Melt index instrument and test method

Abstract

The embodiment of the invention provides a melt index instrument and a test method. The melt index instrument comprises: a tester body for heating and extruding a sample strip of a polyester melt; the number of the first detection assemblies is two, each first detection assembly comprises a first infrared sensor, a height adjusting piece and a connecting piece, the first infrared sensors are arranged on the connecting pieces, the connecting pieces are detachably connected to the height adjusting pieces, and the height adjusting pieces are arranged on the tester body; the height adjusting piece is used for adjusting the height position of the connecting piece; the two first infrared sensors are symmetrically arranged on the two sides of the sample strip and used for detecting the distances between the two first infrared sensors and the sample strip respectively, and the distances between the two first infrared sensors are compared with the distance between the two first infrared sensors for calculation, so that the diameter of the sample strip is obtained. According to the detection instrument, the infrared sensor is used for diameter detection, and the measurement precision is improved.

Description

Technical Field

[0001] The present application relates to the technical field of melt strength testing, and in particular to a melt indexer and a testing method. Background Art

[0002] In the molding process of polyester materials, film blowing is a commonly used processing technology. The film blowing process is to extrude the polyester melt through an annular die and blow it into a film under the action of high-pressure air, and then make a film product through cooling, shaping, pulling, winding and other steps. A key processing parameter in the film blowing process is the stability of the film bubble. One of the key parameters of the stability of the film bubble is the melt strength. Insufficient melt strength will make it difficult for the film bubble to maintain a stable shape during the film blowing process, thereby affecting the uniformity and quality of the film.

[0003] Melt strength refers to the maximum tensile force that a polymer melt can withstand when stretched. In order to accurately evaluate the melt strength of polyester, the melt indexer method (MFR) is usually used in the prior art to reflect the melt strength characteristics of the polymer. The working principle of the melt indexer method (MFR) is to make the plastic to be tested reach a molten state through a heating furnace under specified temperature conditions, and then extrude it through a die of a standard diameter under a certain weight load, wait for the sample strip to come down, cut the sample strip, and then manually measure the diameter of the sample strip with a vernier caliper for calculation.

[0004] However, manual operation is used to measure the diameter of the sample strip, which is prone to errors and affects the measurement results. Summary of the invention

[0005] The embodiment of the present application provides a melt indexer and a testing method to solve the problem that manual operation is used to measure the diameter of a sample strip during the polyester melt strength test, and manual operation is prone to errors, which affects the measurement results.

[0006] In a first aspect, an embodiment of the present application provides a melt indexer, comprising:

[0007] A tester body, the tester body is used to heat and extrude a sample strip of polyester melt;

[0008] A first detection component, wherein the first detection component is provided in two groups, and the first detection component comprises a first infrared sensor, a height adjustment member and a connecting member, wherein the first infrared sensor is provided on the connecting member, and the connecting member is detachably connected to the height adjustment member, and the height adjustment member is provided on the tester body, and the height adjustment member is used to adjust the height position of the connecting member;

[0009] The two first infrared sensors are symmetrically arranged on both sides of the sample strip, respectively detecting the distance between the two first infrared sensors and the sample strip, and comparing and calculating with the distance between the two first infrared sensors to obtain the diameter of the sample strip.

[0010] In a possible embodiment, the height adjustment member includes a fixed rod, a connecting sleeve, a ball and an elastic part. The fixed rod is arranged on the tester body, the connecting sleeve is slidably sleeved on the fixed rod, the ball is slidably arranged on the connecting sleeve, and the elastic part is arranged on the connecting sleeve and connected to the ball to drive the ball to move toward the fixed rod so that the ball is pressed tightly against the fixed rod.

[0011] In a possible embodiment, the elastic part includes a slider, a slide rod and a first spring. The slide rod is arranged in the connecting sleeve, the slider is slidably passed through the slide rod, the ball bearing is arranged on the slider, and the first spring is sleeved on the slide rod and abuts against the slider to drive the slider to move toward the fixed rod.

