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Driving safety on a wet road is closely related to the wet skid resistance of tires. The purpose of this paper is to reveal the evolution of wet skid resistance at different water film thicknesses and provide some guidance on the design of a tread pattern with improved traction on rainy roads.

Brake tests are performed in a laboratory with a viscoelastic tribotester at various water film thicknesses. The initial water film thickness is 3 mm, which decreases with an increase in the test number. Brake friction force is dynamically measured at water film thicknesses ranging from 0 mm to 3 mm.

The results show that water film thickness exerts a great influence on the forms of tire motion and slip ratio. The tire is much easier to slide on the road with thick water film and also with a considerably thin water film (about 0-1 mm) during a sharp braking process. The brake traction can be very low under this road condition despite the apparently safe quality of the road.

The authors design and establish a new viscoelastic tribotester which is used to simulate the real braking sliding process and study the tribological properties between tire rubber and road surface. The variation in the wet friction coefficient and slip ratio at different water film thicknesses have a great influence on the design of a tread pattern with improved traction on rainy roads.

On the basis of earlier studies, an investigation is made into the function of inert and active pigments in anti‐rust paints. Satisfactory explanation of the pigment effect is shown to be impossible without due consideration of the surrounding medium and, if necessary, the substrate. The significance of metal soaps is their increase in the mechanical and chemical resistance of the dried film of binder. This, in turn, results in a reduction of water diffusion through the film in the case of a high PVC and, hence, in an increase in the anti‐corrosive effect.

The purpose of this study was carried out to explore the potential use of carrageenan extracted from marine red seaweed (Kappaphycus alvarezii) collected from Munaikadu, Mandapam region, Ramanathapuram district, Tamil Nadu.

Biodegradable film was developed by using carrageenan extracted by using alcohol extraction method. To improve the mechanical properties of the film, rice starch was incorporated. The biodegradable films were made by phase inversion method with varied carrageenan concentration of 1%, 1.5% and 2% (w/v) and rice starch with concentration of 0%, 1%, 1.5% and 2% (w/v). Physical properties, optical properties, mechanical properties and other properties such as biodegradability, solubility and water vapor permeability of the developed biodegradable films were characterized. The results were analyzed in design expert software using Box–Behnken design.

Results show that the biodegradable film’s mechanical and water vapor permeability increases with an increase in carrageenan and rice starch concentration. The optimized film structure was obtained with carrageenan and rice starch composition of 1.5% and 2%, respectively.

The results shown a broad spectrum of commercial applications and future rice starch possibilities incorporated in the carrageenan-based biodegradable film.

The purpose of this paper is to provide a nondestructive monitoring method based on wireless sensor technology to measure the continuous circumferential film pressure on radial cross-section of water-lubricated bearing, in addition, to study the influence factors to wireless communication.

The unique shaft and wireless equipments are designed, the pressure sensors are installed in right shoulder of shaft, the wireless transmitter is installed at the end of shaft and the sensors are connected with wireless transmitter by data cable. By this way, the film pressure can be obtained via wireless communication. The film pressure of eight grooved water-lubricated rubber bearings with concave staves is measured, the performance evaluation of wireless equipments is conducted and the influence factors to wireless communication is analyzed by Doppler frequency shift theory.

The rupturing and nonuniform water film is observed, the grooves decrease the film pressure of rubber bearing which is in mixed lubricating state. The main influence factor to wireless communication is shaft speed which has greater effect on packet loss rate than that on bit error rate.

By studying the actual continuous water film pressure, the bearing properties can be studied in-depth, and this has significant meaning to the design and application of bearing. Moreover, the study on influence factors to wireless communication can be used for references to other wireless monitoring on rotating machinery.

The continuous water film pressure can be monitored by this method, the lubricating state of bearing working surface cannot be damaged and the signal attenuation can be avoided. Therefore, the measuring accuracy is promoted and the measuring process also becomes convenient and high efficiency.

