Encontrados 15 documentos, a visualizar página 1 de 2

Inverse gas chromatography and XPS of extracted kraft pulps

Kraft pulps at the kappa number level of 15 obtained from Acer saccharum (sugar maple) and Eucalyptus globulus prepared with and without hot water pre-extraction (HWE) were analysed by inverse gas chromatography (IGC) and X-ray photoelectron spectroscopy (XPS). In the case of A. saccharum pulps, the dispersive component of the surface energy (γsd) at 40ºC determined by IGC was 39.8 mJ m-2 (control pulp without ...

Modeling the Turbulent Flow of Pulp Suspensions

Pulp fiber suspensions are complex systems because the components present singular and complex interactions between them. A mechanistic model for the turbulent flow regime of industrial pulp suspensions was developed on the basis of a CFD code, using the chemical engineering module of COMSOL Multiphysics software. The standard k-ε turbulence model, chosen to simulate turbulence, was tested and validated using f...

Characterization of Eucalitptus grandis kraft pulps treated with phosphonates i...

New modified filler obtained by silica formed by sol–gel method

This study focus on the modification of the particles of precipitated calcium carbonate (PCC) with silica formed in situ by sol–gel method. The new materials were characterized by several spectroscopic, analytical and microscopic techniques. A dense film of highly branched silica was formed at the surface of the scalenohedral PCC crystals. The amount of silica deposited at the PCC surface, as determined by ther...

Paper surface chemistry as a tool to improve inkjet printing quality

Hygroexpansivity profiles on a commercial paper machine

A New Approach for the Modification of Paper Surface Properties Using Polyoxome...

A new approach for the chemical modification of the surface of paper based on the application of colloidal mixtures containing cationic starch and polyoxometalates on uncoated base paper is presented. Polyoxometalates with the Keggin-type structure and physical properties similar to those presented by coating pigments, namely H3PW12O40·23H2O, H4SiW12O40·24H2O, and K7PW11O39·9H2O, have been used in order to impr...

The influence of paper surface sizing on inkjet

The effect of paper surface sizing on inkjet pigment penetration was evaluated by studying four different paper samples: one taken as reference, without surface sizing (paper RP), one surface sized with cationic starch (RPS1), one with a mixture of cationic starch and poly(styrene-co-maleic anhydride) (RPS2), and one with a mixture of cationic starch and poly(styreneco- acrylate) (RPS3). Assessment was based on...

Application of FT-IR-ATR Spectroscopy to Evaluate the Penetration of Surface Si...

It is widely recognized that the surface properties of paper depend on the fibrous matrix and the final surface treatment applied to the paper. Regarding chemical paper surface treatments, an important issue is the evaluation of the penetration of chemical compounds into the fibrous matrix, as the chemicals can potentially cause changes in the intrinsic properties of paper. The work presented here aimed to use ...

Impact of surface sizing on inkjet printing quality

Printing quality is strongly influenced by the structural and chemical properties of paper surface, and is one of the most important factors concerning costumer’s evaluation. Thus, all studies regarding the evaluation of paper surface characteristics, the effects of surface treatments, paper-ink interactions as well as the influence of all these parameters on printing quality, are of utmost importance. The aim ...