Fractal Analysis of Coated Papers

2012 ◽  
Vol 730-732 ◽  
pp. 209-214
Author(s):  
J. Velho ◽  
N.F. Santos
Keyword(s):  
Fractal Dimension ◽  
Calcium Carbonate ◽  
Fractal Analysis ◽  
Coated Paper ◽  
Precipitated Calcium Carbonate ◽  
Coated Papers ◽  
Coating Colour ◽  
Ground Calcium Carbonate

The main goal of this research is to apply AFM to the analysis of coated paper topography in order to find out relationships between sheet gloss and some parameters obtained from AFM, such as roughness and fractal dimension (D). Flooding technique was also developed using appropriated software. Number of hills/flooding volume for 25%, 50% and 75% flooded volume was applied in this research. Ground calcium carbonate and precipitated calcium carbonate were applied in coating colour formulations, alone and blended in three formulations, 75:25, 50:50 and 25:75. The results obtained showed high correlations between sheet gloss with fractal dimension (D) parameter. Finally, flooding technique showed to be very interesting, all of them gave useful information in interpreting the influence of topography on sheet gloss.

scholarly journals Hybrid Precipitated Calcium Carbonate Containing Wood Flour for Paper Applications – A Comparative Handsheet Study

2019 ◽  
pp. 1-13
Author(s):  
Klaus Dölle ◽  
Kilian F. Baumgartner ◽  
Neil F. Goodman ◽  
Alexander Klitsiotisoris
Keyword(s):  
Calcium Carbonate ◽  
Filler Content ◽  
Wood Flour ◽  
Filler Material ◽  
Carbonate Mineral ◽  
Precipitated Calcium Carbonate ◽  
Hybrid Filler ◽  
Different Types ◽  
Flour Blends ◽  
Ground Calcium Carbonate

The main objective of this paper handsheet study is to investigate if a hybrid filler material containing wood flour and precipitated calcium carbonate can replace and/or supplement commercially available ground calcium carbonate and precipitated calcium carbonate mineral filler material for papermaking. The handsheet study contains 25 different furnish mixtures. Four different types of wood flour were used to manufacture the hybrid filler material, including two wood flour blends with a strengthening agent. All handsheet were manufactured with an 80% harwood and 20% softwood mix. The filler content varied between 10, 15 and 20%. The study showed that the hybrid filler material achieved a retention of up to 92.68% as well as a higher caliper of up to 208 μm compared to commercial ground and precipitated calcium carbonate of 120.4 μm and 145.6 μm respectively. Tensile and tear strength did not show an improvement. Elongation and tensile energy absorption did improve of up to 30% with the strength additive containing hybrid filler material. Opacity was improved of up to 10% with the hybrid filler material. Brightness and color values were lower due to the natural brow color of the wood flower material.

Study of Culture Paper Making with P-RC APMP by Different Papermaking Process

2012 ◽  
Vol 629 ◽  
pp. 347-351
Author(s):  
Tao Lin ◽  
Jian Wei Song ◽  
Xue Feng Yin ◽  
Zhi Jie Wang
Keyword(s):  
Calcium Carbonate ◽  
Raw Materials ◽  
Strength Properties ◽  
Precipitated Calcium Carbonate ◽  
Sem Images ◽  
Paper Properties ◽  
Fiber Network ◽  
Paper Making ◽  
Flocculation Process ◽  
Ground Calcium Carbonate

Using Poplar P-RC APMP as raw materials for culture paper making, the effect of conventional papermaking process and P-RC APMP fines-calcium carbonate co-flocculation process on the P-RC APMP culture paper properties were studied. The result showed that, comparing to the conventional papermaking process, co-flocculation process can supply paper with better strength properties, bulk and whiteness. When precipitated calcium carbonate (PCC) or ground calcium carbonate (GCC) were added respectively in conventional papermaking process, the PCC supplied handsheets with better bulk and whiteness, while GCC supplied handsheets with better strength properties. In the co-flocculation process, the effects of PCC and GCC were nearly the same in strength properties and bulk of handsheets, but PCC was more beneficial for whiteness. SEM images showed that PCC distributed more evenly in the fiber network, and well-bonded with fiber network. The particle size of GCC is relatively small, mainly filled in the fiber network and wrapped on the fiber.

scholarly journals Effect which the Particle Size of Ground Calcium Carbonate Exerts on Color Rheology and Coated Paper Property

1999 ◽  
Vol 53 (9) ◽  
pp. 1174-1178,053
Author(s):  
Yasushi Umeda ◽  
Shigeo Watabe ◽  
Yumiko Takase ◽  
Seiji Katayama
Keyword(s):  
Particle Size ◽  
Calcium Carbonate ◽  
Coated Paper ◽  
Paper Property ◽  
Ground Calcium Carbonate

scholarly journals PENINGKATAN SIFAT CETAK KERTAS SALUT DENGAN PIGMEN PRESIPITASI KALSIUM KARBONAT BERUKURAN SUBMIKRON ( DEVELOPMENT OF PRINTING PROPERTIES ON COATED PAPER USING SUBMICRON PIGMENT PRECIPITATED CALCIUM CARBONATE )

