers and other raw fibers and creates a glossy surface. Ru. In contrast, a gloss calender finish is applied to the surface of the coating (for uncoated papers) The upper surface of the fibrous substrate is then molded, flattened, and glossed, but the rest of the sheet is pressed. Supercalendar finishes are also much less likely to shrink.

Examples of gloss calendering are U.S. Pat. No. 3,124.504; No. 480, No. 3,124,481, No. 3,190,212, No. 3,254, No. 593. These patents are below the boiling point of water and above 232°C (4 temperature up to 50″F) and 1,722 to 17.220 KN/M2 (2 A list of devices that enable nip pressures of 50 to 2500 p, s, i, ) are doing.

No. 3,124,480, at least one surface of the coating in contact with the hot drum is A finishing process designed to heat the coating on the paper to a temperature that temporarily plasticizes it. Are listed. Super calender where the roll is heated to a relatively high temperature The finishing method is described in U.S. Patent Nos. 3,442,685 and 3,451,331. Disclosed. These patents include at least one supercalendar stack. Heat the roll of books to a temperature of 82°C to 163°C (180'F to 325"F). It is possible to produce high gloss on coated paper by plasticizing the coating. Disclosed are methods and apparatus that enable this.

Most critical in gloss calendering and super calendering It turned out that the parameter was the moisture content of the paper. High moisture content of coating and paper substrate Improves both smoothing and brightening effects. Bar/golden finish and gloss A number of developments in loss calendering have occurred in the web or in the web prior to finishing. At least in part, it is related to the method of increasing the water content in a part.

Unfortunately, moisture is an undesirable control parameter. slight amount of moisture Even fluctuations can greatly change the final properties of the paper. Also, uneven winding and stacking To avoid curling of the sheet due to drying and subsequent drying, the moisture content in the finished sheet should be approximately 3. It is undesirable for the content to be more than 5% to about 4.5%. This amount of water is a stable amount and such sheets will dry significantly below this level under ambient conditions. It will never dry up.

Ensures the finished product has the desired low moisture content while promoting a calendered finish In order to have the high moisture content (e.g. 7% to 9%) required for In the finishing process, the drum temperature is increased to dry the wet web.

Uneven moisture in the sheet can be a bigger problem than too much moisture. No Uniform means that the moisture content in one area of the sheet is higher than in other areas in the width direction of the sheet. means low. Non-uniformity also exists in the machine direction and thickness direction of the sheet. No Uniformity is achieved when calendering is done immediately after coating (i.e. calendering is continuous to the coater) is the most severe.

If coating is done in a separate operation from calendering, calendering There is time for the moisture content of the coated paper to equalize throughout the web.

The above cited U.S. Pat. No. 3,124.504 primarily focuses on very wet webs (water content (up to 35% or 50%) and dry while finishing the web. Contains concepts. Very high temperatures are used for drying, but they are lower than the boiling point of water. Higher temperatures may occur if the web is wetter than 5% to 8% of the bone dry mass. It is stated that this is necessary only in cases where The moisture content of the web is determined by the above-cited U.S. Patent No. 5.4. Also in the methods disclosed in No. 42,685 and No. 3,451,331 It is stated that this is an important element. These patents indicate that the paper has a moisture content of approximately 7%. It is best to do so before super calendaring to improve the finishing effect. It teaches that water can be added to the water.

Addition of moisture before finishing is described in the above-cited U.S. patent for producing high-gloss uncoated papers. It is also described in No. 3,124,481. Also U.S. Patent No. 2,214,641 The surface of the web is moistened before finishing. In U.S. Patent No. 4,012,543, Gloss calender finish is applied after coating, but before a large amount of moisture is lost from the coating. will be carried out immediately.

In this disclosure, the finishing is done at a web moisture content of 9% to 10% on bone dry mass. . In contrast, U.S. Patent No. 3,268,354 is for drying the surface of the coating. , but keep a wet interface between the coating and the fibrous web before gloss calendering. A special process is used. The web in this disclosure is at least at an interface. It has a moisture content of 15 cm.

The present invention provides a supercalender finishing grade without the above-mentioned disadvantages of supercalenders. This is a new method that allows the production of paper with smoothness and gloss.

The present invention A. Smooth metal finishing drum and pressure on the paper web of at least 13,78 to form a nip with 0KN/M2(2[)00p,s,i,) Press against the drum with a force of up to 700KN/M (4000 lbs/linear inch) providing a finishing device consisting of an elastic packing roll with a sharp edge; B. Papermaking fibers whose water content is 6% to 7% based on the absolute dry mass of the fibers. The web is rotated between [ ] at a speed that results in web retention during the nip between 3 ms and 12 ms. move forward; and C1 At the same time as step B, the drum was heated to a temperature 20'C below the value determined by the following formula. Heating to a surface temperature of no less than 30°F: Ts-(TiX, 357t-' 79-234.2e-・1")/C, 3 57t-・479-1　〕[However, Ts - surface temperature of heating drum (0C) T1 - Initial temperature of the web just before entering the nip ('(1); is the initial temperature of the web in the nip Residence time (milliseconds); e = base of natural logarithm; and m - Moisture content of fibers in web (weight % relative to bone-dry fiber mass)] A method of imparting gloss and smoothness to the surface of a paper web.

Although much of the prior art discloses broad operating conditions that include some of the conditions of the present invention, They have not been successful in teaching the special requirements of low moisture paper bins, and et al.'s disclosure is too broad to appreciate the critical operating scope of the present invention. that etc., all of which are calendered at lower temperatures and/or pressures than the present invention. , or calendering the web in an overly wet state, or by chance It teaches a very wide temperature range, encompassing a range of .

The success of the present invention is due to a phenomenon that appears to have been unrecognized prior to the invention, and precisely This seems to be due to another phenomenon that has begun to be recognized. For the first requirement, light An unexpected increase in the degree and smoothness can be obtained in the critical temperature range, and its The increase is at a nip pressure of 13,780 KN/M2 (2000 p, s, i,) or more. It was found that it became larger. For the second requirement, papermaking fibers such as Cellulose fibers appear to exhibit thermoplastic properties, especially the glass transition temperature (rT gJ), and above that temperature the fibers will change when subjected to pressure. Becomes much more flexible and moldable. The Tg of cellulose in paper is greatly affected by the moisture content of paper. Wet paper such as paper that is highly sensitive and receives an old-fashioned supercalender finish is very low. However, it is exactly what promotes a super calender finish. This property leads to undesirable insensitivity to moisture fluctuations and throughout the thickness of the web. This results in undesirable ultra-densification.

