Adam Skrobak

Effect of Particle Size of Recycled Polyamide 6 to Impact Toughness and Hardness

This work aims to investigate the effect of recycled material and effect of particle size on the mechanical properties of the recycled material. Tested material is polyamide 6. Every manufacture of any plastic parts produces certain amount of waste, such as defective injects or cold runner system from injection molding technology. When size of this material is reduced, particles of different sizes are made. From large particles similar to the original granulate material, to dust particles. This size variation can cause problems during subsequent processing. These particles of different size have distinct melting rate. To determine behavior of recycled material at room temperature. Impact toughness and hardness tests are performed.

Mechanical Properties of Rubber Samples

This article demonstrates what influence has a change in production technology on mechanical properties of rubber testing samples. It compares two basic production technologies compression molding and injection molding. The aim of this research is to show and evaluate to what extent the properties (tensile strength, extension, tear strength and microhardness) are influenced by the used production technology and to quantify this potential difference on the basis of standard tests. The mechanical tension test according the standard ISO 37, the test determining tear strength according to the standard ISO 34-1 and the instrumented microhardness test (DSI) according to the standard ISO 6507-1.

Mechanical Properties of Selected Types Thermoplastic Materials Modified by High Doses of Ionizing Beta Radiation under Thermal Stress

This study deals with the effect of high doses of ionizing beta radiation (132, 165 and 198 kGy) on mechanical properties (tensile strength, tensile modulus and elongation) of low and high density polyethylene under thermal loading. The measurement results of this study indicate that with an increasing dose of radiation grows tensile strength and modulus of low and high density polyethylene. For all examined materials were also observed changes in elongation.

EFFECT OF LENGTH OF GLASS FIBERS IN RECYCLED POLYPROPYLENE ON MECHANICAL PROPERTIES

This article investigates the effect of recycled material particle size on the resulting mechanical properties of products. The product material was polypropylene with glass fibers. Recycled material was prepared by mechanical way of recyclation, then it was categorized by sieve analysis to different size of particles. After preparation, the samples were subjugated to mechanical tests. The samples were subjected to the Charpy impact test, the hardness of Shore D test. Testing was conducted at ambient temperatures. The effect of reprocessing of the material is mainly represented by fiber shortening. As a result, considerable reduction of mechanical properties can be observed.

Effect of Beta Irradiation on Mechanical Properties of Surface Layer of Injection Moulded High Density Polyethylene (HDPE)

TBU in Zlin - resources of specific university research and Technology Agency of the Czech Republic [IGA/FT/2015/006, TA03010724 AV]; Ministry of Education of the Czech Republic [MSMT-7778/2014]; European Regional Development Fund under the Project CEBIA-Tech [CZ.1.05/2.1.00/03.0089.]

Effect of Recycled Particle Size to Micro-Hardness Properties of Styrene Acrylonitrile

The aim of this research paper is to study the effect of particle size of recycled material on the micro harness. Valuation of recycled material effect takes place in several mixtures of materials. These mixtures differ in particle size, which are made during grinding of plastic waste, from large particles similar to the original material to dust particles. The recycled material is always the same as is the original material. Tested material is styrene acrylonitrile SAN. Testing is performed at ambient temperature of 23°C. After the first recycling there is a change of hardness; which decrease mostly in mixture with the smallest particles.

The Effect of Ageing on the Micro-Creep Properties of Radiation Cross-Linked Materials

Radiation crosslinking of polymeric materials have placed and nowadays in the field of long-term use of loaded products. This article aims to identify the long-term effect of radiation crosslinking on micro-creep properties. The article compares the micro-creep properties of HDPE measured two years ago with the results of tests conducted under the same conditions and on the same samples now. The effect of time on the mechanical properties of the radiation crosslinked materials was demonstrated in short-term tests. These findings demonstrate the positive effect of time on the evaluated parameters.

The Effect of Technology on Micromechanical Properties of Rubber

The aim of this article is to demonstrate to what extent there is an impact on the micromechanical properties of a standardized testing sample made of rubber compound based on synthetic rubber EPDM and produced by injection molding in comparison with a sample produced by classic preparation (cutting off a compression molded plate). Measurement of the properties was carried out according to the instrumented test (DSI), in compliance with ISO 14577 on the measuring device micro-combi-tester.

The behaviour of recycled material with particles of various sizes of polyamide 6 to micro hardness

Every manufacture of any plastic parts produces some waste, such as defective injects or cold runner system from injection molding technology. This waste can be directly used several times. But when size of this material is reduced, particles of different sizes are made. From large particles similar to the original granulate material, to dust particles. This size variation can cause problems during subsequent processing. These particles of different size have distinct melting rate. That can cause an inhomogeneity of a melt and diverse structure of solidified polymer. This research paper studies the influence of the particle size of recycled polymeric material on the micro harness properties of semi-crystalline polyamide 6 at room temperature.

Use of Theory of Hypothesis at Evaluation of Creep Curves

This article focuses on the evaluation of tests with a small repeatability which are characterized by their financial or time demands. The beginning of the article assess the current state of the problem and different approaches to it, focusing on the evaluation of creep tests characterized especially by their very typical little repeatability. Then the article describes the method for testing the creep properties of the irradiated material at raised temperatures. Next, the results are graphically confronted with the subjective evaluation of the observer and using the Mann-Whitney test. This test is used to determine whether the measured data comes from the same basic set or originate with the chosen confidence level. The results show the significance of the use of this test which is calculated with a certain probability.