KR100877494B1 - Mixed-Flow Rheometer - Google Patents

Abstract

The present invention relates to a mixed flow rheometer for measuring the behavior of mixed-flow in which shear and extension (compression) flows are mixed. Specifically, the present invention relates to a rheometer for introducing a mixed flow direction to a fluid under test by introducing a direction changer for converting a rotational motion of a rotating shaft into a spiral motion in a conventional rotational rheometer. The mixed flow rheometer of the present invention simultaneously introduces rotational motion and vertical motion to the fluid under test, so that shear flow and elongation (compression) flow appear together, which cannot be realized in the conventional rotational rheometer or capillary rheometer. The biggest feature is that mixed flow can be realized. As a result, the behavior of viscoelastic materials such as polymer materials can be more similarly simulated in actual industrial sites, thereby providing more accurate physical property values for process design and control. Furthermore, the above effects can be achieved only by replacing some components of the conventional rotatable rheometer, and thus, the conventional apparatus can be used as it is, and as a result, a high economic efficiency is also achieved.

Mixed flow, rheometer, reversal, shear flow, elongation (compression) flow

Description

Mixed-Flow Rheometer

1 is a longitudinal sectional view schematically showing a conventional rotatable rheometer.

2 is a longitudinal sectional view schematically showing another conventional rotatable rheometer.

Figure 3 is a schematic diagram of the shear flow induced in the fluid under test in the conventional rotational rheometer.

Figure 4 is a schematic diagram of the stretching or compression flow induced in the test fluid in the conventional capillary rheometer.

5 is a graph showing the measurement range of the viscosity according to the type of flow.

6 is a front view of another conventional rotary rheometer.

7 is a longitudinal sectional view schematically showing a lower unit in one embodiment of the mixed flow rheometer of the present invention.

8 is an explanatory view schematically showing a second direction change member of the present invention.

** Explanation of symbols for main parts of drawings **

10: lower friction plate 10 ': upper friction plate

20: casing 21: linear bush

25: guide groove 30: guide holder

35: guide protrusion 40: ball screw nut

50: clamp holder 51: clamp bolt

55: rotating plate 60: base

70: lower fixture 70 ': upper fixture

75: vertical motion fixture 80: transducer

The present invention relates to a mixed flow rheometer for measuring the behavior of mixed-flow in which shear and extension (compression) flows are mixed. Specifically, the present invention relates to a rheometer for introducing a mixed flow direction to a fluid under test by introducing a direction changer for converting a rotational motion of a rotating shaft into a spiral motion in a conventional rotational rheometer.

Until now, the technique of measuring the viscosity of a sample by a rotary viscometer has been described as the motor 105 is rotated using the Hall sensor 103 as shown in 101 in Figure 1 to detect the torque according to the contact resistance of the rotating rod Rotating rod when the motor 205 rotates by measuring the electromotive force varying according to the contact resistance between the rotating rod 111 and the sample 109 to be measured or using the torque meter 203 as shown in FIG. According to the magnitude of the contact resistance between 207 and the sample 209 to be measured, the torque change value has been used in terms of the measured viscosity.

That is, in the case of the viscometer 101 illustrated in FIG. 1, when the motor 105 is rotated and driven, the coupling 107 is also rotated to rotate the rotating rod 111 connected to the coupling 107, and the container 113 is rotated. Contact resistance occurs due to friction between the sample 109 and the circumferential surface of the rotating rod 111 contained therein. According to the magnitude of the contact resistance, the change in motor electromotive force is detected by the hall sensor 103 and detected as a DC microvoltage signal, and the amplifier and the A / D converter 115 amplify and convert the microanalog signal into a digital signal, and then By the calculation of the computer 117, it displays on the digital display window 119 as a viscosity value. At this time, the rotational speed of the motor 105 is adjusted using a volume or digital motor controller 121, and the speed at the time of adjustment can be monitored on the digital display window 119.

In the case of the viscometer 201 shown in FIG. 2, when the motor 205 is rotated, the torque meter 203 connected to the coupling 211 and the rotating rod 207 connected by another coupling 213 to the lower portion thereof are connected. As a result, contact resistance is applied to the rotating rod 207 due to friction between the sample 209 and the rotating rod 207 circumferential surface contained in the container 215. At this time, the contact resistance is detected as the magnitude of the torque in the torque meter 203, and the small voltage signal detected by the torque meter 203 is amplified by the amplifier and the A / D converter 215 and converted into a digital signal. Calculated by the microcomputer 217 and displayed as a viscosity value through the display window 219, at this time, the rotational speed of the motor 205 is made by the motor controller 221 like the viscometer 101 of FIG.