Consisting of the prior art regarding gloss calendering Fi broken and uncoated Although we recognize the effect of temperature on the formability of surface fibers in paper, supercalender – of fibers that must be formed flat to obtain the flatness and smoothness of the finish. No one is aware of the existence of a critical layer beneath the surface.

The invention, which can be described as base layer thermoforming, converts the critical base layer of the web into a flat layer. After shaping, the surface and optional coating of the fibrous web can be obtained by supercalendering. to be flattened, smoothed and glossed to the extent that Based on. This layer is the foundation of the surface and molding below this level is super – Not critical for achieving calender-grade flatness. Therefore, superkaren Molding of the full thickness of the sheet as in hard finishing is not necessary and provides little benefit. However, the above-mentioned disadvantages arise.

In the present invention, the web generally has a super calender finish or a gloss calender finish. It doesn't need to be as wet as the one you receive. The present invention is based on the absolute dry mass of fibers. Can be performed satisfactorily with webs having a moisture content of less than 7% and less than 6% or 5% even possible. Surprisingly, the present invention can be applied at very low moisture contents, even at 3%. , works satisfactorily. As a result, the finished product does not need to be dried during the finishing process. It can be easily manufactured with a desired moisture content. In addition, the web has a low moisture content. The ability to finish the web immediately before finishing ensures that the moisture content is substantially uniform throughout the web ( drying to a low level (preferably no more than 0.5% deviation from the average). enable. Therefore, the present invention allows coating and finishing to be carried out in line with each other. This is particularly valuable when

This is especially true when coating and finishing are carried out continuously on the paper machine and on-line. has value.

The main disadvantage of traditional hot calendering on coated paper is that it This means that the coating was merely formed with almost no effect. in the end, Although it was possible to obtain a high gloss, the surface of the supercalendered finish was very flat and smooth. Couldn't get a face. For uncoated paper, conventional techniques treat only surface fibers. The surface of the sheet was formed and solidified or sealed. needed to flatten the web An effect that requires reaching a critical substratum, which is thought to exist, was not confirmed. child What made the teachings even more confusing was the lack of understanding of the principles of moisture and temperature in sheet forming. This was something I had not been able to understand. For example, many of the prior art techniques do not work well with the present invention at low moisture levels. Temperatures below the range are sufficient; higher temperatures will dry the sheet with higher moisture content. It teaches that it is necessary to

In a preferred embodiment of the invention, the finishing device includes a second finishing device pressed against the drum. Form a second nip with an elastic packing roll, preferably within the same pressure range as the first As in, have. After the first web is inserted into the Advances in the development process provide significant benefits unique to the present invention, and will be discussed further below. Explained below. The key to the invention is to heat the web's critical substrate layer to its Tg. . Obviously, this requires a drum surface temperature above Tg. At the same time, Tg is water It becomes higher due to the decrease in the number of minutes. Therefore, there are conflicting goals in drum temperature selection. do. If the temperature is too low, the required heating time (which is limited to the residence time in the nip) If the length of the web is too long, the web will lose too much moisture and the web temperature will increase. This causes a tendency to raise the temperature to the same temperature throughout. If the temperature is too high, The web must pass through the nip so quickly that the required residence time is Not only would this not be possible, but it would exceed industrially viable machine speeds.

As indicated in the above description of the invention, the drum temperature range within which the invention operates satisfactorily is as follows. There is an enclosure. However, when using 22 sonos per drum, the drum temperature It can be lowered and the present invention can work more satisfactorily. cormorant The first and second parts of the web heat the web surface in contact with the drum at a relatively high temperature and quickly. Although it heats up quickly, the temperature on the opposite side hardly increases at all. first Immediately after leaving the two tubes, the temperature of the web changes depending on how much heat escapes from both sides to the atmosphere. It tends to be uniform throughout the thickness of the web.

As a result, the entire web and most importantly the critical substratum enters the second mop. When the temperature is higher than the previous temperature, it has a temperature lower than Tg. second In the two tubes, the same type of temperature gradient that existed in the first tube is established. However, the internal temperature of the web is higher than before. Therefore, the critical part of the web is Using lower drum temperatures or faster process speeds than is required in can be raised to ambient temperature. Of course, the pressure added by 2 Nitsuzo Time will also cause surface improvement.

In a preferred form of the invention, the web is heated outside the nip for the above reasons. Pass through the nip (singular or plural) without contacting the ram. However, further There may be cases where some contact with the drum is desirable and not too detrimental. Probably. When darning, it is preferable to limit contact to less than 20% of the drum circumference. .

Brief description of the drawing FIG. 1 schematically shows an apparatus suitable for carrying out the invention; Figure 2 shows the glossiness and gloss of uncoated paper finished at various temperatures in Example 1. A graph representing the values of smoothness and smoothness; Figure 3 shows the glossiness and gloss of coated paper finished at various temperatures in Example 2. A graph showing the values of smoothness and smoothness; Figure 4 shows the glossiness and gloss of coated paper finished at various temperatures in Example B. This is a graph showing the values of smoothness and smoothness; FIG. 5 is a graph showing the dynamic Tg of cellulose fibers for various moisture contents; Figure 6 schematically shows the temperature gradient in the paper thickness direction in the nip of the device shown in Figure 1. Figure 7 shows the web graph for various residence times of the web in the nip. FIG. 8 is a graph showing the temperature gradient in the thickness direction of is a graph showing the drum surface temperature required for the present invention versus residence time; and Figure 9 shows the coated paper finished at various temperatures and pressures in Example 4. Graph Representing Glossiness Values Better Understand Terms in the Specification and Claims We have prepared the following regulations for this purpose.

