scholarly journals Analysis of the Statistical Comparability of the Hardness and Wear of Polymeric Materials for Orthodontic Applications

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2925
Author(s):  
Ivo Domagała ◽  
Krzysztof Przystupa ◽  
Marcel Firlej ◽  
Daniel Pieniak ◽  
Leszek Gil ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Sliding Wear ◽  
Polymeric Materials ◽  
Polymer Materials ◽  
Orthodontic Appliances ◽  
Indentation Hardness ◽  
Shore Hardness ◽  
Scratch Hardness ◽  
Scientific Goal ◽  
Materials Used

Background: Clinical success depends on the contact strength and wear resistance of medical devices made of polymer materials. The scientific goal resulted from the problem of using different methods of surface evaluation of materials used in the production of orthodontic appliances. The purpose of the work was an experimental comparative assessment of indentation hardness and scratch hardness and the sliding wear of four selected polymeric materials used in the manufacture of orthodontic appliances. Methods: Four commercial materials were compared. Shore hardness tests and a scratch test with a Rockwell indenter were performed. A sliding wear test was performed using the ball-on-disc method. Statistical PCA and correlation analyses were performed. Results: The results of scratch hardness measurements using a contact profilometer correlated with the Shore hardness to a greater extent than measurements made using an optical microscope. PCA showed that Shore hardness explains 45% of the total variance in all the results across the materials. Conclusions: The scratch hardness method allows for a more explicit ranking of orthodontic polymeric materials when measurements are made with a profilometer. The ranking of sliding wear resistance should be made separately.

scholarly journals Bending Behaviour of Polymeric Materials Used on Biomechanics Orthodontic Appliances

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5579
Author(s):  
Ivo Domagała ◽  
Krzysztof Przystupa ◽  
Marcel Firlej ◽  
Daniel Pieniak ◽  
Agata Niewczas ◽  
...  
Keyword(s):  
Creep Resistance ◽  
Bending Strength ◽  
Clinical Success ◽  
Artificial Saliva ◽  
Polymeric Materials ◽  
Polymer Materials ◽  
Orthodontic Appliances ◽  
Creep Tests ◽  
Three Point Bending ◽  
Materials Used

This paper discusses the issues of strength and creep of polymeric materials used in orthodontic appliances. Orthodontic biomechanics is focused on the movement of individual teeth or dental groups as a result of the force applied by orthodontic appliances. Stresses in the construction of functional and biomechanical appliances is generated when using the apparatus in the oral cavity. The orthodontic appliance must maintain its shape and not be damaged during treatment so strength and creep resistance are fundamental properties. It was assumed that the clinical success of orthodontic appliances can be determined by these performance properties. The aim of the work was the experimental assessment of comparative bending strength and creep resistance of selected popular polymer materials used in the production of biomechanical orthodontic appliances. Four commercial materials manufactured by the world class producers were tested: NextDent Ortho Rigid (Vertex-Dental B.V., Soesterberg, The Netherlands) marked as “1A”; Erkocryl (ERKODENT Erich Kopp GmbH, Pfalzgrafenweiler, Germany)-“2A”; Vertex Orthoplast (Vertex Dental B.V.), blue, marked as “3A” and material with the same name as “3A” but orange, marked in the article as “4A”. All the tests were carried out after aging in artificial saliva for 48 h at a temperature of 37 °C. Flexular strength and flexular modulus were made using the three point bending method according to the ISO 178 technical standard. Creep tests were carried out according to the method contained in ISO 899-2. The creep test was carried out in an artificial saliva bath at 37 °C. The creep tests showed significant differences in the strength, modulus and deformability of the tested materials. The strength reliability of the tested materials also varied. The research shows that the 2A material can be used for orthodontic applications in which long-term stresses should be lower than 20 MPa.

scholarly journals Evaluation of Tribological Properties of Polymer Materials Used for Sliding Bearings in Agricultural Machinery

2017 ◽  
Vol 21 (1) ◽  
pp. 95-103 ◽  
Author(s):  
Mariusz Walczak ◽  
Jacek Caban ◽  
Andrzej Marczuk
Keyword(s):  
Tribological Properties ◽  
Technological Development ◽  
Polymeric Materials ◽  
Polymer Materials ◽  
Agricultural Machinery ◽  
Sliding Bearings ◽  
Economic Criterion ◽  
Agricultural Engineering ◽  
Polymer Metal ◽  
Materials Used

Abstract The continuous technological development requires the use of modern materials also in agricultural engineering. Knowledge of the characteristics of tribological materials pairs cooperating with each other is useful for developing sliding nodes of agricultural machinery. Tribological properties of materials should be assessed for selection of technological materials beyond the economic criterion. The article presents analysis of the characteristics of tribological ball-on-disc wear of polymeric materials used as sliding elements for farm machines. Tribological tests were carried out under dry friction for a polymer-metal pair, and a wear rate and friction coefficient of the sample; the signs of wear were submitted to SEM observations.

