Patent Abstract:
A method and apparatus are disclosed for making a high bulk, coated paper of a unique structure with the coating forming a lower portion of the total caliper and the paper base forming a higher portion of the total caliper than conventionally made coated paper of the same weight. The process includes the step of using furnish with a high percentage of mechanical pulp, applying that furnish to papermachine wires, preferably with a gap former, coating the paper with a coating containing a plastic pigment, preferably of 4 or more parts per 100 parts of coating pigment, and calendering the coated paper at a nip loading less than conventional supercalendering nip loading. Preferably, the finished coated paper will have a 75° TAPPI gloss of 40 or above. The method and apparatus can be used to make lightweight or other weights of coated paper.

Full Description:
BACKGROUND OF THE INVENTION 
     Heretofore, it has been known to make lightweight, high bulk paper. For example, see U.S. Pat. No. 5,283,129, the teachings of which are incorporated herein by reference. However, that patent achieves high bulk by using coating that tends to be bulkier than conventional coating. 
     Other prior art attempts have been used to make high bulk coated paper by utilizing lower than conventional supercalendering nip pressures. However, these papers generally had low gloss, usually well below a 75° TAPPI gloss of 40, namely about 35. Consolidated Papers, Inc., the assignee of the present invention, had commercially sold similarly made lower gloss, high bulk papers as early as 1993. Such lower gloss paper is not acceptable for many publication purposes, such as magazines where lightweight, high bulk paper, with high gloss and good print gloss has been desired and sought for years due to ever increasing mailing rates. 
     BRIEF SUMMARY OF THE INVENTION 
     A method and apparatus is disclosed for making a high bulk, coated paper of a unique structure with the coating forming a lower portion of the total caliper and the paper base forming a higher portion of the total caliper than conventionally made coated paper of the same weight. This approach provides a bulkier, coated paper. The process includes the steps of using furnish with a high percentage, say over 50%, and preferably in a range of 55 to 75%, with a target of 60 to 65%, of mechanical pulp, or other similar pulps described herein, applying that furnish to two or twin wire papermachines, preferably with a gap former, coating the paper with a coating containing a plastic pigment in a concentration of 4 or more parts, and preferably 7 or more parts per 100 parts of coating pigment, and calendering the coated paper at a loading less than conventional supercalender loading. The use of mechanical pulp in the base sheet and a high content of plastic pigment in the coating gives a good surface finish that is easily calendered, either by lower pounds per linear inch supercalendering or hot-soft calendering to a high gloss acceptable to most publishers interested in lightweight coated paper for magazines or other similar uses. Preferably, the finished coated paper will have a 75° TAPPI gloss of 40 or above. The method or process and apparatus of the present invention can also be used to make other than lightweight grades of coated paper such as ultra lightweight coated paper. While the invention is directed toward coated paper for offset printing, it can be utilized for other coated papers for gravure, flexographic or letterpress printing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention method, apparatus and paper itself is described in conjunction with the following drawings wherein: 
     FIG. 1 shows a gap former section for use with the present invention; 
     FIG. 2A shows a conventional press section; FIG. 2B shows an extended nip press section for use with the present invention; 
     FIG. 2C shows another version of an extended nip press for use with the present invention; 
     FIG. 3 shows a main dryer section for use with the present invention, which connects to FIG. 4 as shown by the heavy arrows; 
     FIG. 4 shows two online coaters and accompanying coater dryers for use with the present invention; 
     FIG. 5A shows tandem hot-soft calenders for use with the present invention; 
     FIG. 5B shows a supercalender for use with the present invention; 
     FIG. 6A shows conventional prior art lightweight coated paper of the same weight as in FIGS. 6B to  6 D; 
     FIG. 6B shows prior art Consolidated Papers, Inc. made coated paper; 
     FIG. 6C shows other prior art coated paper; and 
     FIG. 6D shows coated paper of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As briefly discussed above, publishers and printers generally desire paper with gloss in unprinted portions and high print gloss with good ink/color properties in printed portions. Attempts have been ongoing to develop high bulk, lightweight coated papers with high print gloss. 
     In the present invention, a high bulk coated paper is developed which proportionally uses more base stock and less coat weight than similar grades of conventional paper of the same total weight. For example, while a conventional 30 pounds per ream paper, where herein a ream is 3300 square feet of paper, may have the following properties: 
     
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 Base Weight 
                 Coating Weight 
               
               
                   
                   
               
               
                   
                 22 lbs./rm 
                 8 lbs./rm 
               
               
                   
                   
               
             
          
         
       
     
     paper of the present invention has: 
     
