Abrasive Cleaning Research Articles

El láser en la restauración de hierros arqueológicos intensamente mineralizados: criterios y protocolo de intervención en el caso de las armas de una necrópolis Vaccea (Valladolid, España)

The aim of this paper is to present the conservation treatment of a set of iron weapons from the Vaccean necropolis of the Ruedas de Pintia (Padilla de Duero, Valladolid) dated between the 4th century BCE and 2nd century CE. The cremation and burial conditions have been very detrimental to their state of conservation, generating an intense corrosion and their complete mineralization. This left the weapons in a very fragile and brittle state that made their restoration difficult, since it implied the removal of hard crusts that were much adhered to the surface and, during this process, the pieces were in danger of further fragmentation. Our proposal is the combined use of traditional abrasive cleaning techniques together with the 1064nm Nd:YAG laser cleaning that, in addition to removing corrosion products, transforms the surface into magnetite, a stable iron oxide.

Analysis the Effect of Different Surface Preparation Methods on Corrosion Resistance and Adhesion Strength of ASTM A36 Steel Substrate with Surface Tolerant Epoxy Paint as Coating Material

In the industrial world, to extend the service life of materials, protection methods are carried out to slow down the material's corrosion rate. The protection method that is often used is the coating method. The coating method is a protection method by coating the substrate material using a coating material to prevent contact between the substrate material and the environment. In this research, the substrate material used is ASTM A36 steel and the coating material used is Surface Tolerant Epoxy paint. The independent variable used in this study lies in the surface preparation method which consists of: solvent cleaning, hand tool cleaning, power tool cleaning, power tool to bare metal cleaning, and abrasive blast cleaning. Different preparation methods result in different roughness and cleanliness of the surface. This can affect changes in the mechanical properties of the coating material, such as corrosion resistance and adhesion strength. Based on the corrosion resistance test, it is found that the abrasive blast cleaning and power tool to bare metal cleaning methods produce the highest corrosion resistance properties because both have a rating number of 8 in the salt spray test results. Based on the adhesion strength test, it is found that the abrasive blast cleaning method also produces the highest adhesion strength. This conclusion refers to the results of the tape x-cut test where the sample produces a rating number 5A where the sample does not experience peeling after testing. In addition, the abrasive blast cleaning method produced the highest adhesion strength in the pull-off test, which was 7.16 Mpa. Thus, the abrasive blast cleaning method is the most effective surface preparation method for ASTM A36 steel before being coated with the coating material. In addition, it can also be concluded that the higher the surface roughness of the sample, the better the corrosion resistance and adhesion strength.

Development of ultra-low cycle fatigue life prediction model for structural steel considering the effects of surface roughness, loading frequency, and loading amplitude

Abrasive blast cleaning is often done for steel structures before applying various protective coatings, which produces rough surfaces with changes in fatigue properties. This problem has been addressed in the low- and high-cycle fatigue regimes; however, the effect of surface roughness in combination with different loading parameters on the ultra-low cycle fatigue (ULCF) life has not been reported thus far. To this aim, a total of 59 ULCF tests on designed specimens of SM400 steel with five levels of surface roughness were performed under various loading frequencies and displacement amplitudes. The analysis of experimental results indicates a substantial reduction in fatigue life with an increase in the surface roughness and loading amplitude and a decrease in the loading frequency. Additionally, the strength degradation, dissipation energy, and load–displacement curves are discussed in detail. With the use of experimental data, a new life prediction model characterizing the combined effects of surface roughness, loading frequency, and loading amplitude on the ULCF life is proposed. Moreover, the proposed model is validated by predicting the fatigue life under variable and constant loading amplitude patterns. Comparison between experimental and theoretical results shows that the proposed model accurately estimates the ULCF life within an error band of ±15%, with a reasonable selection of model parameters.

