GB1593828A - Creation of Inventions and Patents with Artificial Intelligence

GB1593828A – Apparatus for measuring the dynamic visco-elastic properties of non-liquid viscous compounds including gels
– Google Patents

GB1593828A – Apparatus for measuring the dynamic visco-elastic properties of non-liquid viscous compounds including gels
– Google Patents
Apparatus for measuring the dynamic visco-elastic properties of non-liquid viscous compounds including gels

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Publication number
GB1593828A

GB1593828A
GB1397978A
GB1397978A
GB1593828A
GB 1593828 A
GB1593828 A
GB 1593828A
GB 1397978 A
GB1397978 A
GB 1397978A
GB 1397978 A
GB1397978 A
GB 1397978A
GB 1593828 A
GB1593828 A
GB 1593828A
Authority
GB
United Kingdom
Prior art keywords
tested
substance
vessel
measuring
elastic properties
Prior art date
1977-05-02
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)

Expired

Application number
GB1397978A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)

SNCF Mobilites

Original Assignee
SNCF Mobilites
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
1977-05-02
Filing date
1978-04-10
Publication date
1981-07-22

1978-04-10
Application filed by SNCF Mobilites
filed
Critical
SNCF Mobilites

1981-07-22
Publication of GB1593828A
publication
Critical
patent/GB1593828A/en

Status
Expired
legal-status
Critical
Current

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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

G01N11/10—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by moving a body within the material

