Effect of Moisture on GR-S Rate of Cure and Physical Properties

1946 ◽  
Vol 19 (3) ◽  
pp. 773-780
Author(s):  
Ian C. Rush

Abstract Moisture has been discussed as a factor which may give rise to variable rates of cure of GR-S. This moisture may be present in GR-S itself or in the compounding ingredients used. Accordingly, a program was initiated in the spring of 1944 to establish the influence of moisture, not only on the rate of cure of GR-S, but also on its physical properties. Since that time two papers have been published on this subject by other investigators. The results reported here verify some of the conclusions drawn by these investigators but seem to be at variance with others. In this study various proportions of water were added in the following ways : by premixing with carbon black, by adding directly on the mill rolls at the completion of normal milling, and by soaking GR-S crumb in water. Curing curves were obtained for each batch, and were used to evaluate the rate of cure. To eliminate day-to-day variations in physical properties due to error in testing methods, three batches of different moisture contents were mixed and tested on the same day. This same group was then remixed and tested on successive days until at least three batches had been tested for each moisture content and each method of addition. The averages of the individual results (stress-strain data and percentage moisture retained) on batches to which the same percentage of water was added, were then considered free from day-to-day variations.

2018 ◽  
Vol 34 (3) ◽  
pp. 599-602 ◽  
Author(s):  
Jonathan P. Chiputula ◽  
Ray A. Bucklin ◽  
Ann R. Blount

Abstract. Grain physical properties such as coefficients of friction are required to design harvesting, cleaning, and handing equipment, and storage structures. The objective of this study was to measure coefficients of friction between triticale grain and galvanized steel at grain pressures and velocities typical of those seen when filling and emptying storage bins and hoppers. Coefficients of friction were measured using an apparatus consisting of a box with openings so that a galvanized steel blade could be pulled through a sample of grain. The forces required to pulling the blades through the grain were measured for three different moisture contents [8%, 12%, and 16% wet basis(wb)] and three different normal pressures (6.9, 10.3, and 13.8 kPa). The velocity of the blade being pulled through grain was kept constant at 50 mm/min for all pressures and moisture contents. Keywords: Grain bin, Grain pressure, Grain storage.Coefficients of friction were found to be statistically significantly dependent (p <0.0001) on moisture contents of triticale grain and were not statistically significantly influenced (p=0.149) by normal pressures. Coefficients of friction increased with increasing moisture content as has been observed in similar studies for grains including corn, wheat and soybeans. These results provide guidance for selecting physical properties for design of storage structures for triticale. Keywords: Grain bin, Grain pressure, Grain storage.


1979 ◽  
Vol 59 (4) ◽  
pp. 911-916 ◽  
Author(s):  
R. N. SINHA ◽  
N. D. G. WHITE ◽  
H. A. H. WALLACE ◽  
R. I. H. McKENZIE

The effects of various seed moisture contents in hulless (cv. Terra) and hulled oats (cv. Random) on susceptibility to mite infestation and on mycofloral growth and germination loss were studied at weekly intervals. Fat acidity values were determined for Terra oats only after 4 wk of storage. Moisture content-relative humidity adsorption and desorption curves were determined for Terra at 22 °C and at relative humidities of 35–100%. Terra oats, which had a higher level of Penicillium infection at 90–100% RH than Random oats, lost viability more rapidly than Random. Fat acidity values of Terra increased rapidly from 35 mg KOH/100 g of seed to 87–118 mg KOH/100 g of seed, only when seeds were stored at 90–100% RH. Terra offered a more favorable substrate for the multiplication of the mites Tyrophagus putrescentiae, Acarus farris, and Lepidoglyphus destructor than did Random. With the exception of susceptibility to mite infestation, safe storage criteria are similar for hulled and hulless oats at usual moisture contents.


Author(s):  
Fabie T. Dummapi ◽  
Jacqueline I. Liniasan ◽  
Marvin T. Valentin ◽  
Milagros B. Onalan ◽  
Leonardo D. Dumalhin ◽  
...  