Parker commonly used in the paper industry to reduce printing roughness and porosity of paper Cylinder-surf (Parker Pr1nt-5urf) quantitative measurement is done by Sun By detecting air leakage at low pressure between the surface of the pull and the measuring detection head. It was done. The lower the value, the smoother the paper. Parker cylinder - surf measured It can be measured using several types of pressure dams on paper. This specification and in the claims, both were measured at a pressure of 10 kg/cIrL2. Sue Percalendar coated high-quality papers generally have a Parker cylinder diameter of less than 1.4. However, at very high quality it is less than 1.0. gloss calender Coated high-quality papers generally have a Parker Print-Surf of 1.2 to 2.0. There is.

75° Hunter gloss is specular reflection at an angle of 75° from a line perpendicular to the plane of the paper. is a well-known quantitative measurement of the amount of light emitted. Glossy grade coated paper is It generally has a gloss level of 50-90. 70 or higher is considered very high gloss.

The invention can be implemented in an apparatus such as that shown in FIG. Paper web 1 has a smooth surface A first nip formed by the surface finishing drum 2 and the elastic packing roll 3 Pass through the inside, go around guide roll 4, set and press against drum 2 and drum 2. through the second claw formed by the second elastic backing roll 5 move forward. Then, if you need to finish the other side of the web, is a pair of knits formed by elastic packing rolls similar to the first unit. a second smooth-surfaced finishing drum (not shown for brevity) Move forward to (i). The finished web is then wound onto reel 6. of the process Variations can be made by omitting or bypassing the second horn on each drum and/or Or finish only one side (in this case, the second drum is bypassed and the second drum is bypassed). It can be implemented by

? The web 1 fed to the finishing device is fed to a paper machine 7 and/or a coater 8 (where the paper is coated). ted) can come directly from you. Instead, web 1 is prefabricated a coated paper roll (which may or may not already be coated) It can also be supplied from The paper machine and coater are manufactured using well-known and conventional equipment. Since it can be prepared as a block, it is simply displayed as a block.

The finishing equipment used in the present invention is as described above for gloss calendering. If any of the many disclosed techniques and pressure and velocity conditions. can be done. Therefore, here, heating to the temperature required by the present invention is performed. Select a finishing drum that can be polished and has a smooth metal surface. It is obedient, but at operating temperature it can reach 35-700KN/M (200-400KN/M). 0f: linear inch) nip [which is 6000KN/1 at the local end of that range] A2 (8,700 p, s, i-) of sufficient hardness to give a high pressure of Kk Besides stressing the importance of choosing an elastic packing roll that has the equipment There is almost no mention of it. The actual pressure the paper experiences in the nip is the applied force and depends on the width of the two horns. The elastic packing roll becomes somewhat flattened at the nip. , 1.27-2.54 cm (0.5 ear f-1.00 inch) for the present invention. It is preferable to have a nip width of ). nip width shorter than 1.27 cm and 2 ．． Nip widths longer than 54Cr++ could also be used with the present invention. however, Nip widths shorter than approximately 635 cm require undesirably slow machine speeds. Also, a nip width wider than 2.54 cm is undesirably large. This may require packing rolls of diameter and/or housing or flexibility. Patsukin The grol surface has a P of about 4 or more to develop the necessary nip width and pressure, & J, hardness is preferred. Maintaining this hardness requires internal cooling of the roll. may request. Typical elastic roll materials soften very quickly at high temperatures. This is because it becomes soft. Examples of roles that can be satisfactorily performed in the present invention No. 3,617,445.

Next, the present invention will be explained by examples.

Example 1 A non-coated product manufactured using the kraft pulping method and made from a mixture of nine-norden hardwood and soft-leaved fiber. The non-calendared body material is rolled bare from the roll and is shown in Figure 1. I passed it through a similar device. This web is inorganically filled and cyzonized to 1o The weight of the web is 93.3 El/m2 (63 points). The total length was 33 [10ft2]. The finishing equipment is 175 kn/M (100 With a force of 0 lbs/lineal inch and a width of 47 cm (,185 inches) The temperature of the zero web operated by the horn is approximately 26.7°G (80″F) just before entering the nip. )Met. The moisture content of the web was determined to be 4.8% based on the bone dry mass of the fibers. It was.

Since the web passes through the finishing equipment at 1-02 m/5 (20 DCl ft/min) The residence time in the nip was 4.5 milliJ seconds. The temperature of the drum is maintained throughout the test. Adjust the surface temperature from 82.2°C (180’F) to 171.1°C (34[]’F). samples of the finished product were processed at various intervals. sample were tested for 75° Hunter Gloss Value and Parker Cylinder Surf Value. Figure 2 shows the equivalent values for the drum surface temperature. 14.8 fj/m2 (10 bonds/ream 360 0 ft2) and the surface temperature of the finishing drum was 25 ．． except that it was regulated between 6’C (78°F’) and 190.6°C (375″F). It was run through the same equipment as in Example 1 with the same procedure. The coater was directly connected to the finishing equipment. . The moisture content of the coated web was approximately 3.9% based on the bone dry mass of the fibers. cormorant The temperature of the web was approximately 48.9°0 (120″F’) just before entering the nip. Samples were processed at various temperature intervals and 75° Hunter gloss values and Parker Print-Surf values and their equivalent values are shown in Figure 3. plotted against surface temperature.

The data are slightly distorted due to the small number of readings taken for each sample included. Since it is uneven, check the glossiness and Parker print-surf ratio (it is constant). ), and an on-machine generated gloss curve (which was measured on a large number of samples) ) to create a glossiness curve using the Parker Print - Surf Point I got a curve.

Example 3 Body material similar to Examples 1 and 2 with same type and quantity as Example 2 on one side Examples 1 and 2 were coated with a dressing of and connected to a coater. It is passed through finishing equipment similar to that used but with two finishing drums. Ta. The nip pressure of the first drum was 263KN/M (1500 bonds/line) throughout the test. inch) to 333 KN/M (1900 pounds per lineal inch). trial Through the experiment, the second drum leek 1EEu”+33KN/M<1900Xnd/m inch) and its drum surface temperature was maintained at 162.8°C (325″F). Ta. One of the elastic packing rolls on the first drum was removed for the duration of the test.

