Conventional Finishing Research Articles

Nano surface generation of grinding process using carbon nano tubes

Nano surface finish has become an important parameter in the semiconductor, optical, electrical and mechanical industries. The materials used in these industries are classified as difficult to machine materials such as ceramics, glasses and silicon wafers. Machining of these materials up to nano accuracy is a great challenge in the manufacturing industry. Finishing of micro components such as micro-moulds, micro-lenses and micro-holes need different processing techniques. Conventional finishing methods used so far become almost impossible or cumbersome. In this paper, a nano material especially multi wall carbon nano tube is used in the machining process like grinding to improve the surface characteristics from micro to nano level.

Influence of Corona Plasma Treatment on Polypropylene and Polyamide 6.6 on the Release of a Model Drug

Low-temperature plasma has been studied for the textile industry as an environmentally friendly alternative to conventional finishing treatments but its biomedical applications are limited. The present work is devoted to analyze how plasma treatment modifies the wetting properties of polypropylene and polyamide 6.6 fabrics and its influence on the drug release from these textile materials. Drug release studies from textiles pre-treated by plasma are unexplored and constitute an innovative research that could provide a new way to develop controlled drug delivery systems. Methods of surface analysis for polypropylene and polyamide 6.6, including contact angle measurements, drop test, SEM, as well as drug release studies, using ketoprofen as a model drug, are considered in this research. Results obtained have shown that the increase of the hydrophilic properties of polypropylene and polyamide fabrics with plasma treatment reverts in a higher release of the model drug studied from plasma-treated fabrics.

Measurement of Surface Roughness by Computer Vision in Planning Operations

Detection and Recognition of the surface roughness in the images is a topic which has received a lot of attention in the field of image processing. In this paper, a new non-contact measurement method of surface roughness, by texture analysis, is developed based on Charge Coupled Device (CCD) image in planning operations. The surface image of the workpiece is first acquired using the A102f CCD digital camera. The image captured will be converted to others kinds of images (Binary, and Gray scale) to be suitable for the detection algorithms used for the different types of surface. The main Image processing approaches is used such as Smoothing process, Noise reduction, Edge detection, Region Splitting, and Hough Transform etc. The predicted surface finish values using this measurement method are found to correlate well with the conventional stylus surface finish ( Ra ) values.

Linear dimensional change in acrylic resin disinfected by microwave energy

The purpose of this study was to characterize the linear dimensional change in specimens made in aluminum rectangular dies (65.0x12.0x3.5mm), with 4 reference demarcations, using the Clássico, Onda-Cryl and QC-20 brands of acrylic resin. Wax patterns with 67.0x15.0x5.0mm were embedded in metallic or plastic flasks with stone gypsum, according to the conventional technique. After stone gypsum setting, the wax molds were removed and the aluminum dies impressed in the stone gypsum mold with silicone material. The powder/liquid proportion and acrylic resin were manipulated according to manufacturer’s instructions. The metallic flask pressure was achieved using the RS tension method. After polymerization in water at 74OC for 9 hours, ebullition water for 20 minutes or microwave energy (900 W) for 10 minutes, the specimens were cooled at room temperature and then removed from the flasks and submitted to conventional finishing. The distances between the A-B, C-D, A-C, and B-D reference points were measured before and after disinfection by microwave energy (650W for 3 minutes). The linear dimensional evaluation of the distances was performed by the same operator with an Olympus optical comparator microscope, with an accuracy of 0.0005mm. Obtained data were submitted to ANOVA and Tukey’s test (α=.05%). The disinfection by microwave energy did not alter the original linear dimensions of the specimens.