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 Base Weight 
                 Coating Weight 
               
               
                   
                   
               
               
                   
                 25 lbs./rm 
                 5 lbs./rm 
               
               
                   
                   
               
             
          
         
       
     
     For a heavier paper of 32 lbs. per ream the data is: 
     
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 Conventional Base Weight 
                 Conventional Coating Weight 
               
               
                   
                   
               
               
                   
                 24 lbs./rm 
                 8 lbs./rm 
               
               
                   
                   
               
               
                   
                 Present Invention 
                 Present Invention 
               
               
                   
                 Base Weight 
                 Coating Weight 
               
               
                   
                   
               
               
                   
                 26.5 lbs./rm 
                 5.5 lbs./rm 
               
               
                   
                   
               
             
          
         
       
     
     For 38 pound paper: 
     
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 Conventional Base Weight 
                 Conventional Coating Weight 
               
               
                   
                   
               
               
                   
                 27 lbs./rm 
                 11 lbs./rm 
               
               
                   
                   
               
               
                   
                 Present Invention 
                 Present Invention 
               
               
                   
                 Base Weight 
                 Coating Weight 
               
               
                   
                   
               
               
                   
                 31.5 lbs./rm 
                 6.5 lbs./rm 
               
               
                   
                   
               
             
          
         
       
     
     The caliper of the papers above are as follows: 
     
       
         
               
               
               
             
           
               
                   
               
               
                   
                 Caliper 
                 Caliper 
               
               
                 Pound 
                 Conventional 
                 Present Invention 
               
               
                   
               
             
             
               
                 30 
                 1.5 to 1.65 mils 
                 1.75 to 1.9 mils 
               
               
                 32 
                 1.6 to 1.75 mils 
                 1.85 to 2.0 mils 
               
               
                 38 
                 1.8 to 2.0 mils 
                  2.0 to 2.2 mils 
               
               
                   
               
             
          
         
       
     
     The paper of the present invention, made using the method and apparatus of the present invention, would start with a waterborne furnish having a high percentage of mechanical pulp, generally in excess of 50%, usually in the 55 to 75% range, and preferably about 65%. Mechanical pulp gives a well formed base. As used herein, the term mechanical pulp may include stone ground wood (SGW), pressurized ground wood (PGW) and chemi ground wood (CGW), refiner mechanical pulp (RMP), thermal mechanical pulp (TMP), and chemi thermal mechanical pulp (CTMP). Sample furnish formulations are: (1) 45% TMP/20% SGW/35% softwood Kraft (SWK) and (2) 50% TMP/25% PGW/25% SWK. SWK is not considered a mechanical pulp. Another example might be 70-85% CTMP/30-15% SWK. 
     The furnish preferably is utilized in a papermaking apparatus or machine having a gap former (FIG. 1) instead of a conventional fourdinier. A typical gap former for use with the present invention is a Voith-Sulzer GmbH Duo Former CFD. The gap former provides somewhat denser web base surfaces so that an AVS formation index of 75% or greater with a floc index of 15 or less and a void index of 15 or less are achieved, providing a smooth, more uniform base paper which is more easily covered with less coat weight as discussed below. The less porous paper surface reduces or minimizes coating penetration. The inherent ability of former gap to reduce two sidedness of the paper base permits achieving minimum coating application with good gloss. 
     The above made paper then moves into the press section wherein it can be conventionally pressed. Preferably, the press section may include a wide shoe or extended nip press (FIG. 2B or  2 C) which is believed will compress the web less than is conventional, resulting in the paper web retaining more bulk and/or caliper. The extended nip press preserves bulk, yet permits water removal from the web due to the extended time the web is in the nip, which permits use of a nip pressure that is lower than conventional. Such an extended nip press is made by Beloit Corporation as model ENP-C. 
     The web is then sent through the dryer section (FIG. 3) and dried to a moisture content of below 10%, and preferably to 5% or less. The paper may then be coated on or off the papermaking machine. 
     As noted above, the coating weight applied to the web is less than conventional, but because of the smoothness and uniformity of the gap formed paper base, the paper base can be acceptably coated with a lesser amount of coating, thus yielding high bulk and allowing a given weight paper to proportionally comprise a greater percentage of paper base and a lesser percentage of coating than is conventional. Additionally, to provide increased stiffness and good gloss, the coating contains a small percentage of plastic pigment, advantageously at least 4% and preferably over 7%, and up to 20%. The amount of plastic pigment used can be increased to compensate for the use of lower amounts of mechanical pulp. Plastic pigment is relatively expensive, presently over one dollar a pound. The pigments used may be, for example, #2 clay, delaminated clay, calcined clay, TiO 2  and plastic pigment. The coating is generally, but need not be, applied to both sides of the paper web. A sample pigment formulation is 89% delaminated clay, 4% TiO 2 , and 7% HSP 1055 plastic pigment made by Rohm Haas. This pigment can be made up into a typical coating with the addition of other materials as may include starch, polymeric latex binders and additives as shown below: 
     