Effect of biodegradable oil use on the mechanical properties of plastics used in the railway surface (Odziaływanie biodegradowalnego oleju na właściwości mechaniczne tworzyw sztucznych stosowanych w nawierzchni kolejowej)

2020 ◽  
Vol 128 ◽  
pp. 81-88 ◽  
Author(s):  
Paweł Kowalik ◽  
Mariusz Fabijański
Keyword(s):  
Mechanical Properties ◽  
Polymeric Materials ◽  
Polymer Materials ◽  
Strength Parameters ◽  
Properties Of Materials ◽  
Materials Used ◽  
Plastic Components ◽  
Biodegradable Lubricant ◽  
The Impact ◽  
Railway Turnout

The purpose of this study is to present the requirements, methodology, and results of research on the impact of biodegradable oil on plastic components used in the construction of a railway turnout. Briefly discussed are what railroad turnouts are, how they work, and what problems occur with substances used for their lubrication. They have an impact on the mechanical properties and durability of products made of polymeric materials. These types of materials absorb various kinds of chemicals, to a greater or lesser degree, and this affects their properties. For the tests, we used a universal lubrication oil with biodegradable properties, which is its most significant advantage. However, it may not cause deterioration of the turnout operation and change the properties of materials used for its construction. These types of oils require more frequent applications on cooperating components. We used the two most popular polymer materials. The first is high-density polyethylene (HDPE), used to make all kinds of rail spacers, dowels for fixing rails, sleeves, etc. The second, polyurethane (PUR) is most commonly used for rail pads of various shapes. The methodology and results of testing the impact of a lubricant (biodegradable oil) on the change of mechanical properties such as strength and hardness are presented. The tests were carried out at various temperatures; the time of exposure to oil was seven days; the results were referred to samples conditioned under standard conditions. The tests carried out on the impact of the biodegradable lubricant on polymeric materials (HDPE and PUR) showed little effect on the change of strength parameters of these materials. Celem niniejszego opracowania jest przedstawienie wymagań, metodyki oraz wyników badań oddziałania biodegradowalnego oleju na elementy z tworzyw sztucznych stosownych w budo-wie rozjazdu kolejowego. Krótko omówiono czym są rozjazdy kolejowe i jak działają oraz jakie występują problemy z substancjami używanymi do ich smarowania, które nie pozostają bez wpływu na właściwości mechaniczne i trwałość wyrobów z materiałów polimerowych. Materiały tego typu wchłaniają różnego rodzaju substancje chemiczne w większym lub mniejszym stopniu, a to ma wpływ na ich właściwości. Do badań został wykorzystany uniwersalny olej do smarowania o biodegradowalnych właściwościach, co jest jego największą zaletą. Jednak nie może on powodować pogorszenia pracy rozjazdu oraz zmieniać właściwości materiałów użytych do jego budowy. Tego typu oleje wymagają częstszego aplikowania na elementy współpracujące ze sobą. W pracy wykorzystano dwa najbardziej popularne materiały polimerowe. Pierw-szy to polietylen o dużej gęstości (HDPE), z którego wykonuje się wszelkiego rodzaju przekładki podszynowe, dyble do mocowania szyn, tuleje, itp. Drugi to poliuretan (PUR) stosowany najczęściej na przekładki podszynowe o różnym kształcie. Zaprezentowano metodykę i wyniki ba-dań oddziaływania środka smarnego (biodegradowalnego oleju) na zmianę właściwości mechanicznych takich jak wytrzymałość oraz twardość. Badania zostały przeprowadzone w różnych temperaturach, a czas ekspozycji na olej wynosił 7 dób, wyniki odniesiono do próbek klimatyzowanych w standardowych warunkach. Przeprowadzone badania oddziaływania biodegradowalnego środka smarnego na tworzywa polimerowe (HDPE i PUR), wykazały niewielki wpływ na zmianę parametrów wytrzymałościowych tych materiałów.

