scholarly journals Physical and Mechanical Properties of Hydroxypropyl Methylcellulose–Coated Paper as Affected by Coating Weight and Coating Composition

BioResources ◽  
2013 ◽  
Vol 8 (3) ◽  
Author(s):  
Khaoula Khwaldia
Author(s):  
Zainab Abdulmohsin Hadi Radhi ◽  
Mowafaq Mohammed Ghareeb

Abstract The aim of this study was to prepare rebamipide ocular inserts in order to extend its release on the ocular surface for dry eye treatment. Solubility study was applied to the drug with or without l-arginine using different solvents. Solvent casting technique was used to prepare the inserts; l-arginine was used to solubilize the drug, hydroxypropyl methylcellulose grades (E5 and K15M) and poly ethylene glycol 200 were used as excipients. The inserts were evaluated for their physical and mechanical properties, moisture loss% and absorption %, surface pH, and in-vitro drug release. The use l-arginine exhibited an enhancement of rebamipide solubility in both deionized water and phosphate buffer (pH 7.4) by approximately 250 times and 3 times, respectively. The formulations showed uniform weight and thickness except for F1, and all showed uniform drug content. The absence of plasticizer in F1 caused haziness in its appearance and brittleness of the inserts. F3 which contain hydroxypropyl methylcellulose K15M showed good physical and mechanical properties thus was selected for in vitro release and was compared to the marketed brand Mucosta® suspension eye drop; F3 showed significant enhancement in extending the release of rebamipide compared to the reference marketed brand. Keywords: Rebamipide, L-arginine, Ocular insert, Solvent casting technique     ???????                         ????? ?? ??? ??????? ?? ????? ?????????? ?????? ???? ???? ????? ??????????? ??? ??? ????? ????? ????? ?????. ??? ?????  ??????? ?????? ????? ???????? ? ???? ????? ???????? ?????? ??????. ??????? ????? ??????? ? ???? ?????? ??????? ? ?????? ???????? ?????? ?????? ? ?? ??????? ??????????? ?????? ???? ???????? ?????? (K15M  ? E5 ) ? ?????? ?????? ??????? ?????. ?? ????? ?????? ?????????? ? ?????????? ??????? ? ???? ?????? ??????? ??????? ????? ? ?????? ??????? ? ???? ???? ??????????? ???? ??????? ????? ?????  ????? ??????  ?? ???????. ????? ??????? ?? ???????? ???? ??? ????? ??????? ???????????? ?? ?? ?? ????? ??????? ???????? ? ????? ???????? ?????? (?? ??????????? 7.4 ), ?????? ????? 250 ??? ? ???? ???? ??? ???????. ???????? ????? ??? ? ????? ??????? ???? ??? (F1 ) ? ?? ???????????? ????? ????? ?????? ????????.  ??? ???? ???? ??(F1 ) ??? ??? ?????? ??????? ? ??????. ( F3) ???? ????? ??? ??????????? ?????? ???? ?????????? (M 15 K) ???? ???? ???????? ? ????????? ???? ? ??? ?? ??????? ?????? ??????? ?????? ?????? ?? ??????? ? ??????? ??????? ?????? ? ?? ????? ????? ????? ?????? ???? (????????) ? ?? ???? ?? ??????? F3 ???? ????? ???? ?? ????? ????? ???????????? ?????? ??????? ?????? ?????? ?????.                          ??????? ?????????: ??????????, ????????, ??????? ??????, ????? ??????? ? ????         


TAPPI Journal ◽  
2013 ◽  
Vol 12 (4) ◽  
pp. 19-27
Author(s):  
PATRICK HUBER ◽  
LAURENT LYANNAZ ◽  
BRUNO CARRÉ

The fraction of deinked pulp for coated paper production is continually increasing, with some mills using 100% deinked pulp for the base paper. The brightness of the coated paper made from deinked pulp may be reached through a combination of more or less extensive deinking, compensated by appropriate coating, to optimize costs overall. The authors proposed general optimization methods combined with Kubelka-Munk multilayer calculations to find the most economical combination of deinking and coating process that would produce a coated paper made from DIP, at a given target brightness, while maintaining mechanical properties.