Methods of protection and decoration of aluminum profiles

The article provides a review of scientific and technical information on methods of applying a special protective coating to aluminum profiles to increase their properties and improve the marketability of products used as decoration. The most common among them are: anodizing (anodic oxidation), painting, coloring, laser processing, chemical etching, electropolishing, etc. It is shown that almost all processing methods begin with special preparation of the profile surface: degreasing, washing, etching and lightening (deoxidation). Anodizing is an electrochemical process in which a strong porous oxide film is formed on the surface of aluminum, which provides more reliable protection of the surface compared to a natural oxide film. This process allows you to improve the appearance of the aluminum profile, increases the corrosion resistance of the profiles, gives the surface layer wear resistance, as well as thermal and electrical insulating properties, increases the adhesion strength to the surface of the paint coating product. Anodized aluminum is easy to clean and can withstand short-term exposure to temperatures at which pure aluminum melts. Anodizing technologies used to achieve the required coating color are described. Painting is the process of applying a liquid or powder organic coating to the surface of the profile, which must resist the effects of sunlight, moisture, aggressive environments, temperature changes, and physical damage. Powder coatings have practically the same performance characteristics as liquid coatings of the same material, but the cost of their application is lower. They are applied electrostatically. The ingredients of the powder are binders (resin and polymer), organic and inorganic pigments to ensure the color of the coating, additives that improve the technological properties of the powder. Most often, the process of chromating and applying a conversion coating is used for aluminum profiles that can be powder coated. The chromate layer improves the adhesion between the surface of the profile and the coating, increases the corrosion resistance of the painted profile. A thick chromate coating has good corrosion resistance, but less adhesion compared to a thinner layer. They use "yellow" and "green" chromating, which, above all, differ in composition, number of components and processing time. Technological features of applying powder coating are considered. Abrasive cleaning is used as an independent way to give a special appearance to the surface of the profile, as well as to prepare the surface before anodizing or painting. Abrasive cleaning is carried out by blowing the surface of the profile with a high-speed stream of dry metal or non-metal particles, as a rule, washed quartz sand or aluminum oxide is used. This type of treatment can be used before painting not only for cleaning, but also for obtaining a matte texture. Laser processing makes it possible to manufacture products without roughness and notches, to increase corrosion resistance, wear resistance and strengthening of aluminum profiles due to surface alloying with chromium, nickel, niobium disilicide, etc. The saturation of the surface layers of the alloy with alloying elements occurs as a result of diffusion and mass transfer in the liquid phase with possible convective or purely mechanical mixing of the melt in the zone of action of laser radiation. Chemical polishing is carried out in acid solutions. Small concentrations of heavy metals in the solution enhance the polishing effect, especially when processing alloys with a small copper content. Air mixing is used, although a mechanical method is preferred. Agitation that is too intense can lead to streaking and pitting of the profile metal. The technological process of electropolishing includes preliminary treatment (cleaning, washing) and, in fact, electropolishing. The profiles are placed in a bath through which a direct current pass, where it acts as an anode. This type of treatment is used both as an independent operation and in technological processes of surface treatment, which include anodization. Typical modes of electropolishing depend significantly on the chemical composition of aluminum and its alloys. Patent studies conducted by the authors of this work showed that despite the variety of surface treatment methods, achieving a shiny profile surface is a complex technical task, the solution of which largely depends on the chemical composition of the aluminum alloy.

Bone morphogenetic protein-2 incorporated calcium phosphate graft promotes peri-implant bone defect healing in dogs: A pilot study.