The moisture content of the web is about 4.7% just before the first drum, and it is about 4.7% in the second drum. It was 0.5% less. (The decrease is due to the evaporation of water from the surface of the heated web between the drums. It is. ) The web moves at 8.89 m/S (1750 ft/min) through the nip. It has passed. The nip width was approximately 2.21 cm (8 inches), so approximately 1. A nip residence time of 5 milliseconds resulted. The temperature of the web is about 7 just before entering the first and second horns. The temperature was 1.1°C (160”F’). Samples of the resulting product were The finishing drum No. 1 was processed under the following conditions.

Sample, % nip number pressure temperature 1 2 333 121°C 22!133 147.8℃ 3 2 263 147.8℃ 4 1 263 147.8°0 5 1 263 135°C 61263121°C 72263121℃ The sample is 75° on the first side with Hunter-Gloss and Parker Print-Surf values. The equivalent values are plotted against temperature in FIG. same sun The gloss values for the second side of the pull are very constant (71, 7, 72, 5, 71, 9). , 71, 5, 71, 6, 71, 7, 71, 8), Parker Print-Surf Value The same was true (, 951.951.971.9951.961.951.88 ). This differs from supercalender finishing in that it combines the surface properties of one side with the other. This shows that the surface can be controlled independently from that of the surface. This is possible because pressure Temperature is the main factor, and the high surface temperature of the drum causes the web to pass through the web. This seems to be the reason why the light is not transmitted to one surface of the web.

Example 4 Uncoated mixture of Saden hardwood and softwood fibers produced by kraft pulping process A non-calendared body stock was manufactured for this example. This web is inorganic It was filled and sized to have an ash content of about 10% by weight. The weight of this web is It was about 79.99/m2 (54 bonds/3300 ft2). this web One side is coated with ordinary pigment binder coating material 12117m” (8.1 bond/33 reams) 00 ft2), dried and shown in Figure 1. passed through a similar device. This equipment was operated with a double-sided finishing nip. . The operation run has four different nip loads: 78.8KN/M (450 bonds/line) inch), 122.5KN/M (700pli), 157.5KN/ M (900pli), and 2152.5KN/M (1500pli) It was.

These loads are each nip width, 816 cm (,321 inches) 1.912 cm (,359 inches) 1.99 cm (,391 inches), and 1.27 cm ( , 50 inches) and average nip pressure of 9.500 KN 7M2 ( 1400p, s, i, ), 13,50[)KN/M2 (1950p, s, i, ), 16.000KN/M2 (2300p, s, i,), and 20,500 KN/M” (3000 p, s, i,) was produced.

The coater was connected to finishing equipment. After coating, the web is dried and Immediately before entering the first and second tubes, the moisture content is approximately 4.0% based on the absolute dry mass of the fibers. and entered the finishing equipment at a web temperature of approximately 60°C (140'F). Web is 2.7 It passed through the finishing equipment at a speed of 3 m/5 (500 ft/min), so at the above pressure. The Ninozo residence time was 3.21.3.59.3.91 and 5.0 ms. Ta. At each of these pressures, the temperature of the drum surface is 177°G ( 350'F) to 75° Hunter - Finished temperature for on-machine measurement of gloss values. The temperature dropped to 110°C (230°F). 75° hunter gloss at each nip load The temperature values are plotted against the drum surface temperature in FIG. sample of yijo Off-machine measurements indicate that there are some points where gloss values are higher than on-machine measurements. It should be noted that the latter measurement has a much larger sample size. It was plotted because it is an average with many.

Referring to Figure 2, the curve is shown in two parts, with a temperature of about 110°C (2 It covers a temperature range of up to 30'F) and the stone has a temperature range of approximately 104.4°C (220'F). F) and above are covered. The curve on the left shows gloss and Parker print. The surf is about 104.4°C! (up to 220 raw), it increases at a constant rate as the temperature rises. You can see that. This comes from shaping and agglomerating the surface of the web. This effect appears to be one that was predicted from the prior art.

The stone side 1fC of FIG. 2 shows an unexpected result of the present invention. That is, the temperature is high Then, at a certain temperature [in this case about 110°C (230°F)], the parka Lintosar suddenly improves rapidly. Also, the gloss increases as well, but this This is considered to be due to the mutual relationship between flatness and gloss. gloss and flatness This additional increment was not expected, but once discovered, it A subsurface portion or subsurface layer is heated to its glass transition temperature and suddenly softens. This is thought to be due to the fact that it becomes moldable and the surface can be made more flat than before. Ru. The benefit provided by the thermoformability of the subsurface layer is only about 148.8'C. (3D C1) and then during the next 16.7°C (30°F) There is no improvement in gloss or flatness.

FIG. 6 displays a phenomenon similar to FIG. From the left side, there is a hoodie print sample. The gloss and gloss level remain constant with increasing temperature up to approximately 93.6°C (200″F’). It is clear that the temperature increases at Karu. This leveling of the curve is likely due to the thermoforming behavior of the coating and is not consistent with the prior art. This seems to have been predicted from the This is a super calendered finish with higher temperature Limited Gloss Calendar Finish - Why Parker Print - Surf This also explains why it was thought to have the ability to improve values. The stone side in Figure 3 shows the results of the present invention. Gloss at approximately 126.7°C (260°F’) and a rapid improvement in flatness, which lasted for the next 36.8°C (65°'F) Hagiku. This result is entirely unexpected.

In order to better explain the effect of the present invention, and to determine the temperature at which this phenomenon occurs under various conditions. An experiment was conducted to determine whether predictions could be made. The experiment was carried out by flattening the surface of the fiber web. It is said that the base layer of fibers in the web can be heated to the Tg of the fibers to flatten it. Depart with confidence.

The present invention accomplishes this at a speed that is feasible for mass production and in a system that is not previously required. Prove that ♀ can also be carried out at the desired moisture content. To reach this temperature, many factors are involved. First, Tg is high speed finishing (i.e. 2.54-25.4 M/S or 500-5000 ft/min) must be adjusted to. This simply means that the readability or formability of the fiber This means that it depends not only on the temperature but also on its compression ratio. The fiber is In fact, based on dynamic conditions, and above the static Tg, the apparent are doing. (Unless otherwise mentioned, rTgJ is the apparent value under dynamic conditions. means glass transition temperature. In addition, dynamic heat transfer conditions It must be satisfied that the temperature of the critical substrate of the web is raised to its Tg. stomach.