Surface strength of silicon nitride in relation to rolling contact performance measured on ball-on-rod and modified four-ball tests

Silicon nitride (Si3N4) has been used in various rolling contact applications in turbomachinery, automotive and power industry. It is favoured to replace conventional steel due to its low density, low friction, corrosion resistance and good performance under extreme condition. However, a major limitation of its wider application is its high material and machining cost, especially the cost associated with the finishing process. In the present study, a low cost sintered and reaction bonded silicon nitride (SRBSN) is used to study the surface machining effects on its rolling contact performance. Attempt has been made to link the surface strengths of Si3N4 derived from half-rod and C-sphere flexure strength specimens to the rolling contact lifetimes of Si3N4 rod and ball specimens. The rolling contact fatigue tests are carried out on ball-on-rod and modified four ball machines. Three types of surfaces with coarse, fine and conventional finishing conditions are examined. Flexure strength tests on half-rod and C-sphere show an increasing surface strength from specimens with coarse, fine to conventionally machined conditions. During rolling contact fatigue test of as-machined specimens, there are no failures observed on both ball-on-rod and four ball tests after 100 million stress cycles. However, there is a trend of decreasing wear volumes measured on the contact path of rods and balls with coarse, fine and conventional conditions. In four ball test, spall failures are observed on pre-crack specimens. There is a trend of increasing rolling contact fatigue lifetime from pre-cracked specimens with coarse, fine to conventional machining conditions.

Study on a Magnetic Deburring Method by the Application of the Plane Magnetic Abrasive Machining Process

This research studies the influence of constant pressure acting on the magnetic particles brush for the precision machining of planar and curved workpieces. In particular, it examined the effects of constant pressure on improving the formal accuracy of the workpiece. This process method, constant pressure is applied to the magnetic pole of a conventional magnetic brush, the constant pressure acted to the surface of the workpiece through the magnetic particle brush formed at the magnetic pole surface. The authors conducted a plane magnetic abrasive finishing experiment using both the conventional magnetic abrasive finishing process and the newly proposed constant-pressure magnetic abrasive finishing process to compare the deburring characteristics between the processes for removing burrs from holes drilled in brass plate workpieces. In this experiment, a brass disk with a drilled hole was used as a workpiece. As a result, the difference in finishing characteristics was clarified. The results showed that the burr can be removed by use of this new plane magnetic abrasive finishing process and it is more useful than the conventional magnetic brush for improving the shape accuracy of the workpiece.

Dermatological Testing of an Emollient-Treated Menstrual Pad with a Novel Foam Absorbent Core

Dermatological testing was used to assess the skin compatibility of a menstrual pad with an emollient-treated surface layer and a novel, polymeric absorbent foam core. The test program included: 1) skin patch tests to assess cumulative skin irritation, 2) human repeat insult patch tests to assess the potential for contact sensitization, and 3) repeated application to the popliteal fossa (“behind-the-knee” test) to assess combined chemical irritation and frictional effects. Studies showed the new product and its components to be as mild to skin as other commercially available materials with no evidence for the induction of delayed contact hypersensitivity. Pads with an emollient-based topsheet finish were milder to the skin than pads with a conventional topsheet finish. The test program provides reassurance that the skin compatibility of the new menstrual pad is similar to that of conventional marketed pads with a history of safe use and consumer acceptance.

Modelling feeding behaviour, rate of feed passage and daily feeding cycles, as possible causes of fatigued pigs

This study was initiated to understand whether feeding behaviour and physiology may contribute to the rate of fatigued pigs at processing plants. Specifically, this study sought to determine: (1) how often pigs eat during the day, (2) the times of the day they eat and (3) a first approximation of the time from feed consumption to excretion (rate of passage) when housed in a group in conventional finishing facilities. Finally, models were constructed to try to predict the percentage of pigs with empty/diminished gastrointestinal (GI) tracts depending on the time of day of truck loading and transport durations. Pigs were randomly selected, weighed and selected for behavioural observations. From video records and live observations, the number of meals (feeding bouts) per day and the time of the day meals took place were recorded. Feed containing chromic oxide was fed to determine when a given meal was excreted. With the feeding times of day determined, models were constructed of the percentage of pigs that would have empty stomachs depending on the time of day pigs were removed from the barn and the length of transport/lairage. Finishing pigs housed in groups ate 5.6 ± 0.6 meals per day with an average feeding bout (meal) length of 11.3 ± 1.1 min. Many pigs fed ad libitum ate most of their meals during the afternoon and evening. The rate of passage of feed was 20.5 h (range = 18 to 24 h). Because fewer pigs ate in the late evening through morning, if pigs were shipped at these times they would have an increased risk of arriving at the stun at a plant with an empty GI tract. Some of the variation in rates of fatigued pigs and pork quality may be explained by times of day taken off feed and transport duration. Shipping in the afternoon or early evening may result in fewer pigs with empty/diminished GI tracts at processing which may influence the rate of fatigued pigs and pork quality.