From the electrochemical theory of corrosion it follows that corrosion can be stopped by suppressing either the cathodic or the anodic reaction, or by inserting between the cathodic and anodic areas a large resistance, which impedes the movement of ions. Calculations indicate that paint films are so permeable to water and oxygen that they cannot suppress the cathodic reaction. Paints can inhibit corrosion by modifying the anodic reaction; for this to occur the pigment must be either metallic, or basic, or soluble. In general, paint films protect by virtue of their high electrolytic resistance; they readily acquire a charge, consequently they are relatively impermeable to ions. Soap formation is beneficial, since it renders the film less permeable to electrolytes; it also yields soluble inhibitive degradation products, which have been identified.

A numerical solution for ‘running wet’ aircraft anti‐icing systems is developed. The model includes breakup of the water film, which exists in regions of direct impingement, into individual rivulets. The wetness factor distribution resulting from the film breakup and rivulet configuration on the surface are predicted in the numerical solution procedure. The solid wall is modelled as a multi‐layer structure and the anti‐icing system used is of the thermal type utilizing hot air and/or electrical heating elements embedded within the layers. Details of the calculation procedure and the methods used are presented.

Water soluble epoxy resins were prepared from epoxy resin, linseed fatty acids, maleic anhydride, trimellitic anhydride, maleinised dehydrated castor oil and maleopimaric acid. Pigmented coating compositions for anodic electrodepositions were prepared from water soluble epoxy resins using red oxide of iron and zinc phosphate as pigment. The electrodeposition parameters such as voltage, time, solid content and pH value were optimised. The mechanical and chemical film properties of different electrocoating compositions were studied.

The cleaning of food production equipment using cleaning detergents may contaminate the lubricant of the bearings, thereby reducing the bearing service life. The purpose of this paper is to investigate the cause and mechanism of such damage of bearings lubricated by cleaning detergent/water-in-oil emulsions.

The emulsion was prepared by adding a mixture of cleaning detergent and water in one base oil. A self-designed ball-on-disc optical interference test rig was applied to examine the effect of emulsion on lubrication and wear of bearing contacts under pure sliding conditions.

The emulsion reduced lubricating film thickness at a relatively low-sliding speed but only when the water concentration (20%) in emulsion was high. Water droplets were trapped around the ball-on-disc contact area under static conditions because of a high capillary force. The emulsion can induce damages on the soft surface in the startup mainly due to the presence of water around the contact.

The basic lubrication behaviour of water/oil emulsions containing cleaning detergent under pure sliding was experimental studied and the mechanism of bearing damage in food production equipment was investigated. Based on the study, the solution to avoid such damage was proposed.

The purpose of this study is to reveal the underlying mechanism in film formation of oil-in-water (O/W) emulsion.

This study focuses on the film forming characteristics of O/W emulsion between the surface of a steel ball and a glass disc coated with chromium. The lubricant film thicknesses of O/W emulsion with various mechanical stirring strength were discussed, which were observed by technique of relative optical interference intensity.

The authors directly observed the oil pool in the contact area, finding the size of oil pool was closely related to the film-forming ability of emulsion. Enrichment phenomenon occurs in oil pool, which was caused by phase inversion. Further investigations revealed that the emulsion is stable with strong stirring strength, resulting in a smaller oil pool size and worse film forming ability.

With the wide usage of O/W emulsion in both biological and industrial systems, the ability of emulsion film formation is considered as an important factor to evaluate the lubrication effectiveness.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2022-0354/

For conservation of petochemical solvents and reduction of air pollution, the water soluble polymers will play an important role in surface coating industry. The coatings based on water soluble polymers are thinned with water instead of petroleum solvent. Basically, the water based coatings may be made from oils, alkyds, polyesters, aminoes, phenolics, epoxies and acrylics. In spite of a large number of other synthetic resins being available for use in coating formulations, the alkyd resins surpass all of them in versatility, and low cost; combining a broad spectrum of performance properties with economy. Water soluble alkyd resins are similar to their solvent borne counterparts. The major difference is that their formulation is modified to introduce pendant carboxylic acid groups along the polymer backbone. These pendant acid groups can be neutralised with basic compounds to produce water solubility. Several workers studied preparation and evaluation of film characteristics of water soluble alkyd resins using various types of polybasic acids, polyhydric alcohols and fatty acids. The curing of these resins has been satisfactorily accomplished by stoving in presence of water soluble amino resins.