TAPPI Journal ◽  
2019 ◽  
Vol 18 (2) ◽  
pp. 93-99
Author(s):  
SEYYED MOHAMMAD HASHEMI NAJAFI ◽  
DOUGLAS BOUSFIELD, ◽  
MEHDI TAJVIDI

Cracking at the fold of publication and packaging paper grades is a serious problem that can lead to rejection of product. Recent work has revealed some basic mechanisms and the influence of various parameters on the extent of crack area, but no studies are reported using coating layers with known mechanical properties, especially for double-coated systems. In this study, coating layers with different and known mechanical properties were used to characterize crack formation during folding. The coating formulations were applied on two different basis weight papers, and the coated papers were folded. The binder systems in these formulations were different combinations of a styrene-butadiene latex and mixtures of latex and starch for two different pigment volume concentrations (PVC). Both types of papers were coated with single and double layers. The folded area was scanned with a high-resolution scanner while the samples were kept at their folded angle. The scanned images were analyzed within a constant area. The crack areas were reported for different types of papers, binder system and PVC values. As PVC, starch content, and paper basis weight increased, the crack area increased. Double layer coated papers with high PVC and high starch content at the top layer had more cracks in comparison with a single layer coated paper, but when the PVC of the top layer was low, cracking area decreased. No measurable cracking was observed when the top layer was formulated with a 100% latex layer.


2012 ◽  
Vol 4 (1) ◽  
pp. 1
Author(s):  
Djoko Purwanto

Timber Acacia mangium (Acacia mangium, Willd) for Furniture. The study aims to determine the mechanical and physical properties and the decorative value (color and fiber) wood of acacia mangium with using finishing materials. This type of finishing material used is ultran lasur natural dof ,ultran lasur classic teak, aqua politur clear dof, aqua politur akasia dan aqua politur cherry. After finishing the wood is stored for 3 months. Test parameters were observed, namely, physical and mechanical properties of wood, adhesion of finishing materials, color and appearance of the fiber, and timber dimensions expansion. The results showed that the mechanical physical properties of acacia wood qualified SNI. 01-0608-89 about the physical and mechanical properties of wood for furniture, air dry the moisture content from 13.78 to 14.89%, flexural strength from 509.25 to 680.50 kg/cm2, and compressive strength parallel to fiber 342.1 - 412.9 kg/cm2. Finishing the treatment process using five types of finishing materials can increase the decorative value (color and fiber) wood. Before finishing the process of acacia mangium wood has the appearance of colors and fibers and less attractive (scale scores 2-3), after finishing acacia wood fibers have the appearance of colors and interesting and very interesting (scale 4-5).Keywords: mangium wood, mechanical properties, decorative value, finishing, furniture.


2016 ◽  
Vol 13 (2) ◽  
pp. 67
Author(s):  
Engku Liyana Zafirah Engku Mohd Suhaimi ◽  
Jamil Salleh ◽  
Suzaini Abd Ghani ◽  
Mohamad Faizul Yahya ◽  
Mohd Rozi Ahmad

An investigation on the properties of Tenun Pahang fabric performances using alternative yarns was conducted. The studies were made in order to evaluate whether the Tenun Pahang fabric could be produced economically and at the same time maintain the fabric quality. Traditional Tenun Pahang fabric uses silk for both warp and weft. For this project, two alternative yarns were used which were bamboo and modal, which were a little lower in cost compared to silk. These yarns were woven with two variations, one with the yarns as weft only while maintaining the silk warp and the other with both warp and weft using the alternative yarns. Four (4) physical testings and three (3) mechanical testings conducted on the fabric samples. The fabric samples were evaluated including weight, thickness, thread density, crease recovery angle, stiffness and drapability. The results show that modal/silk and bamboo silk fabrics are comparable in terms of stiffness and drapability, hence they have the potential to replace 100% silk Tenun Pahang.


2014 ◽  
Vol 62 (1) ◽  
pp. 129-137
Author(s):  
A. Sawicki ◽  
J. Mierczyński

Abstract A basic set of experiments for the determination of mechanical properties of sands is described. This includes the determination of basic physical and mechanical properties, as conventionally applied in soil mechanics, as well as some additional experiments, which provide further information on mechanical properties of granular soils. These additional experiments allow for determination of steady state and instability lines, stress-strain relations for isotropic loading and pure shearing, and simple cyclic shearing tests. Unconventional oedometric experiments are also presented. Necessary laboratory equipment is described, which includes a triaxial apparatus equipped with local strain gauges, an oedometer capable of measuring lateral stresses and a simple cyclic shearing apparatus. The above experiments provide additional information on soil’s properties, which is useful in studying the following phenomena: pre-failure deformations of sand including cyclic loading compaction, pore-pressure generation and liquefaction, both static and caused by cyclic loadings, the effect of sand initial anisotropy and various instabilities. An important feature of the experiments described is that they make it possible to determine the initial state of sand, defined as either contractive or dilative. Experimental results for the “Gdynia” model sand are shown.


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