[0012] In a possible implementation manner, a plurality of grooves are evenly distributed on the fixing rod, and the balls are inserted into the grooves.

[0013] In a possible embodiment, the connecting member includes a mounting seat, a positioning block and a limiting portion, a connecting groove is opened on the connecting sleeve, the positioning block is arranged on the mounting seat, the first infrared sensor is arranged on the mounting seat, the positioning block is inserted into the connecting groove, and the limiting portion is arranged on the connecting sleeve to limit the displacement of the positioning block.

[0014] In a possible implementation, the limiting portion includes an insert block and a second spring, the insert block is slidably disposed in the connecting sleeve, and the second spring abuts against the insert block to drive the insert block to abut against the positioning block.

[0015] In a possible implementation manner, a positioning groove is provided on the positioning block, and the inserting block is inserted into the positioning groove.

[0016] In a possible implementation manner, a second infrared sensor is further disposed on the tester body, and the second infrared sensor is disposed toward the end of the sample strip to detect the length of the sample strip.

[0017] In a possible implementation manner, a glass protection plate is provided on the tester body, and the glass protection plate is located between the second infrared sensor and the sample strip.

[0018] In a second aspect, an embodiment of the present application provides a method for testing the melt strength of polyester, using a melt indexer, the method comprising:

[0019] Add the polyester sample to the tester body;

[0020] Starting the tester body to heat the polyester sample to melt and extrude a sample strip;

[0021] adjusting the height of the first infrared sensors so that the sample strip is located between two of the first infrared sensors;

[0022] Using the first infrared sensor to detect the diameter of the sample strip;

[0023] The melt strength was calculated from the diameter of the sample strip.

[0024] A melt indexer and a testing method provided in an embodiment of the present application are provided with a first detection component. After the tester body melts the polyester sample, a sample strip is extruded. The height of two first infrared sensors is adjusted by a height adjustment member so that the sample strip is located between the two first infrared sensors. The distance of the sample strip is detected by the two first infrared sensors respectively, and compared and calculated with the distance between the two first infrared sensors, so as to obtain the diameter of the sample strip at the current position. Compared with the measurement using a vernier caliper, the detection using an infrared sensor is more accurate and rapid, reduces the errors that are easily generated during manual operation, has high measurement accuracy, and improves the accuracy of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0026] Figure 1 A schematic diagram of the structure of a melt indexer provided in this application;

[0027] Figure 2 for Figure 1 A schematic diagram of the structure of the melt indexer from another angle;

[0028] Figure 3 for Figure 2 The structural section enlarged schematic diagram of part A in the middle;

[0029] Figure 4 for Figure 2 Structural cross-sectional view of the middle connector.

[0030] Description of reference numerals:

[0031] 100. Tester body; 110. Exit; 200. First detection component; 210. First infrared sensor; 220. Height adjustment member; 221. Fixing rod; 2211. Groove; 222. Connecting sleeve; 2221. Connecting groove; 223. Ball bearing; 224. Elastic portion; 2241. Sliding block; 2242. Sliding rod; 2243. First spring; 230. Connecting member; 231. Mounting seat; 232. Positioning block; 2321. Positioning groove; 233. Limiting portion; 2331. Insert block; 2332. Second spring; 2333. Guide block; 2334. Guide rod; 240. Second infrared sensor; 250. Glass protection plate.

[0032] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0033] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0034] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0035] In this application, unless otherwise clearly specified and limited, the terms "installation", "connection", "fixation" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0036] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0037] First, the terms involved in this application are explained:

[0038] The working principle of the melt indexer method (MFR) is to make the plastic to be tested reach a molten state through a heating furnace under specified temperature conditions, and then extrude it through a standard diameter die under a certain weight load, and collect the extruded melt within 10 minutes, and calculate its mass flow rate by weighing these extrudates; or wait for the spline to cool down, and after a certain period of time, cut the spline, use a vernier caliper to test the diameter and length for calculation.