scholarly journals Tribological characteristics of polymer materials used for slide bearings

2021 ◽  
Vol 11 (1) ◽  
pp. 624-629
Author(s):  
Mariusz Walczak ◽  
Jacek Caban
Keyword(s):  
Automotive Industry ◽  
Construction Materials ◽  
Polymeric Materials ◽  
Point Of View ◽  
Polymer Materials ◽  
Sliding Bearings ◽  
Metal Pair ◽  
Polymer Metal ◽  
Materials Used ◽  
Ball On Disc

Abstract The automotive industry uses a variety of technologies and construction materials in production process. Knowledge of the characteristics of tribological material pairs cooperating with each other is useful for their selection from the safety point of view sliding pairs, in means of transport, and other machines. The aim of the contribution is the analysis of the characteristics of tribological ball-on-disc wear of polymeric materials used as sliding bearings. Tribological tests were carried out under dry friction for a polymer–metal pair of three types of materials. Among all three groups of the tested materials statistically significant differences (p < 0.05 in Student’s t-test) in wear were observed. The wear rate and friction coefficient of the sample were tested, and the signs of wear were submitted to SEM observations.

scholarly journals Electroplated Nickel Composites with Micron- to Nano-Sized Particles

2008 ◽  
Vol 384 ◽  
pp. 283-309 ◽  
Author(s):  
Bernhard Wielage ◽  
Thomas Lampke ◽  
Manuela Zacher ◽  
Dagmar Dietrich
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Sliding Wear ◽  
Wear Testing ◽  
Indentation Hardness ◽  
Dispersion Hardening ◽  
Sound Waves ◽  
Organic Additives ◽  
Promising Alternative ◽  
Cavitation Wear

Electroplated nickel coatings provide ductility, excellent corrosion resistance and good wear resistance, which qualifies them to meet complex demands of engineering, microtechnology and microelectronics. The co-deposition of particles is a promising alternative to deposit layers with adequate microstructure and properties avoiding the rise of residual stress. The incorporation of the sufficient quantity of particles, monodisperse distribution and downsizing to nanometre scale affect the amount of strengthening by dispersion hardening. To avoid agglomeration in the electroplating bath as well as in the layer is a challenge which has been met by simple Watts nickel electrolyte with a minimum of organic additives and adequate bath agitation comprising sonication, i.e. the exposure of the bath to high-frequency sound waves. Well-dispersed hard particles (titanium oxide and silicon carbide) were incorporated in nickel films. The focus was set on the correlation between the gained microstructure of the composites with particles from micron to nanometre scale and the electrochemical and mechanical properties. Corrosion was quantified from polarisation curves and volumetric erosion measurements. Wear resistance was evaluated by scratch energy density studies, oscillating sliding wear testing and cavitation wear testing and compared to indentation hardness results. Sonication and particle downsizing result in matrix grain refinement and dispersion hardening. Incorporation of different particles with respect to different material and size proved to meet different demands. Submicron TiO2 is best for high corrosion resistance, sonicated nickel without particle incorporation is best for high abrasion resistance, nano TiO2 is best for oscillating sliding wear resistance and submicron SiC is best for cavitation wear resistance.

scholarly journals Effect of Artificial Aging on Mechanical and Tribological Properties of CAD/CAM Composite Materials Used in Dentistry

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4678
Author(s):  
Marcel Firlej ◽  
Daniel Pieniak ◽  
Agata M. Niewczas ◽  
Agata Walczak ◽  
Ivo Domagała ◽  
...  
Keyword(s):  
Wear Resistance ◽  
3D Printing ◽  
Artificial Saliva ◽  
Hertzian Contact ◽  
Indentation Hardness ◽  
Uv Curable ◽  
Average Hardness ◽  
Thermal Chamber ◽  
Cad Cam ◽  
Materials Used