       
         
               
               
               
             
               
               
               
               
             
           
               
                   
                   
               
               
                   
                   
                 Parts by 
               
               
                   
                 Material 
                 Weight B.D. 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Pigments: 
                 Delaminated Clay 
                 88 
               
               
                   
                   
                 TiO 2   
                 5 
               
               
                   
                   
                 HSP 1055 (Plastic Pigment) 
                 7 
               
               
                   
                 Dispersant: 
                 Sodium Polyacrylate 
                 0.1 
               
               
                   
                 Binders: 
                 Starch 
                 5 
               
               
                   
                   
                 SBR Latex 
                 11 
               
               
                   
                   
                 Diglyceride 
                 0.9 
               
               
                   
                 Lubricant: 
                 Water 
                 — 
               
               
                   
                   
                 % Solids 
                 53% 
               
               
                   
                   
               
             
          
         
       
     
     Generally, the coating can be applied with any conventional type blade coater and preferably with a short dwell time applicator as shown in U.S. Pat. Nos. 4,250,211 and 4,512,279 (FIG.  4 ), and/or a fountain type coater shown in U.S. Pat. No. 5,436,030 and/or a double bladed coater as shown in U.S. Pat. No. 5,112,653, the teachings of which patents are incorporated herein by reference. In addition, the coating can be applied by a film coater or Speedcoater applicator made by Voith Sulzer GmbH, such as that shown in U.S. Pat. No. 4,848,268. While blade doctoring is preferred, other suitable types of metering, such as with a doctor rod, grooved or smooth, could be used. The term blade or blade coater as used herein, unless specifically stated, is understood to include such other equivalent metering techniques. The doctor blade shown in U.S. Pat. No. 4,780,336 has been advantageously used to provide low coat weight. 
     The coated paper can then be calendered, preferably hot-soft calendered (FIG. 5A) and/or supercalendered (FIG.  5 B), but for supercalendering the nip pressure is less than normal. The hot-soft calendering provide some improvement in bulk over supercalendering at a lower nip pressure. This improvement could be about 5 to 7% greater bulk. For example, a reduced supercalendering nip load gives a bulk factor of 58, while hot-soft calendering on the same coater paper stock at equal gloss (42) gives a bulk factor of 61. Supercalendering equipment useful in the present invention is a 10 nip supercalender made by Voith Sulzer GmbH. When used to supercalender the coated paper of the invention, the nips of the supercalender would be at a loading of only about two-thirds (⅔) of what is conventionally used. For example, supercalender loading may be 800 to 1200 pounds (per lineal inch) with 1100 to 1200 pounds being preferred and about 1150 pounds being the target, instead of the usual 1500 to 2200 pounds. Hot-soft calendering can be carried out under conventional conditions and may also take place on or off the machine. Hot-soft calendering equipment such as shown in U.S. Pat. Nos. 3,124,480, 3,124,504, 3,230,867 or 4,277,524 and/or currently made and offered by Voith Sulzer GmbH as Model No. G30 2/0 may be used. Generally, but not necessarily, supercalendering will take place off machine. However, if apparatus similar to the Janus calender made by Voith-Sulzer GmbH is used, such low nip load calendering could be performed on-line. 
     The resultant coated paper will generally have a bulk factor of 57-62% which can be expressed as a function of its total weight as follows:          Caliper                 in                 mils   ×   1000       Basis                 weight                 per                 ream                            
     The resultant coated paper will generally have the following characteristics as compared to conventional coated paper of the same weight: 
     (1) 10-20% less lineal feet/roll of paper for the same roll diameter, evidencing the higher bulk of the paper; 
     (2) lesser weight per roll for the same roll diameter; 
     (3) about 10-20% higher caliper; 
     (4) about 10-15% higher stiffness; 
     (5) about 0.5-1.0 pt. or more gain in opacity and brightness; and 
     (6) print smoothness and gloss equivalent to conventional paper. 
     Some of the parameters contemplated for, and for the making of, the high bulk lightweight coated paper of the invention are: 
     
       
         
               
               
               
               
               
               
             
           
               
                   
               
               