[0039] In the molding process of polyester materials, film blowing is a commonly used processing technology. The film blowing process is to extrude the polyester melt through an annular die and blow it into a film under the action of high-pressure air, and then make a film product through cooling, shaping, pulling, winding and other steps. A key processing parameter in the film blowing process is the stability of the film bubble. One of the key parameters of the stability of the film bubble is the melt strength. Insufficient melt strength will make it difficult for the film bubble to maintain a stable shape during the film blowing process, thereby affecting the uniformity and quality of the film.

[0040] Melt strength refers to the maximum tensile force that a polymer melt can withstand when stretched. In order to accurately evaluate the melt strength of polyester, the melt indexer method (MFR) is usually used in the prior art to reflect the melt strength characteristics of the polymer. The working principle of the melt indexer method (MFR) is to make the plastic to be tested reach a molten state through a heating furnace under specified temperature conditions, and then extrude it through a die of a standard diameter under a certain weight load. After the spline is cooled down for a certain period of time, the spline is cut off, and the diameter is measured with a vernier caliper for calculation.

[0041] However, manual operation is used to measure the diameter of the sample strip, which is prone to errors and affects the measurement results.

[0042] The present application provides a melt indexer and a testing method. The melt indexer is provided with a first detection component. After the tester body melts the polyester sample, a sample strip is extruded. The height of two first infrared sensors is adjusted by a height adjustment member so that the sample strip is located between the two first infrared sensors. The distance of the sample strip is detected by the two first infrared sensors respectively, and compared with the distance between the two first infrared sensors, the diameter of the sample strip at the current position can be obtained. Compared with the measurement using a vernier caliper, the detection using an infrared sensor is more accurate and rapid, reduces the errors that are easily generated during manual operation, has high measurement accuracy, and improves the accuracy of the test.

[0043] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0044] In a first aspect, the present application provides a melt indexer, referring to Figures 1 to 4 , melt indexer includes:

[0045] A tester body 100, the tester body 100 is used to heat and extrude a sample strip of polyester melt;

[0046] The first detection assembly 200 is provided in two groups. The first detection assembly 200 includes a first infrared sensor 210, a height adjustment member 220 and a connecting member 230. The first infrared sensor 210 is provided on the connecting member 230. The connecting member 230 is detachably connected to the height adjustment member 220. The height adjustment member 220 is provided on the tester body 100. The height adjustment member 220 is used to adjust the height position of the connecting member 230.

[0047] The two first infrared sensors 210 are symmetrically arranged on both sides of the sample strip, and the distances from the two first infrared sensors 210 to the sample strip are respectively detected and compared with the distance between the two first infrared sensors 210 to obtain the diameter of the sample strip.

[0048] The tester body 100 is a prior art, and has a container for loading polyester samples on the tester body 100, and the polyester is melted in the container, and a weight is placed on the top of the container, and the molten polyester sample is pressed down by the gravity of the weight, so that the polyester sample is squeezed out from the outlet 110 of the standard diameter at the bottom of the container to form a sample strip. In addition, a cutter is also provided at the bottom of the container to cut the sample strip.

[0049] In one possible implementation, refer to Figure 2 and Figure 3The height adjustment member 220 includes a fixed rod 221, a connecting sleeve 222, a ball 223 and an elastic part 224. The fixed rod 221 is set on the tester body 100, the connecting sleeve 222 is slidably set on the fixed rod 221, the ball 223 is slidably set on the connecting sleeve 222, and the elastic part 224 is set on the connecting sleeve 222 and connected to the ball 223, driving the ball 223 to move toward the fixed rod 221 so that the ball 223 is tightly pressed against the fixed rod 221.

[0050] Specifically, the two fixing rods 221 are arranged in the vertical direction, and the two fixing rods 221 are symmetrically arranged on both sides of the sample strip, and when there is no sample strip, the infrared rays emitted by the two first infrared sensors 210 are located on the same straight line, and the infrared rays emitted by the first infrared sensors 210 are located on the diameter of the sample strip. That is, the line connecting the two fixing rods 221 is located on the diameter of the outlet 110 from which the sample strip is extruded.