Moisture plays a major role in determining the Tg of fibers, and the present invention surprisingly is used for super-calendered finishes and has a much lower moisture level. It is possible to achieve parcalender-level quality. In the present invention, the critical base layer The same phenomenon occurs in Kasper calendering, which promotes flattening of the web through its entire thickness. Molding is performed at a temperature above Tg. The reason is that it is used for super calendar finishing. The high moisture content of the paper is due to the temperature of the supercalendered finish (even when not heated). Conditions can produce a sufficiently low Tg that the entire web can reach. This is because that.

In multi-stage nip equipment, moisture evaporates while moving between nips, so Some water is lost. At the low moisture levels of this invention, the amount approximately 0.625% to 0.5% (e.g., 5% to 4.75% or 4.50%). %become). However, that amount requires a significant temperature increase in the subsequent two horns. This may cause this to occur. Preferably, the first drum in a two-drum device The temperature is set to favor the moisture content in the second nip. There are two drums If the temperature of the second drum is the same as that of the web obtained by heating in the first drum. It is preferred that the first water content is also higher to compensate for the lower water content. either The advantages of the present invention are provided to the extent that one horn satisfies the required drum surface temperature. The present invention is applicable to processes where one or more of the two conditions does not meet the temperature requirement. It also includes

Figure 5 represents the Tg values of cellulose fibers at various moisture levels. song The lines are N, L, Salmen (Sa1meΩ) and E, L, Beck (Beck) disaster. Brother Matoken [The influence of moisture on the glass transition temperature of cellulose (The Influenza ence of Watsr on the Glass Transition Temperature of Cellulose), TAPPI Sha Journal, December 1977, Vol. 60, No. 12, and Glass Transition and Formation of Wood Components. Shape and relationship with pulping process (Glass Transition of Wood Components Ho1d Implications fo r Moldingand Pulping Process), TAP PI Journal, July 1982, Vol. 7, No. 7, pp. 107-110)] guided. The curves were adjusted for dynamic conditions in the finishing dyb. That is, , any polymer-like material will yield at a given temperature if a force is applied for a short time. The Tg value is similar to that induced by Salmen and Beck. It has been increased by about 12°C. The result is that under dynamic conditions, the Tg of the material is under static conditions. This means that it is likely to be higher than that. To make this adjustment, use the William Sue The Landeruferi equation was used. The moisture content is within the range of the present invention (6% to 7%). It should be noted that even a small decrease in Tg results in a very large increase in Tg. be.

When implementing the preferred embodiment of the invention, due to the short nip width and fast operating speed, Residence time in the nip is very short. For example, the nip width is 635 to 2.54 mm (1 /4~1'') and machine speed 2.54~25.4u/s (500~5000 ft/min). Web residence time during the nip ranges from 0.6 to 12 milliseconds. Ru. With such short residence times, the heat from the drum (-1) is absorbed very deep inside the web. It's not transparent.

Figure 6 shows a machine speed of 8.9 m/s with a residence time of 1.5 mlJ seconds and a knob width of 1.32 cm. (corresponding to SK). For this explanation, the drum The surface temperature is 138°C, the web temperature before entering the nip is 71°C, and the The surface temperature of the roll was 71°C. The temperature gradient of the web is calculated by the formula T(x,t) - temperature in time at distance X into the interior of the web (°C); To-Drum surface temperature ('C; T1 - Initial temperature of the web entering the doublet (0C); X - Distance to the inside of the web (feet);a-,005ft2/hr; t = time during nip (hr)) It was decided by

Figure 7 shows the temperature gradient in the web thickness direction for various two-horn residence times. There is. In this explanation, the surface temperature of the drum is 137.8°0 (280°). The temperature of the paper just before reaching the two points is 71°C. Approximate critical substratum The location is believed to be at a floor level of approximately 0,076 rrrx (0,3 mils), which is It is represented by the shaded area. Critical substratum temperature depends on residence time and surface temperature I understand that. Whether the temperature of the critical substratum rises to the level of its Tg depends on its moisture content. Depends on. Therefore, for the conditions shown in Figure 7, the critical temperature is not selected. Depending on the residence time applied, a moisture content of 5% to 7.5% may be reached. cormorant.

It should be noted here that the exact location of the critical substrate is not known.

The above location of 0.3 mils in the web is based on the general roughness of the paper. According to a detailed estimate, it is necessary to reduce the heating of the IR fiber in the valleys of the web. However However, as explained later, it is not necessary that this assumption be accurate.

Additionally, Figure 8 shows the residence time, including the residence time, in raising the critical substrate to its Tg. It shows the influence of water rate and drum surface temperature. The curve shown in Figure 8 As in Figure 7, the depth of the critical substratum is estimated to be 0,076 mm (0.3 mil), and The temperature of the web immediately before entering the nip is 71°G. This temperature is from Kochi India and It is not uncommon for finishing to occur immediately after drying.

The web may be heated at any other temperature between ambient temperature and approximately 200'F (93.3°C) in the enclosure. In that case, it is expected that the curve will fluctuate somewhat. .

The drum surface temperature required for the web entering the nip is determined by the formula %formula%) Ts - surface temperature of heating drum (0C); T1 - initial temperature of paper entering the nip ( ℃); 1 - Residence time of the web in the nip (milliseconds); Tg - present in the nip Dynamic glass transition temperature of web under moisture conditions ('C)) It can be determined by

Tg can be calculated from the curve shown in FIG. The equation that closely approximates the curve O is as follows It is as follows: Tg -234, 2x e-°131m Glass transition temperature (℃); e - base of common logarithm; B - Moisture content of fibers in the web (% relative to absolute dry mass of fibers).

Drum surface temperature Ts (0C) required for the present invention The following are indicators for determining web temperature and residence time.