                 Basis Weight 
                 32 
                 30 
                 28 
                 26 
                 24 
               
               
                   
               
             
             
               
                 Base Paper Weight 
                 26-28 
                 24-26 
                 22-24 
                 20-22 
                 18-20 
               
               
                 Coating Weight 
                 4-6 
                 4-6 
                 4-6 
                 4-6 
                 4-6 
               
               
                 Furnish Composition 
               
               
                 % MP 
                 55-75 
                 55-75 
                 55-75 
                 55-75 
                 55-75 
               
               
                 % SW Kraft 
                 25-45 
                 25-45 
                 25-45 
                 25-45 
                 25-45 
               
               
                 % Ash 
                 4-8 
                 4-8 
                 4-8 
                 4-8 
                 4-8 
               
               
                 Coating Formula 
               
               
                 Part DL Clay 
                 85 ± 7  
                 85 ± 7  
                 85 ± 7  
                 85 ± 7  
                 85 ± 7 
               
               
                 Part TiO 2   
                 8 ± 4 
                 8 ± 4 
                 8 ± 4 
                 8 ± 4 
                 8 ± 4 
               
               
                 Part Plastic Pigment 
                 7 ± 3 
                 7 ± 3 
                 7 ± 3 
                 7 ± 3 
                 7 ± 3 
               
               
                 Part Starch 
                 3 ± 3 
                 3 ± 3 
                 3 ± 3 
                 3 ± 3 
                 3 ± 3 
               
               
                 Part Latex 
                 12 ± 3  
                 12 ± 3  
                 12 ± 3  
                 12 ± 3  
                 12 ± 3 
               
               
                 Base Paper 
               
               
                 Kajaani Formation 
                  65-100 
                  65-100 
                  65-100 
                  65-100 
                  65-100 
               
               
                 Supercalender 
               
               
                 # Nips/side 
                 1-5 
                 1-5 
                 1-5 
                 1-5 
                 1-5 
               
               
                 Nip load - pli 
                 1000-1400 
                 1000-1400 
                 1000-1400 
                 1000-1400 
                 1000-1400 
               
               
                 Roll Temperature ° F. 
                  16-225 
                 160-225 
                 160-225 
                 160-225 
                 160-225 
               
               
                   
               
             
          
         
       
     
     While mechanical pulp is preferable, it is contemplated that other pulps could be included, such that a lower percentage of mechanical pulp would be required. Other pulps and proportions thereof contemplated for use are as follows: 
     
       
         
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 Percentage of 
                 Type of Other 
                 Percentage of Other 
               
               
                   
                 Mechanical Pulp 
                 Pulp 
                 Pulp 
               
               
                   
                   
               
             
             
               
                   
                 A. 65% 
                 SWK 
                 35% 
               
               
                   
                 B. 60% 
                 SWK/HWK 
                 30%/10% 
               
               
                   
                 C. 60% 
                 SWK/recycled 
                 30%/10% 
               
               
                   
                   
               
             
          
         
       
     
     While it is preferable to use a gap former, other types of formers, such as twin wire or top wire formers, could instead be used with some small sacrifice in bulk. 
     For example, several or many of the above discussed factors could be used in combination to produce high bulk paper. 
     Factors effecting high bulk are listed as follows in decreasing order of effectiveness: 
     1. Low supercalender nip load or hot-soft calender; 
     2. Gap former; 
     3. Low coat weight/high substrate weight; 
     4. Plastic pigment in coating; 
     5. High % mechanical pulp; 
     6. High latex/starch ratio binder; and 
     7. Extended nip press (uncertain of the effect at the time of filing). 
     Combinations of factors affecting the production of high bulk paper as contemplated by the invention include (1) mechanical pulp, two wire forming, decreased base weight, increased coat weight, plastic pigment, and hot-soft calendering; (2) mechanical pulp, gap forming, increased base weight, decreased coat weight, plastic pigment coating, and supercalendering to a lower loading; (3) mechanical pulp, decreased base weight, two wire forming, extended nip or extended shoe pressing, uncured coat weight, plastic pigment coating, and hot-soft calendering or supercalendering to a lower load. 
     For example, the combination of: 
     1. increasing base substrate weight from 24#/3300 ft 2  to 26#/3300 ft 2 ; 
     2. increasing mechanical pulp in the base subtract from 52% to 65%; 
     3. decreasing coat weight from 8#/3300 ft 2  to 6#/3300 ft 2 ; 
     4. decreasing supercalendering intensity from 1500 pli to 1150 pli; and 
     5. increasing plastic pigment in the coating from 0 parts to 7 parts would increase bulk from 51±1 to 58±1 and increase L&amp;W stiffness from 42±5 to 50±5. 
     Conventional 32#, Conventional 34# and High Bulk 32# are compared as follows: 
     