ObjectivesThe evaluation of three different drug delivery modes of bone morphogenetic protein‐2 (BMP‐2) in healing peri‐implant bone defects in beagle dogs. BMP‐2 was incorporated in or onto calcium phosphate (CaP) granules in various ways: (i) directly on the outer layer of granules CaP: as an adsorbed depot; (ii) during the entire precipitation process of CaP: an internally incorporated depot; or (iii) during the biomimetic coating precipitation of BMP‐2 on the surface of CaP granules: as a coating incorporated depot.Material and MethodsAfter extraction of the lower molars and wound healing in 6 male beagle dogs, 36 implants were placed (n = 6 animal per group). Peri‐implant bone defects were induced. The following treatment groups were evaluated: no treatment; air abrasive surface cleaning (SC) using hydroxyapatite; SC and the subsequent filling of the defect with CaP without BMP‐2; SC plus the subsequent filling of the defect with CaP adsorbed BMP‐2; SC plus the subsequent filling of the defect with CaP internally incorporated BMP‐2; SC plus the subsequent filling of the defect with CaP coating incorporated BMP‐2. Histological and histomorphometric analyses were carried out to quantify and compare the changes in bone tissue surrounding the treated implants.ResultsIn Group 1 with no treatment, four implants were lost. Group 5 with the SC and the subsequent filling of the defect with internally incorporated BMP‐2 biomimetically prepared CaP (BioCaP), whereby the BMP‐2 is incorporated in the entire volume of all BioCaP particles, showed overall the best results to regenerate bone around the implants.ConclusionThis study concluded that the group treated with SC plus the subsequent filling of the defect with CaP BMP‐2 internally incorporated BMP‐2, whereby BMP‐2 has been incorporated in the entire volume of all CaP particles, showed overall the best results when aiming to regenerate bone around the implants.

Evaluation of a Continuous Laser Ablation Coating Removal Device for Steel Bridges

One common method for removing deteriorated coatings from steel bridges is abrasive blast cleaning. Although effective, abrasive blast cleaning can be hazardous to operators and must be conducted using expensive containment. One innovative solution to the hazardous nature and high expense of blast cleaning is laser ablation coating removal (LACR). LACR uses a high-energy laser, rather than conventional blasting, to remove the coating and has the potential to minimize operator hazards and eliminate the need for containment. The purpose of this study was to evaluate a continuous LACR system in relation to its coating removal effectiveness, industrial hygiene (IH), and effect on the steel substrate below the underlying coating. Coating removal and IH evaluation were performed on coated steel samples, including some with lead and other toxic metal coatings. LACR was also performed on bare steel, used to perform mechanical testing, such as tension, fatigue, hardness, and microstructural analysis to evaluate the effect of LACR on a steel substrate. In comparison to the pulsed LACR system evaluated in a previous study, the continuous LACR system was 2–27 times faster at removing most coatings, but it was unable to remove white coatings like the pulsed LACR system was able to do. IH evaluation showed that the continuous LACR system was likely to generate toxic metal fumes when ablating lead coatings, but this could possibly be minimized by designing an attached fume extraction system. Mechanical testing showed that the continuous LACR had no detrimental effects to the steel substrate.

Technological peculiarities of orthotropic bridge deck surface preparation for protective-adhesive layer laying

The article presents the main results of technology developing for continuous span orthotropic bridge deck surface preparation for protective-adhesive layer laying of the Amur bridge near the Khabarovsk. The pavement base on continuous steel spans is made of a metal plate with orthotropic properties, which is under a vehicular load distributed taking into account the pavement thickness. The vehicular load is transferred through the orthotropic deck to the superstructures’ truss members elements. Orthotropic bridge deck surface preparation is essential. This has a direct impact on the slab surface protection reliability from corrosion and the road structure durability as a whole, which is achieved through its reliable adhesion to the metal plate surface. The research object is the technological peculiarities of the pavement base on continuous steel spans preparation of the vehicular bridge orthotropic bridge deck. The authors present the determination results of the grain sand composition for abrasive slab cleaning, and the technological parameters of using a sandblasting machine. Measurement data of the dewpoint temperature formation on the spans of a metal orthotropic deck are given, which makes it possible to give recommendations on preventing the condensate formation on the slab surface that is being cleaned. The experimental study results also made it possible to give recommendations regarding the maximum acceptable temperature of impact on the anti-corrosion protection of the lower orthotropic deck surface, which was +120оC. The obtained results were used to prepare a technical report for the State Company «Khabarovskavtodor» on research work on the construction of road pavement on the upper deck of the Amur bridge.