Description

(54) APPARATUS FOR MEASURING THE DYNAMIC VISCO-ELASTIC
PROPERTIES OF NON-LIQUID, VISCOUS COMPOUNDS,
INCLUDING GELS
(71) We, SOCIETE NATIONALE DES CHEMINS DE FER FRANCAIS, a French
Body Corporate, of 45, Rue Saint Lazare- 75436 Paris Cedex 09, France, GILLES
SAUVAGE, of 9 Rue Jean XXIII- 91800 Brunoy, France, and ROBERT SAGLIER, of 2
Allee Michel-Ange, 91400 Alfortville, France, both citizens of the French Republic, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:
The present invention relates to an apparatus for measuring the dynamic visco-elastic properties of viscous, non-liquid substances, including gels. The invention also concerns a testing method utilising this apparatus.
It is known that it is very difficult to effect the measurement of the visco-elastic properties of certain flexible and malleable products, in view of the inherent physical properties of these products, these products including lubricant greases, gels, natural or synthetic elastomers or rubbers.
The present invention has the object of providing an apparatus for measuring these intermediate compounds between the “genuinely” solid and liquid products.
The apparatus according to the invention is characterised in that it comprises, mounted in an insulated jacket or casing in which circulates a fluid at a given temperature, a vessel or container intended to take the product to be tested, means for imparting vibratory stresses to the product and, mounted on the vessel, a displacement-detecting device cooperating with a reference or target plate placed on the surface of the product to be tested.
The apparatus according to this invention also preferably comprises a thermal probe permanently installed in the vessel containing the product to be tested and, if necessary, a device for stirring the product to be tested, as well as a device emitting radiation.
The present invention also concerns a testing method characterised in that a sample of a product to be tested is placed in the apparatus of the invention and is subjected to a process for the measurement of its dynamic visco-elastic properties by means of vibratory stresses imparted by a conventional vibrator device cooperating with the apparatus of the invention in which case the amplitude responses detected by the pick-up or detector cooperating with the target and reference element are compared with those obtained after the sample has been subjected to various thermal, shearing or radiation stresses, the different comparative measurements being carried out at a predetermined temperature.
The present invention will be better understood from the following description of the non-restrictive embodiments of a measuring apparatus, with reference to the accompanying drawing in which:
Figure 1 is a sectional view of the apparatus according to the present invention
Figure 2 is a partial view of the apparatus in Figure 1 along another axial section;
Figure 3 is a partly sectional view of another embodiment of the apparatus, which can be used in particular for testing elastomeric compounds;
Figure 4 is a partial sectional view of a further embodiment according to the invention, provided with a stirring device;
Figure 5 is a response graph of a substance before testing, and
Figure 6 is a response graph of the substance corresponding to the graph in Figure 5, but after testing.
The container 1 holding the product to be tested, for example a grease, mounted fluidtightly by way of a seal 12 in a jacket 2 surrounded by heat insulation 4. A fluid at a given temperature 0, which is supplied through an inlet pipe 5 and discharged through an outlet pipe 6, circulates between the jacket 2 and the container 1. The jacket 4 is secured to a base plate 15a by a set of screws 7, which plate 15a is itself firmly secured to a frame 13 by screws 14.
A detecting system provided with a proximity detector or sensor 3 is arranged axially relative to the container 1 and is surrounded by a detector guide-support unit 10 which fits onto the aperture of the container 1. This detector 3 is connected by plugs to a suitable device capable of handling the data detected, and cooperates with a reference or target plate 16 (in Figure 3) of the metal pad type placed on the surface of the product to be tested.
A thermal probe 16 (see Figure 2) immersed in the product to be tested is positioned in an orifice 18 which passes through the wall of the container 1. This thermal probe 16 is provided with plugs 17 intended to connect said probe to a suitable display or indicator appliance.
The spindle 19 (see Figure 4) of a propeller-like stirring device 20 passes through a cover plate 21 of the container 1 and can be so arranged that, when the spindle rotates, the propeller 20 can impart shearing stresses to the test product placed in the container 1.
In the embodiment of the apparatus according to Figure 3, the container 22 has a flat bottom 22a designed to receive parallelepipedal samples of the substances to be tested, for example a block of elastomer E, on whose upper face is arranged the target or reference element 16 which cooperates with the detector 3.
By utilising the apparatus according to the invention, it is possible for a sample of the test product to be subjected to the combined (or not) action of various strains or stresses, for example of temperature, shearing, vibrations and/or radiation. It is possible, for example, to obtain a temperature which can be adjusted by about one degree centigrade, within a temperature range of between -40 and 1500C, by passing a suitable fluid through the insulated jacket 2.
The rotating agitator 19, 20 may attain a speed which can be adjusted, for example, within a range of from 10 to 3000 rpm, so as to subject the substance to the desired shearing stresses. Similarly, a vibratory motion can be applied to the test product along any one or more axes, the former being adjustable both in amplitude, for example within a range of from 0 to Smm, and in frequency, for example within a range of from 0 to 10 kHz.
A method of measuring the elastic properties of a lubricant grease will now be described below, solely by way of example.
In this test there is determined the response of the compound to vibratory stresses produced, for example, by means of a suitable commercial vibrator device, the values being read on a visual indicator or recorded, or else by a combination of these means.
The curves shown in Figure 5 are obtained using an appropriate precision measuring instrument. For the solid-line curve the test is conducted at a temperature of 90″C and at 20″C for the broken-line curve. These curves are plotted for the amplitude responses (in Clam) to the stresses of vibrations having different excitation frequencies (in Hz) for an excitation amplitude of + 6mm and frequencies of from 0 to 60 Hz.
The graph in Figure 6 shows the response curves of the preceding examples tested under the same conditions as previously but after they have been subjected for several hours to
the action, combined or not, of the temperature previously set at a given level, of shearing or of radiation. In view of the detachable nature of the detector support in the apparatus
according to the invention, these different tests can be performed in situ by replacing the
detector device with a fluid-tight cover, stirring device or radiation-emitting appliance.
On the response curve shown in solid line in Figure 6 a peak is reached followed by a
decline, the ascending portion ahead of the peak being “less steep”, moreover, on the
y-axis in relation to the corresponding curve in Figure 5. This phenomenon is even more
obvious if a comparison is made between the steepness of the broken-line curves in Figures
5 and 6 respectively.
This method of measurement makes it possible to determine whether or not there exists
one or more resonances for the frequency range investigated, as well as the evaluation of
the ‘unctuousness” of the grease tested. Unctuousness means the property exhibited by
certain lubricants of adhering to a greater or lesser extent to the components which they are
intended to lubricate.
A simple visual examination of the curves in Figures 5 and 6 enables significant
conclusions to be drawn with regard to the influence of various parameters, for example
frequency and temperature, on the behaviour of the grease to be tested.
Mathematical analysis of the physical phenomenon of forced harmonic vibration, to
which the sample is subjected during the test, makes it possible to determine two
parameters which are characteristic of dynamic behaviour, i.e. the modulus of elasticity and
viscosity (unctuousness and internal damping).
The modulus of elasticity can be calculated with a satisfactory degree of approximation using the formula
where p is the density of the grease, h is the height of the sample to be tested and Fl is the value of the primary resonance frequency.
The testing method, which can be carried out by means of the apparatus according to the invention, makes it possible:
– to distinguish a new product by its elasticity (in llm) and also by its resonance frequency;
– to evaluate the combined effect of the parameters of stresses such as temperature, rotation, vibrations, as well as, optionally, the effect of certain parameters, dependent upon the manufacture of the product, on its consistency or mechanical strength;;
– to measure the unctuousness of a lubricant by determining at which value of the force applied to the test specimen the latter becomes detached from the walls to which it adheres in the knowledge of this force (F = my) and also of the wall areas of the test vessel, it is thus possible to determine the stress or strain at which there occurs the loss of adhesion of the lubricant to the walls of the vessel.
WHAT WE CLAIM IS:
1. An apparatus for measuring the dynamic visco-elastic properties of a viscous non-liquid substance comprising a vessel for containing the substance to be tested, means for imparting vibratory stresses to the substance, and a displacement-detecting device mounted on the vessel, the said detecting device cooperating with a reference or target plate able to be placed on the surface of the substance to be tested, wherein the vessel is mounted in an insulated jacket through which a fluid at a given temperature can be circulated.
2. An apparatus as claimed in claim 1 wherein the container is provided with a thermal probe.
3. An apparatus as claimed in claim 1 wherein the detecting device is associated with a stirring or shearing device.
4. An apparatus as claimed in claim 1 wherein the detecting device is associated with a radiation-emitting appliance.
5. An apparatus for measuring the dynamic viscd-elastic properties of a viscous, non-liquid substance substantially as hereinbefore described with reference to and as illustrated in either Figures 1 and 2 or in Figure 1 and 2 as modified by Figure 3 or Figure 4 of the accompanying drawings.
6. A method of testing utilising the apparatus as claimed in a claim 1 comprising placing a sample of a substance to be tested in an apparatus as claimed in claim 1, subjecting the sample to a process for measuring its dynamic visco-elastic properties by means of vibratory stresses imparted by a conventional vibrator device which cooperates with the said apparatus and comprising comparing the amplitude responses detected by the detector cooperating with the target and reference element with those obtained after the sample has been subjected to various thermal, shearing or radiation stresses, the different comparative measurements being carried out at a predetermined temperature.
7. A method as claimed in claim 6 substantially as hereinbefore described.
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. The modulus of elasticity can be calculated with a satisfactory degree of approximation using the formula where p is the density of the grease, h is the height of the sample to be tested and Fl is the value of the primary resonance frequency. The testing method, which can be carried out by means of the apparatus according to the invention, makes it possible: – to distinguish a new product by its elasticity (in llm) and also by its resonance frequency; – to evaluate the combined effect of the parameters of stresses such as temperature, rotation, vibrations, as well as, optionally, the effect of certain parameters, dependent upon the manufacture of the product, on its consistency or mechanical strength;; – to measure the unctuousness of a lubricant by determining at which value of the force applied to the test specimen the latter becomes detached from the walls to which it adheres in the knowledge of this force (F = my) and also of the wall areas of the test vessel, it is thus possible to determine the stress or strain at which there occurs the loss of adhesion of the lubricant to the walls of the vessel. WHAT WE CLAIM IS:

