Clendinning, and Watson B.
The tensile test itself is used to find out and evaluate the strength of material that being tested. By definition, Tensile testing is the measurement of the ability of a material to overcome forces pulling the sample apart and the extent it stretches before breaking .
Before running the test, we must formed specimens in such a way as to form a dumbbell specimen of a certain size, in this experiment we refer to ASTM D plastics and ASTM D rubber.
After that, the specimen is placed in the testing machine and force applied figure 2. Load and elongation within the sample will be controlled via a monitor, and it will stop when the specimen was fractured. Then, all the mechanical data will be compiled in one diagram called stress-strain diagram.
From this diagram figure 2. In solid polymers, there are three types of stress-strain curves figure 2. For crystalline polymer, most of them show viscoelastic properties.
Normally, stress-strain curves start with straight line when the strain increasing, and the stress at which slip becomes noticeable and significant . This point is called yield point. After yield point, stress will constant with increasing strain, this situation is called cold drawing.
At this phase, the sample does not become gradually thinner but suddenly becomes thinner at one point.
At the same moment, the specimen starts to has a whitening effect, which means the chemical structure of the specimen were pulled and their secondary bond starts to break, in this process also known as necking figure 2.
While the stretching is continued, the strain hardening will occur the expenses of undrawn polymer become totally necking.
|XPS FOAM (extruded polystyrene)||Shigeki Morita, Toshiro Kobayashi Abstract: Instrumented Charpy impact test method is possible to obtain various dynamic fracture characteristics from the load-deflection or load-time curve.|
|Search form||Michihiro Takiguchi, Fusahito Yoshida Abstract:|
|Tensile Property Testing of Plastics||Tensile Property Testing of Plastics Ultimate Tensile Strength The ability to resist breaking under tensile stress is one of the most important and widely measured properties of materials used in structural applications. The force per unit area MPa or psi required to break a material in such a manner is the ultimate tensile strength or tensile strength at break.|
|Typical Strength Characteristics - EPS Thermal Insulation Board||This graph shows the thin specimen of polyethylene.|
|Features & Benefits||It is categorized as a standard material, and offers high impact strength, high chemical resistance, and very low water absorption. HDPE offers strength and rigidity for a wide variety of applications requiring basic engineering plastic performance.|
As the result the polymer specimen will rapture. It is expressed in force per unit area. It indicates the relationship between stress and strain in the deformation of a solid body. It describes the stress to break the sample. It also mentions the maximum tensile stress supported by specimen during test.
It is expressed in units of length, commonly as percentage. This area has the units of energy per unit volume and is the work expended in deforming the materials.
Sample during tensile test Figure 2. Instron Machine Figure 3. Vernier Calliper Figure 3. The upper jaw proceeds to move upwards at the rate set.
When failure occurred, the results and stress-strain graph is automatically recorded Return button of the instron machine to allow upper jaw was pressed to allow upper jaw return to its original position For the next plastic samples, steps were repeated For each sample steps were repeated at different cross head speed e.
From those curves we obtained that different specimens give different figure of curves.
Meaning that each curves give a characteristic of each specimen in term of their mechanical properties. It can be seen on table 3. On the other hand, chart 5.Tensile property tests for plastics are illustrated and give average values of ultimate tensile strength, elongation, and tensile modulus for common polymers such as nylon, polyethylene, polypropylene, and acrylic are reported.
tensile and impact properties of composites were determined by the tensile and impact tests. The maximum impact strength is (Kj/m 2) at the weight fraction of (60 % wt) of fibers, comparison with (8 Kj/m 2) for virgin polystyrene material,and the maximum tensile.
Influence of Polymer Blending on Mechanical and Thermal Properties Buthaina A. Ibrahim & Karrer leslutinsduphoenix.com The tensile test and Differential Scanning Calorimetry (DSC) are used to study mechanical and thermal Wycisk R,leslutinsduphoenix.com prepared polymer blend from polyethylene and polystyrene, there are three samples of.
polyethylene (PALF/LDPE) composites. They studied the effects of fibre orientation, High Impact Polystyrene (HIPS) is a type of polystyrene in which polybuta-diene is added during polymerization.
Polystyrene is used in high-quality goods, and its dumbbell cutter for tensile test . Tensile strength is a measure of the amount of force required to break a 1/2 square inch area of foam as it is pulled apart.
Tensile strength is expressed in pounds per square inch (psi). The tensile sample is die cut to a dumbbell shaped, 6” x l” x ” thick. This test method is designed to produce tensile property data for the control and specification of plastic materials.
These data are also useful for qualitative characterization and for .