Design of Sword-Form Electrode and Ultrasonic-Aid in Electrochemical Finishing of AISI 4340 Surface

It is difficult to execute the polishing process for swords surface. This study provides a design of sword-form electrode and a new area finishing process using an ultrasonic energy transmitted into the electrolyte to assist the process of electrochemical finishing on the surface of nickel chromium steels beyond traditional polishing process of sword surface instead of the conventional hand or machines surface finishing. The surface of the sword is electrochemically finished by different types of feeding electrodes as a finishing operation. In the experiment, four types of electrode were used with continuous direct current and axial electrode feed applied. The controlled factors included the chemical composition and concentration of the electrolyte, die material, initial gap width, and flow rate of electrolyte. The experimental parameters were current rating, feed rate of electrode, frequency and power level of ultrasonics, and electrode geometry. The higher current rating with ultrasonic assistance can avoid the difficulty of dregs discharge, thus reducing the finishing time. For the design of electrodes, an electrode of arc-end shape with small end radius and small wedge angle provides larger discharge space and better finishing effect. The electrode of round-pin shape with semicircular end is associated with higher current density and provides more opening discharge space and performs best. A low-cost and effective finishing process of the sword surface is presented. It is a great contribution that the ultrasonic-aided electrochemical finishing after sword finish just needs quite a shorter time than manual or machine polishing to make the surface of swords smooth and bright.

Quantification of Cyclodextrins Fixed onto Cellulose Fibers

Cyclodextrins are fixed onto different textiles using conventional finishing technologies to create new materials with a wide range of applications. One important problem in the textile finishing is evaluation of the amount of cyclodextrins accessible for complexation with guest substances. This research investigated the coordination and adsorption properties of cellulose materials with fixed monochlorotriazine substituted β-cyclodextrin for different primary, secondary and tertiary volatile aliphatic amines. The textiles showed high ability to complex formation from the gas phase due to molecular recognition between internal cyclodextrin cavity and hydrocarbon chains of the amines. The complexation reaction with cyclohexylamine is suggested for quantitative determination of the accessible cyclodextrins fixed on the surface of cellulose fibers.

Some Effects of Ultrasonic Vibration on combined Electrical Discharge Machining and its Practical Use

In electrical discharge machining (EDM), it is well known that removal rate and surface roughness are improved with ultrasonic vibrated tool. However, it is difficult in an actual machining to keep resonant conditions with a tool electrode of various sizes and materials. In this study, a new supporting method of an ultrasonic transducer and the vibration transmission method of a tool electrode are examined. EDM and abrasive machining were performed with ultrasonic vibrated tool. In the machining of steel plate, the machining speed was improved by five times compared with conventional finish EDM. The tool electrode excited by ultrasonic vibration is also applied to diamond abrasive grinding process for removing carbon layer on insulating ceramics after EDM with an assisting electrode. Mirror surface of silicon nitride ceramics can be achieved through the grinding process.

An ultra-precision polishing technique using high-velocity abrasive fluid

This paper deals with a newly developed method of high-velocity fluid polishing using an ultra fine abrasive wheel. In the first part of this process, the workpiece is ground by a wheel; then the wheel is drawn back for a few ?m and the ground surface is polished with a fine abrasive polishing fluid that flows at a high velocity between the wheel and the workpiece. In the conventional finishing process of optical and electrical components such as lenses and mirrors, some complicated processes including grinding and polishing are required. With the new method, the workpiece is finished successively by grinding and polishing on the same machine using the same polishing tool (wheel). In this work, an experimental system capable of successively grinding and polishing an optical component on the same machine was established, and experiments involving optical glass specimens were conducted in order to examine the proposed new method. The experimental results indicated that the workpiece was finished precisely and efficiently with an optimal surface roughness of 9 nm Ra after polishing.

