Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H23/00—Processes or apparatus for adding material to the pulp or to the paper
  • D21H23/02—Processes or apparatus for adding material to the pulp or to the paper characterised by the manner in which substances are added
  • D21H23/22—Addition to the formed paper
  • D21H23/70—Multistep processes; Apparatus for adding one or several substances in portions or in various ways to the paper, not covered by another single group of this main group
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H19/00—Coated paper; Coating material
  • D21H19/80—Paper comprising more than one coating
  • D21H19/84—Paper comprising more than one coating on both sides of the substrate
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
  • Y10T428/24802—Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
  • Y10T428/24917—Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.] including metal layer
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2933—Coated or with bond, impregnation or core
  • Y10T428/2936—Wound or wrapped core or coating [i.e., spiral or helical]
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2933—Coated or with bond, impregnation or core
  • Y10T428/294—Coated or with bond, impregnation or core including metal or compound thereof [excluding glass, ceramic and asbestos]
  • Y10T428/2942—Plural coatings
  • Y10T428/2945—Natural rubber in coating
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31855—Of addition polymer from unsaturated monomers
  • Y10T428/3188—Next to cellulosic
  • Y10T428/31895—Paper or wood
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31855—Of addition polymer from unsaturated monomers
  • Y10T428/3188—Next to cellulosic
  • Y10T428/31895—Paper or wood
  • Y10T428/31906—Ester, halide or nitrile of addition polymer

