عنوان مقاله [English]
نویسندگان [English]چکیده [English]
In this study the effects of separate and combined refining of Hornbeam (Carpinus betulus) CMP and imported long fiber (LF) pulps on the prepared handsheets properties is evaluated in two states. In the first state, Hornbeam CMP and long fiber pulps were separately PFI-milled to reach to 250-400 ml, CSF (261, 309, 362 and 410) and 400-600 ml, CSF (410, 474, 530 and 590), respectively. Then, they were mixed at the ratio of 80/20 and laboratory handsheets were made and their physical, mechanical and optical properties were determined. In the second state, the average freeness value for each mixture of the pulps from the first state (261 Hornbeam + 410 LF, 309 Hornbeam + 474 LF, 362 Hornbeam + 530 LF, 410 Hornbeam + 590 LF) was calculated and the real freeness value for each mixture was reached to the calculated one using combined PFI-milling. Handsheets were then made from each mixture of the pulps and their physical, mechanical and optical properties were determined. The comparison of the results showed no significant difference at 1% experimental error level between properties of the papers prepared from both states. However, higher PFI revolutions improved the properties of papers. On the other hand, it was observed that combined refining of the pulps led to saving in refining energy use and, thus, is recommended.