A method for detecting the open time of adhesive

Abstract

The present invention belongs to the field of adhesives, and specifically relates to a method for detecting the opening time of an adhesive. The method comprises the following steps: a. Starting from the glue dispensing starting point A on a fixed plate, the adhesive is dispensed on the fixed plate at a fixed speed v1 to form a glue line with a length of L3; b. Release paper is laid on the glue line, and a 100g load-bearing plate is placed 1 minute after the glue dispensing; c. The starting point where the glue line width becomes narrower is measured, marked as the narrowing starting point B, and the horizontal distance L1 from A to B is measured; d. The end point where the glue line width becomes narrower is measured, marked as the narrowing end point C, and the horizontal distance L2 from A to C is measured; then the start time of the adhesive opening T1 = L1 / v1+1min; the end time of the adhesive opening T2 = L2 / v1+1min. The method is applicable to all adhesive detection industries, and not only has the characteristics of a wide range of applications, simple operation and determination, but also can ensure the accuracy of detection data and improve detection efficiency.

Description

Technical Field

[0001] The invention belongs to the field of adhesives, and in particular relates to a method for detecting the open time of an adhesive. Background Art

[0002] As an important category of society and science and technology, adhesives are currently widely used in the fields of chips, medicine, military, aerospace, civil, industry and electronics. Especially in the field of adhesive manufacturing, the testing indicators and requirements of its products are diverse. As we all know, the open time is very critical to the use effect of adhesives. Adhesive failure problems caused by inappropriate open time often occur, which creates great quality risks. In addition, on the production line, if the open time is shorter than the production line process beat, even if it is shorter than 1 second, the adhesive performance of the product will be greatly attenuated, resulting in poor adhesion and a large number of scrapped products.

[0003] The current common open time detection method is to use the industry standard HG / T 3716-2003 "Determination of open time of hot melt adhesives". Compared with the existing industry standards, this patented method has more accurate test results and a simpler method, and can be used as an alternative to the industry standard. The existing method is difficult to evaluate the open start time and end time of the adhesive. Therefore, the development of a detection method that is suitable for all and can accurately test the open time of adhesives has become a demand in this field. Summary of the invention

[0004] In order to solve the defects of inaccurate adhesive open time and low efficiency in the above-mentioned adhesive open time detection methods in the prior art, the purpose of the present invention is to provide a method for detecting adhesive open time, which solves the above-mentioned defects and will bring great improvements to the adhesive industry.

[0005] To achieve the above objectives, the technical solutions adopted are:

[0006] A method for detecting the open time of an adhesive comprises the following steps:

[0007] a. Start from the dispensing starting point A on the fixed plate, use the dispensing machine to dispense adhesive on the fixed plate at a fixed speed v1 to form a glue line with a total length of L3, and end at the dispensing end point D;

[0008] b. Place release paper on the glue line and place a 100g weight plate 1 minute after dispensing;

[0009] c. Use an optical microscope to measure the starting point where the glue line width becomes narrow, marked as the narrowing starting point B, and measure the horizontal distance L1 from the glue point A to the narrowing starting point B;

[0010] d. Use an optical microscope to measure the end point where the glue line width becomes narrower, marked as the narrowing end point C, and measure the horizontal distance L2 from the glue dispensing starting point A to the narrowing end point C;

[0011] Then the start time of the adhesive opening is T1=L1 / v1+1min; the end time of the adhesive opening is T2=L2 / v1+1min.

[0012] Furthermore, in step a, the width of the glue line is uniform, which is 2 mm.

[0013] Furthermore, the L3 is 1000 mm.

[0014] Furthermore, the fixing plate is made of polytetrafluoroethylene plate.

[0015] Furthermore, the ambient temperature and humidity when measuring the open time must be kept constant, with the temperature being 25±1° C. and the humidity being 40±5%.

[0016] Furthermore, the fixed speed v1 is 1 to 2 mm / s.

[0017] Furthermore, in step a, the thickness of the glue line is uniform and is 1 to 10 mm.

[0018] Furthermore, the adhesive in step a is a thermosetting or moisture curing adhesive.

[0019] By adopting the above further solution, the roller speed can be set according to the range of the product opening time, which can effectively expand the detection range of the opening time.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The detection method is simple to operate;

[0022] (2) Eliminate the interference of manual judgment and human operation time during the test process;

[0023] (3) The open time of the adhesive has a high correlation with the bonding performance after curing.

[0024] The present invention provides an adhesive testing method, the testing mechanism of which is: using a load at a specific speed to maintain pressure on the adhesive line, and calculating the open time of the adhesive by the influence of the pressure on the cross section of the adhesive line before the adhesive is cured. The method of the present invention does not require manual identification of the bonding area for evaluation and corresponding height measurement, is simple and easy to implement, and the corresponding test data is accurate, which has a huge impact on the application of adhesives.

[0025] This method overcomes the defects of the traditional adhesive open time test process, such as complex operation, serious waste, narrow scope of application, and poor stability of test data. It is suitable for all adhesive testing industries. It not only has a wide range of applications, simple operation and judgment, but also can ensure the accuracy of test data, greatly improve the detection efficiency, and effectively evaluate the physical and chemical properties of adhesives. It has important significance for improving the detection technology level of the adhesive industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the open end of the rubber strip.