[0051] The connecting sleeve 222 is slidably mounted on the fixed rod 221, and the connecting sleeve 222 slides along the length direction of the fixed rod 221. The connecting sleeve 222 and the fixed rod 221 are coaxially arranged. The ball 223 is slidably arranged in the connecting sleeve 222, and the ball 223 moves in the horizontal direction and partially slides out of the inner side wall of the connecting sleeve 222 to abut against the fixed rod 221. The elastic part 224 is arranged in the connecting sleeve 222 to drive the ball 223 to move toward the fixed rod 221, so that the fixed rod 221 and the ball 223 abut tightly, and the connecting sleeve 222 is fixed on the fixed rod 221. The position of the connecting sleeve 222 can be adjusted by moving the connecting sleeve 222 with force, so as to adjust the height position of the first infrared sensor 210. It is beneficial to detect the diameter of the sample strip at different positions.

[0052] In a possible embodiment, the elastic portion 224 includes a slider 2241, a slide rod 2242 and a first spring 2243. The slide rod 2242 is arranged in the connecting sleeve 222, the slider 2241 slides through the slide rod 2242, the ball 223 is arranged on the slider 2241, and the first spring 2243 is sleeved on the slide rod 2242 and abuts against the slider 2241 to drive the slider 2241 to move toward the fixed rod 221.

[0053] Among them, an adjustment groove is opened in the connecting sleeve 222, and the slider 2241 is connected in the adjustment groove by sliding in the horizontal direction. The ball 223 is fixed on the side of the slider 2241 close to the fixed rod 221, and an opening for the ball 223 to move out is opened on the inner wall of the connecting sleeve 222. The length of the slider 2241 is greater than the diameter of the opening to prevent the slider 2241 from moving out of the adjustment groove.

[0054] There are two sliding bars 2242, and the two sliding bars 2242 are fixed in the adjusting groove in parallel along the horizontal direction. The slider 2241 is slidably penetrated on the two sliding bars 2242. There are two first springs 2243, and the two first springs 2243 are sleeved on the two sliding bars 2242. The first spring 2243 is located on the side of the slider 2241 away from the fixed rod 221. One end of the first spring 2243 abuts against the side wall of the adjusting groove, and the other end abuts against the slider 2241. The first spring 2243 is in a compressed state to drive the slider 2241 to slide toward the fixed rod 221, so as to realize the abutment between the ball 223 and the fixed rod 221, thereby achieving the purpose of fixing the connecting sleeve 222, and the adjustment is convenient and quick, so as to facilitate the adjustment of the height of the first infrared sensor 210.

[0055] In a possible implementation manner, a plurality of grooves 2211 are evenly distributed on the fixing rod 221 , and the balls 223 are inserted into the grooves 2211 .

[0056] Among them, the grooves 2211 on the fixing rod 221 are evenly distributed. The setting of the grooves 2211 is conducive to increasing the contact area between the fixing rod 221 and the ball 223, and at the same time provides a certain limiting effect for the ball 223, thereby reducing the possibility of easy sliding between the ball 223 and the fixing rod 221.

[0057] Furthermore, the distance between the centers of two adjacent grooves 2211 is 1 mm, so that the height of the first infrared sensor 210 can be measured by adjusting the grooves 2211 to which the ball 223 is engaged.

[0058] In one possible implementation, refer to Figure 3 and Figure 4 The connecting member 230 includes a mounting seat 231, a positioning block 232 and a limiting portion 233. A connecting groove 2221 is opened on the connecting sleeve 222. The positioning block 232 is arranged on the mounting seat 231. The first infrared sensor 210 is arranged on the mounting seat 231. The positioning block 232 is inserted into the connecting groove 2221. The limiting portion 233 is arranged on the connecting sleeve 222 to limit the displacement of the positioning block 232.

