Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/84—Systems specially adapted for particular applications
  • G01N21/88—Investigating the presence of flaws or contamination
  • G01N21/94—Investigating contamination, e.g. dust

Definitions

• the present invention relates to a method for detecting residues on a component and particularly on the surface of the component .
• a transparent adhesive strip is stuck onto the component.
• dirt located on the surface above all dust, metal dust, abrasions, chips
• the adhesive strip is stuck onto a white background, so that the individual dirt particles are well visible, and are then counted under the microscope (number) or measured using a photometer (grayscale) .
• the contaminations on the surface are chemically dissolved.
• the solution may then be examined using a gas chromatogram, for example (EN ISO 9377- 2) .
• the solution may be evaporated in a rotation evaporator, for example, and the residue on evaporation is subsequently examined in a downstream method.
• the components may be washed using 2-propanol, and subsequently the particles are counted.
• a disadvantage in this case is that lubricant solutions are not detected when they pass as real solutions into the 2-propanol. Undissolved lubricant escapes detection using the present invention as does particle counting.
• Clean sheet steel forms an adherent copper coating in acidic copper sulfate (CuSO 4 ) solution (concentration approximately 25 g/1) , since copper is the more noble metal. A discoloration may thus be observed in a copper sulfate test. It is to be clarified in the specific case whether this method may be applied with relatively noble steels. Because of the toxicity of copper ions and the possible influence on the tendency toward corrosion of the materials used in conductive connection to copper, copper sulfate is precluded for use in the drinking water system.
• CuSO 4 acidic copper sulfate
• the component to be examined is laid in an indicator solution (Berlin blue) or has a droplet of this indicator solution dripped on it. If the surface colors blue, it is not passive.
• the "Berlin blue test” is based on the formation of chemical compounds which the clean steel surfaces form with iron. A color reaction occurs. However, this may be more difficult or impossible to observe on the inner surfaces of hollow components. The influence of a reaction of the material with iron (II) and iron (III) ions may restrict the applicability of the Berlin blue test, however.
• electrochemical procedures which may provide information about the state of the surface (active or passive) , occur on a metallic conductive surface upon the presence of a current or voltage.
• an electrolyte droplet is applied between component surface and counter electrode and a current source is connected between component and counter electrode.
• the time curve of the resulting voltage and the current flowing is recorded and is used as the basis for judging the surface state.
• Two method variations are differentiated: the two electrode technique and the three electrode technique.
• the apparatus outlay required for performing the measurements is relatively large, however.
• Nitrite layers may be detected especially well using the method. However, only smooth surfaces may be analyzed using this method. The method is especially suitable for examinations in the measurement laboratory, it is unsuitable for testing components on location in production.
• XFA x-ray fluorescence analysis
• Contaminations in the nm range may be assayed using electron spectroscopy. However, it requires a high apparatus outlay which is reflected in the costs for the method. In production, methods of this type may typically not be performed routinely because of the high outlay.
• Electron and atomic force microscopy also requires a high apparatus outlay, which is reflected in the cost for the method. In production, methods of this type may typically not be performed routinely because of the high outlay.
• Hydrocarbon chains on the surface of components may be determined quantitatively using carbon determination through oxidation.
• the components to be assayed are heated to temperatures from 200 0 C to 800 0 C in a furnace.
• the temperature required is a function of the dirt composition.
• the hydrocarbon chains of organic contaminants are decomposed and desorbed, the carbon bonding in the furnace with the oxygen-containing transport gas to form a CO/CO2 mixture.
• a conductivity measuring cell in which the gas is admixed with sodium hydroxide (NaOH) , is used for measuring the carbon content of the transport gas. It is possible to differentiate between different hydrocarbon chains by decomposition at different temperatures because of the differences in the carbon released.
• the present invention is based on the object of allowing the testing of surfaces which are difficult to access, without the apparatus outlay growing.
• Preferred embodiments of the present invention are the subject matter of the subclaims.
• the present invention is based on the idea of detecting a contaminant rapidly and sensitively through visual comparison of a "dirt solution” and a reference solution. In particular a narrow area (solvent-water mixing zone) in a test tube is observed, in which the solution of dirt particles is especially noticeable.
• the method according to the present invention for detecting residues on a surface of a component comprises the following steps: producing a base solution and a reference solution from water, producing a washing solution by adding fresh solvent to the base solution, filling the component to be tested with the washing solution, wetting the entire inner surface of the component with a washing solution, draining the washing solution out of the component, producing a test solution by adding the washing solution to the base solution, comparing the test solution to the reference solution and testing whether a turbidity occurs in the mixing zone between the washing solution and the base solution as evidence for lubricant on the surface of the component.
• the method according to the present invention preferably has one or - if possible - multiple of the following features : to produce the base solution and the reference solution, 9 ml water is placed in a test tube, the water being deion- ized or distilled; to produce the washing solution, 1 ml fresh solvent is added using a Pasteur pipette to the base solution, so that a solvent-water mixing zone arises in the upper area of the test tube filling; the component to be tested is filled approximately 5 to 10% of its empty volume with the washing solution, but with not more than 0.1 1 of the washing solution; the component is shaken and/or pivoted after passage of a predefined exposure time to improve the solution of the lubricant from the surface; the exposure time is at least 10 minutes, and the shaking and pivoting is performed 10 to 15 times, the exposure time being doubled for complicated surfaces; to produce the test solution, 1.0 ml of the used washing solution is decanted from above using a Pasteur pipette into a test tube which is filled with 9.0 m
