Noraldin Nazarnezhad; mahin avrand; Hosin Resalati
Abstract
One of the problems of papers and cardboards in the packaging industry is the poor resistance to water, gas, and oil penetration. Nowadays, much research have been done on the use of biodegradable films and coatings based on polysaccharides to solve this problem. Chitosan is one of these polysaccharides ...
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One of the problems of papers and cardboards in the packaging industry is the poor resistance to water, gas, and oil penetration. Nowadays, much research have been done on the use of biodegradable films and coatings based on polysaccharides to solve this problem. Chitosan is one of these polysaccharides that can be used as a biodegradable coating in packaging papers. In this study, the effect of chitosan on the strength and barrier properties of coated liner paper was investigated. Chitosan was used in three levels 10, 15, and 20 g/L acetic acids (1%) and with two softener ratios (glycerol) of 0.5 and 1 (based on dry weight of chitosan) for papers coating. Strength properties including tensile, burst and tear index and barrier properties including water absorption, air resistance, and oil absorption in the coated samples were investigated. The Statistical analysis of results showed that the barrier properties increased significantly. Also, the effect of increasing the concentration of softener in the coating solution on the properties of air resistance and oil absorption was positive but negative for water absorption. The basis weight, burst and tear index of the coated samples increased with increasing coating weight, on the other hand the tensile strength decreased. Moreover, increasing the concentration of softener in the coating solution showed a negative effect on the properties of the samples. The results of the scanning electron microscope images showed that formation of chitosan film and the increase in the uniformity of the liner paper surfaces, especially in higher consumption amounts.
Pulp and paper
Jafar Ebrahimpoor kasmani; Amir mohssen Nazeri; Ali Ashryeh
Abstract
In this investigation , effects of different humidity and heat on quality of Corrugated board , was studied , and optimum treatment indicated Variables in this Paper was : Corrugator speed (50,100,150m/min) ,wraping angle of the paper around preheaters ...
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In this investigation , effects of different humidity and heat on quality of Corrugated board , was studied , and optimum treatment indicated Variables in this Paper was : Corrugator speed (50,100,150m/min) ,wraping angle of the paper around preheaters (90,180,300 degree) and moisture of paper (6.5%,7%,8.5%). Papers that treated for this purpose was included : 125gsm kraft liner ,127 gsm medium paper and 140gsm test liner paper. A flut type of 3ply Corugated board was selected for this study.Moisture of paper was measured in 3 places : Paper on roll stand before single facer , paper after singlefacer preheater and paper before incoming doublefacer in hot plate unit. Also temprature was measured in corrugator rolls ,hot Plates in double facer and final Board after Exiting of the Machine.
Results show that , warp of final board decreased in speed 50 and 100m/min ,moisture 7% and 1800 wraping angle of the paper around preheater.
That means lower speeds and higher wraping angles cause to more heat on corrugated board and decreasing in warp content resulted.It should be noted that lower humidity more than 7% and increase wraping angle more than 180 degree cause to over drying and intensive moisture decrease in final board that cause to reverse warp in final board.
Ramin Veysi
Abstract
In this research, chips of kiwi residues from western Mazandaran (Tonkabon region) were randomly chosen and its kraft pulp was prepared with yield of 53% for 105 minutes. The kraft liner handsheets were prepared from both kiwi and Chooka Mill kraft pulps (control sample), first in a separate and second, ...
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In this research, chips of kiwi residues from western Mazandaran (Tonkabon region) were randomly chosen and its kraft pulp was prepared with yield of 53% for 105 minutes. The kraft liner handsheets were prepared from both kiwi and Chooka Mill kraft pulps (control sample), first in a separate and second, in mixed way. Then, their optical and mechanical properties were compared according to TAPPI standard test methods. Results showed that the highest tear strength and cobb 60 and the lowest breaking length, burst and CMT values were in the handsheets obtained from pure kiwi kraft pulp. The handsheets’ properties increased in the samples prepared from mixed pulps. In general, the highest values of breaking length, burst strength, tear strength, cobb 60, brightness and RCT were observed in the handsheets prepared from mixed 10-30% kiwi kraft pulp and mill kraft pulp. The results also pointed out that the above mentioned strengths could be improved by adding 10-30% of kiwi kraft pulp to 30-70% mill kraft pulp replaces part of mill kraft pulp, but it is not possible for pure kiwi kraft pulp.