T　=　26.7'C (8th yesterday) , 5 160 187.2 217.2 251 288.91.0 132- 2 153.3 177.5 204-2 233.92.5 114.3 1 32.2 152.1 174.2 198.95 107.1 123.6 141.8 162.2 184.910 102.7 118-1 135. 4 154-7 176.215 100.8 116 132.8 151. 6 172.6 Ti = 4s, rc (120'F), 5 137.9 16 5.1 195.6 229.1 266.71.0 119.3 140.8 164.8 191.7 221.12.5 107.4 125.3 14 5.2 167.4 192.15 102.7 119.1 137-4 1 57.7 180.410 99.7 115.2 132.4 151.7 173.215 98.4 113. (S 130.4 149.2 170. 2Tj = 71-1°C (16D°F'), 5 115-5 142.8 1 72.8 206.1 243.31.0 106.7 127.8 152. 2 178.3 208.32.5 100.6 118.3 138.2 1 60-3 1855 98.2 114.6 132.8 153.3 176 ．． 110 96.7 112.1 129.4 148.9 17015 96 ．． 1 111.1 128.1 146.7 167.8Ti = 93-3° G (200’F), 5 93″, 9 121.1 151.4 185.1 222.81.0 93.8 115.3 139.2 165.9 195. 62.5 93.7 111.6 131.5 153.7 178.35 9 3.7 110i 128゜4 148.8 171.410 9ro, 65 1 09.2 126.4 145.7 167.115 93.64. 108. 8 125.7 144.4 165.3 Based on the above expanded formula, the necessary The drum surface temperature (Ts)' can be set for each embodiment.

If the moisture content is 4.8%, the nip residence time is 4.5 milliseconds, and the initial Since the web temperature was approximately 26.7°C in Example 1, (7) Ts was approximately 147.8°C. (298e'F')Truru. Looking at Figure 2, we can see that the line recognized as TS This value is at the top of the temperature range where unexpected increases in gloss and flatness occur. You can see that there is.

The advantages of the present invention actually begin at temperatures about 40°C (70°C) lower.

When the moisture content is about 3.9%, the nip residence time is 4.5 ms, and the initial The Ts value for Example 2, where the web temperature was approximately 48.9°C (120°F), was Chill at approximately 161.7°C (323°F). Looking at Figure 6, it is recognized as Ts. This value, represented by the line shown above, is again due to an unexpected increase in gloss and flatness. It can be seen that this is at the top of the temperature range. The advantage of the present invention is actually about 4 Start at 0°C (70°F') lower temperature. This has a good correlation with the results in Figure 2. It is considered that there is a lot of responsibility.

Example 6 produced too little data to create a complete curve for the other examples; The temperature set in that test showed changes near unexpected increases in gloss and flatness. was selected according to the above formula for the purpose of Moisture content 4.7%, nip residence time 1.5mm ! J seconds, and from an initial web temperature of 71.1°C (160″F’), approximately 153.9 A calculated Ts value of °0 (309'F') is obtained. Figure 4 is recognized as Ts The line indicates where this point lies on the gloss and flatness curve. . This part of the curve appears to correspond to the tail end of the unexpected rise, which is consistent with Example 1 and and 2 are consistent with the results and Eqs.

There are some components that are included in the only equation that can be assumed. The location of the critical substratum has already been identified. That's one thing. The other is the exact value of the two-tube residence time. The formula is Heat occurs throughout the nip, but maximum forming pressure occurs only in the center of the nip All assumptions are made. Therefore, the temperature reached when two pumps meet is the temperature between the center and the ends. It is no more meaningful than what we arrive at at the point of becoming. Which part of the nip is used in the ceremony Determining what should be done is difficult and unnecessary. It is also said that the Tg of the fiber is reached. The meaning needs further explanation. The softening of the polymeric material is a second-order transition, and the softening of the ice over a temperature range that is no longer as sharp as in first-order transitions, such as in melting. It happens all the time. The breadth of the range is also a function of the molecular weight distribution, the wider the Give a range. This same softening occurs before the maximum temperature is reached. Good too. Are all formulas valid for these components? You don't need to know exactly to unfold it.

This is because the formula is only needed in the examples for comparison with test results, and the glossiness This is because corrections are made in order to claim that this is the starting and ending point of an unexpected rise in flatness. be. Which component(s) has been inaccurately estimated (if any)? ), I don't know, and it's not important to know. Empirical adjustments can fix them. correct and suitable for defining the invention as directed to all conditions encompassed by the invention. Give the formula. The good correlation between the examples is evidence of this.

Further, in FIG. 4, the results of Samples 3 and 7 of Example 3 are all included by dotted lines. So As expected, these are slightly higher due to the effect of increased pressure with nip number 2. however, they are located in a non-improving relationship with each other with increasing temperature. this for the reasons stated earlier (two nips that continue quickly equates to a higher drum temperature). This seems to be due to Therefore, the solid curve is as predicted by Fig. 2. If a sea urchin extends to a high temperature, it will become horizontal. Single point is sample 2 This indicates high pressure.

Figure 9 shows a nip with a process of 13.780 KN/M2 (2000 psj) or more. This represents an unexpectedly large benefit of the present invention when performed under pressure. The calculated Ts is approximately Shown for each nip pressure at 142°C to 147°C, each (pressure are different due to different residence times (due to larger nip widths due to increased nip width). Each song The line starts at a temperature 20°C below Ts, and is within the critical temperature range (Ts20). 13,780 groups’ IM2 (2000 p Very rapid gloss improvement that occurs with nip pressures higher than sco)? It shows. in detail The gloss level is determined when the nip pressure is less than 13.780 KN/M” (20 concave psi). In this case, the nip pressure is 13.780KN/M, although it only improves by about 2 points. 2 (2000 pSi) or more, it improves by about 5 points. In addition, motsuto high Improvement at higher pressures makes it more difficult to obtain points of improvement such as higher gloss degree range.

Example 4 has enough data to create a complete curve similar to that shown in Figure 2. collected from. Focus on extremely large gloss gains in critical temperature ranges Therefore, only the part close to the temperature range from Ts -20 to Ts is shown in Figure 9. It is. On either side of this region the curves correspond to all pressure ranges as in Figure 2. and has a slope.