Surface preparation as one of the main factors for ensuring the durability of anti-corrosion coatings

This article is devoted to the protection of bridge metal structures from corrosion. The article was written with the aim of studying one of the stages of anti-corrosion treatment, namely the preparation of the surface before applying a protective coating. In the article, the authors address the problem of the durability of paint coatings, and point to the main reasons, to a greater extent, affecting the service life. Studying the problem of the durability of protective coatings, the authors distinguish such a stage as preparing the metal surface of the bridge structure before applying the paintwork. The authors tell how important the preparation of the surface is and what negative consequences are possible if it is disturbed or not. For a more detailed study of the problem, the authors consider several methods of preparing the surface of the structure, such as: abrasive blast cleaning, phosphating the surface and heat treatment. When studying the above mentioned methods, the authors describe the technology of the work, the main factors affecting the final result of processing, as well as the positive and negative sides of each of the methods. For each of the surface treatment methods, the authors present illustrations that clearly show the basic concept of the selected treatment option. Summing up the comparative analysis of surface treatment methods before applying anti-corrosion coatings, the authors chose the most optimal processing method, as well as concluded that the importance of this stage and the possibility of its further improvement.

Cleaning contactor pins by laser

In semiconductor final electrical testing manufacturing, the contactor pin is very important component as to make a contact between leads of devices to test hardware circuits. The contactor pins are made from metal alloy material which provide a good electrical conductive. In daily test manufacturing, the contactor pins may be up to several thousand contacting insertions, which will collect of many dust at their tips of contactor pins. The classic traditional cleaning of the contactor pins typically use abrasive cleaning, such as brush. In this research, we present the using of laser application to clean the contactor pins with Laser cleaning machine IMT model 600MV with Nd:YAG laser type. The optimized parameter setting up on the laser cleaning machine are studied with varies of number of pulse shot between 2-4 pulses, distance between the tip of contactor between 2-4 inches and energy of the Laser beam between 15-250 mJ/pulse. The cantilever contact pin type of majority used in one of IC Test manufacturing have been put into the evaluation. The testing of the cleaning effects is performed by optical power scope and scanning electron microscopy, including the analysis of metallic pin surface impacted was done by the EDX analyses. The parameters for cleaning effectiveness and safe cleaning of pins corrosion in metallic surface were determined.

Experimental study of brackets adhesion with a novel enamel-protective material compared with conventional etching

IntroductionA reliable adhesion between fixed devices and dental surfaces is a key factor for the clinical success of any orthodontic treatment. Adhesion preparation is associated with damages related to abrasive cleaning, enamel structure defacing caused by etching, enamel loss when removing resin remnants at orthodontic treatment finishing stage or when conditioning surface for adhesive failure and fractures at bracket removal. AimThe objective of this study was to compare the shear bond strength of metallic brackets to enamel adhered with a novel non-damaging and remineralizing material for enamel versus the traditional 37% phosphoric acid etching. Material and methods75 Premolars collected from 15- to 40-years old healthy donors requiring extraction were collected. The teeth were then randomly divided into three groups (n = 25). One group was used for the experimental new method (EX), the second for the conventional phosphoric acid etching (PA) method and the third group was left without any treatment (NT). The metallic brackets were fixed with Transbond® XT adhesive and composite resin polymerized for 40 s with a halogen photocuring lamp. The shear bond strength was quantified by means of a universal testing machine at 1 mm/min crosshead speed and a load cell of 1 kN. Statistical analysis usedTests of normality, adjustment of the data to a root square, a one-way ANOVA and Tukey tests were performed. ResultsStatistically significant differences between the NT (1.4 MPa), PA (32.1 MPa) and EX (9.7 MPa) groups were observed. ConclusionsThe experimental material for conditioning human enamel induces calcium phosphates crystals on the enamel surface and improves the bond strength in comparison to the NT group.