• An advantage of the present invention is that the present invention allows the testing of visually inaccessible surfaces.
• the complex (gas chromatography) assay of an extract or a residue of evaporation is dispensed with, the detection of the component purity is simplified, lubricants or lubricant components chemically dissolved in the solvent are also detected
• the method according to the present invention may be used independently of the component size, it is independent of the ambient humidity, no measuring apparatus is necessary, it is independent of the chemical composition of the lubricant, no materials are used which result in deposits and/or corrosion nuclei in the hollow components and on other surfaces
• the method according to the present invention may be applied to noble and base metals and to glass, ceramic, and many polymers, chemical reactions because of a testing method are avoided, no measuring apparatus are required, the method according to the present invention is independent of the layer thickness of the contamination, no analysis device is required, and the method is thus suitable for use on location.
• Figure 1 shows the sequence of a preferred embodiment of the method according to the present invention.
• step 1 9 ml deionized or distilled water is placed as a base solution in a test tube, step 1.
• a reference sample also referred to as a blind value or null sample
• 9 ml deionized or distilled water is produced, i.e., as 9 ml deionized or distilled water in a test tube.
• fresh solvent is added thereto using a clean Pasteur pipette in step 3 in such a way that a solvent-water mixing zone arises in the upper area of the test tube filling.
• the quantity of the solvent is preferably 1 ml.
• a change of the transparency may occur, which does not represent turbidity, however, and disappears within a minute. If a permanent turbidity forms, the solvent and/or the water is contaminated and may not be used for performing the test. Water and solvent are then to be replaced by fresh substances .
• the component to be tested is filled with the washing solution, step 4, an appropriate quantity of the washing solution being used.
• This washing solution quantity is a function of the volume of the component. Preferably, approximately 5 to 10% of the empty volume of the component is filled with solvent, the quantity is not to exceed 0.1 1 for reasons of environmental protection, however.
• the component is closed by a fitted stopper and rotated and turned in such a way that the entire inner surface is wetted with the washing solution, step 5.
• the washing solution In order to unfold its desired effect, the washing solution must act for at least 10 minutes. For complicated inner surfaces, the exposure time is doubled, so that all surfaces are wetted by the washing solution.
• the component is preferably shaken or pivoted 10 to 15 times. The lubricant solution is thus improved by the flow of the washing solution along the surfaces of the component .
• step 6 the washing solution is drained out of the component.
• a test solution is produced using the used washing solution and the remaining clean base solution, step 7.
• 1.0 ml of the used washing solution is removed using a Pasteur pipette and added from above into a test tube, which is filled with 9.0 ml of the base solution, i.e., deionized or distilled water.
• the test tube is preferably fixed, so that it does not move and the washing solution and the base solution may be situated one over another in layers in the test tube.
• turbidity which is more or less definite occurs in the test solution, which may be observed well in the mixing zone between the washing solution and the base solution. It may take up to 5 minutes until the turbidity occurs and/or is well recognizable in the test solution. How rapidly the turbidity occurs is a function of the type and the concentration of the lubricant. With some silicone lubricants and with lubricants based on polyfluorinated alkanes or per- fluorinated polyethers, the method must be applied multiple times in some circumstances.
• the test solution is preferably compared to the (clear) reference solution, in particular in the event of weak turbidities.
• the proof is furnished, either the lubricant is present on the component, step 10a, since in comparison to the reference a turbidity is recognizable, or no lubricant is present on the component, step 10b, since no turbidity is recognizable in comparison to the reference .
• Distilled or deionized water is to be used for the reference test and for the assay of the solvent applied to the component. If other water qualities are used, interference in the recognition of the turbidity in the samples and/or in the reference may occur. Sample and reference may then no longer be compared to one another .
• the present invention is suitable for small components which may be lifted and turned easily by one person alone.
• the quan- tity of the solvent used is preferably limited to at most 0.1 1.
• the temperature of the component surface to be cleaned may not exceed the boiling point of the solvent used, since it then vaporizes immediately. Temperatures of over 25° are preferably avoided, since many solvents vaporize noticeably then and the lubricant solution becomes worse. Temperatures below +0.1 0 C are preferably also avoided, since aqueous lubricant systems may then be partially or entirely frozen and may withdraw entirely or partially from being dissolved by the solvent.
• the present invention provides the result of the assay of the degree of contamination within a few minutes.
• the present invention may be applied to all solvent-resistant surfaces, such as glass, steels, ceramic, and many polymer materials.
• the present invention may be applied without the presence of a water or power connection, i.e., "in the field" or in running production. No specially trained personnel are required for performing the lubricant detection method described in the scope of the present invention. Laboratory instruments or testing devices are also not required. Some consumable materials such as solvent, deionized or distilled water, and Pasteur pipettes are necessary. No costs are thus caused by the application of the present invention.
• the method according to the present invention displays high efficiency, in particular if the lubricant entirely or partially dissolves in the washing solution.
• the method according to the present invention is thus equal to other detection methods which are based on dissolving, and it manages without further laboratory analysis.
• the method according to the present invention is also independent of the thickness of the lubricant layer.