1. An apparatus for measuring the dynamic visco-elastic properties of a viscous non-liquid substance comprising a vessel for containing the substance to be tested, means for imparting vibratory stresses to the substance, and a displacement-detecting device mounted on the vessel, the said detecting device cooperating with a reference or target plate able to be placed on the surface of the substance to be tested, wherein the vessel is mounted in an insulated jacket through which a fluid at a given temperature can be circulated.

2. An apparatus as claimed in claim 1 wherein the container is provided with a thermal probe.

3. An apparatus as claimed in claim 1 wherein the detecting device is associated with a stirring or shearing device.

4. An apparatus as claimed in claim 1 wherein the detecting device is associated with a radiation-emitting appliance.

5. An apparatus for measuring the dynamic viscd-elastic properties of a viscous, non-liquid substance substantially as hereinbefore described with reference to and as illustrated in either Figures 1 and 2 or in Figure 1 and 2 as modified by Figure 3 or Figure 4 of the accompanying drawings.

6. A method of testing utilising the apparatus as claimed in a claim 1 comprising placing a sample of a substance to be tested in an apparatus as claimed in claim 1, subjecting the sample to a process for measuring its dynamic visco-elastic properties by means of vibratory stresses imparted by a conventional vibrator device which cooperates with the said apparatus and comprising comparing the amplitude responses detected by the detector cooperating with the target and reference element with those obtained after the sample has been subjected to various thermal, shearing or radiation stresses, the different comparative measurements being carried out at a predetermined temperature.

7. A method as claimed in claim 6 substantially as hereinbefore described.

GB1397978A
1977-05-02
1978-04-10
Apparatus for measuring the dynamic visco-elastic properties of non-liquid viscous compounds including gels

Expired

GB1593828A
(en)

Applications Claiming Priority (1)

Application Number
Priority Date
Filing Date
Title

FR7713191A

FR2389884B1
(en)

1977-05-02
1977-05-02

Publications (1)

Publication Number
Publication Date

GB1593828A
true

GB1593828A
(en)

1981-07-22

Family
ID=9190187
Family Applications (1)

Application Number
Title
Priority Date
Filing Date

GB1397978A
Expired

GB1593828A
(en)

1977-05-02
1978-04-10
Apparatus for measuring the dynamic visco-elastic properties of non-liquid viscous compounds including gels

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FR
(1)

FR2389884B1
(en)

GB
(1)

GB1593828A
(en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

US6588254B1
(en)

2002-03-29
2003-07-08
Waters Investment Limited
Rotary rheometer

US6798099B1
(en)

2003-07-14
2004-09-28
Waters Investment Limited
Devices, systems and methods for sensing temperature of a drag cup in a rheometer motor

CN105181529B
(en)

2015-10-29
2018-02-02
中国石油集团渤海钻探工程有限公司
One kind measure viscoelastic method of gel particle

1977

1977-05-02
FR
FR7713191A
patent/FR2389884B1/fr
not_active
Expired

1978

1978-04-10
GB
GB1397978A
patent/GB1593828A/en
not_active
Expired

Also Published As

Publication number
Publication date

FR2389884A1
(en)

1978-12-01

FR2389884B1
(en)

1980-02-15

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