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 Conventional 
                 Conventional 
                 High Bulk 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 Basis Weight #/3,300 ft 2   
                 32 
                 34 
                 32 
               
               
                 Base Substrate Weight #/3,300 
                 24 
                 25 1/2 
                 26 
               
               
                 ft 2   
               
               
                 Coat Weight #/3,300 ft 2   
                  8 
                  8 1/2 
                  6 
               
               
                 Caliper 
                 1.62 ± .04 
                 1.80 ± .04 
                 1.85 ± .04 
               
               
                 Bulk Factor 
                   51 ± 1 
                   52 ± 1 
                   58 ± 1 
               
               
                 L&amp;W Stiffness 
                   42 ± 5 
                   55 ± 5 
                   60 ± 5 
               
               
                   
               
             
          
         
       
     
     The invention provides a high bulk lightweight coated paper that is desirable for use in magazines which require very low basis weight to reduce paper costs by increasing printing area per ton of paper and by reducing mailing cost per magazine. High bulk paper will improve the economics of publishing magazines by allowing a lower basis weight to be substituted for a higher basis weight conventional grade. 
     In addition, the increased stiffness of the paper of the invention improves paper web rigidity for low basis weight paper which results in better runnability on high speed printing presses and folders used to produce magazines. Further, the thicker paper produces a bulkier magazine which is less flimsy when handled. A bulkier magazine “feels more substantial” i.e., it will not droop or feel limp. Individual pages will separate easier and turn without sticking together. 
     FIGS. 6A-6D schematically illustrate these different lightweight coated papers of the prior art, and a lightweight coated paper embodying the present invention, each of which has the same total weight of 30 pounds/rm. The paper of FIG. 6A is conventional lightweight coated paper and has a caliper of 1.6 mils., a base weight of 22 pounds and a coat weight of 4 pounds on each side of the base. The paper of FIG. 6B is also a conventional lightweight coated paper that was earlier made and sold by Consolidated Papers, Inc. and that has a caliper of 1.8 mils, a base weight of 23 pounds and a coat weight of 3.5 pounds on each side of the base. The paper of FIG. 6C is likewise conventional lightweight coated paper and has a caliper of 1.9 mils, a base weight of 24 pounds and a coat weight of 3 pounds on each side of the base. FIG. 6D shows a high bulk lightweight coated paper according to the teachings of the invention, which has a caliper of 2.0 mils, a base weight of 25 pounds and a coat weight of 2.5 pounds on opposite sides of the base. 
     It should be understood that the coating can be applied by any of the coaters discussed herein including a film coater or speed coater. As used herein, the term “blade coater” includes such film and/or speed coater. 
     The following table compares the effects of hot-soft calendering versus supercalendering of high bulk coated paper of 32 pound weight, where FPM means feet per minute, PLI means pounds per lineal inch, RH means relative humidity, MD means machine direction, W means web side and F means felt side: 
     Effect of Hot/Soft Calender vs. Super 
     
       
         
               
               
               
               
             
           
               
                   
                   
               
               
                   
                   
                   
                 Hot/Soft 
               
               
                   
                 Sample 
                 Supercalender 
                 Calender 
               
               
                   
                   
               
             
             
               
                   
                 Identification # 
                 B641122 
                 B641109 
               
               
                   
                 Web Speed-FPM 
                 2000 
                 2500 
               
               
                   
                 Nip Load-PLI 
                 1150 
                 1500 
               
               
                   
                 Temperature-° F. 
                 200° 
                 275° 
               
               
                   
                 Number of Nips/Side 
                 4 
                 2 
               
               
                   
                 Basis Wt. (73°/50% RH) 
                 32.7 
                 32.9 
               
               
                   
                 Coat Wt.W/F 
                 3.1/3.2 
                 3.1/3.2 
               
               
                   
                 Caliper-mils 
                 1.89 
                 2.00 
               
               
                   
                 Bulk Factor 
                 57.7 
                 60.7 
               
               
                   
                 Gloss 
                 42/40 
                 38/40 
               
               
                   
                 Opacity 
                 89.3 
                 90.1 
               
               
                   
                 L&amp;W Stiffness-MD 
                 59 
                 69 
               
               
                   
                 Parker Printsurf W 
                 1.92 
                 2.23 
               
               
                   
                 F 
                 2.34 
                 2.30 
               
               
                   
                 Heidelberg Print 
               
               
                   
