Method for detecting the impregnation of an open steel cord

Abstract

The application discloses a kind of detection methods of open type steel cord impregnation, to accurately reflect the impregnation of steel cord in calendering process, simulate rubber sheet and open type cord calendering process in test, vulcanize together with rubber sheet after applying tension to steel cord.Meanwhile, clear section is obtained by using red inlay powder to carry out hot inlay, polishing and polishing treatment to sample, then observe rubber penetration under microscope.Finally, cover metallographic photo or microscopic field on standard grid transparent paper, count total grid number and rubber penetration grid number, calculate impregnation rate.Compared with prior art, the method not only effectively simulates the impregnation behavior of open type steel cord and rubber during calendering, but also clearly displays and quantifies the rubber distribution of rubber in open type steel cord, to provide reliable basis for process optimization.

Description

Technical Field

[0001] This invention relates to the field of steel cord testing technology, and in particular to a method for detecting adhesive penetration in open-type steel cords. Background Technology

[0002] Steel cord is widely used in rubber products such as tires and conveyor belts. Its adhesion to rubber directly affects the product's service life and safety.

[0003] Open-type steel cords have a structure with periodic gaps between the monofilaments, which makes it easier for rubber to penetrate them. However, in the calendering of rubber products with open-type steel cords, the cords are usually subjected to unwinding tension, causing the gaps between the cords to narrow. Traditional rubber penetration testing methods cannot accurately assess the impact of unwinding tension on the rubber penetration performance of open-type steel cords, nor can they clearly observe the penetration of black rubber in different layers of open-type steel cords, thus failing to provide effective guidance for process adjustments.

[0004] Therefore, a testing method that can accurately reflect the adhesive penetration of open-type steel cords is needed. Summary of the Invention

[0005] The purpose of this invention is to provide a method for detecting rubber seepage in open-type steel cords. This method not only simulates the rubber seepage situation when open-type steel cords are calendered together with rubber, but also clearly displays and calculates the rubber seepage situation in different layers of open-type steel cords, providing a reliable basis for process optimization and solving the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for detecting adhesive leakage in open-type steel cord includes the following steps:

[0008] Step 1: Melt the open steel cord to be tested into a standard length and lock it at both ends with a lock. At the same time, two rubber sheets of the same size need to be prepared.

[0009] Step 2: Place the steel cord with the lock into the groove of the mold in the vulcanizer, so that the lock at one end is locked into the groove at one end of the mold. Hang a weight with a hook on the other end of the steel cord. Place two rubber sheets of the same size in the groove. The steel cord passes between the two rubber sheets to simulate the vulcanization process of the rubber sheets and the open steel cord during calendering. Then, vulcanize the open steel cord and the rubber sheets together according to the vulcanization temperature, pressure and time of the rubber sheets.

[0010] Step 3: After vulcanization, quickly remove the mold and demold the sample, and leave it at room temperature for more than 16 hours.

[0011] Step 4: Trim the prepared adhesive-coated steel cord sample, then use colored inlay powder to perform two hot inlay processes on the trimmed sample, followed by grinding and polishing until the sample reveals a complete and clear cross-sectional shape.

[0012] Step 5: Observe the rubber penetration of the steel cord under a stereomicroscope and take pictures.

[0013] Step 6: Using transparent paper with a standard-sized grid, cover the metallographic photograph or microscope field of view with the grid paper, and calculate the ratio of the total number of grids covered by the steel cord section to the number of grids covered by the rubber penetration area to obtain the rubber penetration rate.

[0014] A further improvement of the present invention is that the mold is a rectangular block, and a groove is provided on the front side of the mold; the groove includes a rectangular insert groove located in the middle of the mold, the upper and lower ends of the insert groove are connected to wire grooves, and the two wire grooves extend to both ends of the mold.

[0015] A further improvement of the present invention is that the latch is cylindrical and the latch locks the two ends of the steel cord to form a ring; the steel cord passes through the wire groove and the insert groove, the top locking block is engaged with the top of the mold, and the weight is hung on the bottom ring.

[0016] A further improvement of the present invention is that the rubber sheet is housed in the insert groove, the steel cord passes between the two rubber sheets, and the steel cord is in contact with the two rubber sheets.

[0017] A further improvement of the present invention is that, in step 2, the vulcanization temperature is 140–180°C, the vulcanization pressure is 0–40 MPa, and the vulcanization time is 10–80 min.

[0018] The beneficial effects of this invention are:

[0019] The method for detecting rubber seepage in open-type steel cords of the present invention simulates the situation of rubber products and steel cords during calendering during the test. Tension is applied to the cords before they are vulcanized together with the rubber, which can accurately reflect the rubber seepage of open-type steel cords during the rubber calendering process.

[0020] The method for detecting rubber penetration in open-type steel cords of the present invention involves using red inlay powder for two hot inlay processes, followed by grinding and polishing to obtain a clear cross-section, and then observing the distribution of rubber in the open-type steel cords under a microscope in order to more clearly see the distribution of rubber in the steel cords.