Although the temperature effect of the present invention starts at a temperature about 40°C lower than the calculated Ts, The surface should give the pressure effect of the present invention even when heated more than 20°C below Ts. Ru. In order to obtain all the temperature effects of the present invention, the drum must be added above the calculated Ts. Heating is more preferred.

The critical upper limit is not well defined, but for economic and other reasons it can be It is particularly preferred for coated papers that the temperature does not rise above 25°C.

It is also desirable to limit the depth of the web heated to that Tg to only the critical layer. stomach. The reason is that all pressed parts higher than Tg are super calendered. This is because the desired thickness and opacity are No loss involved. To obtain super calendered quality on the surface, critical Only the layers need to be so densified that they can be heated more than nine times. The additional flatness obtained by would be uneconomical. To achieve this you need higher drum temperatures, slower process speeds, and/or Large sheet moisture reduces overall process efficiency and requires more expensive equipment and larger energy cost) and have the disadvantage of a supercalender finish. There is.

Again referring to Figure 2, another speed increase in gloss and smoothness of uncoated paper is shown. Any increase is approximately 160°C (320°F') [i.e. approximately 17°C (30°F') below Ts. This discovery is a book in itself. It is considered an invention. Think of it as another, deeper layer of thermoforming. and perhaps because of the distinct nature of the fibers in the web offer different advantages than the first one. It will be. The data obtained in Example 4 shows that similar effects can be found with coated paper. It showed that. Operation within this additional advantage has the disadvantages mentioned above, but It may be worthwhile to do so if particularly high smoothness is required.

Further significant and unexpected benefits have been obtained from the present invention.

Glossy paper with a super-calender finish and a very smooth flat surface? I'll manufacture it Theoretically, if we try to imagine an ideal finishing operation for nip, the pressure and temperature in the nip Therefore, it will be necessary to strictly control the control parameters of moisture content and residence time. the most controlled What is easy to control is pressure. This is because it can be changed accurately and instantly.

The most difficult to control is moisture content. It changes slowly and maintains uniformity This is because it is often difficult. Therefore, the ideal process has large properties Changes occur due to small changes in pressure, and small changes in properties result in large changes in moisture content. Therefore, it would be something that would occur.

The present invention provides control parameters that bring about the above-mentioned ideal control, and also provides super Provides calendar-level quality. These advantages are due to the super calendar finish. can't be obtained. This is because the control parameters for super calender finishing range that makes pressure control the least effective and moisture control the most This is because it will be effective.

It is believed that the temperature effect of the present invention is applicable to most pressures applied to the nip. It will be done. That is, the effect of increasing pressure is that the results would of course be significantly better. is expected to follow those known curves, except for . However, the main To obtain maximum value from light, the pressure is preferably 13.780" (2000 volts). (in./sq.in.) or more. Super calender finish grade and above It is under such pressure conditions that the quality can be obtained, and the temperature effect of the present invention It is at such pressure that the value increases greatly.

It should be noted that determining nip pressure is complex. Accurate nip load (unit force/unit roll length) is the easily measurable force applied across the elastic press roll. It can be easily determined by dividing by the nip length, which is easy to measure. However, the nip Width is difficult to measure.

A widely accepted method that appears to provide a satisfactory approximation of nip width for many common devices. The formula given is Narayan V.

TAP by Deshpande (Narayan V, Deshpande) PI October 1978 (Vol. 61 No. 10) pp. 115-118 [Elastic coating Calculation of nip width, press fit and pressure for contact between cylinders with atjonof Njp Wjdth, Penetrati, on and Pressure for Con-tact Between Cylind ers With Elastomeric Covering)) This is the Hertzian formula.

This formula is C) (=half the nip width; F = force per unit length; R = Equivalence involving the radius of the heating drum (R1) and the radius of the elastic roll (R2) radius [:R=RIR2/(R1-4-R2)]σ=Poisson's ratio of elastic roll cover ( 0.5) for the type of cover used in the invention; and E = elasticity of the roll Young's modulus of cover] It is. Young's modulus depends on the hardness of the elastic roll cover. For example, at operating temperature 4 A roll cover with a P, &J hardness of ~5 is about 517. O[]OKMAA” It will have an elasticity ik of (75,000 p, s, i, ). The elastic modulus is Rollka It changes significantly with changes in bar temperature.

Average nip for various common nip loads and roll radii (denoted by equivalent radius R) The index for requesting drop pressure (KN/M”) is shown below. The elastic modulus of the cover is one of the following: A 5.447 500 B 1.379 200 c 689 100 D 517 75 E 345 50 F 172 25 A20 16 14 12 11 28 23 20 18 16B 1210 9 8 7 18141211 10c 9 7 6 6 5 12 10 9 8 7D 8 6 5 5 4 11 9 8 7 6E 65444 9 7665 F　44333　65444 A 33 27 23 21 19 39 32 28 25 23B 21 17 15 13 12 25 20 18 16 14C151210991 814121110D 1310 9 8 7 151211 10 9E 1 0 9 7 7 6 12 1 [11987F 76554 97665 A 47 38 33 30 27 56 46 39 35 32B 30 24 21 19 17 35 29 25 22 20c 21 17 15 13 12 25 20 18 16 14p 18 15 13 11 1 0 22 18 15 14 12E 151210 9 9 1814121 1 1OF 10 9 7 7 6 12 10 9 8 7 Most suitable for the present invention Another valuable application is the production of supercalendered quality coated papers. However, the principle of the present invention is that whether coated or uncoated, For any type of web of papermaking fibers, whether fine-chilled or bleached It seems that it can also be applied. The present invention is directed to high-quality paper (herein, its papermaking fiber content is low). (provided that at least 80% of the content is provided by chemical pulp) as well as recycled paper ( wherein at least 50% of the papermaking fiber is provided by groundwood pulp (defined as 50% to 80% chemical pulp fiber and ground wood) (consisting of 20% to 50% fiber) is also beneficial. The coating on the high-quality sheet is good. Preferably at least 7.5. ? /m2 child's cage and other sheet coatings Preferably the amount is at least 4.5 F/-2. This invention is very heavy We believe that this method is applicable to all conventional basis weights, including heavy weight paperboard products.

