For predictive purposes and for understanding the relationship between the US market and Canadian newsprint producers an econometric model was built. In this study, a simultaneous-equation model was developed, which c...For predictive purposes and for understanding the relationship between the US market and Canadian newsprint producers an econometric model was built. In this study, a simultaneous-equation model was developed, which consisted of four equations, one each for the supply, export, consumption and price of newsprint. The period of 1955-1986 was covered by this model. The data for the years 1985 and 1986 were reserved to test the predictive power of the model. In fitting the four equations for the period of 1955 -1984, the coefficients of determination, the R -square values, between observed and predicted values were higher than 99 per cent. The test results of the forecasting power showed that there was no statistically significant difference between predicted and observed values at the 5 per cent level of significance. Sources of forecasting error are expressed as three partial inequality coefficients associated with bias, variance and covariance of predicted and observed values. The error could not be展开更多
The aim of this research is to study the floatation deinking abilities of black mold enzyme and chemicals in newsprint paper application. In this experiment, the properties of deinked pulp from three different additiv...The aim of this research is to study the floatation deinking abilities of black mold enzyme and chemicals in newsprint paper application. In this experiment, the properties of deinked pulp from three different additives--chemicals, black mold enzyme, and chemicals together with black mold enzyme, are studied. The first part of the experiment was to find the optimal amount of chemicals and the optimal pH through the use of sodium hydroxide and surfactant. As a result, 0.2% of sodium hydroxide and 0.4% of surfactant on oven dried weight at pH 9 was found to be the optimal condition for the deinked pulp to yield the lowest ERIC （effective residual concentration） and the highest brightness. The second part of the experiment was to find the optimal amount of black mold enzyme used in the deinking process. As a result, the optimal condition for deinked pulp to retain the lowest ERIC and the highest brightness was 100 ppm of black mold enzyme and 10 minutes of enzyme reaction time. The third part of experiment was to study the de-inking ability of black mold enzyme and chemicals. Consequently, with 30 min of chemicals reaction time and 60 min of black mold reaction time, the deinked pulp retained low ERIC but higher brightness.展开更多
The mechanical and chemical effect on the pulping properties of the old newsprint was studied using a FORMAX Micro-Maelstrom Laboratory Pulper, and the flotation conditions such as velocity of air flow, air pressure a...The mechanical and chemical effect on the pulping properties of the old newsprint was studied using a FORMAX Micro-Maelstrom Laboratory Pulper, and the flotation conditions such as velocity of air flow, air pressure and flotation time were also discussed with a FORMAX Deink Cell. The results show that sodium hydroxide, sodium silicate, hydrogen peroxide and deinking agent are the key factors in the chemical effect, and pulping consistency is more important than pulping time and rotation speed in the mechanical effect during the high consistency pulping of the ONP. In general, the chemical effect has a greater influence on the deinked pulp properties than the mechanical effect.展开更多
In this paper, modal colloidal substances (MCS) were employed to study the effects of in-process colloid on the properties of newsprint. The adsorption of MCS on fibers and optical and physical properties of newsprint...In this paper, modal colloidal substances (MCS) were employed to study the effects of in-process colloid on the properties of newsprint. The adsorption of MCS on fibers and optical and physical properties of newsprint were both investigated with and without retention systems including agglomerating agent and flocculent. Results showed that MCS could be absorbed on the fibers without retention system, and retention systems could promote the MCS retention efficiency while the physical properties of sheets was affected by blocking the formation of hydrogen bonding between fibers and the surface tension of water and density of paper展开更多
文摘For predictive purposes and for understanding the relationship between the US market and Canadian newsprint producers an econometric model was built. In this study, a simultaneous-equation model was developed, which consisted of four equations, one each for the supply, export, consumption and price of newsprint. The period of 1955-1986 was covered by this model. The data for the years 1985 and 1986 were reserved to test the predictive power of the model. In fitting the four equations for the period of 1955 -1984, the coefficients of determination, the R -square values, between observed and predicted values were higher than 99 per cent. The test results of the forecasting power showed that there was no statistically significant difference between predicted and observed values at the 5 per cent level of significance. Sources of forecasting error are expressed as three partial inequality coefficients associated with bias, variance and covariance of predicted and observed values. The error could not be
文摘The aim of this research is to study the floatation deinking abilities of black mold enzyme and chemicals in newsprint paper application. In this experiment, the properties of deinked pulp from three different additives--chemicals, black mold enzyme, and chemicals together with black mold enzyme, are studied. The first part of the experiment was to find the optimal amount of chemicals and the optimal pH through the use of sodium hydroxide and surfactant. As a result, 0.2% of sodium hydroxide and 0.4% of surfactant on oven dried weight at pH 9 was found to be the optimal condition for the deinked pulp to yield the lowest ERIC （effective residual concentration） and the highest brightness. The second part of the experiment was to find the optimal amount of black mold enzyme used in the deinking process. As a result, the optimal condition for deinked pulp to retain the lowest ERIC and the highest brightness was 100 ppm of black mold enzyme and 10 minutes of enzyme reaction time. The third part of experiment was to study the de-inking ability of black mold enzyme and chemicals. Consequently, with 30 min of chemicals reaction time and 60 min of black mold reaction time, the deinked pulp retained low ERIC but higher brightness.
文摘The mechanical and chemical effect on the pulping properties of the old newsprint was studied using a FORMAX Micro-Maelstrom Laboratory Pulper, and the flotation conditions such as velocity of air flow, air pressure and flotation time were also discussed with a FORMAX Deink Cell. The results show that sodium hydroxide, sodium silicate, hydrogen peroxide and deinking agent are the key factors in the chemical effect, and pulping consistency is more important than pulping time and rotation speed in the mechanical effect during the high consistency pulping of the ONP. In general, the chemical effect has a greater influence on the deinked pulp properties than the mechanical effect.
文摘In this paper, modal colloidal substances (MCS) were employed to study the effects of in-process colloid on the properties of newsprint. The adsorption of MCS on fibers and optical and physical properties of newsprint were both investigated with and without retention systems including agglomerating agent and flocculent. Results showed that MCS could be absorbed on the fibers without retention system, and retention systems could promote the MCS retention efficiency while the physical properties of sheets was affected by blocking the formation of hydrogen bonding between fibers and the surface tension of water and density of paper