Definitions

• the present invention relates to the manufacture of coated paper and relates in particular to improvements aimed at improving the properties of coated paper intended for making labels for bottles.
• the label supports must ensure perfect labeling, that is to say have perfect adhesion to the bottles. Suitability for labeling is defined by the loss of stiffness of the paper in the wet state, which is linked to the speed of absorption of water.
• the label supports must be dimensionally stable over a wide range of relative humidity levels so as to remain perfectly flat during the manipulations to which they are subjected.
• the label support must be made as least polluting as possible and, for this purpose, the labels must have a high resistance to chemical agents (caustic soda) so as not to not pollute the washing baths and they must contain the lowest possible free formaldehyde content because free formaldehyde inconveniences people handling the labels and it deposits traces on the bottles which destroy the yeasts of the drinks.
• chemical agents such as calcium silicate
• free formaldehyde inconveniences people handling the labels and it deposits traces on the bottles which destroy the yeasts of the drinks.
• the label paper is made up of a fibrous support, the front side of which carries a layer of material provided for printing and the back side of which is covered with a sauce intended to ensure the qualities of labeling.
• the qualities of labeling are obtained by using, to cover the back side, a sauce relatively waterproof.
• the amount of water absorbed by the paper is then usually of the order of 12 to 15 grams per square meter.
• the subject of the invention is a technique for manufacturing coated paper which remarkably improves the labeling performance and qualities of coated paper for labels.
• the subject of the invention is also a technique for manufacturing coated paper which very substantially reduces the pollution of washing baths, while moving in the direction of the evolution of European standards in the matter.
• the invention relates to a new generation of coated label paper which meets the requirements of breweries.
• the invention relates to improvements in the manufacture of coated paper, which develop essentially along three axes: 1) the composition of the sauce applied to the back side of the paper so as to improve the labeling ability,
• FIG. 1 is a simplified general diagram of an exemplary paper manufacturing installation using the method according to the invention.
• FIG. 2 is a diagram showing a typical water absorption curve for a paper produced according to the invention and, by way of comparison, a typical water absorption curve for paper according to the invention. prior art. Description of an exemplary embodiment
• the fibrous pulps intended to serve as a support for the paper are mixed in a mixing tank to which are also added the usual fillers (kaolin, talc, titanium) and the bonding agents and any wet strength agents.
• the fibrous composition is for example:
• Additives can also be added to the mixture continuously, respecting the minimum contact times recommended upstream of the machine headbox.
• the dough is poured into the headbox 1.
• the headbox is shown in 1.
• the dough then passes over a table of draining 2 to remove the water and under pressure rollers 3, then the support F passes through a first dryer 4.
• the support then contains 0.5 to 8% water.
• the dryer is a known device which can be produced in various embodiments.
• the support passes under a friction cylinder 5 which finishes preparing the support for coating the front and back sides.
• the support then passes into a coating station 6 in which the coating of the back and front sides is carried out using sauces.
• the coating device can be any known device (blade device, rotary doctor blade and / or roller for example).
• the coating station is advantageously arranged to simultaneously coat the back and front sides. The coating may possibly be carried out successively on each of the faces with an intermediate drying.
• the composition is selected sauces soigneuse ⁇ ment according ⁇ invention to optimize these performan ⁇ paper.
• the composition of the sauce applied to the back side is selected to improve the labeling ability. This improvement is obtained by accelerating the reaction of the sauce with water so as to produce rapid water absorption.
• the quality of a labeling is indeed linked to the loss of rigidity of the support in the wet state which represents the speed of absorption of water by the back sauce. While the back sauce according to the prior art is commonly made less absorbent in water, the composition of the back sauce according to the invention is produced in such a way that the sauce is hydrophilic.
• FIG. 2 shows the speed of water absorption speed of a paper according to the invention (curve A) compared to a speed curve of water absorption typical of a paper according to prior art (curve B).
• the abscissa axis carries the scale 'of the time and the ordinate is shown the rate of water penetration to the back of the paper facing the front side.
• Curve A shows that the absorption of water by the paper produced according to the invention is greatly accelerated. This rapid, almost immediate reaction to water not only ensures excellent adhesion of the label to a bottle but also prevents the edges of the label affixed to the bottle from coming off.
• a second aspect of the invention relates to the composition of the front layer which is selected to increase the adhesion of inks and varnishes compared to the prior art while reducing the pollution of washing baths during recycling of bottles with labels.
• the invention chooses for the binder a combination of crosslinkable latex and soft latex with the addition of an insolubilizing agent which fixes all the free bonds of the crosslinkable latex.
• an insolubilizing agent which fixes all the free bonds of the crosslinkable latex.
• For the pigmentation charge a mixture of kaolin and calcium carbonate with very fine particles is chosen.
• An exemplary composition for the front layer is given below t
• the particle size of the calcium carbonate has a distribution of 98% of particles smaller than 2 microns and 80% of particles smaller than 1 micron.
• the paper After the coating operation on the back and front sides, the paper passes through a second dryer 7 in order to dry the coated back and front sides, then between straightening cylinders 8, before being conveyed to a rewetting oste 9 consisting of a spray bar. The rewetted paper then passes into another dryer 10. At the exit from the latter, the paper again passes under a last rewetting ramp 11 before being wound on a winder 12.
• the paper is subjected to successive controlled drying-rewetting cycles which have the effect of providing the paper with remarkable dimensional stability regardless of the humidity and thus guaranteeing the labels. an exceptional dish.
• the invention provides a rigorous control of the humidity of the paper as soon as the felt is ready for coating.
• three devices denoted 13 Î the first upstream of the coating station 6, the second downstream of the dryer 7 and the third downstream of the dryer 10.
• These devices are humidity measurement which can be of any known type, for example an Accuray brand humidity measurement device.
• These measurement devices are mounted so as to scan the surface of the paper and produce a measurement signal showing the humidity level.
• the measurement signals of the three devices 13 in FIG. 1 are denoted H1, H2 and H3.
• the number of measuring devices 13 is obviously not limited to three.
• the measurement signals are received in a control station where each measurement signal is compared with a predetermined setpoint signal: the signal Hl is compared with the setpoint signal Cl, the signal H2 with the setpoint signal C2 and the signal H3 to the setpoint signal C3.
• the setpoint signals are generated and stored in a control processor 15.
• the con ⁇ signs are chosen according to the characteristics of the paper to be produced.
• the setpoint and measurement signals are compared in a comparison device 14 organized to respectively produce a control signal S1, S2, S3 representing the difference between each measurement signal and the corresponding setpoint signal.
• the control signal Si is used to adjust the heating power of the dryer 4 in order to reduce to zero the difference between the measured humidity represented by the signal H1 and the corresponding setpoint represented by the signal Cl.
• the signal S2 serves to adjust the heating power of the dryer 7 in order to reduce zero the difference between the measured humidity represented by the signal H2 and the corresponding setpoint represented by the signal C2.
• the signal S3 is used to adjust the heating power of the dryer 10 in order to reduce to zero the difference between the measured humidity represented by the signal H3 and the corresponding setpoint represented by the signal C3.
• the absolute humidity is adjusted by the instructions C1, C2 and C3 to a value of 5.5%.
• the method according to the invention thus makes it possible to obtain coated paper for labels having performances significantly improved compared to those of paper for labels produced according to the prior art.
• the performances obtained according to the invention can be summarized as follows:

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• 1989
  • 1989-01-18 EP EP89901257A patent/EP0409836A1/de not_active Ceased
  • 1989-01-18 WO PCT/BE1989/000005 patent/WO1990008223A1/fr not_active Application Discontinuation
  • 1989-01-18 US US07/474,840 patent/US5209982A/en not_active Expired - Fee Related

Non-Patent Citations (1)

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