[0021] The present invention provides a method for detecting adhesive penetration in open-type steel cords. This method involves covering a metallographic photograph or microscope field of view with transparent paper containing a standard-sized grid, counting the total number of grids covered by the steel cord cross-section and the number of grids covered by the rubber penetration area, and calculating the adhesive penetration rate. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the steel cord of the present invention, which is locked at both ends with a latch.

[0023] Figure 2 This is a schematic diagram of the structure of the mold used in the vulcanizing apparatus of the present invention.

[0024] Figure 3 This is a schematic diagram of the structure of the steel cord passing through the mold of the present invention.

[0025] Figure 4 This is a diagram showing the positional relationship between the steel cord and the rubber sheet in this invention.

[0026] Figure 5 This is a schematic diagram showing the adhesive penetration of the 3×0.30 OC HT steel cord in Example 1.

[0027] Figure 6 This is a schematic diagram showing the adhesive seepage situation of the 4×0.225 OC UT steel cord in Example 2.

[0028] Figure 7 This is a schematic diagram showing the adhesive penetration of the 5×0.225 OC UT steel cord in Example 3.

[0029] In the diagram: 1-steel cord, 2-locking buckle, 3-rubber sheet, 4-mold, 401-insertion groove, 402-wire guide groove, 5-weight. Detailed Implementation

[0030] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments. Example 1

[0031] Step 1: Cut the open-type steel cord (3×0.30 OC HT) to a length of 1.8–2.0 m, and then... Figure 1 As shown, the cord is secured with steel wire locks 2 at 0.6m and 0.4m from both ends. At the same time, two rubber sheets 3 with a length and width of 16.5mm × 1.25mm and a weight of 4.5 to 5.5g are also required.

[0032] Step 2, as follows Figure 2 , 3 As shown in Figure 4, peel off the polyethylene films on both sides of the rubber sheet 3, place it into the mold 4 with the smooth side facing up, and place the open-type steel cord 3×0.30 OC HT with the buckle 2 into the groove of the mold 4, so that the buckle 2 at one end of the steel cord 1 locks the groove of the mold 4, and hang a 1000g weight 5 with a hook on one end of the steel cord 1. Then vulcanize the steel cord 1 sample and the rubber sheet 3 together. The vulcanization conditions are 151℃×40min×15MPa.

[0033] Step 3: After vulcanization, quickly remove the mold 4 and demold the sample, then place it at room temperature for more than 16 hours.

[0034] Step 4: Trim the prepared adhesive-coated steel cord sample 1, and then perform two hot-mounting processes on the trimmed sample before grinding and polishing until the sample reveals a complete and clear cross-sectional shape.

[0035] Step 5: Observe and photograph the rubber seepage in the steel cord 1 under a 50x stereomicroscope. The results are as follows: Figure 5 As shown.

[0036] Step 6: Cover the metallographic photograph with 1mm×1mm transparent paper with standard-sized grids, and calculate the ratio of the number of grids covered by the rubber seepage area to the total number of grids covered by the steel cord 1 section. The result shows that the seepage rate of the open steel cord 3×0.30OC HT under the tension brought by the 1000g weight 5 is 98.42%. Example 2

[0037] Step 1: Cut the open-type steel cord (4×0.225 OC UT) to a length of 1.8–2.0 m, and then... Figure 1 As shown, the cord is secured with steel wire locks 2 at 0.6m and 0.4m from both ends. At the same time, two rubber sheets 3 with a length and width of 16.5mm × 1.25mm and a weight of 4.5 to 5.5g are also required.

[0038] Step 2, as follows Figure 2 , 3 As shown in Figure 4, peel off the polyethylene films on both sides of the rubber sheet 3, place it into the mold 4 with the smooth side facing up, and place the open-type steel cord 4×0.225 OC UT equipped with the buckle 2 into the groove of the mold 4, so that the buckle 2 at one end of the steel cord 1 locks the groove of the mold 4, and hang a 1000g weight 5 with a hook on the other end of the steel cord 1. Then vulcanize the steel cord 1 sample and the rubber sheet 3 together. The vulcanization conditions are 151℃×40min×15MPa.

[0039] Step 3: After vulcanization, quickly remove the mold 4 and demold the sample, then place it at room temperature for more than 16 hours.

[0040] Step 4: Trim the prepared adhesive-coated steel cord sample 1, and then perform two hot-mounting processes on the trimmed sample before grinding and polishing until the sample reveals a complete and clear cross-sectional shape.

[0041] Step 5: Observe and photograph the rubber seepage in the steel cord 1 under a 50x stereomicroscope. The results are as follows: Figure 6 As shown.