[0059] The first infrared sensor 210 is fixedly mounted on a side of the mounting seat 231 away from the fixing rod 221. A mounting groove is provided on the side of the mounting seat 231, and the height of the connecting sleeve 222 is equal to the height of the mounting groove, so that the connecting sleeve 222 is partially inserted into the mounting groove, thereby improving the stability of the connection between the mounting seat 231 and the connecting sleeve 222. The positioning block 232 is located in the middle of the mounting groove, and the positioning block 232 is inserted into the connecting groove 2221, so that a mutually nested connection is formed between the connecting sleeve 222 and the mounting seat 231, further improving the stability of the connection.

[0060] In a possible implementation, the limiting portion 233 includes an insert block 2331 and a second spring 2332 . The insert block 2331 is slidably disposed in the connecting sleeve 222 . The second spring 2332 abuts against the insert block 2331 to drive the insert block 2331 to abut against the positioning block 232 .

[0061] Furthermore, two limiting portions 233 are provided, and the two limiting portions 233 are respectively located on both sides of the positioning block 232 , and the two limiting portions 233 are used to limit the movement of the positioning block 232 , thereby improving the limiting effect on the positioning block 232 and improving the stability of the mounting seat 231 .

[0062] The upper and lower sides of the connection groove 2221 are respectively provided with moving grooves, and the inserting block 2331 is slidably arranged in the moving grooves, and the inserting block 2331 moves along the vertical direction.

[0063] The limiting portion 233 also includes a guide block 2333 and a guide rod 2334. The guide rod 2334 is fixed on the side of the plug block 2331 away from the positioning block 232. The guide block 2333 is fixed on the side of the guide rod 2334 away from the plug block 2331. The second spring 2332 is located in the movable groove. One end of the second spring 2332 abuts against the end of the movable groove, and the other end abuts against the side of the guide block 2333 away from the guide rod 2334. The second spring 2332 is in a compressed state, thereby driving the plug block 2331 to abut against the positioning block 232, thereby limiting the movement of the positioning block 232.

[0064] In a possible implementation manner, a positioning groove 2321 is provided on the positioning block 232 , and the inserting block 2331 is inserted into the positioning groove 2321 .

[0065] Furthermore, the positioning groove 2321 on the positioning block 232 is triangular, and the end of the plug block 2331 is adapted to the positioning groove 2321 to form a triangular block. After the plug block 2331 is inserted into the positioning groove 2321, by pulling the mounting seat 231 outward, the mounting seat 231 drives the positioning block 232 to move outward, and the inclined surface on the positioning groove 2321 drives the plug block 2331 to slide in a direction away from the positioning block 232, so that the plug block 2331 is separated from the positioning groove 2321, and the positioning block 232 can be pulled out, and the disassembly is simple and quick. Similarly, during the installation process, it is only necessary to push the positioning block 232 toward the connecting groove 2221, and after the positioning block 232 contacts the inclined surface on the plug block 2331, the plug block 2331 is pushed to slide in a direction away from the positioning block 232, thereby realizing the installation of the mounting seat 231, and the disassembly is convenient and quick.

[0066] In a possible implementation manner, a second infrared sensor 240 is further disposed on the tester body 100 , and the second infrared sensor 240 is disposed toward the end of the sample strip to detect the length of the sample strip.

[0067] The second infrared sensor 240 is disposed at the bottom of the tester body 100 and is directly opposite to the outlet 110 of the sample strip, so that the length of the sample strip can be calculated based on the distance between the second infrared sensor 240 and the outlet 110 of the sample strip by detecting the distance between the sample strip and the second infrared sensor 240.

[0068] Furthermore, the first infrared sensor 210 and the second infrared sensor 240 are both electrically connected to the computer processing system on the tester body 100 to detect the length and diameter of the sample strip in real time and form a change curve graph for the operator to select different points for intensity calculation at any time.

