Enough wood supplying for pulp and paper industry of our country has been encountered with serious difficulties caused by destruction of forest and wood shortage and fiber resources. Thanks to the developments in the widespread plantation of canola in Iran, in this research, we have studied the specific features of CMP pulp prepared from Rapeseed Straw. For this purpose, Rapeseed Straw CMP pulp was prepared at 160°C temperature, 40 minute time, 5 and 10 percent chemicals charge and 7: 1 cooking liquor and canola stem ratio. In order to brighten the resulted pulp, hydrogen peroxide (5.5%) was applied. The yield of pulp obtained in 5% and 10% cooking chemicals conditions, were 78.07% and 74.07% respectively. In this content, the Strength Properties of the hand sheets prepared were measured as followings: tensile strength, 19.33 and 20.033 Nm/g; Burst strength, 0.83 and 0.57 Kpa.m2/g; tear strength, 2.57 and 3.25 mN.m2/g and Opacity 95.02% and 96.32%. This study has shown that, considering limitations in wood resources, the Rapeseed Straw, could be successfully substituted impart, in pulp and paper industry of our country, as a cheap and available lignocelluloses material for producing CMP pulp and papers.

This study was carried out to investigate papermaking properties comparison of fast growth poplar species (Poulus euramericana) at two growing periods of 8 and 18 years for NEWSPRINT production in MWPI. This special poplar, has been selected from Safrabasteh research station in Gilan province. Selected poplar was chipping in MWPI. Based on the results of experimental tests, cooking conditions of 20% chemicals ( based on oven dry wood), cooking temperature of 160oC, L:W = 7 : 1 and cooking time of 90 min for 8 years poplar and 130 min for 18 years was selected in order to obtain pulping yield of about 85%. After chemical treatment of wood chips with Na2SO3 solution the treated chips were defibrated in three stages and bleached by H2O2, refined in PFI mill to freeness of about 300 ml.CSF. Laboratory standard hand sheet with gramage of 60g/m2 were made from the refined pulps. The results show that, in respect to physical and strength properties, the paper from poplar wood were superior to the paper produced from CMP pulp of the normal wood furnish(75% hornbeam + 25% beech ), except in optical property of opacity which has shown some reduction. Therefore, by making necessary changes in cooking conditions, to improve the paper opacity, it may be possible to use poplar ( populus euramericana ) as pure for NEWSPRINT production in MWPI. In applying this respect, 8 years growth poplar has more priority.

The anisotropic and mechanical properties of NEWSPRINT paper made in Iran were studied in this research. Tear and tensile strengths, modulus of elasticity and breaking length of NEWSPRINT were determined at different angles to machine direction (MD) and at an interval angle of 15o (15, 30, 45, 60, 75) and cross machine direction (CD). The results show that modulus of elasticity, tensile strengths and breaking length of NEWSPRINT paper are the highest in machine direction, decreasing with increase of angle and reach the lowest (half) in cross machine direction. There is no significant difference between mentioned properties from 60o to CD. Tear strength of NEWSPRINT paper was the lowest values in machine direction, increasing with increase of angle and reach highest (half) at of and then decreases up to CD.

In this research, the effect of cationized CMP fines on NEWSPRINT pulp properties was investigated.The fines were first separated using a Dynamic Drainage Jar (DDJ) apparatus and then the cationic groups were established and firmly fixed on fines by chemical reactions and grafting with copolymerization mechanism so that the surface electrical charge of fines was changed to cationic. The cationized CMP fines were added alone and also together with polymeric retention aid, the cationic poly acryl amid, in NEWSPRINT furnish at three levels of consumption (low, medium and high) and the pulp properties including drain ability (freeness), first pass retention and also zeta potential and filtrate cationic demand variations were measured and compared with the control sample (pulp with only cationic poly acryl amid which is the main retention aid polymer in Mazandran Wood and Paper Industries Company). The results showed that although the cat ionized CMP fines by themselves could not have good effects on NEWSPRINT pulp quality, by cooperation with cationic poly acryl amid, the pulp quality and also retention aid polymer efficiency were increased. Indeed, the cationized CMP fines have a synergic effect on retention aid polymer efficiency. Therefore, the use of cationized CMP fines with cationic poly acryl amid can be recommended for increasing pulp drainability and first pass retention.

In this study a single – equation model have used for estimating NEWSPRINT demand function in Iran. The data are annual NEWSPRINT consumption per capita as dependent variable and national income with a lag; printing and writing paper price and real NEWSPRINT price are used as explanatory variables for the time period 1981 to 2003. Functional form of the model is a Linear Regression Model (Log-Log). After specification the model Ordinary Least squares (OLS) have used for estimation coefficients of the model. Finally the income elasticity is estimated at 0.05 level 1.82 and the value of price elasticity is estimated - 0.46. Both income and price elasticity are statistically significant at 0.05 level. In addition, statistically significant coefficient of printing paper price indicates that with increasing its price, per capita consumption of NEWSPRINT will decrease up to 0.33 percent. By this model the per capita consumption of NEWSPRINT in Iran in year 2007 is estimated 2.56±1.15 kg.