However, such a conventional rotational rheometer was able to cause only simple shear flow generated when the rotating rods 111 and 207 are rotated at a constant speed, or dynamic shear flow generated when the rotating rods 111 and 207 are decelerated or accelerated. (FIG. 3). In addition, the conventional capillary rheometer can only induce kidney flow or compression flow (FIG. 4), and no rheometer capable of inducing the shear flow and extension (compression) flow together has not been reported to date.

5 is a graph showing the viscosity measurement area of a conventional rheometer, clearly showing the need for a rheometer capable of measuring the mixed flow. In other words, when using a conventional rheometer, each measurement device has a limited range of measurement, and therefore, data obtained by using a conventional viscometer has limitations.

In actual industrial processes, especially in processes dealing with viscoelastic materials such as polymers, mixed flows of shear and elongation (compression) flows frequently occur. Therefore, mixed flows including both shear and extension (compression) flows must be analyzed and new rheometers such as mixed-flow rheometers are necessary.

The present invention has been made to solve the above problems, by introducing a motion direction conversion unit for converting the rotational motion by the motor in the rotational rheometer to the spiral motion, causing shear flow and elongation (compression) flow together It is an object of the present invention to provide a rheometer capable of measuring the mixed flow of fluid.

In order to achieve the object as described above, the mixed flow rheometer of the present invention,

A rotatable rheometer comprising an upper friction plate in contact with a fluid under test and vertically upward, and an upper unit comprising the lower friction plate in contact with the fluid under test and a lower unit including the lower friction plate.

The upper unit includes a motor, a rotating shaft for receiving a rotational force of the motor, and a rotating shaft, and an axial direction converting portion for converting the rotating motion of the rotating shaft into a helical motion, wherein the upper friction plate transmits the helical motion of the moving direction converting part. Take a spiral,

The lower unit includes a motor, a rotating shaft for receiving a rotational force of the motor to rotate, and a motion direction converting part for converting the rotating motion of the rotating shaft into a spiral motion, wherein the lower friction plate transmits the helical motion of the motion direction converting part. It is characterized by receiving spiral movement.

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The mixed flow rheometer according to the present invention can induce rotational flow and extension or compression flow to the fluid under test by reciprocating helical motion of the upper or lower friction plate by the direction of motion conversion unit. It is possible to measure the behavior accordingly.

In addition, the movement direction conversion unit

A first movement direction converting member for converting the rotational movement of the rotary shaft into a vertical movement; And

Second direction changing member for converting vertical motion into spiral motion

It is preferable to include.

Specifically, the present invention can be applied to any of the members for converting the rotational motion into a helical motion directly to the motor and the rotation axis, the two-stage movement direction for converting the linear motion from the rotational motion, and again from the linear motion to the spiral motion It is more preferable to introduce a conversion method.

In addition, the first movement direction conversion member may be any member for converting the rotational movement into a vertical movement, and includes a ball screw nut, various cams, and the like. In the present invention, ball screw nuts are particularly preferable.

In addition, the second direction of motion conversion member may be any member for converting the vertical motion into the spiral motion, in particular in the present invention

A linear bush provided on a side core portion of the casing in which vertical motion is transmitted by the first movement direction converting member, and a guide groove formed in an oblique direction on an outer circumferential surface thereof; And

A guide holder having a guide protrusion inserted into the guide groove of the linear bush and converting vertical motion into spiral motion

It is preferable to include.

In addition, the lower friction plate may be in the form of a flat plate for measuring the behavior of high viscosity fluid, or may be in the form of a container in which the outer circumferential surface is vertically extended. Through this, there is an advantage in that the mixed flow can be induced not only for a high viscosity fluid such as a polymer material but also for a low viscosity fluid.

In addition, it is preferable that the lower unit includes the motor, the rotating shaft, and the direction change unit. By doing so, the upper unit of the fluid under test has a transducer which can calculate a viscosity or modulus by measuring torque or normal force and the like, and the lower unit causes movement and It will be in charge of changing its direction.

Hereinafter, with reference to the accompanying drawings, a preferred embodiment of the present invention will be described in detail. First, in adding reference numerals to the elements of each drawing, it should be noted that the same elements are denoted by the same reference numerals as much as possible even if they are displayed on different drawings. In addition, in the following description there are shown a number of specific details such as specific components, which are provided only to help a more comprehensive understanding of the present invention, it is common in the art that the present invention may be practiced without these specific details. It is self-evident to those who have knowledge of the world. In describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

Example

6 is a front view of a conventional rotatable rheometer, and FIG. 7 is a longitudinal sectional view of a lower unit in one embodiment of the mixed flow rheometer of the present invention.