2016 ◽  
Vol 6 (02) ◽  
Author(s):  
Evi Oktavia ◽  
Sonny Kurnia Wirawan ◽  
Nina Elyani
Keyword(s):  
Calcium Carbonate ◽  
White Paper ◽  
National Standard ◽  
Paper Machine ◽  
Coated Paper ◽  
Precipitated Calcium Carbonate ◽  
High Brightness ◽  
Coating Color ◽  
Oil Penetration ◽  
High Degree

This research has been conducted to maximize the calcium carbonate usage without optical brigthening agent additional. The improvement on printing properties and a high degree of white paper was addressed the problem of meta-stable materials coated on the submicron of crystalline vaterite precipitated calcium carbonate (PCC) by composite it with latex. This study characterized the coating pigment, preparation of coating color, applied to paper sheets and compared with previous research and Indonesia National Standard specification of coated printing paper (SNI 0154:2010). The use of mixed submicron PCC (SPCC) and regular PCC (RPCC) as a white-coated paper produces a high brightness, low roughness, low oil penetration, high picking strength, high gloss, and low water absorption. Mostly those testing parameters meet the requirement of the Indonesia Standard National of printing coated-paper SNI 0154: 2010. Improvement also achieved on composite of submicron PCC-binder latex. A significant improvement of gloss value of the laboratory-scale processes was equal with supercalender using the paper machine and 23.6-28.9% of increasing of brigthness prior to previous study. ABSTRAKPenelitian ini bermaksud untuk memaksimalkan penggunaan pigmen kalsium karbonat tanpa menggunakan tambahan optical brigthening agent. Sifat cetak dan derajat cerah kertas ditingkatkan dengan cara mengatasi masalah meta-stabil pada bahan salut presipitat kalsium karbonat (PCC) submikron bentuk kristal vaterit melalui pembentukan komposit dengan lateks. Penelitian ini meliputi tahap karakterisasi bahan salut, pembuatan bahan salut, dan aplikasinya pada kertas, serta analisis sifat fisik, cetak dan optis pada kertas cetak salut, lalu membandingkannya dengan penelitian sebelumnya dan SNI spesifikasi kertas cetak salut SNI 0154:2010. Penggunaan campuran PCC submikron (SPCC)dengan PCC reguler (PCC) sebagai bahan salut menghasilkan derajat cerah kertas tinggi, kekasaran rendah, penetrasi minyak rendah, ketahanan cabut tinggi, kilap tinggi, dan daya serap air rendah. Sebagian besar parameter tersebut memenuhi standar SNI spesifikasi kertas cetak salut (SNI 0154 : 2010). Peningkatan juga terjadi pada komposit PCC submikron (SPCC) dengan binder lateks. Peningkatan signifikan terjadi pada analisa kilap kertas cetak salut skala laboratorium yang menunjukkan hasil sama dengan superkalender pada mesin kertas, dan terjadi peningkatan derajat cerah yaitu sekitar 23,6 – 28,9% terhadap penelitian sebelumnya.Kata kunci: bahan salut, kertas cetak salut, kilap tinggi, SNI 0154:2010 

Coating factors influencing the fold cracking of coated papers

2020 ◽  
Vol 35 (3) ◽  
pp. 419-431
Author(s):  
Qinwen Wang ◽  
Ning Ding
Keyword(s):  
Calcium Carbonate ◽  
Coating Thickness ◽  
Coating Properties ◽  
Coated Paper ◽  
Product Packaging ◽  
White Area ◽  
Minimum Value ◽  
Coated Papers ◽  
Factors Influencing ◽  
Solids Content

AbstractWith the increasing popularity of coated paper, it has been more widely used in printing, publishing, product packaging and commercial promotion. However, coated paper is prone to cracks after printing and folding which exposes to a white area which is referred to as fold cracking. This study investigated the coating properties of paper and coating factors influencing the fold cracking and aimed to provide guidance on how to reduce the problems of fold cracking. This paper mainly discusses the effects of pigment proportion, binder dosage, solids content, coating thickness and calendering pressure on fold cracking of coated paper after printing. Experiments show that when the coating consisted entirely of calcium carbonate, the degree of fold cracking is most serious. With the addition of kaolin, the fold cracking reduces. When the ratio of the number of parts of calcium carbonate to kaolin is 25/75, the area of fold cracking reaches its minimum value of 10.28 %. With increasing solids content of the coating, the fold cracking decreases initially and then increases. When the solids content is 55 %, the fold cracking reaches a minimum. Increased latex content reduced coating thickness and an increase in calendering pressure gradually reduce the degree of fold cracking.

