JP3237334B2 - Capillary rheometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extruded capillary rheometer for measuring flow characteristics, molecular weight distribution, viscosity characteristics, etc. of a sample such as plastic, ceramic, rubber and the like.

[0002]

2. Description of the Related Art In general, a capillary rheometer has a sample T inserted into a sample insertion hole 123e as shown in a schematic diagram of FIG.
P is heated to a predetermined temperature in a heating furnace 120 and the piston 106 is heated.
The sample is pushed out from the capillary 125 by applying pressure, and the fluidity of the sample is analyzed and measured from the moving speed of the piston 106 at this time.

[0003] As a procedure of such an analytical measurement, ASTM standard states, "After cleaning the rheometer, heat equilibrium is established at a set temperature with the capillary and piston mounted. After that, the piston is pulled out and the barrel is filled with a sample. Then, insert the piston back into the barrel, and after the sample has melted, lower the piston at a low speed to stop the tip of the piston in place, and wait for the barrel temperature to return to the test temperature. Wait and start timer to measure preheating time ".

[0004] Here, when the temperature of the piston is lowered when the piston is inserted again into the barrel after the piston is removed, the time required for the piston to recover to the test temperature becomes very long, and the deterioration of the melted sample is reduced. Therefore, it is necessary to provide some heat retaining means so that the temperature of the piston does not decrease. However, regarding the heat retention of such a piston, J
The IS standard does not specify anything, and the ASTM standard merely describes that the piston is placed on the heat insulating material. For this reason, in the conventional analytical measurement using a capillary rheometer, the piston is not kept warm, but is kept warm by placing the piston on a heat insulating material as described in the ASTM standard.

[0005]

However, in the method in which the piston is placed on the heat insulating material, the diffusion of heat due to contact can be prevented to some extent, but the temperature of the piston decreases due to direct contact with low-temperature air. It is inevitable to do.

On the other hand, if a means for keeping the piston warm is provided separately from the capillary rheometer, the whole apparatus becomes complicated, and there is a problem that extra heat energy is required for keeping the heat.

Accordingly, the present invention has been made in order to solve these problems, and an object of the present invention is to provide a capillary rheometer capable of realizing the heat retention of a piston withdrawn from a sample insertion hole with a simpler configuration. And

[0008]

The configuration of the present invention will be described below with reference to FIG. 1 which is an embodiment of the present invention. The capillary rheometer according to the present invention includes a heating furnace 20 for heating a sample TP in a sample insertion hole 23e provided at a central portion, a piston 6 for sliding in the sample insertion hole 23e and pressurizing the sample TP, and a hollow. A base 7 having a portion 7 'and holding the heating furnace 20 in the hollow portion 7';
Piston holding means 8 for holding the piston 6 extracted from the inside of the pedestal 7 in a hollow portion 7 ′ so as to face the heating furnace 20. The piston 6 can be pre-insulated by radiant heat from the heating furnace 20. It is characterized by having such a configuration.

[0009]

The operation of the present invention will be described below with reference to FIG. 3, which is an embodiment of the present invention.

The piston 6 extracted from the sample insertion hole 23e is held opposite to the heating furnace 20 by the piston holding means 8 provided in the hollow portion 7 'of the gantry 7, so that the radiant heat from the heating furnace 20 is removed. It is kept warm by receiving it directly.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. In FIG. 1, reference numeral 1 denotes a table of a material testing machine main body, and 2 denotes a crosshead which is laid on a pair of columns (not shown) and which can move up and down. The load cell 3 is placed. A load rod 4 that penetrates the crosshead 2 is attached to the load cell 3, and a piston 6 for pressing and extruding the sample TP through a connector 5 is attached to a lower end of the load rod 4.
Are connected.

On the other hand, on the table 1, a gate-shaped hollow portion 7 '
Is mounted, and a heating furnace 20 is suspended from the mount 7. As shown in FIG. 1, the heating furnace 20 includes an upper furnace body 21 installed on the upper surface of the gantry 7 and a lower furnace body 22 attached to the lower surface of the gantry 7 with bolts. The barrel 23 is inserted through the center of the. As shown in FIG. 2, the barrel 23 includes a cylindrical barrel base material 23 a and a cylindrical inner lining 23 b fitted inside the base material 23 a, and the member 23 a is provided on the upper furnace body 21. It is screwed and hung on the ball seat 21a.

The inner lining 23b is formed by separately forming the upper lining 23c and the lower inner lining 23d and connecting them by shrink fitting in the barrel base material 23a, thereby facilitating the formation of the sample insertion hole 23e. The accuracy of the inner diameter is improved, and the thermal interference between the upper and lower zone furnace bodies 22c and 22d at the joint surface can be suppressed. A capillary 25 is attached to the lower end of the sample insertion hole 23e via a capillary nut 24.

