Search

In this paper, the stiffness and folding endurance of the paper were investigated with three kinds of pulp, such as the mechanical wood pulp, chemical pulp and composite pulp, after using common additives and cleaning additives. The results indicated that the stiffness of the paper can be increased by 20% ~ 30% and folding endurance can improve 20% ~ 60% after using new kind of cleaning additives no matter what kind of filler. New cleaning additives can not only improve the physical properties of paper, but also change "acidic papermaking" of the traditional paper industry into clean neutral papermaking environment. Especially, it is suitable for the production of food card paper.

Paper defects mean that there are some defects in the paper such as hole, emboss, and fold during the paper production, which mainly results from the limitation of technological level. In the past time, artificial visual inspection and off-line checking were often used to detect the paper defects. However, its shortcoming was highlighted along with the improvement of industrial technology level and increasing demand for paper. In order to realize the online detection and markers for paper defects, the project designs the on-line detection system based on line-scan digital camera. Firstly, the principle and detection scheme of the system for the paper defects was presented. Then the overall structure of the system was designed. After that, the hardware circuit of the system was designed using TMS320F2812 as main control chip. It mainly consists of the function of each module and the working process of the system. Finally, the software of the image acquisition system was presented. With the experimental verification, the system has advantages of low cost, high efficiency and strong resistance to interference. The functions and indexes achieved the design requirements.

In paper dryer section of the paper machine, paper dehydration is small, but the steam consumption for the process of dehydration is very large, this steam consumption has a great influence to the total steam consumption of the whole papermaking process. A method optimization of the dryer section based on genetic algorithm is proposed to reduce the dryer section steam consumption, which can reduce the total steam consumption of the papermaking process. After analyzing steam consumption of the whole drying process, the result is that the temperature of dryer section air is the key factor that influences the steam consumption. The model of paper machine dryer section is build with supply air temperature as a variable and steam consumption as the objective function, then using the genetic algorithm to optimize the supply air temperature. Simulation results show that after optimizing air temperature by genetic algorithm steam consumption of papermaking process is further reduced.

In order to realize precise control of the vertical inverting feeding of paper, the paper proposes the scheme to analyse the accuracy. Based on the geometric constraint relations of the feeding device, the position constraint equation of the device is established, together with the speed-acceleration formula; and the relationship between the paper inverting deviation angle and its drop height is obtained using the general equation of dynamics of the horizontal projectile motion as vertical inverting accuracy analysis of the device. The results of the study show that the precise control of the vertical inverting feeding of paper can be realized through the control of the angle.

In this paper a new method is proposed for intelligent sort of battery from waste paper based on Invariant Moments and Fractal Dimension (IMFD). In IMFD, a new distinctive feature that based on the edge contours is extracted to describe the target picture. At first invariant moments technique is used to extract Hus seven moments as the global descriptors from the target image. Then the fractal dimensions are extracted as local invariant descriptors by using Fractal Dimension. At last, a combing descriptor is built according the distinctive feature, which combines the global descriptor and the local descriptor together. The features are highly distinctive, and can be matched with high probability against a large database of features. The practical tests performed in this article show that the proposed method has a significant effect on increasing the stability, the accuracy of classification, and also can effectively against the huge-information during the image processing.

In order to research the relationship between ink permeability and dot gain of different paper, four kinds of coated paper and two kinds of printing paper were chosen. Ink marks method was used to measure ink permeability of four kinds of coated paper and two kinds of common printing paper. After the ink marks were printed on each of the six kinds of paper, the length of them were measured, then the reciprocal of the ink marks length was multiplied by 1000 to obtain the value of the ink permeability. Inkjet printer was also used to print yellow GATF step-wedge simulating offset printing on the six kinds of paper, then using an optical densitometer to measure the dot gain. Conclusion shows that non-coated paper is higher in permeability than coated paper, which results in high percentage of dot gain.

Microfibrillated cellulose (MFC) was prepared from the bleached kraft hardwood pulp using TEMPO/NaClO/NaBr oxidation system and high pressure homogenization. By changing dosages of the TEMPO, NaClO and NaBr, the pressure and times of homogenization, pretreatment and homogenization process were optimized. Experimental investigation indicated that for making MFC of high quality, 0.25%TEMPO, 2.5%NaBr, 60%NaClO (based on oven dry pulp), 20 times of homogenization, pressure of 60MPa in the process of treatment were required. At last, the mechanical and barrier properties were tested after the base paper was coated by homemade MFC. The study suggested that mechanical properties (especially 5 times increase of the folding strength) increased substantially and air permeability decreased by 100times.

The influence of coating layer structure on both physical and printing quality of the paper was studied. Different coating layers were obtained by changing the ratio of polyvinyl alcohol adhesives and silicon dioxide pigments in the coating formula. Then the structure, physical properties and ink-jet printing performance of the coated paper were measured. The influences of coating structure on physical properties and ink-jet printing performance were evaluated. The results showed that as the ratio of adhesive increased, the coating porosity decreased; the average pore diameter increased at first and then decreased, but in general tended to decrease; the initial drop contact angle increased, which testified the stronger hydrophobicity of the coated surface with higher adhesive ratio. The average pore diameter has a negative linear correlation with paper roughness while has a positive linear correlation with air permeability. The larger the average pore diameter, the greater the density values, as well as the better tone reproduction and the larger color gamut range. Average pore diameter also has a weak correlation with dot area and dot roundness.