MODIFICATION OF JACK PINE TMP LONG FIBERS BY ALKALINE PEROXIDE – PART 1. CHEMICAL CHARACTERISTICS OF FIBERS AND SPENT LIQUOR
The purpose of this work was to improve the quality of jack pine TMP long fibers, particularly with respect to the strength properties, by alkaline peroxide treatment. This paper reports the chemical characteristics of the treated long fibers and the spent liquors originating from various treatments. It was observed that, in comparison with hydrogen peroxide, the alkalinity of the treatment solutions had a greater influence on most fibre characteristics and spent liquor properties.
Optimization of an alkaline peroxide interstage treatment of jack pine (Pinus banksiana lamb.) using a D‐optimal design
For many decades, the utilization of jack pine in the pulp and paper industry has attracted considerable interest but without any major breakthrough. However, in the past few years the emergence of new technologies has provided hope for its potential use. One of these technologies consists in the addition of hydrogen peroxide within the thermomechanical pulping process. To study the influence of numerous process parameters on the interstage treatment of jack pine and to optimize this complex process, a D-optimal experimental design was conducted. A total of 7 variables were considered. 
 
 
 
It was found that to maximize the properties of the fibres and the resulting paper, a temperature of 115°C with a narrow plate gap at the first refining stage and a high consistency at the second stage had to prevail. A sodium hydroxide treatment radically improved the fibre bonding properties without affecting the tear strength but at the expense of a loss of 4,6 points in ISO brightness. Validation trials allow to draw some conclusions on the advantages and shortcomings of this type of experimental design. This design is efficient, provided sufficient information is available to target likely interactions. Otherwise, a screening design would be required thus increasing the total cost of the study. 
 
 
 
L'utilisation du pin gris dans l'industrie des pâtes et papiers suscite un grand intert depuis de nombreuses decennies. Ces dernieres annees, l'emergence de nouvelles technologies apporte un regain d'espoir pour le futur. Une de ces technologies consiste a utiliser du peroxyde d'hydrogene lors du procede de mise en pâte thermomecanique. Un plan d'essais D-Optimal a ete utilise pour etudier l'influence de plusieurs parametres de ce procede. Ce type de plan d'experimentation permet de traiter un nombre important de variables simultanement tout en requerant peu d'essais, meme lorsque 7 variables sont mises en cause. 
 
 
 
Pour le pin gris, l'utilisation d'une temperature de 115°C accompagnee d'un faible entrefer lors du premier stade de raffinage ainsi que d'une consistance elevee au deuxieme stade, permet de developper au maximum les proprietes des fibres et du papier produit. Un traitement intermediaire a la soude augmente radicalement les proprietes de liaison interfibres sans affecter l'indice de dechirure mais fait, par ailleurs, chuter la blancheur de 4,6 points. Des essais de confirmation permettent de discuter des lacunes et des avantages de ce type de plan d'essais. Ce plan est efficace a la condition de connaitre assez le procede pour pouvoir cibler les interactions d'interet. Sinon, un plan de tri serait necessaire, ce qui augmenterait le co-t global de l'etude.
On the fractionation of β-lactoglobulin and α-lactalbumin
Abstract Existing methods for the preparation of α-lactalbumin and β-lactoglobulin are examined critically. It is proposed that the most satisfactory method for the preparation of the whey protein fraction from bovine milk is (NH 4 ) 2 SO 4 fractionation. A number of new gentle procedures for the fractionation of the whey proteins are compared with some existing methods. The distribution of total protein at various stages is determined by total Kjeldahl nitrogen and the kind of protein by starch-gel electrophoresis. The effect of variables, such as pH, salt concentration and temperature on the separation of α-lactalbumin and serum albumin from β-lactoglobulin is studied. Differences in the behavior ( e.g. solubility) of genetic variants of β-lactoglobulin are noted. The solubility of each of the major whey proteins, under similar conditions to those used in the fractionation, is compared with its solubility in the whey protein mixture. The understanding gained of factors important in the fractionation is used in recommending new procedures for α-lactalbumin and β-lactoglobulin isolation.