                 Print Gloss W 
                 54 
                 49 
               
               
                   
                 F 
                 46 
                 52 
               
               
                   
                 Print Density W 
                 1.36 
                 1.30 
               
               
                   
                 F 
                 1.31 
                 1.31 
               
               
                   
                 Print solid W 
                 4 
                 5 
               
               
                   
                 F 
                 4 
                 5 
               
               
                   
                 50% Halftone W 
                 7.7 
                 7.1 
               
               
                   
                 F 
                 6.0 
                 7.2 
               
               
                   
                 Pickouts W 
                 54 
                 53 
               
               
                   
                 F 
                 52 
                 54 
               
               
                   
                   
               
             
          
         
       
     
     The following table shows parameters involved in the production of 32 pound lightweight coated having a 75° TAPPI gloss of 45: 
     
       
         
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 Reels 
                 Control 
                 Trial 
                   
                 95% Conf. 
               
             
          
           
               
                 SUPERED TESTS 
                 Significance 
                 Std 
                 / 
                 Tri 
                 Average 
                 Average 
                 Difference 
                 interval 
               
               
                   
               
             
          
           
               
                 Basis wt. 
                 ** 
                 8 
                 / 
                 4 
                 32.0 
                 31.8 
                 −2.0 
                 ±0.2 
               
               
                 Caliper 
                 *** 
                 8 
                 / 
                 4 
                 18.3 
                 18.2 
                 1.9 
                 ±0.5 
               
               
                 Bulk 
                 *** 
                 8 
                 / 
                 4 
                 50.8 
                 57.2 
                 6.4 
                 ±1.6 
               
               
                 Opacity 
                   
                 8 
                 / 
                 4 
                 88.1 
                 88.0 
                 −0.1 
                 ±0.3 
               
               
                 Gloss Wire 
                 * 
                 8 
                 / 
                 4 
                 45 
                 43 
                 −2 
                 ±2.0 
               
               
                 Gloss Felt 
                 * 
                 8 
                 / 
                 4 
                 45 
                 44 
                 −1 
                 ±0.9 
               
               
                 Print Surf Wire 
                 *** 
                 8 
                 / 
                 4 
                 1.5 
                 1.7 
                 0.2 
                 ±0.1 
               
               
                 Print Surf Felt 
                 *** 
                 8 
                 / 
                 4 
                 1.6 
                 1.8 
                 0.2 
                 ±0.1 
               
               
                 L&amp;W 
                 *** 
                 8 
                 / 
                 4 
                 42 
                 47 
                 5 
                 ±2.2 
               
               
                 HEIDELBERG 
               
               
                 Ink Density Wire 
                 ** 
                 2 
                 / 
                 4 
                 1.44 
                 1.36 
                 −0.08 
                 ±0.0 
               
               
                 Ink Density Felt 
                 ** 
                 2 
                 / 
                 4 
                 1.40 
                 1.36 
                 −0.04 
                 ±0.0 
               
               
                 Ink Gloss Wire 
                 *** 
                 2 
                 / 
                 4 
                 62 
                 54 
                 −8 
                 ±2.7 
               
               
                 Ink Gloss Felt 
                 *** 
                 2 
                 / 
                 4 
                 58 
                 54 
                 −4 
                 ±1.8 
               
               
                 I.A. 50% Halftone W 
                 * 
                 2 
                 / 
                 4 
                 6 
                 7.8 
                 1.8 
                 ±1.6 
               
               
                 I.A. 50% Halftone F 
                   
                 2 
                 / 
                 4 
                 6.2 
                 7.3 
                 1.1 
                 ±2.4 
               
               
                 I.A. 75% Halftone W 
                   
                 2 
                 / 
                 4 
                 5.4 
                 5.8 
                 0.4 
                 ±1.6 
               
               
                 I.A. 75% Halftone F 
                   
                 2 
                 / 
                 4 
                 5.5 
                 6.4 
                 0.9 
                 ±3.4 
               
               
                   
               
               
                 ***Significantly different @ 99% confidence level.  
               
               
                 **Significantly different @ 95% confidence level.  
               
               
                 *Significantly different @ 90% confidence level.  
               
