Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Compression strength


Improved Wear Rate Resistance, Compression Strength and Hardness of Polymethylmethacrylate Resin with Orange Peel Powder for Artificial Denture Base

Reem A. Mohammed

Engineering and Technology Journal, 2020, Volume 38, Issue 3A, Pages 308-318
DOI: 10.30684/etj.v38i3A.341

The material utilized for manufacturing artificial dentures should have high-grade mechanical properties in order to resist heavy forces inside the mouth. This study includes investigation of some of the mechanical properties (wear rate resistance, compression strength, and hardness) of the specimens prepared by (hand lay-up) method. The wear behavior experiments were performed on (a pin-on-disk tester) under various factors 5%, 8%, 11%, 14%, 17% weight fraction of orange peel, (10, 15, 20 N) load applied and (5, 10, 15 minutes) sliding time, and analysis these experimentally by using the Taguchi’s experimental design (L9) (MINITAB 16). Tests explicated that the specimens (polymethylmethacrylate - 17% orange peel) composites have the best wear rate resistance, compression strength and hardness shore D (0.040×10-5 cm3/N.mm, 142 MPa, 86 shore D) respectively than other specimens (polymethylmethacrylate - 5%, 8%, 11%, 14% wt. orange peel) and these specimens better than the specimens standard polymethylmethacrylate, which could be attributed to the homogeneous dispersion of orange peel particles in the polymethylmethacrylate resin matrix. The results (signal to noise ratio) showed the factors (17% weight fraction) orange peels, (20 N) load applied, and (5 min) sliding time gives the best wear rate resistance. The results of the analysis of variance showed the sliding time (C) is the essential factor effect on the wear rate resistance followed by (A) weight fraction of orange peels and (B) load applied were less affected on wear behavior rate.

Study Compression, Hardness and Density properties of PMMA Reinforced by Natural Powder Used in Denture Base applications

Jawad Oleiwi; Q. A. Hamad; N. N. Kadhim

Engineering and Technology Journal, 2019, Volume 37, Issue 12A, Pages 522-527
DOI: 10.30684/etj.37.12A.5

 This research had been done to investigate the effect of adding natural powder of Pistachio Shell to PMMA, which popularly used in denture applications. The powder added in different weights fraction (3%, 6%, 9%, and 12%), and different average particle size (53µm, 106 µm, 150 µm, and 212µm %), and studying Compression Strength, Surface Hardness, and Density properties. Hand Lay-Up represented the method used to prepare the specimens in this research. The results were statistically analyzed by SPSS (one-way ANOVA) to determine the mean value and showed a significant difference for each particle size. The highest value of compression strength and surface hardness of PMMA composite specimens happened at (9%wt.) of the filler particles. Also the results represented that the density values for the composite specimens are increased with increasing the weight fraction of the filler particles.

Studying Some Of Mechanical properties Of (sawdust/Un Saturated Polyester) Composite in salt solution

Sanaa A. A. Hafad

Engineering and Technology Journal, 2010, Volume 28, Issue 16, Pages 5238-5245

Commercial sawdust is the most common wood filler used for polyster
thermosetting and is produced from graduated particles of different sizes which has in general has a lower aspect ratio than wood and other natural fibers. Wood additives include a mixture of sawdust and short chopped fibers. To study how characteristics of fibers and sawdust influence the mechanical properties of unsaturated polyester composites .Investigations were made by studying the effects of different volumetric fractions from sawdust and fiber fillers (up to limit
of 1.4mm), then these results were compared with the properties of sawdust –fiber filled composites immersed for different periods in a salt solution of (2 N) . wood volume fractions {(20, 30, 50) vf %} selected to be added for un saturated polyester were studied which gave improvement in their selected studied mechanical properties for all reinforced composites -(only impact is decreased)- and particularly at higher values of volume fractions ,were hardness showed an improvement by (15% ) , compressive strength gave obvious Improvement by
(38% ) ,while impact resistance decreased by (16%) with the reinforcement of (50 vf %) sawdust . The above values were reduced when the items were immersed in asalt solution for (60days).