scholarly journals Artificial and Natural Aging of Polypropylene Used in Passenger Vehicle Bumpers

2021 ◽  
Vol 58 (2) ◽  
pp. 201-210
Author(s):  
Hongshen Zhang ◽  
Hongfei Zheng
Keyword(s):  
Accelerated Aging ◽  
Natural Aging ◽  
Short Term ◽  
Uv Aging ◽  
Accelerated Aging Test ◽  
Aging Test ◽  
Wide Range ◽  
Aging Properties ◽  
Materials Used ◽  
The Impact

Polypropylene (PP) has a wide range of applications in the automobile bumpers due to its many excellent properties. Mechanical properties of PP for automobile bumpers are investigated through an artificial accelerated aging test. The aging rules after different years of normal use and the artificial accelerated aging test are analyzed. The correlation between natural and artificially accelerated aging is also explored. It provides a reference for the study of the aging properties of polymers for automotive applications. Results show that the UV aging test can effectively simulate changes in tensile and bending strengths after natural aging and can be used to evaluate the weathering resistance of PP materials used in automotive bumpers. The tensile and bending strengths of these materials remain good during aging, and elongation is sensitive to aging. The short-term artificial accelerated aging test does not exert a significant influence on the impact strength of materials, and artificial accelerated aging does not completely reproduce the aging process of the material.

scholarly journals Pengembangan Metode Pengusangan Cepat Fisik Benih Pepaya (Carica papaya L.)

2019 ◽  
Vol 2 (3) ◽  
pp. 7
Author(s):  
Dyah Priandini ◽  
Muhamad Rahmad Suhartanto ◽  
Abdul Qadir
Keyword(s):  
Moisture Content ◽  
Aging Time ◽  
Seed Quality ◽  
Block Design ◽  
Accelerated Aging ◽  
Seed Moisture Content ◽  
Accelerated Aging Test ◽  
Aging Test ◽  
The Impact ◽  
Papaya Seed

Development of papaya fruit production is influenced by the availability of seed quality. High seed quality is maintained during seed storage. Estimation of vigor in relation to storability can be detected by accelerated aging test. This research aims to develop physicall accelerated aging test by, 1)determine the impact of physical accelerated aging on vigor and viability parameters on papaya seed variety Callina and Sukma, 2) determine the levels of seed moisture content and effective period of physicall accelerated aging to predict vigor of papaya seed. This research was conducted at the Laboratory of Seed Science and Technology and Green House Leuwikopo, Department of Agronomy and Horticulture, IPB in January-May 2016 using a randomized complete block design with three replications. Seeds aged by the aging equipment MPC IPB 77-1 MMM. The results showed that the aging time decreased germination value in papaya seed variety Callina and Sukma with equation y=-0.1389x3+3.3333x2–25.25x+81.5 and y=0.0171x3+0.2028x2-9.9956x+81.095. Effective imbibition is 96 hour with moisture content 63-70% in both varieties. The effective of aging time treatment at 0x4, 1x4, 2x4, 3x4, dan 4x4 minutes.Keywords:imbibition, moisture content, viability, vigor

Research on Hygrothermal Aging of Dynamic Injection Molded Polypropylene Products

2010 ◽  
Vol 447-448 ◽  
pp. 391-395
Author(s):  
Bin Liu ◽  
Sheng Jin Wu ◽  
Qing Hui Liu ◽  
Jin Ping Qu
Keyword(s):  
Injection Molding ◽  
Test Chamber ◽  
Accelerated Aging ◽  
Molding Machine ◽  
Hygrothermal Aging ◽  
Accelerated Aging Test ◽  
Aging Test ◽  
Aging Properties ◽  
Before And After ◽  
Injection Molded

The polypropylene products are injection molded by the dynamic injection molding machine. The performance characteristics of polypropylene products under steady and dynamic injection molding are gained by the DSC indicating methods. Accelerated aging test with hygrothermal test chamber (the aging temperature is 90°C, and the humidity is 95%) is conducted in the study. The regularity for impact strength property of polypropylene is studied during the test in contrast. The change of carbonyl content in the polypropylene products is analyzed both before and after aging by FTIR. The results show that the dynamic injection molding could significantly improve the anti-hygrothermal aging properties of the polypropylene products.