             
          
         
       
     
     The following table shows various average results obtained with 32 pound lightweight coated paper of and made according to the present invention: 
     
       
         
               
             
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                   
               
               
                 AVERAGE TEST RESULTS 
               
             
          
           
               
                 Samples 
                   
                 970097 
                 970098 
                 970102 
                 970093 
                   
               
               
                 Identification 
                   
                 Control 
                 Trial 1 
                 Trial 2 
                 Trial 3 
               
               
                 Reels 
                   
                 BS41122 
                 BS411095 
                 BS411055 
                 BS41109 
               
               
                 Fastening 
                   
                 H/S @ Wch. 
                 H/S @ B.P. 
                 H/S @ S.P. 
                 H/S @ Beloit 
               
               
                 Web Speed 
                   
                 2000 
                 2500 
                 2500t 
                 4000 
                 POOLED 
               
               
                 Nip Load PLI 
                   
                 1150 
                 1500 
                 1500 
                 1600 
                 STD. 
               
               
                 Temperature ° F. 
                   
                 200 
                 275 
                 325 
                 250 
                 DEV. 
               
               
                   
               
             
          
           
               
                 Basis Weight (Cond.) 
                 1 
                 32.7 
                 32.9 
                 33.0 
                 33.1 
                   
               
               
                 Cost Weight - W 
                 1 
                 3.1 
                 3.1 
                 3.1 
                 3.1 
               
               
                 Cost Weight - F 
                 1 
                 3.2 
                 3.2 
                 3.2 
                 3.2 
               
               
                 Ash 
                 1 
                 18.0 
                 17.5 
                 17.5 
                 17.4 
               
               
                 Caliper 
                 8 
                 1.89 
                 2.00 
                 2.02 
                 2.02 
                 0.02 
               
               
                 Bulk 
                 8 
                 57.7 
                 60.7 
                 61.2 
                 61.0 
                 0.6 
               
               
                 75° Paper Gloss - W 
                 8 
                 42 
                 38 
                 38 
                 38 
                 1 
               
               
                 75° Paper Gloss - F 
                 8 
                 40 
                 40 
                 38 
                 36 
                 1 
               
               
                 Brightness - W 
                 2 
                 70.1 
                 88.4 
                 86.8 
                 67.9 
                 0.2 
               
               
                 Brightness - F 
                 2 
                 71.5 
                 68.4 
                 67.6 
                 68.1 
                 0.6 
               
               
                 Color ‘a’ - W 
                 2 
                 −0.1 
                 −0.1 
                 −0.1 
                 0.0 
                 0.0 
               
               
                 Color ‘a’ - F 
                 2 
                 0.2 
                 0.1 
                 0.3 
                 −0.1 
                 0.1 
               
               
                 Color ‘b’ - W 
                 2 
                 3.2 
                 4.1 
                 4.8 
                 3.9 
                 0.2 
               
               
                 Color ‘b’ - F 
                 2 
                 2.5 
                 3.7 
                 4.3 
                 4.1 
                 0.4 
               
               
                 Opacity 
                 8 
                 89.3 
                 90.1 
                 90.4 
                 90.0 
                 0.4 
               
               
                 Undertone - W 
                 2 
                 4 
                 4 
                 4 
                 5 
                 0 
               
               
                 Undertone - F 
                 2 
                 4 
                 4 
                 4 
                 5 
                 0 
               
               
                 Micro. Galv. - W 
                 2 
                 4 
                 4 
                 4 
                 3 
                 0 
               
               
                 Micro. Galv. - F 
                 2 
                 4 
                 4 
                 4 
                 3 
                 0 
               
               
                 Tensile 
                 8 
                 11.1 
                 10.5 
                 10.8 
                 10.6 
                 0.7 
               
               
                 Tear C.D. 
                 4 
                 25.3 
                 25.4 
                 24.6 
                 26.6 
                 0.5 
               
               
                 L&amp;W Stiffness 
                 8 
                 59 
                 69 
                 68 
                 87 
                 2 
               
               
                 Scott Bond 
                 5 
                 176 
                 177 
                 179 
                 185 
                 8 
               
               
                 H.P.D. 
                 8 
                 127 
                 117 
                 101 
                 110 
                 10 
               
               
                 Print Surf - W 
                 8 
                 1.92 
                 2.23 
                 2.33 
                 2.72 
                 0.10 
               
               
                 Print Surf - F 
                 8 
                 2.34 
                 2.30 
                 2.45 
                 2.48 
                 0.08 
               
               
                 Croda Holdout - W 
                 2 
                 60.0 
                 59.5 
                 60.0 
                 59.0 
                 1.1 
               
               
                 Croda Holdout - F 
                 2 
                 51.5 
                 60.0 
                 62.0 
                 61.0 
                 1.1 
               
               
                 Water Drope - W 
                 2 
                 10 
                 12 
                 12 
                 10 
                 1 
               
               
                 Water Drop - F 
                 2 
                 10 
                 11 
                 12 
                 9 
                 1 
               
