Tribological characteristics at running‐in of repaired tractor engines using friction modifiers

PurposeThe purpose of this paper is to determine and compare the tribological characteristics (weight wear and friction moment) of a friction couple C45/C330 at running‐in with motor oil SAE 30 and different friction modifiers of copper oleate and zinc oleate.Design/methodology/approachFriction couples are tested using the model “roller‐sector” and they are lubricated with oil SAE 30 and two other samples of SAE 30 containing 0.6 per cent copper oleate and 0.6 per cent zinc oleate, respectively. Graphic dependencies are drawn for the weight wear of the sectors, rollers and couples; as well as for the running‐in moment, the friction moments at the end of the loading and at the end of the test.FindingsThe weight wear, running‐in moment and friction moments are evaluated for friction with SAE 30 as reference and oils containing copper oleate and zinc oleate as friction modifiers. The best performing material is the oil with zinc oleate.Originality/valueFrom a practical point of view this paper offers a new idea about a friction modifier – zinc oleate. Data for tribological characteristics and suitable concentration in the oil composition are given in the paper.

THE EFFECT OF WEATHERING ON COTTON FABRIC CONTAINING CERTAIN COPPER ROTPROOFERS

On exposure to outdoor weathering for three months, No. 8 cotton duck showed substantial loss in breaking strength. The untreated fabric showed a loss of the same order as the losses of samples treated with copper naphthenate, copper hydroxynaphthenate, copper oleate, and copper tallate containing 0.1 to 1.0% copper. The copper treated samples showed slight evidence of increased actinic degradation as measured by cuprammonium fluidity. There was an appreciable decrease in the copper content of the treated samples on weathering. The decrease in copper content and breaking strength on weathering and the extent of attack by micro-organisms in soil burial testing were reduced considerably by the presence of a waterproofing compound of the wax-pigment-filler type. The initial water resistance of the proofing was modified by the presence of the copper compounds, being reduced by copper naphthenate, oleate, and tallate and increased by copper hydroxynaphthenate although on ageing and weathering these effects were minimized.

Determination of Guanidines in Rubber Stocks and Consumption of Guanidines during Cure

QUANTITATIVE determinations of various accelerators that may be present in vulcanized rubber stocks are necessary, not only for fundamental investigations into the mechanism of acceleration, but also for routine control analyses and the examination of unknown stocks. The determination of any organic material in vulcanized rubber stocks is beset with numerous difficulties, however, and reliable methods are scarce. For accelerators, the only ones described in the literature are the now generally employed copper oleate method for mercaptobenzothiazole and an extension of Callan and Strafford's (1) picric acid method for guanidines, both described by Wistinghausen (2). Using these two procedures, Wistinghausen made an extended investigation of the consumption of mercaptobenzothiazole and of diphenylguanidine (D. P. G.) during cure. Considerable difficulty was encountered in this laboratory in the use of Wistinghausen's method. Especially with di-o-tolylguanidine (D. O. T. G.) stocks, the results were highly variable and the proportion of guanidine recovered seemed to be much smaller than that recovered by Wistinghausen from similar stocks. As a test of both the method and the technic, an uncured di-o-tolylguanidine tread stock was analyzed, since it was believed that, in this case, an effective procedure should account for substantially all of the guanidine put into the stock. The result was that little or no more guanidine was recovered from the uncured stock than from the same stock at an optimum cure. Guanidine recoveries from either one ranged from 30 to 50 per cent.

The Preservation of Fibre Ropes for Use in Sea-Water

1. For the preservation of ropes the importance of the preservative against bacterial decay being also an internal lubricant for the rope fibres must be remembered.2. Tests have been carried out for one year in sea-water, which was much contaminated by sewage at times, under Plymouth Pier and in cleaner water of a tidal basin outside Plymouth Sound Breakwater for 10½ months, using 2-inch and 0-6-inch ropes respectively; the latter was manila, the former were manila, hemp, sisal and coir.3. The preservatives included cutch, cutch bichromate, cutch ammonia copper sulphate, coal tar distillates, including those of the Coalite process, also hardwood and softwood tars. The tars and tar oils were tried alone and mixed with copper soaps, naphthenate (Cuprinol and Shell products), oleate and resinate, also zinc and iron naphthenates (Cuprinol). The naphthenates and oleate are good lubricants.4. Very good results were obtained with green Cuprinol containing tar and with 10 per cent copper oleate in a light coal tar; slightly inferior were 10 per cent copper resinate in Coalite heavy oil or in creosote oil as now used largely in Plymouth; also 10 per cent copper oleate with 20 per cent of Coalite tar in Coalite neutral oil, b.p. 100–245° C, which i s a very cheap solvent. All these maintained the thin manila rope at or above 70 per cent of its initial strength after 10½ months; the untreated control was down to 13 per cent.

The Deterioration of Fabrics Exposed on a Roof after Treatment with Fishing-net Preservatives

(1) Cotton and linen fabrics were exposed horizontally on the Laboratory roof at Plymouth for two years. During this time the fabrics lost from one to two-thirds of their initial tensile strengths in both warp and weft.(2) The application of copper oleate, mixed copper soaps, also of the latter with resin or tar as binding agents, had no effect or a slight effect only in lessening deterioration; such weakening must therefore be due to weathering, chiefly the action of light, since these substances have been shown to be useful antiseptics on nets immersed in salt or fresh water.(3) No deleterious action may be expected when nets treated with these substances are exposed to light, since the treated fabrics were no weaker than the untreated; but where Cuprinol had been used, there appears to have been some weakening, though the antiseptic properties of Cuprinol are excellent.