Accelerated aging test of hydrogenated nitrile butadiene rubber using the time–temperature–strain superposition principle

RSC Advances ◽  
2015 ◽  
Vol 5 (109) ◽  
pp. 90178-90183 ◽  
Author(s):  
Zhongmeng Zhu ◽  
Chengkai Jiang ◽  
Qian Cheng ◽  
Jianwei Zhang ◽  
Shaoyun Guo ◽  
...  
Keyword(s):  
Fracture Strain ◽  
Superposition Principle ◽  
Accelerated Aging ◽  
Butadiene Rubber ◽  
Test Results ◽  
Short Term ◽  
Accelerated Aging Test ◽  
Aging Test ◽  
Temperature Strain

The long-term (~550 days) degradation of fracture strain of HNBR under the reference condition of 60 °C @ zero strain can be predicted using the time–temperature–strain superposition principle with the short-term (<10 days) test results.

Aging of Rubber and Its Retardation by the Surface Application of Antioxygens Diffusion Process

1930 ◽  
Vol 3 (3) ◽  
pp. 370-377
Author(s):  
Charles Moureu ◽  
Charles Dufraisse ◽  
Pierre Lotte
Keyword(s):  
Diffusion Process ◽  
Accelerated Aging ◽  
Natural Aging ◽  
Excessive Amount ◽  
Surface Application ◽  
Number Of Factors ◽  
Accelerated Aging Test ◽  
Aging Test ◽  
Actual Service ◽  
Service Conditions

Abstract THE deterioration of rubber may be due to any one or a combination of a large number of factors, such as oxidation, depolymerization, continued vulcanization, action of heat or light, and so on. The present paper will deal with the preservative action of antioxygens (12, 15) when applied on the surface of articles, and with some general remarks on the use of antioxygens. Comparison of Accelerated Aging Tests The only test not open to criticism is one which measures the aging of an article under actual service conditions and the writers used it in many control experiments. This test has the disadvantage of consuming an excessive amount of time and of not being suitable for a series of studies. Hence the necessity for artificially hastening the deterioration of the rubber articles. This accelerated aging is obtained, as is well known, by the use of such agents as heat, light, or compressed oxygen used separately or simultaneously. There is some doubt as to which accelerated aging test gives results most similar to natural aging.

Corrosion resistance of hoisting ropes

2020 ◽  
Vol 62 (12) ◽  
pp. 1173-1180
Author(s):  
Haşim Fırat Karasu ◽  
Mine Demirsoy
Keyword(s):  
Corrosion Resistance ◽  
Aging Process ◽  
Steel Wire ◽  
Accelerated Aging ◽  
Electrochemical Test ◽  
Accelerated Aging Test ◽  
Aging Test ◽  
Different Types ◽  
Before And After ◽  
The Impact

Abstract In this study, the goal is to determine the types of steel rope best used in environments such as harbors and on ships, by examining the behavior of different types of steel wire hoisting ropes used in cranes with respect to corrosion. Initially, hemp and steel wire core ropes were taken from 6 × 19 Standard, 8 × 19 Seale and 6 × 36 Warrington Seale rope groups that have the same diameter. Corrosion resistance was compared in these ropes through the application of three methods. According to the first method, corrosion resistance was examined via change in material mass. For this purpose, ropes were subjected to an accelerated aging test in an aging test cabin in accordance with ASTM B117 standard for one month for each aging process. 3 different 30-day processes were followed with 24-hour cycles. Corrosion exposure rates differed for each process. After going through the aging process, the damage suffered by the ropes was determined via visual inspection and the impact left by corrosion was evaluated by examining the mass changes seen in the ropes before and after aging for each process. The Tafel extrapolation, which is an electrochemical test, was applied in the second method. Ecorr and Icorr values of the ropes as well as their corrosion rates were determined and compared. Corrosion behavior was investigated in the third method through the application of mechanical experiments on aged steel ropes. In conclusion, corrosion resistant hoisting ropes were identified by comparing the results attained from the three methods.

Aging of Rubber in the Oxygen Bomb at Room Temperature

1943 ◽  
Vol 16 (4) ◽  
pp. 924-925
Author(s):  
J. R. Scott
Keyword(s):  
Tensile Strength ◽  
Oxygen Concentration ◽  
Room Temperature ◽  
Accelerated Aging ◽  
Natural Aging ◽  
Tensile Tests ◽  
Oxygen Bomb ◽  
Vulcanized Rubber ◽  
Accelerated Aging Test ◽  
Aging Test