Increasing the Efficiency of Diagnostics of Gas Pipelines Based on Preliminary Abrasive Cleaning

The need for preliminary abrasive cleaning of gas pipelines to increase the efficiency of in-pipe diagnostics by magnetic longitudinal magnetization flaw detectors is evaluated. The method of abrasive cleaning of pipes and a tool that implements the method is presented. Results from pilot tests under conditions typical of Saratovorgdiagnostika company are presented.

Numerical modeling of particle embedment during solid particle erosion of ductile materials

Particle embedment may occur in erosion testing, abrasive jet machining, blast cleaning and other industrial processes in which high speed impact of particles on relatively ductile targets occurs. It may strongly affect erosion rates, and lead to undesirable changes in surface roughness. Three-dimensional smoothed particle hydrodynamics (SPH) simulations were used to simulate particle embedment when 219.2µm and 362.9µm angular silicon carbide particles impacted a strain and strain rate hardening 6061-T6 aluminum alloy target under various process conditions. The models were assessed by comparison with measured embedment. Analysis of the results showed the following: (i) once the value of the effective friction coefficient between the substrate and the abrasive was determined by comparing predicted and measured embedment at one set of process conditions (particle velocity, size, angle of attack), the same friction coefficient could be used in models of all other combinations of process conditions to correctly predict embedment. (ii) Consistent with a previous simplified rigid-plastic analysis of idealized rhomboid particles impacting a polymer target, the static frictional force occurring after the maximum depth has been reached, the particle orientation and the impact angle all strongly affected embedment. Unlike the previous simplified model, the present model considered local strain rate and strain hardening, making it applicable for ductile metal targets. (iii) Consistent with some, but not all, reports in the literature, embedment at a given velocity increased with particle size. (iv) For a given particle size, embedment increased with incident velocity. (v) A critical minimum velocity below which embedment would not occur was predicted. The trends were discussed in terms of embedment mechanisms and particle impact kinematics. Overall, the work demonstrates that SPH methods can be used to provide insight into complex solid particle erosion phenomena.

Research into methods of cleaning silicate sandstones used for historical monuments

The cleaning of monuments ranks among the most critical processes in monument restoration, both from an aesthetic and a technological point of view. This article deals with research into the cleaning methods used for the removal of soiling firmly sticking to fine-grained silicate sandstones. The work contains petrological characterization of the substrates and the modes of soiling deposited on the surface. For the cleaning tests, two types of laser have been used (Q-switch and short free running), micro-abrasive cleaning using two different abrasives, and chemical cleaning based on ammonium fluoride. The effects of fluency, frequency, pre-moistening, and the type of device have been examined within the laser cleaning tests. These results have been compared with the results of the abrasive cleaning and chemical cleaning tests from the point of view of sensitivity to substrate, cleaning efficiency and rate of controllability. To evaluate the tests we have used a visual examination of the surface, microscopic examination of the surface and polished sections, and electron microscopy. After the cleaning tests, the changes in the physical properties of the surface were examined.

Prehispanic goldwork technology study by PIXE analysis

Technological characterization of pre-Hispanic gold metallurgy has still a wide deficit of analytical data. A set of 103 pieces from the so called “Quimbaya’s treasure” (QT) and the “Costa Rica collection” (CRC) of the Museo de America of Madrid were submitted to IBA analysis (PIXE and RBS) at the CMAM in three phases and the metal composition was determined. Only in a limited number of cases, due to the dramatic erosion of the gilded layer, produced by abrasive cleaning methods applied after the discovery and before the seventies, it was possible to determine also the sequence of layers, which gives information on the manufacture technology and the type and purity of the metals. PIXE results are reported and discussed. Data show that the CRC objects have very high gold levels (>80% in weight) while the QT have a more variable composition with significant Cu levels associated to the so called Tumbaga-alloy. In the cases where polishing had a tolerable effect, PIXE (and RBS), point to depletion gilding as a standard finishing process in the Costa Rica production, resulting in a gold rich surface alloy, while the variable composition of the QT objects may well be linked to deliberate colour choice.