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• General Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Biochemistry (AREA)
• Immunology (AREA)
• General Physics & Mathematics (AREA)
• Health & Medical Sciences (AREA)
• Pathology (AREA)
• Physics & Mathematics (AREA)
• Investigating Or Analysing Materials By Optical Means (AREA)
• Sampling And Sample Adjustment (AREA)
• Investigating Or Analysing Materials By The Use Of Chemical Reactions (AREA)
• Cleaning By Liquid Or Steam (AREA)

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• 2005
  • 2005-10-06 DE DE102005048151A patent/DE102005048151A1/de not_active Withdrawn
• 2006
  • 2006-10-06 US US12/083,075 patent/US7942037B2/en not_active Expired - Fee Related
  • 2006-10-06 RU RU2008118012/28A patent/RU2400734C2/ru not_active IP Right Cessation
  • 2006-10-06 BR BRPI0616922-8A patent/BRPI0616922A2/pt not_active IP Right Cessation
  • 2006-10-06 DE DE602006004618T patent/DE602006004618D1/de active Active
  • 2006-10-06 CA CA002622540A patent/CA2622540A1/en not_active Abandoned
  • 2006-10-06 JP JP2008534025A patent/JP4918552B2/ja not_active Expired - Fee Related
  • 2006-10-06 CN CN2006800370318A patent/CN101283267B/zh not_active Expired - Fee Related
  • 2006-10-06 EP EP06807044A patent/EP1946084B1/en not_active Not-in-force
  • 2006-10-06 WO PCT/EP2006/067143 patent/WO2007039644A1/en not_active Ceased

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