[0027] Among them, A, starting point of glue dispensing; B, starting point of narrowing; C, end point of narrowing; D, end point of glue dispensing; L1, horizontal distance from starting point A of glue dispensing to starting point B of narrowing; L2, horizontal distance from starting point A of glue dispensing to end point C of narrowing; L3, total length of glue line. DETAILED DESCRIPTION

[0028] The present invention is described below in conjunction with examples, which are only used to explain the present invention and are not used to limit the scope of the present invention.

[0029] Example 1

[0030] a. Starting from the polytetrafluoroethylene plate as the dispensing starting point A on the fixed plate, use the dispensing machine to dispense adhesive 1 (PUR50N) on the fixed plate at a fixed speed v1 of 1mm / s to form a glue line with a total length of 1000mm, a width of 2mm, and a thickness of 1mm, and end at the dispensing end point D;

[0031] b. Place release paper on the glue line and place a 100g weight plate 1 minute after dispensing;

[0032] c. Use an optical microscope to measure the starting point where the glue line width becomes narrow, marked as the narrowing starting point B, and measure the horizontal distance L1 from the glue point A to the narrowing starting point B;

[0033] d. Use an optical microscope to measure the end point where the glue line width becomes narrower, marked as the narrowing end point C, and measure the horizontal distance L2 from the glue dispensing starting point A to the narrowing end point C;

[0034] Then the start time of the adhesive opening is T1=L1 / v1+1min; the end time of the adhesive opening is T2=L2 / v1+1min.

[0035] Example 2

[0036] In the implementation case, fixed speeds were set according to product characteristics, and adhesives with different open times were used for comparative verification.

[0037] Embodiment 2 is the same as Embodiment 1 except that the fixed speed V1 is 1 mm / s and Adhesive 2 is 160820 instead of Adhesive 1.

[0038] The test data results are listed in Table 1.

[0039] Table 1. Adhesive open time test data

[0040] sample PUR50N 160820 Set speed V1 10mm / s 1mm / s <![CDATA[L1(mm)]]> 20 262 <![CDATA[L2(mm)]]> 650 345 T1(min) 1’02 5’22 T2(min) 2’05 6’45 Opening hours 1’02～2’05 5’22～6’45

[0041] The open time of Adhesive 1 in Example 1 of the present invention and Adhesive 2 in Example 2 were measured according to the methods of HG / T 3716-2003 "Determination of open time of hot melt adhesives" and HG / T 3716-2003 "Determination of open time of hot melt adhesives", respectively. The comparison of the obtained data is shown in Table 2.

[0042] Table 2. Comparison of open time data of Examples 1-2 and other standard adhesives

[0043]

[0044]

[0045] Combining the data obtained in Tables 1 and 2, it can be seen that the method for detecting the open time of the adhesive of the present invention is simple and easy to operate, improves efficiency, can fully evaluate the curing start and end time of the adhesive, can meet the technical requirements for the application of the adhesive in the client production line, and has huge market potential.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for detecting the open time of an adhesive, characterized in that: The following steps are involved: a. Starting from the dispensing starting point A on the fixed plate, use the dispensing machine to dispense adhesive on the fixed plate at a fixed speed v1 to form a glue line with a total length of L3, and end at the dispensing end point D; b. Place release paper on the glue line and place a 100g weight plate 1 minute after glue application; c. Use an optical microscope to measure the starting point where the glue line width becomes narrower, mark it as the narrowing starting point B, and measure the horizontal distance L1 from the glue point A to the narrowing starting point B; d. Use an optical microscope to measure the end point where the glue line width becomes narrower, mark it as the narrowing end point C, and measure the horizontal distance L2 from the glue dispensing starting point A to the narrowing end point C; Then the start time of the adhesive opening is T1=L1 / v1+1min; the end time of the adhesive opening is T2=L2 / v1+1min.

2. The method for detecting the open time of an adhesive according to claim 1, characterized in that: The width of the glue line in step a is uniform, which is 2 mm.

3. The method for detecting the open time of an adhesive according to claim 1, characterized in that: The L3 is 1000 mm.

4. The method for detecting the open time of an adhesive according to claim 1, characterized in that: The material of the fixing plate is a polytetrafluoroethylene plate.

5. The method for detecting the open time of an adhesive according to claim 1, characterized in that: The ambient temperature and humidity when measuring the open time must be kept constant, with a temperature of 25±1°C and a humidity of 40±5%.

6. The method for detecting the open time of an adhesive according to claim 1, characterized in that: The fixed speed v1 is 1~2mm / s.

7. The method for detecting the open time of an adhesive according to claim 1, characterized in that: The thickness of the glue line in step a is uniform, ranging from 1 to 10 mm.

8. The method for detecting the open time of an adhesive according to claim 1, characterized in that: The adhesive in step a is a thermosetting adhesive or a moisture curing adhesive.

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