Specific features of steel corrosion propagation and inhibition during abrasive dilatant treatment

The rate of corrosion damage development on steel after hydroabrasive and abrasive dilatant cleaning treatment, as well as the effect of some inhibitors on the rate of corrosion development on specimens cleaned by different methods have been studied. It has been shown that abrasive-dilatant treatment combined with inhibition efficiently hinders corrosion on freshly-cleaned surfaces and can slow down the formation and growth of corrosion sites by an order of magnitude.

System of Premixed Abrasive Jet Cleaning and Derusting on Steel Tube Inwall

The pretreatment of the tube wall's surface needs to be done before coating and plating. The cleaning and derusting play an important role in the pretreatment. This paper designs the cleaning and derusting system of the steel tube inwall by premixed abrasive jet technique. The system consists of the generating device of premixed abrasive jet, the abrasive retrieval device and working mechanism. The test of clean and derust were carried on steel tube inwall by the system. In the test, the large inner diameter of pipe fittings adopted the oblique type nozzle, the small ones adopted the conic abrasive jet nozzle. The test shows that the designed system can achieve the purpose of cleaning and derusting on steel tube inwall. The appropriate working parameters: the working pressure is 12MPa, the rate of water flow is 30L/min, the abrasive weight consistency is 30%.

Self-traveling robotic system for autonomous abrasive blast cleaning in double-hulled structures of ships

The aim of this paper is to propose the design, simulation, manufacture, and experimental validation of a new robotic system for fully automated blast cleaning in the double-hulled block. The entire robotic system consists of a new type of manipulator for the blast cleaning of the entire transverse web floors, and a specially developed 6-dof RRX mobile platform for self-traveling within the application area. The full cross section of the robotic system should be small enough to be placed inside the double-hulled structure, via a conventional access hole of 600 × 800-mm, from the outside shipyard floor. Moreover, the maximum height of the structures has a range of, typically, 2-m to 3-m, and the robotic platform is able to be located on the longitudinal stiffeners at a height range from 400-mm to 800-mm. Thus, the investigation of a customized manipulator, having a bi-directional stroke in order to approach the upper sections, is a most worthwhile subject in the automation of the shipbuilding process since such a system should be capable of carrying out continuous blast cleaning from the upper to the lower sections at one time, without the need for any additional operations. Throughout the field testing, significant results have been obtained, indicating that the new proposed system can successfully perform continuous blast cleaning for the entire transverse web floor and the longitudinal stiffeners without any dynamical instability of the robot platform. Proposed robotic platform, will bring great benefits to ship yard automation.

Effect of mechanical cleaning with granular material on the permeability of submerged membranes in the MBR process

The research on fouling reduction and permeability loss in membrane bioreactors (MBRs) was carried out at two MBR pilot plants with synthetic and real wastewater. On the one hand, the effect of mechanical cleaning with an abrasive granular material on the performance of a submerged MBR process was tested. Additionally, scanning electron microscopy (SEM) measurements and integrity tests were conducted to check whether the membrane material was damaged by the granulate. The results indicate that the fouling layer formation was significantly reduced by abrasion using the granular material. This technique allowed a long-term operation of more than 600 days at a flux up to 40 L/(m 2 h) without chemical cleaning of the membranes. Moreover, it was demonstrated that the membrane bioreactor (MBR) with granulate could be operated with more than 20% higher flux compared to a conventional MBR operation. SEM images and integrity tests showed that in consequence of abrasive cleaning, the granular material left brush marks on the membrane surface, however, the membrane function was not affected. In a parallel experimental set up, the impact of the operationally defined “truly soluble fraction” <0.04 μm from wastewater and activated sludge on the ultrafiltration membrane fouling characteristics was investigated. It was shown that the permeability loss was caused predominantly by the colloidal fraction >0.04 μm rather than by the dissolved fraction of wastewater and activated sludge.

