Deproteinized Rubber

1937 ◽  
Vol 10 (2) ◽  
pp. 288-298
Author(s):  
C. R. Boggs ◽  
J. T. Blake

Abstract FOR some years deproteinized rubber has been used by this company in the manufacture of rubber insulation, and the rate of consumption is increasing rapidly. This new and unique raw material is now also being manufactured for the Simplex Wire and Cable Company by The Goodyear Tire and Rubber Company on plantations in the Far East. The special virtue of deproteinized rubber is its low water absorption and the electrical stability which it imparts to vulcanized rubber compounds immersed in water. Electrical engineers are specifying such compounds for submarine, underground, and duct cables and all other insulation that may be exposed to water. The electrical properties of ordinary rubber insulation are impaired by increasing water absorption; the dielectric strength decreases, and the capacitance and leakance (or dielectric loss) increase. Power cables become useless when decreasing dielectric strength is insufficient to withstand operating voltage. Communication cables deteriorate rapidly by water absorption because their increasing capacitance and leakance prevent the practical transmission of signals long before dielectric strength is low enough to cause failure at the extremely low operating voltage of such cables.

1931 ◽  
Vol 4 (3) ◽  
pp. 426-436
Author(s):  
K. J. Soule

Abstract Further work is very desirable on the effect of different accelerators, antioxidants, and fluxes. It is possible that their study will throw more light on the mechanism of the swelling phenomena, and also help to explain the anomalous behavior of some of the fillers tested. It would also seem to be worth while to study the action of a few selected stocks in water, at several temperatures between room temperature and 100° C., to determine if the water absorption and swelling merely increase with rising temperatures, or whether there might be an actual change in behavior at different temperatures.


2019 ◽  
Vol 51 (2) ◽  
pp. 223-232 ◽  
Author(s):  
Blasius Ngayakamo ◽  
Eugene Park

The present work has evaluated Kalalani vermiculite as a potential raw material for the production of high strength porcelain insulators. Three porcelain compositions were prepared to contain 0, 20 and 30 wt% of Kalalani vermiculite. Porcelain samples were fabricated using a semi-drying method. The chemical, mineralogical phases and microstructural characterization of the raw materials were carried out using XRF, XRD, and SEM techniques, respectively. Water absorption, bulk density, dielectric and bending strengths were performed on porcelain samples fired up to 1300?C. However, at the sintering temperature of 1250?C, the porcelain sample with 20 wt% of Kalalani vermiculite gave the dielectric strength of 61.3 kV/mm, bending strength of 30.54 MPa, bulk density of 2.21 g/cm3 and low water absorption value of 0.21 % which is the prerequisite properties for high strength porcelain insulators. It was therefore concluded that Kalalani vermiculite has the potential to be used for the production of high strength porcelain insulators


1937 ◽  
Vol 10 (3) ◽  
pp. 474-491
Author(s):  
A. R. Kemp

Abstract THE water absorption and the dielectric stability of soft rubber insulating compounds under wet conditions is influenced by the kind of crude rubber employed. For most rubber-covered aerial and building wire where moisture conditions are not severe, the better grades of plantation rubber are satisfactory. However, for service involving immersion for long periods in fresh water, a need exists for rubber containing less nonhydrocarbon water-absorbing substances than the plantation product. This is particularly true when the insulating wall is thin and a high degree of electrical stability is required. Only recently has the preparation of such a type of purified rubber been given serious consideration on the plantations in the Far East. In the past, coöperation on such a problem with the plantation has been difficult, and for that and other reasons methods have been developed here for preparing this rubber in the factory. The purpose of this paper is to discuss the nature and role of protein and other substances found in Hevea rubber and to outline various methods for purifying rubber. Data are presented on the composition and properties of the resulting products.