In this study, the production of bleached chemi-mechanical pulp from wheat straw for the NEWSPRINT production was investigated. Wheat straw was collected from Lorestan province and wheat straw CMP pulp was prepared using 120, 140, and 160oC chemical treatment temperature, 45 minutes time, 10, 12, and 14% chemicals charge and 10: 1 liquor to straw ratio. The yield after defibration treatment varied between 56.5% and 72.5%. Two optimum pulps were bleached using TCF method applying 2% and 3% NaOH, 1.5% and 2% H2O2, and 60 and 120 minutes bleaching time. One way analysis variance method showed that bleaching time had the most significant effect on optical properties of handsheet. Applying 3% NaOH (based on oven dry weight of the unbleached pulp), 2% H2O2, and 120 minutes time improved the brightness and opacity to 52.9%, and 79.5% ISO, respectively. Optimum pulp strengths including tensile, burst and tear indices were measured as 43.87 Nm/g, 2.18kPa.m2/g, and 8.46mN.m2/g, respectively. All the strengths were higher than NEWSPRINT paper strength produced at Mazandaran wood and paper and Korean companies.

The objective of this research was using Bamboo and Reed CMP pulp for NEWSPRINT production. For this purpose, some bamboo stem chips were randomly selected from west of Mazandaran. Then CMP pulps were prepared at the yield 85% applying 120 minute pulping time for Bamboo and 31 minutes for Reed, using cooking conditions of Mazandaran Wood and Paper Industries. The 60 gr/m2 handsheets were prepared using bamboo and reed CMP pulps and mill (MWPI) CMP pulp as control and also with mixtures of 25, 50, 75% mill pulp combined with either bamboo or reed CMP pulp. Then the optical and mechanical properties of the handsheets were measured as defined in TAPPI Standard test methods. The results showed that the handsheets obtained from 100% the bamboo CMP pulp showed the highest burst, breaking length, tensile, tear strength, yellowness and opacity and the lowest strength (except brightness) was related to reed CMP pulp. The results also revealed that the above mentioned strength (except brightness) can be improved using any combination of bamboo CMP pulp with mill pulp. However, if it is intended to use reed CMP, then 25% of the reed CMP pulp can be used for NEWSPRINT production.

In this study, the reinforcing effect of recycled NEWSPRINT paper (RNP) in cement boards has been investigated. The experiment was designed to apply two variable factors, RNP and calcium chloride (CaCl2). Cement-fiber boards with the density of 0. 7 kg/m3 were manufactured using fiber/cement ratios of 10: 90, 15: 85, 20: 80 and 25: 75 (w/w) and 3% and 5% CaCl2 as accelerator. Minimum four boards (replications) were fabricated for each combination of variables, and the mechanical and physical properties of the boards were evaluated. The statistical analysis showed that the effect of the RNP and CaCl2 contents on modulus of rupture of cement fiber boards were significant at 1% significant level. The results showed that addition of CaCl2 enhanced the mechanical properties of the boards. All properties of the boards were improved as the CaCl2 content was increased from 3% to 5%. The modulus of rupture and modulus of elasticity of the boards decreased with addition of RNP, and the maximum values were obtained at RNP loading of 10%. The results also showed that as the fiber content was increased, significant increase in water absorption and thickness swelling occurred. Increasing RNP fiber content from 10% to 25% reduced both the mechanical and physical properties considerably. The optimum condition was obtained when the RNP and CaCl2 contents were 10% and 5%, respectively.

Stress relaxation behavior of milled NEWSPRINT/HDPE composite containing coupling agent was studied. Composites containing 25 and 50% filler in weight were produced, and were compared to neat polymer. Melt blending followed by injection molding was the manufacturing process. Results showed that incorporating filler to polymer increases the flexural strength and modulus. It was observed that higher stress is needed to maintain higher strain levels. Furthermore, comparing the stress ratio patterns revealed that the difference among relaxation of different samples develops over time. Power law computed parameters showed that higher strain level results in higher stress relaxation amplitude (A) and lower time exponent (t). It was also found that, almost complete linear relationship could be established between strain level and parameter A, and the effect of strain level on parameter A is more pronounced at higher filler contents.

The application of chelating agents to increase the efficiency of hydrogen peroxide is important in various related processes. Synthetic chemicals such as ethylenediaminetetraacetic acid (EDTA) are commonly used in these processes. The feasibility of using natural and environmentally friendly products instead of synthetic materials is an important and interesting subject. In this study, the performance of hydrogen peroxide in the deinking process was considered and the use of chitosan as a natural chelating agent in the deinking process of waste newspapers was investigated. The results showed that hydrogen peroxide bleaching along with the deinking process had a positive impact on the optical properties and reduced the burst and tear indices with no effect on the tensile and fold strengths. Chitosan, similar to the EDTA chelating agent, improved brightness, whiteness, dirt removal, and metal ion absorption in comparison with the treatment without a chelating agent. EDTA performs better than chitosan in removing ink from the pulp. Furthermore, in comparison to the treatment without a chelating agent, both chelating agents improved tear and burst indices, but had no effect on the fold and tensile strengths. The current research can be a small but promising step in using natural materials, such as chitosan biopolymers, instead of synthetic chelating agents, such as EDTA.