Study on the Machined Surface Topography and Performances on Electrochemical Finishing

In this paper, electrochemical finishing（ECF） is presented. Compared with conventional finishing technology, the characterization of surface topography machined by ECF and its effect on the performance, including friction coefficient, original wear and tear, precision durability, fatigue strength, contact stiffness, corrosion resistance and adhesiveness are analyzed and studied. Experimental results have testified that ECF can observably improve surface quality of parts and finally improve its physical mechanical performances and lifetime to a large extent.

Study on the inner surface finishing of tubing by magnetic abrasive finishing

With the development of industry manufacturing technology, fine surface finish is in high demand in a wide spectrum of industrial applications. Presently, it is required that the parts used in manufacturing semiconductors, atomic energy parts, medical instruments and aerospace components have a very precise surface roughness. Amongst them, vacuum tubes, wave guides and sanitary tubes are difficult to polish by conventional finishing methods such as lapping, because of their shapes. The surface roughness of these tubes affects the performance of the entire system, but the finishing technology for these tubes is very scant in manufacturing fields. This project was proposed by a Shanghai Far East pharmaceutial and mechanical factory. They stated that the roughness of the inner surface must be less than 0.3 μm Ra after finishing. An internal magnetic abrasive finishing (MAF) process is proposed for producing highly finished inner surfaces of tubes used in this study. The process principle and the finishing characteristics of unbounded magnetic abrasive within internal tubing finishing are described first. MAF setup was designed for finishing three kinds of materials tubing, such as Ly12 aluminum alloy, 316L stainless steel and H62 brass. Experimental results indicated that finishing parameters such as polishing speed, magnetic abrasive supply, abrasive material, magnetic abrasive manufacturing process and grain size have critical effects on the material removal rate (MRR). How the inner surface micro shape changes course during finishing of an aluminous tube is demonstrated.

Wrinkle Recovery for Cellulosic Fabric by Means of Ionic Crosslinking

Methods are developed for imparting crease angle recovery performance to cellulosic fabrics based on durable ionic crosslinks. These methods, which avoid the formaldehyde release of conventional finishes, include treating cellulose with chloroacetic acid (or an other reactive anion) and cationized chitosan (or another polycation). Alternative methods include treating cellulose with 3-chloro-2-hydroxypropyl trimethyl ammonium chloride or another cationization reagent) and a polyanion, or with chloroacetic acid and 3-chloro- 2-hydroxypropyl trimethyl ammonium chloride. A method for producing highly cationic chitosan is also presented. Crease angle recovery and strength data are correlated to the amount of polyelectrolyte add-on.

A Study of a New Precision Finishing Process for Inside Surface of Silicon Nitride Fine Ceramic Pipe by Application of Magnetic Abrasive Machining

Results ar presented of a new process for internal precision finishing of slender fine ceramic pipes using a magnetic field generated by a permanent magnets. For finishing the interior surface of a long pipe, a new type of finishing equipment was developed which can be very easily used in an industrial surrounding. In general, the pipe is so slender that a conventional finishing tool is hardly inserted into the pipe deeply, being impossible to finish. Therefore, a new technology has been considered to finish inside of a slender ceramic pipe by a simple technique. In this experimental, Magnetic Abrasive Machining is applied for the inner surface of silicon nitride fine ceramic pipe using ferromagnetic particles mixed with chromium-oxide powder. It is shown the initial roughness of 2.6㎛ Ry(0.42㎛ Ra) in the inside surface can be precisely finished to the roughness of 0.1㎛ Ry(0.01㎛ Ra). This paper discusses the outline of the processing by the application of magnetic abrasive machining and a few finishing characteristics.