1933 ◽  
Vol 6 (1) ◽  
pp. 24-32
Author(s):  
H. A. Daynes

Abstract The absorption of water by rubber has occupied a prominent place in recent literature, especially in connection with cable and other insulating materials, since it is well known that their electrical properties are adversely affected by absorbed moisture. Many other classes of rubber goods and materials also are subject to water absorption, e. g., rubber soling, tires, washers, packings, hose, tank and grinding mill linings, hot-water bottles, and surgical goods. Apart from the performance, of such articles in service, moisture absorption is important in relation to factory operations, such as drying and vulcanizing, and to storage and mechanical testing. This paper deals with the selection of a method for measuring the amount of water absorbed by rubber when saturation has been reached. In the work for which the method was developed, the rate of absorption was of no interest; but it was necessary to correlate the water absorbed by the vulcanized product with that absorbed by the raw material, so that a method was required which could be applied equally well to raw rubber, vulcanized rubber, and ebonite. It is not proposed to discuss in detail the mechanism of absorption. The literature has already been briefly reviewed by Lowry and Kohman (J. Phys. Chem., 31, 23 (1927)), who have been largely responsible for present ideas on the subject. It will be sufficient to recall that the process is a reversible one, and that the amount absorbed at any temperature depends on the humidity of the surrounding gas and the nature of the rubber.


Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 485
Author(s):  
Vera Schmid ◽  
Antje Trabert ◽  
Judith (Schäfer) Keller ◽  
Mirko Bunzel ◽  
Heike P. Karbstein ◽  
...  

Food by-products can be used as natural and sustainable food ingredients. However, a modification is needed to improve the technofunctional properties according to the specific needs of designated applications. A lab-scale twin-screw extruder was used to process enzymatically treated apple pomace from commercial fruit juice production. To vary the range of the thermomechanical treatment, various screw speeds (200, 600, 1000 min−1), and screw configurations were applied to the raw material. Detailed chemical and functional analyses were performed to develop a comprehensive understanding of the impact of the extrusion processing on apple pomace composition and technofunctional properties as well as structures of individual polymers. Extrusion at moderate thermomechanical conditions increased the water absorption, swelling, and viscosity of the material. An increase in thermomechanical stress resulted in a higher water solubility index, but negatively affected the water absorption index, viscosity, and swelling. Scanning electron microscopy showed an extrusion-processing-related disruption of the cell wall. Dietary fiber analysis revealed an increase of soluble dietary fiber from 12.6 to 17.2 g/100 g dry matter at maximum thermo-mechanical treatment. Dietary fiber polysaccharide analysis demonstrated compositional changes, mainly in the insoluble dietary fiber fraction. In short, pectin polysaccharides seem to be susceptible to thermo-mechanical stress, especially arabinans as neutral side chains of rhamnogalacturonan I.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3363
Author(s):  
Jolanta Latosińska ◽  
Maria Żygadło ◽  
Przemysław Czapik

Wastewater treatment processes produce sewage sludge (SS), which, in line with environmental sustainability principles, can be a valuable source of matter in the production of lightweight expanded clay aggregate (LECA). The literature on the influence of SS content and sintering temperature on the properties of LECA is scarce. This paper aims to statistically evaluate the effects of SS content and sintering temperature on LECA physical properties. Total porosity, pore volume, and apparent density were determined with the use of a density analyzer. A helium pycnometer was utilized to determine the specific density. Closed porosity was calculated. The test results demonstrated a statistically significant influence of the SS content on the specific density and water absorption of LECA. The sintering temperature had a significant effect on the specific density, apparent density, total porosity, closed porosity, total volume of pores, and water absorption. It was proved that a broad range of the SS content is admissible in the raw material mass for the production of LECA.


2018 ◽  
Vol 42 (2) ◽  
pp. 186-194 ◽  
Author(s):  
Evelyn Hoffmamm Martins ◽  
Alan Pereira Vilela ◽  
Rafael Farinassi Mendes ◽  
Lourival Marin Mendes ◽  
Lívia Elisabeth Vasconcellos de Siqueira Brandão Vaz ◽  
...  