The upper furnace body 21 is covered with a heat insulating material 21b on the upper and lower surfaces and the peripheral surface, is filled with a ring-shaped cement material 21c, and has a pair of nichrome ring heaters inside the cement material 21c. 21d is buried concentrically. Further, a sensor insertion hole 21e is provided on the peripheral surface of the upper furnace body 21, and a temperature sensor 31 is inserted therein. The lower furnace body 22 is formed by stacking four ring-shaped cement materials 22f in a cylindrical container 22e. The barrel 23 is inserted into the center hole of each cement material 22f,
An air layer is formed between the barrel 23 and the cement material 22f. Bottom, top and each cement material 2 of container 22e
A ring-shaped heat insulating material 22g is arranged between 2f, and the inner peripheral surface of the heat insulating material 22g protrudes to near the peripheral surface of the barrel base material 23a. Four nichrome ring heaters 22 are vertically arranged inside each cement material 22f.
h is buried, and the ring heater 22h heats the sample TP in the sample insertion hole 23e via the barrel 23. Also, four zones 2 divided by the heat insulating material 22g
Temperature sensors 32a to 32d are inserted into 2a to 22d, and the temperature of the barrel is measured. Then, a temperature signal of the above-described temperature sensor is taken in by a control unit (not shown), and the ring heaters 22h and 21d are heated so that the sample TP in the barrel 23 has a desired temperature.

A piston holding means 8 is provided in the vicinity of the gantry 7 where the heating furnace 20 is hung. As shown in FIG. 3, the piston holding means 8 includes a cylindrical step 8 a protrudingly provided from the gantry 7, a semi-cylindrical half pipe 8 b opened only on the side facing the heating furnace 20, and Half pipe 8b
Heat insulating material 8 adhered to the closing side of
c. Here, when the piston 6 pulled out from the sample insertion hole 23e is suspended by the step 8a as shown in the figure, the piston 6 is held in the hollow portion 7 '. Since the half pipe 8b is open toward the heating furnace 20, the piston 6 directly receives the radiant heat radiated from the heating furnace 20. Thereby, the sample insertion hole 23e
It is possible to keep the temperature of the piston 6 at the time of melting the sample TP therein. Further, since the radiant heat from the heating furnace 20 for melting the sample TP is used, the temperature of the piston 6 can be kept at a temperature close to the temperature of the melted sample TP. For this reason, when the piston 6 is inserted into the sample insertion hole 23e again after the sample TP is melted, the time required for the barrel to recover to the test temperature can be significantly reduced, and the accuracy of the molten sample by preventing deterioration and the like can be reduced. High sample analysis becomes possible. Further, by using the half pipe 8b, only the portion where the piston 6 receives the radiant heat can be opened, so that the heat retaining effect can be further improved. If the heat insulating material 8c is combined as shown in the figure, the heat retaining effect can be obtained. Can be more enhanced. If the hollow portion 7 'of the gantry 7 is kept in a closed state, the heat retaining effect can be further enhanced.

Although the embodiment shown in FIG. 3 is shown as the piston holding means 8, the present invention is not limited to these embodiments, and the heating furnace 20 for heating the sample TP in the hollow portion 7 ′ of the gantry 7 is not limited thereto. What is necessary is just to hold the piston 6 in opposition and to keep the temperature of the piston 6 by the radiant heat of the heating furnace 20.

[0017]

According to the present invention, since the capillary rheometer employs a configuration in which the piston is held opposite to the heating furnace for melting the sample, the piston is heated using the radiant heat of the heating furnace. This allows the piston to be kept warm during the sample filling. In particular,
Since the present invention employs a configuration utilizing the radiant heat of the heating furnace for melting the sample, the piston can be kept at a temperature close to the temperature of the molten sample, and the test temperature when the piston is re-inserted into the sample insertion hole is reduced. The recovery time is greatly reduced, and high-precision analytical measurement can be performed by preventing thermal deterioration of the sample.

Further, according to the present invention, there is no need to separately provide a special heating means for keeping the piston warm.
Since it is only necessary to provide the piston holding means on the gantry of the main body, the warming means of the piston can be realized with a simpler configuration.

[Brief description of the drawings]

FIG. 1 is an overall view showing one embodiment of the present invention.

FIG. 2 is a view showing one embodiment of a heating furnace of the present invention.

FIG. 3 is a view showing one embodiment of a piston holding means of the present invention.

FIG. 4 is a schematic view of a conventional capillary rheometer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Table of the main body of a material testing machine 2 Cross head 3 Load cell 4 Load rod 5 Connecting device 6 Piston 7 Stand 7 'Hollow part 8 Piston holding means 8a Step part 8b Half pipe 8c Heat insulating material 20 Heating furnace

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01N 11/00-11/16 JICST file (JOIS)

Claims (1)

(57) [Claims] 1. A heating furnace for heating a sample in a sample insertion hole provided in a central portion, a piston for sliding in the sample insertion hole and pressurizing the sample, and a hollow portion having a hollow portion. A pedestal for holding a heating furnace, and a piston holding means for holding the piston withdrawn from the sample insertion hole in the hollow portion of the gantry so as to face the heating furnace, and the piston is withdrawn and in a standby state. Wherein the preheating is carried out by the radiant heat of the heating furnace.