Comparison of conventional and organic beef production systems II. Carcass characteristics

Carcass characteristics were evaluated as part of a comprehensive study comparing organic and conventional beef production systems. Preconditioned crossbred steers from conventional (C; n=24) and low-input (O; n=30) farming systems were randomly divided into two groups and assigned to either organic (o) or conventional (c) feedlot systems. Conventionally fed steers received an ionophore, implants on day 0 and 70, and an anthelmintic on day 0. Steers were fed individually using Calan Feed Access Doors. Each calf was fed to reach target end points of 567 kg body weight and 0.75 to 0.90 cm back fat measured between the 12th and 13th ribs using real-time ultrasound when steers approached the target weight. Fixed effect of production system was fitted with age of steers at the start of the feedlot phase as a covariate. Steers in the Cc system had the heaviest (P<0.05) hot carcass weights and Oo steers the lightest (P<0.01). Ribeye areas from Cc steers were larger than those from Oo (P<0.01) and Oc steers (P<0.05). Steers in group Cc had less back fat than Oc (P<0.01) and Oo steers (P<0.05). There was no effect of production system on kidney, pelvic and heart fat or dressing percentage. Fixed effect of finishing system only was also analyzed. Steers in conventional finishing had heavier (P<0.01) carcasses, larger (P<0.01) ribeyes and less (P<0.05) marbling than steers in organic finishing.

X-ray Topography Study of Surface Damage in Single-Crystal Sapphire

ABSTRACTX-ray diffraction topography was used to investigate the relationship between subsurface damage, near-surface microstructure, and fracture strength in a series of sapphire modulus of rupture (MOR) bars which had been fabricated to proof test fabrication processes. The strength of the bars was determined by failure in four point bending. The tensile surface of the bars was also examined using optical microscopy and non-contacting surface profilometry. Both show that the bars have good surface finish, with a typical RMS roughness of 0.7 nm. No correlation was found between RMS surface finish and fracture strength. Although the bars appeared to be indistinguishable, topographs taken prior to fracture testing revealed that they are of two distinct types. Type 1 has an oriented microstructure consisting of a pattern of linear features running the length of the bars. Type 2 was typical of well-polished sapphire, containing individual dislocations and occasional damage from handling. We attribute the Type 1 microstructure to fabrication damage that was not removed by subsequent processing and/or polishing. Fracture strength data showed that the Type I (damaged) bars had strengths less than 70 % of the bars without damage. Topography is sensitive to near-surface damage that can be correlated to fracture strength. Neither low magnification optical microscopy nor conventional surface finish statistics could be correlated to strength.

A disc‐on‐flat wear test under starved lubrication

AbstractThe ‘disc‐on‐flat’ system has been used for testing wear under starved lubrication conditions. The rotating discs were made of a carbon steel, the surface finish of the discs being ground. Some of the discs were treated by ‘vibrogrooving’, to form regular microrelief. The flat counterface was made of a ground copper alloy. An industrial oil was used as a lubricant in a one‐drop test procedure. Microreliefs of a non‐touching design with a relative groove area of 34% caused less wear than microreliefs of a touching type with a relative groove area of 50%, whereas the wear caused by the ground disc was high, with seizure after 200–250 m of sliding distance. A one‐drop disc‐on‐cylinder test also showed that the wear caused by discs with regular microrelief was considerably less than that caused by discs treated by conventional finishing (grinding, polishing).

Development of a magnetic abrasive jet machining system for precision internal polishing of circular tubes

A recently developed finishing process using a rotating magnetic field is known to be very efficient for the finishing of parts such as vacuum tubes, sanitary tubes, etc. which are difficult to be finished by conventional finishing methods as they are generally curved tubes. However, the finishing system using a rotating magnetic field has the defect that the cross-section of the workpiece can only be circular because of the internal rotating tool. Therefore, a new finishing process for workpieces of non-circular cross-section is required. Magnetic abrasive jet machining is a new concept in finishing processes, being a precision internal finishing method using a working fluid mixed with magnetic abrasives, which is jetted into the internal surface of the tube, with magnetic poles being provided on the external surface of the tube. In this study, the new-concept finishing process, or the magnetic abrasive jet machining system, was developed. The machining conditions were predicted using simulation and some characteristics of the finishing process were analyzed.