               
                 IGT, #3 @ 3.5 m/s - W 
                 4 
                 88 
                 111 
                 75 
                 115 
                 11 
               
               
                 IGT, #3 @ 3.5 m/s - F 
                 4 
                 70 
                 98 
                 102 
                 108 
                 11 
               
               
                 Prufbau Dry Pick - W 
                 2 
                 4.0 
                 4.0 
                 4.0 
                 4.0 
                 0.0 
               
               
                 Prufbau Dry Pick - F 
                 2 
                 4.0 
                 4.0 
                 3.0 
                 4.0 
                 0.0 
               
               
                 Prufbau Wet Pick - W 
                 1 
                 5.0 
                 5.0 
                 5.0 
                 4.0 
               
               
                 Prufbau Wet Pick - F 
                 1 
                 4.0 
                 5.0 
                 4.0 
                 4.0 
               
               
                 Adam&#39;s Wet Rub - W 
                 2 
                 1.1 
                 0.9 
                 1.0 
                 1.0 
                 0.2 
               
               
                 Adam&#39;s Wet Rub - F 
                 2 
                 1.6 
                 1.0 
                 1.2 
                 1.1 
                 0.1 
               
               
                 Sutherland Rub - W 
                 2 
                 4.0 
                 4.0 
                 4.0 
                 4.0 
                 0.0 
               
               
                 Sutherland Rub - F 
                 2 
                 4.0 
                 4.0 
                 4.0 
                 4.0 
                 0.0 
               
               
                 VC Absorbency - W 
                 4 
                 89 
                 91 
                 98 
                 90 
                 4 
               
               
                 VC Absorbency - F 
                 4 
                 91 
                 94 
                 91 
                 91 
                 2 
               
               
                 Heidelberg Halftone - W 
                 1 
                 6 
                 5 
                 6 
                 4 
               
               
                 Heidelberg Halftone - F 
                 1 
                 4 
                 5 
                 5 
                 4 
               
               
                 Heidelberg Solid - W 
                 1 
                 4 
                 5 
                 6 
                 4 
               
               
                 Heidelberg Solid - F 
                 1 
                 4 
                 5 
                 5 
                 7 
               
               
                 Heidelberg 50% Halftone - W 
                 3 
                 7.7 
                 7.1 
                 8.7 
                 8.1 
                 0.3 
               
               
                 Heidelberg 50% Halftone - F 
                 3 
                 6.0 
                 7.2 
                 8.2 
                 8.9 
                 0.5 
               
               
                 Heidelberg 75% Halftone - W 
                 3 
                 2.7 
                 4.3 
                 4.8 
                 1.8 
                 1.5 
               
               
                 Heidelberg 75% Halftone - F 
                 3 
                 2.9 
                 5.9 
                 5.4 
                 2.7 
                 1.5 
               
               
                 Heidelberg Ink Gloss - W 
                 1 
                 54 
                 49 
                 48 
                 46 
               
               
                 Heidelberg Ink Gloss - F 
                 1 
                 48 
                 52 
                 50 
                 44 
               
               
                 Heidelberg Ink Density - W 
                 1 
                 1.38 
                 1.30 
                 1.33 
                 1.33 
               
               
                 Heidelberg Ink Density - F 
                 1 
                 1.31 
                 1.31 
                 1.32 
                 1.30 
               
               
                 Heidelberg Coating Pick - W 
                 1 
                 25 
                 33 
                 38 
                 34 
               
               
                 Heidelberg Coating Pick - F 
                 1 
                 28 
                 38 
                 42 
                 35 
               
               
                 Heidelberg Total Picks - W 
                 1 
                 54 
                 53 
                 54 
                 53 
               
               
                 Heidelberg Total Picks - F 
                 1 
                 52 
                 54 
                 51 
                 50 
               
               
                   
               
             
          
         
       
     
     The present invention is usable in conjunction with papers for web offset, rotogravure, flexographic, letterpress and others. 
     As used herein the term lightcoat weight refers to papers of 30-40 pounds per ream and ultra light coat weight refers to papers of 24-28 pounds per ream. The present invention contemplates producing lightweight coated paper of high bulk with a gloss of 40 or above, and in fact Consolidated Papers, Inc. has achieved a gloss of 45. For ultra lightweight coated papers of high bulk, the present invention contemplates a gloss of 35. 
     While embodiments of the invention have been described in detail, various modifications and other embodiments thereof may be devised by one skilled in the art without departing from the spirit and scope of the invention, as defined in the appended claims.

Technology Classification (CPC): 3