[0069] In a possible implementation manner, a glass protection plate 250 is disposed on the tester body 100 , and the glass protection plate 250 is located between the second infrared sensor 240 and the sample strip.

[0070] The provision of the glass protection plate 250 is helpful to prevent the sample strip from falling onto the second infrared sensor 240, and the transparent glass protection plate 250 does not hinder the normal use of the infrared sensor.

[0071] In a second aspect, an embodiment of the present application provides a method for testing the melt strength of polyester, using a melt indexer, the method comprising:

[0072] A polyester sample is added to the tester body 100 .

[0073] Specifically, a polyester sample of required mass is weighed and added into the tester body 100 . The polyester sample is weighed accurately to 0.1 mg. The addition is completed within 1 minute. Furthermore, the polyester sample needs to be compacted during the addition process.

[0074] The tester body 100 is activated to heat the polyester sample to melt and extrude a sample strip.

[0075] The test is started by clicking the touch screen on the tester body 100 , and the sample strip begins to flow out from the outlet 110 . After reaching the predetermined displacement position, the cutter begins to cut off the excess sample strip.

[0076] The heights of the first infrared sensors 210 are adjusted so that the sample strip is located between the two first infrared sensors 210 .

[0077] The first infrared sensor 210 is used to detect the diameter of the sample strip.

[0078] Furthermore, the length of the sample strip corresponding to when the diameter of the sample strip is reduced by 50% is recorded. The length of the sample strip at this time can be detected by the second infrared sensor 240 or measured by a scale.

[0079] The melt strength was calculated from the diameter of the sample bar.

[0080] Exemplarily, the melting temperature of the tester body 100 is set to 190° C., and the weight is set to 2.16 kg.

[0081] Weigh 5.0g of sample and add it to the tester body 100. Click on the touch screen to start the test. The melt starts to flow out of the sample strip from the outlet 110. After reaching the predetermined displacement position, the cutter starts to cut off the excess sample strip. That is, the 50mm sample strip that starts to flow out needs to be intercepted and cut. The presence of bubbles and other reasons in this part cause the sample strip to not meet the test requirements. The length is then calculated from the cut end. The infrared sensor detects the diameter of the sample strip. The second infrared sensor 240 detects the length of the sample strip as the length of the sample strip, and selects the diameters corresponding to 1.59mm, 6.35mm, and 12.7mm calculated from the starting point.

[0082] Table 1 Comparison table of length and diameter of sample strips

[0083] Length of sample strip (mm) 1.59 6.35 12.7 Diameter(mm) 2.26 2.12 2.04

[0084] And record the length of the sample strip when the diameter decreases by 50%, which is 148 mm. According to Table 1, the average diameter is calculated to be 2.14 mm, that is, the average radius is 1.07 mm, and the MFR is 2.055 g / 10 min.

[0085] MS=0.085×ΔI 2 r0 2 / MFR

[0086] Wherein, MS is the melt strength (Pa.s); ΔI is the extrudate length when the extrudate diameter is reduced by 50% (mm); and r0 is the radius of the extrudate initially exposed from the die (mm).

[0087] In the embodiments of the present application,

[0088] MS=(0.085×1.07×148 2 ×1.07 / 2.055)=1037.3Pa.S.

[0089] The polyester melt strength testing method provided in the embodiment of the present application is as follows: after the tester body 100 melts the polyester sample, a sample strip is extruded, and the height of the two first infrared sensors 210 is adjusted by the height adjustment member 220 so that the sample strip is located between the two first infrared sensors 210, and the distance of the sample strip is detected by the two first infrared sensors 210 respectively, and compared and calculated with the distance between the two first infrared sensors 210, the diameter of the sample strip at the current position can be obtained. Compared with the measurement using a vernier caliper, the detection using an infrared sensor is more accurate and rapid, reduces the errors that are easily generated during manual operation, has high measurement accuracy, and improves the accuracy of the test.