ABSTRACT Brazil is the second largest soybean producer in the world, with a yield of around 96.2 million tons per crop. This high yield leads to a great amount of waste resulting from soybean cultivation, which can reach approximately 41 million tons of waste per year. This material has lignocellulosic properties, which may enable its use as a raw material for particleboard production. Therefore, the objective of this study was to evaluate the use of soybean pods in particleboard production. For particleboard manufacture, wood of the hybrid Eucalyptus urophylla and Eucalyptus grandis was used, added with soybean pods, at proportions of 0%, 25%, 50%, 75% and 100%. For particleboard evaluation, a completely randomized design was used, with five treatments and three replicates, using linear regression and the Scott-Knott test at 5% significance for comparison among the different treatments. The properties apparent density, compaction ratio, water absorption after 2 and 24 hours, thickness swelling after 2 and 24 hours in water immersion, internal bonding, modulus of rupture and modulus of elasticity in bending properties were evaluated. The ratio soybean pod waste and eucalyptus particles in the panels led to an increase in water absorption values and thickness swelling, in addition to a decrease in mechanical properties. The production of panels with approximately 23% soybean pods is feasible.


Author(s):  
Martins Andzs ◽  
Voldemars Skrupskis

Obtaining of a new ecological heat insulation material from always renewable raw material in nature, wood and hemp, derived from wood and hemp fibre remains left from the production process. The study was carried out to find hemp wood parts (shives), fiber, and material first possible compositions together with wood fibres, to produce heat insulation materials. The use of the heat insulation material would be meant for dwelling and recreation houses. In the present research the main characteristics of these materials are determined: moisture content, density, water absorption, as well as the coefficient of heat transmission.


2019 ◽  
Vol 16 (33) ◽  
pp. 823-840
Author(s):  
M. K. TARABAI ◽  
S. G. de AZEVEDO

This paper discusses a possible solution regarding the final disposal of sludge from Sanitary Sewage Treatment Stations (ET), aiming at environmental preservation. The solid waste generated after the wastewater treatment processes is highly contaminating and detrimental to the area in which it is deposited. Given this, the use of sludge with the application of reuse techniques becomes pertinent, both from the economic point of view and from the ecological point of view. By replacing the use of aggregates from mineral deposits, the main clay raw material in the manufacture of ceramic products (Vieira, 2000), by the treated sludge of WWTP we will save on the sources of granular materials. Aiming its reintegration to the production cycle through the introduction of sludge as raw material incorporated in the ceramic mass in the manufacture of hollow bricks, the viability of use was verified through performance analysis, compared to the control brick made of pottery, without the addition of sludge. Specimens were prepared with three types of samples: 90% clay and 10% sludge; 80% clay and 20% sludge; 70% clay and 30% sludge. Mass loss, water absorption index and compressive strength tests were performed. As for the tests, the specimens with 10% and 20% of sludge were the ones that had better adaptation to the technical requirements, but because it is a larger volume of the residue for the application of reuse techniques, the brick with 20% sludge dosage. is the most suitable. NBR7.171, November 1992: Ceramic Block for masonry; Specification NBR 6.461, June 1983: Masonry Ceramic Block - Compressive Strength Check: Test Method; NBR 8.947, November 1992: Ceramic Tile- Determination of Mass and Water Absorption: Test Method. As for the tests, the specimen with 20% of sludge was the one that had the best adaptation to technical and environmental requirements. The present article approaches a possible solution regarding the destination of the sludge coming from Sanitary Sewage Treatment Stations, aiming at environmental preservation. Aiming at its reintegration into the productive cycle through applications of reuse techniques, the sludge became raw material when the ceramic mass was incorporated into the brick fabrication. Three types of samples were elaborated: 90% of clay and 10% of mud; 80% clay and 20% sludge; 70% clay and 30% sludge. As for the tests, the test specimen with 20% of sludge was the one that had more adequacy to the technical and environmental requirements.


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