One embodiment of the mixed flow rheometer of the present invention replaces the lower fixture 70 including the lower friction plate 10 in FIG. 6 with the lower unit of the present invention in FIG. 7. 30 is fixed, and the rotating plate 55 coupled with the rotating shaft (not shown) of the motor (not shown) is connected and fixed to the clamp holder 50 by the clamp bolt 51.

The mixing flow rheometer of the present invention induces mixing flow in the fluid under test between the upper friction plate 10 ′ and the lower friction plate 10 as follows.

First, when the rotational force of the motor (not shown) rotates the rotating shaft (not shown), the combined rotating plate 55 rotates, and the clamp holder 50 connected thereto is rotated. The rotational movement of the clamp holder 50 is converted to vertical movement moving up and down by the ball-screw nut 40, so that the casing 20 is vertical movement.

At this time, the linear bush 21 provided on the side core portion of the casing 20 has a linear bush 21 of the guide holder 30 in the guide groove 25 formed in an oblique direction on the outer circumferential surface thereof, as shown in FIG. The guide protrusion 35 formed at the side end is inserted and guided, thereby guiding the casing 20 in a spiral motion.

Therefore, the vertical motion fixture 75 coupled to the casing 20 and the lower friction plate 10 fixed to the vertical motion fixture 75 also perform a spiral motion.

When the motor (not shown) rotates the rotating shaft (not shown) in one direction and then rotates the rotating shaft (not shown) in the opposite direction, the ball-screw nut according to the rotation angle of the clamp holder 50. 40 is reciprocating up and down at a constant height, the lower friction plate 10 is to reciprocate the spiral movement, as a result of the fluid under test due to the presence of the relatively fixed upper friction plate (10 ') Elongation or compression flow is expressed simultaneously with shear flow, resulting in mixed flow behavior.

Although the above has been illustrated and described with respect to the preferred embodiments of the present invention, the present invention is not limited to the specific embodiments described above, those skilled in the art without departing from the gist of the present invention various modifications Of course, implementation is possible. Therefore, the scope of the present invention should not be construed as being limited to the above embodiments, but should be defined by the claims below and equivalents thereof.

The mixed flow rheometer of the present invention simultaneously introduces rotational motion and vertical motion to the fluid under test, so that shear flow and elongation (compression) flow appear together, which cannot be realized in the conventional rotational rheometer or capillary rheometer. The biggest feature is that mixed flow can be realized. As a result, the behavior of viscoelastic materials such as polymer materials can be more similarly simulated in actual industrial sites, thereby providing more accurate physical property values for process design and control.

Furthermore, the above effects can be achieved only by replacing some components of the conventional rotatable rheometer, and thus, the conventional apparatus can be used as it is, and as a result, a high economic efficiency is also achieved.

Claims (6)

A rotatable rheometer comprising an upper friction plate in contact with a fluid under test and vertically upward, and an upper unit comprising the lower friction plate in contact with the fluid under test and a lower unit including the lower friction plate. The upper unit includes a motor, a rotating shaft for receiving a rotational force of the motor, and a rotating shaft, and an axial direction converting portion for converting the rotating motion of the rotating shaft into a helical motion, wherein the upper friction plate transmits the helical motion of the moving direction converting part. Take a spiral, The lower unit includes a motor, a rotating shaft for receiving a rotational force of the motor to rotate, and a motion direction converting part for converting the rotating motion of the rotating shaft into a spiral motion, wherein the lower friction plate transmits the helical motion of the motion direction converting part. Rheometer for mixed flow measurement, characterized in that the spiral movement. The method of claim 1, The movement direction conversion unit A first movement direction converting member for converting the rotational movement of the rotary shaft into a vertical movement; And Second direction changing member for converting vertical motion into spiral motion Rheometer for mixed flow measurement, comprising a. The method of claim 2, The first movement direction conversion member is a rheometer for mixed flow measurement, characterized in that it comprises a ball screw nut (ball screw nut). The method of claim 2, The second direction of motion conversion member A linear bush provided on a side core portion of the casing in which vertical motion is transmitted by the first movement direction converting member, and a guide groove formed in an oblique direction on an outer circumferential surface thereof; And A guide holder having a guide protrusion inserted into the guide groove of the linear bush and converting vertical motion into spiral motion Rheometer for mixed flow measurement, comprising a. The method according to any one of claims 1 to 4, The lower friction plate is a rheometer for mixed flow measurement, characterized in that the outer peripheral surface is formed in a vertical shape extending upwardly. The method according to any one of claims 1 to 4, The rheometer for mixing flow measurement, characterized in that the lower unit including the motor, the rotating shaft, and the direction change unit.

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