With easy-to-process 3D printing materials and fast production, the quality of dental services can be improved. In the conventional procedure, the dentist makes temporary crowns directly in the patient’s mouth, e.g., from the most commonly used bis-acrylic composites. Temporary crowns made directly in the office without the use of CAD/CAM are often of inferior quality, which directly results in impaired hygiene, poorer masticatory mechanics, greater deposition of plaque, calculus and sediment, and may adversely affect periodontal and gum health. The mechanical strength, resistance to aging and abrasion of 3D printing materials are higher than those of the soft materials used in conventional methods. This translates into durability. The patient leaves the surgery with a restoration of higher utility quality compared to the conventional method. The objective of the paper was to determine the influence of aging in artificial saliva of AM (additive manufacturing) orthodontic composites on their functional properties. For the purpose of the study, fillings well-known worldwide were selected. These were traditional UV-curable resins (M I, M II, M III, M V) and a hybrid material based on a UV-curable resin (M VI). Samples were stored in artificial saliva at 37 ± 1 °C in a thermal chamber for 6 months. Indentation hardness, frictional tests and sliding wear measurements were conducted. A comparison between various materials was made. Descriptive statistics, degradation coefficients, H2E, Archard wear and specific wear rate were calculated. The Weibull statistical test for indentation hardness was performed and Hertzian contact stresses for the frictional association were calculated for unaged (M I, M II, M III, M V, M VI) and aged (M I AS, M II AS, M III AS, M V AS, M VI AS) samples. M I exhibited the lowest average hardness among the unaged materials, while M III AS had the lowest average hardness among the aged materials. Comparably low hardness was demonstrated by the M I AS material. The coefficient of friction values for the aged samples were found to be higher. The lowest wear value was demonstrated by the M I material. The wear resistance of most of the tested materials deteriorated after aging. The M VI AS material had the highest increase in wear. According to the results provided, not only the chemical composition and structure, but also aging have a great impact on the indentation hardness and wear resistance of the tested orthodontic materials.

Design of Polymeric Materials for Triboelectric Nanogenerators (TENGs)

2021 ◽  
Vol 30 (1/2) ◽  
pp. 12-19
Author(s):  
Woongbi CHO ◽  
Jeong Jae WIE
Keyword(s):  
Energy Harvesting ◽  
Mechanical Energy ◽  
Polymeric Materials ◽  
Electrical Energy ◽  
Dielectric Constants ◽  
Polymer Materials ◽  
Harvesting Systems ◽  
Triboelectric Nanogenerators ◽  
Materials Used ◽  
The Relationship

Triboelectric nanogenerators (TENGs) are eco-friendly energy-harvesting systems that produce electrical energy from disordered mechanical energy. To enhance the triboelectric performances of TENGs, many researchers have conducted in-depth studies of the polymer materials utilized in TENGs, so numerous studies have been reported on the relationship between their material properties and their energy-harvesting capabilities. Triboelectric performance depends on the electrical properties of the materials used, such as their electron affinities and dielectric constants. Representative examples of positive and negative tribomaterials include PA6, PEO, PVDF, and fluorinated sulfur copolymers, respectively. This article introduces the relationship among the compositions, structures, triboelectric performances of the polymer materials, and composites used in TENGs and summarizes the representative polymer materials applied in the latest TENGs.

Structure-property relationships of PE/PP sandwiched films

1987 ◽  
Vol 45 ◽  
pp. 454-455
Author(s):  
J. Petermann ◽  
G. Broza ◽  
U. Rieck ◽  
A. Jaballah ◽  
A. Kawaguchi
Keyword(s):  
Mechanical Tests ◽  
Polymer Materials ◽  
Ionic Crystals ◽  
Structure Property ◽  
Polymer Systems ◽  
Structure Property Relationships ◽  
Oriented Films ◽  
Materials Used ◽  
Polymer Laminates ◽  
Heated Glass

Oriented overgrowth of polymer materials onto ionic crystals is well known and recently it was demonstrated that this epitaxial crystallisation can also occur in polymer/polymer systems, under certain conditions. The morphologies and the resulting physical properties of such systems will be presented, especially the influence of epitaxial interfaces on the adhesion of polymer laminates and the mechanical properties of epitaxially crystallized sandwiched layers.Materials used were polyethylene, PE, Lupolen 6021 DX (HDPE) and 1810 D (LDPE) from BASF AG; polypropylene, PP, (PPN) provided by Höchst AG and polybutene-1, PB-1, Vestolen BT from Chemische Werke Hüls. Thin oriented films were prepared according to the method of Petermann and Gohil, by winding up two different polymer films from two separately heated glass-plates simultaneously with the help of a motor driven cylinder. One double layer was used for TEM investigations, while about 1000 sandwiched layers were taken for mechanical tests.

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