Abstract The work described below was carried out as a first step in determining whether an oxygen-bomb test at room temperature could be used as an accelerated aging test for unvulcanized rubber compositions, e.g., as used on surgical and adhesive plasters and for combining shoe fabrics, because a high-temperature test is unsatisfactory in such cases, owing to the melting of the compositions. The only infallible way of assessing the value of an accelerated test for such compositions is by comparison with natural aging, but as this is a very lengthy process and as the deterioration is difficult to measure quantitatively, it was decided to make preliminary tests on the effect of high oxygen concentration at room temperature by using vulcanized rubber. Although the results proved to be negative so far as the original purpose of the work was concerned, it is considered of interest to place them on record in view of the prominence given in some papers on aging to the relationship between oxygen concentration and rate of oxidation and deterioration of rubber. A mix composed of rubber 100, sulfur 3, zinc oxide 5, stearic acid 1, and diphenylguanidine 0.75, was vulcanized for 30 minutes at 153° C. Tensile tests, using standard ring-specimens and the Schopper machine, were made on unaged specimens and on specimens that had been aged (1) in an oxygen bomb at 300 lb. per sq. in. oxygen pressure and at room temperature (about 10° C), (2) in a Geer oven at 70° C. Four rings were used for each test, the tensile strength and breaking elongation figures quoted being the average for the two rings giving the highest tensile strength, and the figures for the elongations at constant loads the average of all four rings.

scholarly journals Effect of Accelerated Ageing on the Mechanical and Structural Properties of the Material System Used in Protectors

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1263 ◽  
Author(s):  
Longina Madej-Kiełbik ◽  
Katarzyna Kośla ◽  
Dorota Zielińska ◽  
Edyta Chmal-Fudali ◽  
Magdalena Maciejewska
Keyword(s):  
Structural Properties ◽  
Accelerated Aging ◽  
Accelerated Ageing ◽  
Material System ◽  
Wide Range ◽  
Mechanical And Structural Properties ◽  
Before And After ◽  
Ft Ir ◽  
Materials Used ◽  
The Impact

Currently, there is a wide range of materials for motorcyclists available on the market that have a significant ability to absorb impact energy. Understanding the aging processes of materials is crucial for guaranteeing the long-term durability and safety of a new product. For this reason, the effect of accelerated aging on the mechanical and structural properties of the multifunctional materials used in commercial protectors was analyzed. The accelerated aging considered in this study simulated 3 years of use under real conditions. Then, DMTA and FT-IR research, as well as impact tests, were carried out on the commercially available protectors for motorcyclists, before and after the accelerated aging processes. Structural analysis using FT-IR showed no significant changes in the structure of the polymers used for producing the protectors. The DMA test results are consistent with those obtained from the impact study. Both methods showed that the samples maintain their protective properties, after accelerated aging. All of the examined protectors show that an increase in force is transferred through the sample, after the accelerated aging processes, but they still provide protection, according to the ISO standard.

scholarly journals STRESS CONDITIONS AND ITS EFFECTS ON THE PHYSIOLOGICAL POTENTIAL OF PAPAVER SP. SEEDS

2019 ◽  
Vol 21 (3) ◽  
pp. 166-182
Author(s):  
Andréa Bicca Noguez Martins ◽  
Ivan Ricardo Carvalho ◽  
Giordano Gelain Conte ◽  
Anna dos Santos Suñe ◽  
Bruna Barreto Dos Reis ◽  
...  
Keyword(s):  
Saline Solution ◽  
Seedling Emergence ◽  
Accelerated Aging ◽  
Accelerated Aging Test ◽  
Aging Test ◽  
Wide Range ◽  
Poppy Seeds ◽  
Physiological Quality ◽  
Rate Of Emergence

The physiological quality of seeds is commonly characterized by the germination and vigor, which can be defined as the sum of attributes that confers the potential for seeds to germinate, rapidly emerge and result in normal seedlings under a wide range of environmental conditions. The purpose of the study was to test alternative methodologies for the accelerated aging test to evaluate the physiological potential of poppy seeds. Samples obtained from four batches were subjected to germination test at a temperature of 20 °C, traditional accelerated aging and accelerated aging diluted with saline solution (11 g of NaCl  in 100 mL-1  of water) using three temperatures, 41 °C, 42 ºC and 43 ºC , for periods of 12 and 24 hours. The percentage of germination, the rate of emergence velocity, performed together with the emergence speed and the percentage of seedling emergence test were evaluated. It is concluded that the methodology of traditional accelerated aging with temperature of 43 °C and period of 12h shows to be promising for the verification of the physiological quality of poppy seeds.

Sign in / Sign up

Export Citation Format

Share Document