[0042] Step 6: Cover the metallographic photograph with 1mm×1mm transparent paper with standard-sized grids, and calculate the ratio of the number of grids covered by the rubber seepage area to the total number of grids covered by the steel cord 1 section. The result shows that the seepage rate of the open steel cord 4×0.225OC UT under the tension brought by the 1000g weight 5 is 79.32%. Example 3

[0043] Step 1: Cut the open-type steel cord (5×0.225 OC UT) to a length of 1.8–2.0 m, and then... Figure 1 As shown, the cord is secured with steel wire locks 2 at 0.6m and 0.4m from both ends. At the same time, two rubber sheets 3 with a length and width of 16.5mm × 1.25mm and a weight of 4.5 to 5.5g are also required.

[0044] Step 2, as follows Figure 2 , 3 As shown in Figure 4, peel off the polyethylene films on both sides of the rubber sheet 3, place it into the mold 4 with the smooth side facing up, and place the open-type steel cord 5 × 0.225 OC UT with the buckle 2 into the groove of the mold 4, so that the buckle 2 at one end of the steel cord 1 locks the groove of the mold 4, and hang an 800g weight 5 with a hook on the other end of the steel cord 1. Then vulcanize the steel cord 1 sample and the rubber sheet 3 together. The vulcanization conditions are 151℃ × 40min × 15MPa.

[0045] Step 3: After vulcanization, quickly remove the mold 4 and demold the sample, then place it at room temperature for more than 16 hours.

[0046] Step 4: Trim the prepared adhesive-coated steel cord sample 1, and then perform two hot-mounting processes on the trimmed sample before grinding and polishing until the sample reveals a complete and clear cross-sectional shape.

[0047] Step 5: Observe and photograph the rubber seepage in the steel cord 1 under a 50x stereomicroscope. The results are as follows: Figure 7 As shown.

[0048] Step 6: Cover the metallographic photograph with 1mm×1mm transparent paper with standard-sized grids, and calculate the ratio of the number of grids covered by the rubber seepage area to the total number of grids covered by the steel cord 1 section. The result shows that the seepage rate of the open steel cord 5×0.225OC UT under the tension brought by the 800g weight 5 is 80.11%.

[0049] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent transformations or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for detecting adhesive leakage in open-type steel cord, characterized in that, Includes the following steps: Step 1: Melt the open steel cord (1) to be tested into a standard length and lock it at both ends of the steel cord (1) with buckles (2). At the same time, two rubber sheets (3) of the same size need to be prepared. Step 2: Place the steel cord (1) with the buckle (2) into the groove of the mold (4) of the vulcanizer, so that the buckle (2) at one end is locked into the groove at one end of the mold (4), and hang a weight (5) with a hook of a certain mass on the other end of the steel cord (1). Two rubber sheets (3) of the same size are placed in the groove, and the steel cord (1) passes between the two rubber sheets (3) to simulate the vulcanization process of the rubber sheet (3) and the open steel cord (1) in the calendering process. Then, according to the vulcanization temperature, pressure and time of the rubber sheet (3), the open steel cord (1) and the rubber sheet (3) are vulcanized together. Step 3: After vulcanization, quickly remove the mold (4) and demold the sample, and place it at room temperature for more than 16 hours; Step 4: Trim the above-prepared adhesive steel cord (1) sample, and then use colored inlay powder to perform two hot inlays on the trimmed sample before grinding and polishing until the sample reveals a complete and clear cross-sectional shape. Step 5: Observe the rubber seepage in the steel cord (1) under a stereomicroscope and take pictures; Step 6: Using transparent paper with a standard-sized grid, cover the metallographic photograph or microscope field of view with the grid paper, and calculate the ratio of the total number of grids covered by the steel cord (1) section to the number of grids covered by the rubber penetration area to obtain the rubber penetration rate.

2. The method for detecting adhesive leakage in open-type steel cord as described in claim 1, characterized in that: The mold (4) is a rectangular block with a groove on the front side of the mold (4). The groove includes a rectangular insert groove (401) located in the middle of the mold (4). The upper and lower ends of the insert groove (401) are connected to wire grooves (402), and the two wire grooves (402) extend to both ends of the mold (4).

3. The method for detecting adhesive leakage in open-type steel cord as described in claim 2, characterized in that: The buckle (2) is cylindrical and locks the two ends of the steel cord (1) to form a ring buckle. The steel cord (1) passes through the wire groove (402) and the insert groove (401). The top lock block is attached to the top of the mold (4), and the weight (5) is hung on the bottom ring buckle.

4. A method for detecting adhesive leakage in open-type steel cord as described in claim 2 or 3, characterized in that: The rubber sheet (3) is housed in the insert groove (401), and the steel cord (1) passes between the two rubber sheets (3) and is in contact with the two rubber sheets (3).

5. The method for detecting adhesive leakage in open-type steel cord as described in claim 1, characterized in that: In step 2, the vulcanization temperature is 140–180℃, the vulcanization pressure is 0–40MPa, and the vulcanization time is 10–80min.

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