Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N11/00—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N11/00—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties
  • G01N11/10—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by moving a body within the material

Definitions

• the invention relates to a method for measuring the effective viscosity and the elastic properties of coatings according to the preamble of the main claim and to an apparatus for performing this method.
• a computer-controlled measuring apparatus is described in DE 34 20 341 C2 and allows the apparent viscosity during the flash-off and baking process to be determined quantitatively.
• a coated sheet is placed obliquely to the horizontal at a defined angle (for example 30 °) and the rolling movement of a steel ball in the paint film is compensated for by rotating the sheet with the help of a motor drive around an axis perpendicular to its plane and leading through its center.
• a punctiform light source and an associated light detector are used in conjunction with an electrical unit to control the motor drive, the motor rotating the coated sheet against the direction of movement of the ball in order to hold it in approximately the same position in the vertical direction.
• the speed of rotation of the coated sheet is inversely proportional to the viscosity of the coating. In this way, the film viscosity can be measured as a function of the time or temperature of the film.
• Inclination of the coated sheet causes both the formation of runners and the falling of the relatively heavy solvent vapors during the physical drying process. So it can happen that the steel balls used for the measurement run in areas of different layer thickness, which has an unfavorable effect on the measurement accuracy.
• the invention has for its object to provide a measuring method and a measuring device in which the disturbing runner formation as well as the falling of solvent vapors is avoided and in which the magnitude of the force acting on the ball is adjustable in a wide range, so that an expansion of the viscosity measuring range can be achieved.
• the coated substrate can be arranged horizontally and thus both the annoying runner formation and the falling off of solvent vapors is avoided.
• the magnitude of the magnetic force acting on the ball consisting of ferromagnetic material can be adjusted within a wide range, which means a substantial expansion of the viscosity measuring range from approximately 10 mPas to approximately 1000 Pas or more. This makes it possible to technically record a larger, previously unknown range of viscosity during the baking process of the coating than with the previous measuring apparatus.
• the measurement of the speed of the ball in the viscous lacquer film can be carried out on-line and the measurement process can therefore be fully automated.
• Fig. 1 is a sketch of the magnetic measuring arrangement and in Fig. 2 with the measuring according to the invention device received curve display.
• FIG. 1 the essential parts of the measuring apparatus are shown.
• a magnetisable ball 1 is in a coating 2 when moving a horizontally arranged, made of non-ferromagnetic material, z. B. glass existing substrate 3 under the influence of the Fe dgradient a below the substrate 3 arranged permanent or electromagnet 4 excited for rolling motion.
• the speed of movement v of the substrate 3 is regulated with the magnet 4 fixed so that the ball 1 is kept rolling at a constant distance .DELTA.x from the rest position.
• the Kugelposi tion is detected by means of a non-contact sensor. This corresponds to an experiment with constant magnetic driving force on the ball 1, whereby an Rone speed is established which is proportional to the reciprocal of the effective coating viscosity.
• the movement of the substrate 3 by a servo motor drive can be either a pure linear movement or a rotation (circular path). However, it can also be a combination of both (e.g. spiral track).
• the generation of the field by an electromagnet 4 has the advantage that the force acting on the ball 1 can be varied and regulated over a wide range via the coil current. This means a significant advantage over the previous measuring devices, in which a constant force, namely gravity, acts on the rolling ball. According to the invention, this results in an expansion of the viscosity measurement range to values between 10 mPas and 1000 Pas or more.
• the measuring method according to the invention also contains further possibilities for adapting the driving force or rolling speed of the ball 1 to the variable coating viscosity:
• the size of the magnetic force acting on the ball 1 can be adjusted within a wide range.
• Viscosity range 10 mPas to 1000 Pas or more.
• Measuring method can be extended to oscillatory rolling movements for measuring viscoelasticity.
• Fig. 2 shows a graph obtained with the magnetic measuring device described.
• oil films film thickness 250 pm
• Balls 1 of diameter 2.5 mm made of soft iron were used.
• Five calibration oils of different viscosity in the range of 80 - 1200 mPas were selected for the measurements.
• the oil films were produced with a drawing ruler on glass plates 3 with a thickness of 1 mm.
• the measuring temperature was 20.0 ° C, the length of the measuring distance ⁇ x was 3 cm.
• the physical-mathematical relationship shown in FIG. 1 means that the rolling speed of the ball 1 is inversely proportional to the effective viscosity of the coating 2.
• This theoretically derived linear relationship between the measuring time t (or ball rolling speed v) and the viscosity of the coating 2, e.g. the oil films is experimentally confirmed by the measurement results according to FIG. 2. This results in the
• the measuring device can be expanded so that the ball 1 under the additional influence of a lateral alternating magnetic field of an electromagnet 4 performs oscillatory rolling movements.
• the elastic properties of coatings 2 can be determined.
• Real and imaginary parts of the complex shear module (storage or loss module) as a function of frequency can be determined.

Landscapes

• Immunology (AREA)
• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Pathology (AREA)
• Analytical Chemistry (AREA)
• Biochemistry (AREA)
• General Health & Medical Sciences (AREA)
• General Physics & Mathematics (AREA)
• Health & Medical Sciences (AREA)
• Physics & Mathematics (AREA)
• Paints Or Removers (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Sampling And Sample Adjustment (AREA)
• Investigating Or Analysing Biological Materials (AREA)
• Length Measuring Devices With Unspecified Measuring Means (AREA)
• Coating Apparatus (AREA)
• Medicinal Preparation (AREA)
• Lubricants (AREA)
• Measuring Volume Flow (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=6345036

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Family Applications After (1)

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• 1988
  • 1988-01-11 DE DE3800474A patent/DE3800474A1/de not_active Withdrawn
  • 1988-11-24 JP JP63509441A patent/JPH03501770A/ja active Granted
  • 1988-11-24 AT AT88119574T patent/ATE69107T1/de not_active IP Right Cessation
  • 1988-11-24 DE DE8888119574T patent/DE3865958D1/de not_active Expired - Lifetime
  • 1988-11-24 WO PCT/EP1988/001070 patent/WO1989006352A1/de not_active Application Discontinuation
  • 1988-11-24 ES ES198888119574T patent/ES2027368T3/es not_active Expired - Lifetime
  • 1988-11-24 EP EP88910028A patent/EP0386089A1/de active Pending
  • 1988-11-24 BR BR888807875A patent/BR8807875A/pt not_active IP Right Cessation
  • 1988-11-24 US US07/536,595 patent/US5212981A/en not_active Expired - Fee Related
  • 1988-11-24 KR KR1019890701249A patent/KR920009415B1/ko not_active Expired
  • 1988-11-24 EP EP19880119574 patent/EP0324087B1/de not_active Expired - Lifetime
  • 1988-12-29 ZA ZA889704A patent/ZA889704B/xx unknown
• 1989
  • 1989-01-10 CN CN89100160A patent/CN1014930B/zh not_active Expired
  • 1989-01-10 CA CA000587821A patent/CA1314731C/en not_active Expired - Fee Related
• 1990
  • 1990-07-03 NO NO902969A patent/NO180736C/no not_active IP Right Cessation
  • 1990-07-06 DK DK199001633A patent/DK174172B1/da not_active IP Right Cessation

Non-Patent Citations (1)

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