[0090] Finally, it should be noted that those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary technical means in the art not disclosed by the present invention, are not limited to the precise structure described above and shown in the drawings, and may be modified and changed in various ways without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A melt indexer, characterized in that: include: A tester body (100), the tester body (100) being used to heat and extrude a sample strip of polyester melt; A first detection component (200), the first detection component (200) is arranged in two groups, the first detection component (200) comprises a first infrared sensor (210), a height adjustment member (220) and a connecting member (230), the first infrared sensor (210) is arranged on the connecting member (230), the connecting member (230) is detachably connected to the height adjustment member (220), the height adjustment member (220) is arranged on the tester body (100), and the height adjustment member (220) is used to adjust the height position of the connecting member (230); The two first infrared sensors (210) are symmetrically arranged on both sides of the sample strip, respectively detecting the distance between the two first infrared sensors (210) and the sample strip, and comparing and calculating with the distance between the two first infrared sensors (210) to obtain the diameter of the sample strip.

2. The melt indexer according to claim 1, characterized in that The height adjustment member (220) comprises a fixing rod (221), a connecting sleeve (222), a ball (223) and an elastic part (224); the fixing rod (221) is arranged on the tester body (100); the connecting sleeve (222) is slidably mounted on the fixing rod (221); the ball (223) is slidably mounted on the connecting sleeve (222); the elastic part (224) is arranged on the connecting sleeve (222) and is connected to the ball (223) to drive the ball (223) to move toward the fixing rod (221) so that the ball (223) is tightly pressed against the fixing rod (221).

3. The melt indexer according to claim 2, characterized in that The elastic part (224) includes a slider (2241), a slide rod (2242) and a first spring (2243); the slide rod (2242) is arranged in the connecting sleeve (222); the slider (2241) is slidably inserted into the slide rod (2242); the ball (223) is arranged on the slider (2241); the first spring (2243) is sleeved on the slide rod (2242) and abuts against the slider (2241) to drive the slider (2241) to move toward the fixing rod (221).

4. The melt indexer according to claim 2, characterized in that The fixing rod (221) is evenly provided with a plurality of grooves (2211), and the balls (223) are inserted into the grooves (2211).

5. The melt indexer according to claim 2, characterized in that: The connecting member (230) comprises a mounting seat (231), a positioning block (232) and a limiting portion (233); a connecting groove (2221) is provided on the connecting sleeve (222); the positioning block (232) is arranged on the mounting seat (231); the first infrared sensor (210) is arranged on the mounting seat (231); the positioning block (232) is plugged into the connecting groove (2221); and the limiting portion (233) is arranged on the connecting sleeve (222) for limiting the displacement of the positioning block (232).

6. The melt indexer according to claim 5, characterized in that The limiting portion (233) comprises an insert block (2331) and a second spring (2332); the insert block (2331) is slidably disposed in the connecting sleeve (222); the second spring (2332) abuts against the insert block (2331) to drive the insert block (2331) to abut against the positioning block (232).

7. The melt indexer according to claim 6, characterized in that The positioning block (232) is provided with a positioning groove (2321), and the inserting block (2331) is inserted into the positioning groove (2321).

8. The melt indexer according to any one of claims 1 to 7, characterized in that: The tester body (100) is also provided with a second infrared sensor (240), which is arranged toward the end of the sample strip to detect the length of the sample strip.

9. The melt indexer according to claim 8, characterized in that A glass protection plate (250) is provided on the tester body (100), and the glass protection plate (250) is located between the second infrared sensor (240) and the sample strip.

10. A method for testing polyester melt strength, characterized in that: Using the melt indexer according to any one of claims 1 to 9, the method comprises: Adding a polyester sample into the tester body (100); Starting the tester body (100) to heat the polyester sample to melt it and extrude a sample strip; Adjusting the height of the first infrared sensors (210) so that the sample strip is located between two of the first infrared sensors (210); Using the first infrared sensor (210) to detect the diameter of the sample strip; The melt strength was calculated from the diameter of the sample strip.

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