Wild sunflower with moisture contents of 16%, 12% and 8% was densified without the addition of binding agent. The physical properties of the formed briquettes such as mass, dimensions, volume, density and shattering resistance were evaluated. Thermal properties like ignition time, burning time, ash content, and thermal fuel efficiency by means of boiling test were also evaluated. Wild Sunflower stems were gathered and shredded using locally fabricated biomass shredder available at the Research Office of Benguet State University, and were processed into the desired size and moisture contents. Right after the briquetting operation, the physical properties of the briquette were measured and then stored in a zip bag for 24 hours. After the storage, same measurement was conducted. Results show that the influence of moisture contents on the average mass, dimension, shattering resistance, volume and density was statistically insignificant. The wild sunflower with moisture content of 16% had the highest shattering resistance of 88.85%. Furthermore, the influence of moisture content on the thermal properties like ignition time, burning time and ash content are statistically insignificant. Among the moisture contents, the fastest ignition time of 43.75 sec with longest burning time was recorded under 12%. Ash content was also lowest at 12%.


2008 ◽  
Vol 8 (1) ◽  
pp. 90-95 ◽  
Author(s):  
M. Karimi ◽  
K. Kheiralipo ◽  
A. Tabatabaee ◽  
G.M. Khoubakht ◽  
M. Naderi ◽  
...  

1991 ◽  
Vol 64 (2) ◽  
pp. 234-242
Author(s):  
R. F. Bauer ◽  
A. H. Crossland

Abstract Properties of the individual phases in a 70/30 carbon-black-loaded BR/NR blend could be successfully resolved using large deformation stress-strain modelling. Since the dispersed NR phase of the example had a lower modulus than the continuous BR phase, the interaction between the blend phases could be modelled by a simple parallel coupling arrangement. The stress behavior of each individual carbon-black-loaded polymer phase was then determined with respect to strain using a specially derived stress-strain relationship. The blend components also have to be characterized with respect to state-of-cure by empirically establishing how the parameters in the stress-strain relationship vary with respect to cure. The properties of the phases in the blend are then determined by finding the combination of component parameters which precisely reproduce the stress-strain behavior of the blend. In the demonstration example of this paper, there was evidence of a significant amount of curative migration between phases during the vulcanization process.


2013 ◽  
Vol 40 (1) ◽  
pp. 3-7
Author(s):  
M. C. Lamb ◽  
C. L. Butts ◽  
P. D. Blankenship

ABSTRACT Runner-type peanut kernel moisture content (MC) is measured periodically during curing and post harvest processing with electronic moisture meters for marketing and quality control. MC is predicted for 250 g samples of kernels with a mathematical function from measurements of various physical properties. To examine the accuracy of the function used in the Dickey-john GAC2100 for measuring MC of runner-type peanuts, 421 samples were measured with the meter and compared to oven MC data subsequently determined using ASAE Standard S410.1. Peanut moisture content for the peanuts according to the meter averaged 19.1% with a SD of 15.4%. Oven moisture contents had a mean of 17.3% and a SD of 8.5%. Means were significantly different (P  =  0.001). A calibration equation was derived from capacitance, conductance, temperature, and test weight data provided by the meter and compared to oven MC data. Moisture contents calculated from the calibration equation had a 17.3% mean and an 8.5% SD equaling values for oven determined moisture contents. Results of the study indicate that the accuracy of the meter in predicting moisture content can be improved considerably utilizing currently collected data and the derived calibration equation developed.


1937 ◽  
Vol 10 (4) ◽  
pp. 807-819 ◽  
Author(s):  
J. H. Fielding

Abstract THE precise grading of carbon black has been a problem to rubber manufacturers for years. Empirical specification tests inherited from the paint and ink industries have been used extensively; although they may have great merit in predicting the behavior of a black in paint or ink, they generally tell very little of its value in rubber. Since neither these tests nor the usual stress-strain data showed any great differences that could be associated with type of carbon black, chemists have been inclined to believe in the past that the rubber grade of channel black was quite a uniform material, at least when used in mercaptobenzothiazole stocks. Among the tests which have been used recently in the grading of black is resilience of the cured stock as determined by an impact pendulum. Although superficially it seems to measure no fundamental property of the black, it is a very practical test from a laboratory standpoint and appears to be capable of at least rough correlation with more fundamental properties. It is not a new property; the fact that it is influenced by carbon black is not new; but its application to the separation of blacks within the range of rubber channel black is new, and this phase will be discussed here.


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