Heterogeneity of Cerebral Blood Flow: a Fractal Approach

2000 ◽  
Vol 39 (02) ◽  
pp. 37-42 ◽  
Author(s):  
P. Hartikainen ◽  
J. T. Kuikka
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Fractal Dimension ◽  
Frontal Lobe ◽  
Fractal Analysis ◽  
Relative Dispersion ◽  
Emission Computed Tomography ◽  
Brain Blood Flow ◽  
Healthy Controls ◽  
Fractal Approach

Summary Aim: We demonstrate the heterogeneity of regional cerebral blood flow using a fractal approach and singlephoton emission computed tomography (SPECT). Method: Tc-99m-labelled ethylcysteine dimer was injected intravenously in 10 healthy controls and in 10 patients with dementia of frontal lobe type. The head was imaged with a gamma camera and transaxial, sagittal and coronal slices were reconstructed. Two hundred fifty-six symmetrical regions of interest (ROIs) were drawn onto each hemisphere of functioning brain matter. Fractal analysis was used to examine the spatial heterogeneity of blood flow as a function of the number of ROIs. Results: Relative dispersion (= coefficient of variation of the regional flows) was fractal-like in healthy subjects and could be characterized by a fractal dimension of 1.17 ± 0.05 (mean ± SD) for the left hemisphere and 1.15 ± 0.04 for the right hemisphere, respectively. The fractal dimension of 1.0 reflects completely homogeneous blood flow and 1.5 indicates a random blood flow distribution. Patients with dementia of frontal lobe type had a significantly lower fractal dimension of 1.04 ± 0.03 than in healthy controls. Conclusion: Within the limits of spatial resolution of SPECT, the heterogeneity of brain blood flow is well characterized by a fractal dimension. Fractal analysis may help brain scientists to assess age-, sex- and laterality-related anatomic and physiological changes of brain blood flow and possibly to improve precision of diagnostic information available for patient care.

A method for measuring the in-plane compressive strength and the compression behavior of coating layers

TAPPI Journal ◽  
2011 ◽  
Vol 10 (7) ◽  
pp. 29-34
Author(s):  
TEEMU PUHAKKA ◽  
ISKO KAJANTO ◽  
NINA PYKÄLÄINEN
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Calcium Carbonate ◽  
Coating Layer ◽  
Test Methods ◽  
Coating Films ◽  
Precipitated Calcium Carbonate ◽  
Coating Color ◽  
Mineral Coatings ◽  
Styrene Butadiene

Cracking at the fold is a quality defect sometimes observed in coated paper and board. Although tensile and compressive stresses occur during folding, test methods to measure the compressive strength of a coating have not been available. Our objective was to develop a method to measure the compressive strength of a coating layer and to investigate how different mineral coatings behave under compression. We used the short-span compressive strength test (SCT) to measure the in-plane compressive strength of a free coating layer. Unsupported free coating films were prepared for the measurements. Results indicate that the SCT method was suitable for measuring the in-plane compressive strength of a coating layer. Coating color formulations containing different kaolin and calcium carbonate minerals were used to study the effect of pigment particles’ shape on the compressive and tensile strengths of coatings. Latices having two different glass transition temperatures were used. Results showed that pigment particle shape influenced the strength of a coating layer. Platy clay gave better strength than spherical or needle-shaped carbonate pigments. Compressive and tensile strength decreased as a function of the amount of calcium carbonate in the coating color, particularly with precipitated calcium carbonate. We also assessed the influence of styrene-butadiene binder on the compressive strength of the coating layer, which increased with the binder level. The compressive strength of the coating layer was about three times the tensile strength.

Cracking at the fold in double layer coated paper: the influence of latex and starch composition

TAPPI Journal ◽  
2019 ◽  
Vol 18 (2) ◽  
pp. 93-99
Author(s):  
SEYYED MOHAMMAD HASHEMI NAJAFI ◽  
DOUGLAS BOUSFIELD, ◽  
MEHDI TAJVIDI
Keyword(s):  
Mechanical Properties ◽  
Double Layer ◽  
Starch Content ◽  
Single Layer ◽  
Double Layers ◽  
Coated Paper ◽  
Coated Papers ◽  
Coating Layers ◽  
Scanned Images ◽  
Packaging Paper

Cracking at the fold of publication and packaging paper grades is a serious problem that can lead to rejection of product. Recent work has revealed some basic mechanisms and the influence of various parameters on the extent of crack area, but no studies are reported using coating layers with known mechanical properties, especially for double-coated systems. In this study, coating layers with different and known mechanical properties were used to characterize crack formation during folding. The coating formulations were applied on two different basis weight papers, and the coated papers were folded. The binder systems in these formulations were different combinations of a styrene-butadiene latex and mixtures of latex and starch for two different pigment volume concentrations (PVC). Both types of papers were coated with single and double layers. The folded area was scanned with a high-resolution scanner while the samples were kept at their folded angle. The scanned images were analyzed within a constant area. The crack areas were reported for different types of papers, binder system and PVC values. As PVC, starch content, and paper basis weight increased, the crack area increased. Double layer coated papers with high PVC and high starch content at the top layer had more cracks in comparison with a single layer coated paper, but when the PVC of the top layer was low, cracking area decreased. No measurable cracking was observed when the top layer was formulated with a 100% latex layer.

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