Is the invention at least coated paper? Higher than 50 when used, in some cases 7 Higher gloss than 0 and parka better than 1.4 and in some cases better than 1.0 -Print surf can be generated.

Although the present invention appears to provide similar benefits for all papermaking fibers, groundwood This is believed to result from the large amount of lignin in the web. N, L, monkey Static Tg i 15°C (239°F) or dynamic when member moisture content is 2.5% or more. Lignin is fully described as having a target Tg of 127°C (260’″F). . [The Salmen and Beck materials cited above, as well as thermal softening of paper components and mechanical Thermal Softelng of the C Components of Paper and Effects nMechanjcal Properties) (N, L-Salmen, C ,P,P.

A, 65th Annual Conference, February 1979, pp. B11-B17). ]This value does not include It is equal to the Tg of cellulose with a water content of 4.7. A typical groundwood web contains about 6 lignins. 0%1[, so it would be the same, but the Tg is If such were achieved, gloss and smoothness would probably increase slightly. cell Tg of loin (it may be higher or lower than Tg of lignin depending on moisture content) A second and possibly larger rise would occur if the . Therefore, in the present invention, a groundwood web (at least 50% groundwood) is also used with a water content of 4.7%. Is the drum surface at least as high as that calculated by the formula using it? receive.

-1T Momme・5 Uefu “inside: / 采斥(M) Return time (MS) Long side temperature (0c) 5゛°"a+ioa"'"9"°"0°"' PCT/USl15102194

Claims (23)

[Claims] 1. A. A smooth metal finishing drum and a pressure on the paper web of at least 13, 7 to form a nip with 780 KN/M2 (2000 p.s.i.) Press against the drum with a force of up to 00KN/M (4000 lbs/linear inch) providing a finishing device comprising: an elastic backing roll; B. A papermaking fiber with a moisture content of 3% to 7% based on the absolute dry mass of the fiber. The web is nipped at a speed that results in web retention in the nip of 0.3 ms to 12 ms. advance inside; and C. At the same time as step B, the drum was heated to a temperature 20°C lower than the value determined by the following formula. heating to a surface temperature below the mutual value; Ts=[Tix. 357t-. 479-234.2e-. 131m]/[. 35 7t-. 479-1] [However, Ts = surface temperature of heating drum (℃) Ti = initial temperature of the web just before entering the nip (°C); t = retention of the web in the nip Time (milliseconds); e = base of natural logarithm: and m = Moisture content of fibers in the web (% by weight relative to the mass of bone-dry fibers)] A method of imparting gloss and smoothness to the surface of a paper web, comprising the steps of: 2. The moisture content of the web in Step B is less than 6% based on the bone dry fiber mass. The method described in item 1 of the scope of the request. 3. The moisture content of the web in Step B is less than 5% based on the bone dry fiber mass. The method described in item 1 of the scope of the request. 4. Claim No. 1, wherein the moisture content of the web is substantially uniform throughout the web. Method in section 1. 5. The finishing device is formed by a smooth metal finishing roll and an elastic backing roll. The web has a second nip that is Advance through the nip so that the same side of the web faces the drum in both nips. , the method of claim 1. 6. The finishing device consists of a second smooth metal finishing drum and an elastic backing roll. has an additional nip formed in the nip, and the web passes through the nip facing the drum. the side of the web facing the first drum in the first nip is on the side opposite to the side facing the first drum. The surface temperature of the drum at the nip advances, and the surface temperature of the drum at the additional nip is the same as that of the first drum. The same requirement as the first nip while compensating for the decrease in moisture content between the drums. The method described in item 1 of the scope of the request. 7. The web is coated in a finishing process and a continuous line operation. Method in section 1. 8. Claim 1, wherein the web is formed in a paper machine that operates continuously with the finishing process. Section method. 9. The web is formed by a paper machine that operates continuously with the coating and finishing processes. 8. The method of claim 7. 10. At least 80% of the papermaking fibers are applied onto chemical pulp. Method of scope 1. 11. The claimed papermaking fiber is provided by at least 50% of the papermaking fibers by groundwood pulp. Method of scope 1. 12. 50% to 80% of papermaking fibers are provided by chemical pulp and papermaking Claim 1, wherein 20% to 50% of the fibers are provided by groundwood pulp. Method. 13. Before step B, the web is coated with a paper coating consisting of pigment and binder. at least 4.5 g/m2 (3 lb/3300 square feet) and has a coated composition Claim 11, wherein at least one side faces the drum upon passage through the nip. Method. 14. Before step B, the web is coated with paper coating pigment and binder on at least one side. A coating composition comprising at least 7.5 g/m2 (5 lb/3300 square feet) and has a coated composition Claim 10, wherein at least one side faces the drum when passing through the nip. Method. 15. A process applied to one side of the web results in a process applied to the other side. The gloss and smoothness of each other significantly affect the given gloss and smoothness. Law. 16. The produced web has at least one side with the coating composition at a 75° angle. Claimed to have a gloss level of at least 50 and a parka print-to-surf value of 1.4 or less The method of item 14 within the scope of . 17. The produced web has at least one side with the coating composition at a 75° angle. Claimed to have a gloss level of at least 70 and a Parker Print-Surf value of 1.0 or less The method of item 16 within the scope of. 18. The drum surface has a value not less than the value determined by the formula shown in claim 1. 2. The method of claim 1, wherein the method is heated to a temperature above. 19. The drum surface is determined from Ts determined by the formula shown in claim 1. The method of claim 1, wherein the method is heated to a temperature above 25°C or below. 20. The drum surface has Ts determined by the formula shown in claim 1. 2. The method of claim 1, wherein the method is heated to a temperature of 17° C. above or below. 21. The drum surface is shown in claim 1 using a moisture content of 4.7%. 12. The method of claim 11, wherein the method is heated to a temperature that is less than or equal to the temperature calculated from the formula. 22. In step B, the web contacts the drum except at the nip(s). The method of claim 1, wherein the method does not. 23. In step B, the web extends over more than 20% of the drum circumference. 2. The method of claim 1, wherein there is no contact with the surface.