The Vulcanization of Thick Sheets of Rubber

1953 ◽  
Vol 26 (3) ◽  
pp. 674-690
Author(s):  
E. C. B. Bott

Abstract Schmidt's method for the determination of temperatures attained by various thicknesses of solid sheets during heating and cooling is adapted for the calculation of the amounts of vulcanization obtained for flat sheets of soft rubber and of the extra time needed to obtain a full vulcanization in the center of the sheets. The uniformity of vulcanization of the central portion of the sheets is investigated.

2021 ◽  
Vol 15 (2) ◽  
pp. 177-186
Author(s):  
Caner-Veli Ince ◽  
Anna Chugreeva ◽  
Christoph Böhm ◽  
Fadi Aldakheel ◽  
Johanna Uhe ◽  
...  

AbstractThe demand for lightweight construction is constantly increasing. One approach to meet this challenge is the development of hybrid components made of dissimilar materials. The use of the hybrid construction method for bulk components has a high potential for weight reduction and increased functionality. However, forming workpieces consisting of dissimilar materials requires specific temperature profiles for achieving sufficient formability. This paper deals with the development of a specific heating and cooling strategy to generate an inhomogeneous temperature distribution in hybrid workpieces. Firstly, the heating process boundaries with regard to temperature parameters required for a successful forming are experimentally defined. Secondly, a design based on the obtained cooling strategy is developed. Next a modelling embedded within an electro-thermal framework provides the basis for a numerical determination of admissible cooling rates to fulfil the temperature constraint. Here, the authors illustrate an algorithmic approach for the optimisation of cooling parameters towards an effective minimum, required for applicable forming processes of tailored forming.


1973 ◽  
Vol 24 (1) ◽  
pp. 112-115
Author(s):  
V. A. Ostaf'ev ◽  
A. A. Chernyavskaya

1997 ◽  
Vol 467 ◽  
Author(s):  
A. J. Franz ◽  
W. B. Jackson ◽  
J. L. Gland

ABSTRACTHydrogen plays an important role in the electronic behavior, structure and stability of amorphous silicon films. Therefore, determination of the hydrogen density of states (DOS) and correlation of the hydrogen DOS with the electronic film properties are important research goals. We have developed a novel method for determination of hydrogen DOS in silicon films, based on fractional evolution experiments. Fractional evolution experiments are performed by subjecting a silicon film to a series of linear, alternating heating and cooling ramps, while monitoring the hydrogen evolution rate. The fractional evolution data can be analyzed using two complementary memods, the fixed frequency factor approach and Arrhenius analysis. Using a rigorous, mean-field evolution model, we demonstrate the applicability of the two approaches to obtaining the hydrogen DOS in silicon films. We further validate both methods by analyzing experimental fractional evolution data foran amorphous silicon carbide film. Both types of analysis yield a similar double peaked density of states for the a-Si:C:H:D film.


2017 ◽  
Vol 17 (4) ◽  
pp. 133-136 ◽  
Author(s):  
R. Przeliorz ◽  
J. Piątkowski

Abstract The paper presents results of calorimetric studies of foundry nickel superalloys: IN100, IN713C, Mar-M247 and ŻS6U. Particular attention was paid to determination of phase transitions temperatures during heating and cooling. The samples were heated to a temperature of 1500°C with a rate of 10°C⋅min-1 and then held at this temperature for 5 min. After a complete melting, the samples were cooled with the same rate. Argon with a purity of 99.99% constituted the protective atmosphere. The sample was placed in an alundum crucible with a capacity of 0.45 cm3. Temperature and heat calibration was carried out based on the melting point of high-purity Ni. The tests were carried out by the differential scanning calorimetry (DSC) using a Multi HTC high-temperature calorimeter from Setaram. Based on the DSC curves, the following temperatures were determined: solidus and liquidus, dissolution and precipitation of the γ’ phase, MC carbides and melting of the γ’/γ eutectic. In the temperature range of 100-1100°C, specific heat capacity of the investigated superalloys was determined. It was found that the IN713C and IN100 alloys exhibit a higher specific heat while compared to the Mar-M247 and ŻS6U alloys.


1925 ◽  
Vol 17 (2) ◽  
pp. 161-163
Author(s):  
R. T. Mease ◽  
N. P. Hanna

2006 ◽  
Vol 513 ◽  
pp. 61-68
Author(s):  
P. Kula ◽  
T. Liskiewicz ◽  
T. Pacyniak

The process of induction heating followed by forced cooling of large-scale castings is considered. The main goal of this study is to develop a reliable design methodology of surface heat treatment process to provide high quality of the treated component. It is assured by determination of the material constants and convection coefficient during heating and cooling experiments carried out on the specimens made of material adequate to the considered large-scale casting. The main part of the investigations was preceded by wide analyses of the mechanical and chemical properties of the tested specimens. The presented global design methodology of large-scale castings gives a possibility to predict the temperature distribution on the hardened surface during induction heating and forced cooling. This allows to select the most adequate parameters and apply them in a real specific process. The obtained results have been analyzed and discussed.


2021 ◽  
Vol 11 (16) ◽  
pp. 7652
Author(s):  
Meng Gao ◽  
Chengrong Cao ◽  
John H. Perepezko

The advent of chip calorimetry has enabled an unprecedented extension of the capability of differential scanning calorimetry to explore new domains of materials behavior. In this paper, we highlight some of our recent work: the application of heating and cooling rates above 104 K/s allows for the clear determination of the glass transition temperature, Tg, in systems where Tg and the onset temperature for crystallization, Tx, overlap; the evaluation of the delay time for crystal nucleation; the discovery of new polyamorphous materials; and the in-situ formation of glass in liquid crystals. From these application examples, it is evident that chip calorimetry has the potential to reveal new reaction and transformation behavior and to develop a new understanding.


1867 ◽  
Vol 15 ◽  
pp. 19-20

In these experiments a cylindrical rod of glass is subjected to a bending couple of known moment, applied near its ends. The amount of bending produced in the central portion of the rod is measured by means of two mirrors, rigidly attached to the rod at distances of several diameters from each end, which form by reflexion upon a screen two images of a fine wire placed in front of a lamp-flame. The separation or approach of these two images, which takes place on applying the bending couple, serves to determine the amount of flexure. In like manner, when a twisting couple is applied, the separation or approach of the images serves to determine the amount of torsion.


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