Dirt-binding particles consisting of hydrogenated castor oil beads constitute a nonirritating alternative for abrasive cleaning of recalcitrant oily skin contamination in a three-step programme of occupational skin protection

In occupational fields with exposure to grease, oil, metal particles, coal, black lead or soot, cleansing formulations containing abrasive bodies (e.g. refined walnut shell, corn, wood, plastic or pumice) are used. These may constitute an irritant per se. As an alternative, hydrogenated castor oil (also known as castor wax) beads have been developed as dirt-binding particles. A polar surface contributes to their mechanical cleaning effects in removal of oily grime. Standardized examination of the in vivo effects upon the skin barrier of castor wax beads in comparison with abrasive bodies and pure detergent. Three cleansing preparations - (i) detergent, (ii) detergent containing castor wax beads, (iii) detergent containing walnut shell powder - were each repetitively applied in vivo (four times daily for 3 weeks), mimicking workplace conditions, in 30 healthy volunteers (15 with and 15 without an atopic skin diathesis) and compared vs. (iv) no treatment. The treatment effects upon the skin barrier were monitored by repeated measurements of functional parameters [transepidermal water loss (TEWL), redness] and surface topography. After a 3-week treatment, a significant global treatment effect (P < 0.0001) was found in the atopic group concerning TEWL as indicator for barrier function. A significantly higher TEWL and increasing erythema in the area treated with detergent containing walnut shell powder reflected its irritant effect compared with castor wax beads dispensed in the identical detergent. Cleaning properties of the two formulas were comparably superior to detergent alone. Castor wax beads constitute a novel nonirritating alternative for abrasive cleaning of recalcitrant oily skin contamination appropriate for individuals with an atopic skin diathesis in a three-step programme of occupational skin protection. As the skin barrier may additionally be influenced by the composition of dirt and use of skin protection and skin care measures under real workplace conditions, this component may now be used and examined further in different occupations.

Interactions between toothbrush and toothpaste particles during simulated abrasive cleaning

Most people clean their teeth using toothpaste, consisting of abrasive particles in a carrier fluid, and a filament-based toothbrush to remove plaque and stain. In order to optimize cleaning efficiency, it is important to understand how toothbrush filaments, abrasive particles, and fluid interact in a tooth cleaning contact. Work has been carried out to visualize, simulate, and model the processes in teeth cleaning. Laboratory cleaning contacts were created between a toothbrush and a transparent surface. Video and short-duration flash photography were used to study the processes by which a toothbrush traps abrasive particles, loads them against the counterface, and removes material. Small abrasive particles tend to be trapped at the contact between the filament tip and the counterface, while larger particles are trapped by clumps of filaments or at the contact with the side of a bent filament. Measurements of brush friction force were recorded during cleaning for a range of operating conditions. The presence of abrasive particles in the cleaning mixture increased the coefficient of friction, but the absolute particle concentration showed a lesser effect. It is surmised that only a few particles carry any load and cause any abrasion; increasing the particle concentration does not directly increase the number of load bearing particles. Abrasive scratch tests were also carried out, using polymethyl methacrylate (PMMA) as a wearing substrate. The scratches produced during these tests were studied. The microscopy images were used to deduce how the filaments deflect and drag, and how particles are trapped by filaments and scratch the surface. Again, it was observed that few of the brush filaments loaded particles to produce scratches, and that when a filament changes direction of travel the trapped particle is lost. Results of these studies were used to develop both qualitative and quantitative models of the process by which material is removed in teeth cleaning. The quantitative model contains, by necessity, several empirical factors, but nonetheless predictions compare well with in vitro wear results from the literature. The results were also used to draw some broad conclusions on appropriate brushing techniques for optimum tooth cleaning.