Q

During the curing of polyurethane adhesive, there is a phenomenon of local non drying or complete liquid

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A

When polyurethane adhesive is cured, local non drying or complete liquid phenomenon occurs, usually caused by uneven manual mixing or inaccurate AB component ratio. The following methods can effectively improve the problem of non drying of adhesive: When manual sealing is used, the AB component needs to be thoroughly mixed during mixing; When using equipment encapsulation, it is necessary to measure the AB weight ratio online. If there is no change after one day of storage, it is often caused by the lack of component A; If the surface begins to solidify or turn white, it is usually caused by the lack of component B.

Q

After the colloid solidifies, the hardness changes slightly higher or lower

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A

After the solidification of colloids, the hardness changes on the high or low side are often related to the proportion of component A: If the proportion of component A is too high, it will lead to a situation of high hardness: If the proportion of component A is too small, it will lead to a situation of low hardness. At this point, it is necessary to retest the ratio of AB components, reduce and supplement more to ensure that the ratio of AB components meets the standard sealing ratio.

Q

What should I do when the surface of the product shows non dryness and adhesion after sealing?

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A

When the surface of the product shows non dryness and adhesion after sealing, it may be caused by the low proportion of component A due to excessive air humidity on site. The problem of surface adhesion can be solved by adjusting the proportion of component A: When the on-site air humidity is too high, the moisture in the air will consume part of component A, and then component B will produce an excess situation; When the proportion of component A is low, it also shows a low hardness of the cured material.

Q

Surface foaming is a common problem in polyurethane encapsulation

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A

Surface foaming is a common problem in polyurethane sealing. Damping of adhesive (logistics or storage), wetting of sealing products, high on-site humidity, and a high proportion of component A can all lead to surface foaming in sealed products. The following methods can effectively avoid such problems: 1. After opening the barrel, the glue should be used up as soon as possible to avoid dampness of the glue; 2. It is best to first configure air conditioning equipment to maintain a constant temperature and humidity working environment on site; 3. Before sealing the product, it is necessary to maintain a dry state. If it is an electronic product, it is recommended to pre dry it before sealing if conditions permit; 4. The surface bubbles caused by the high proportion of component A will also present bright and high hardness of the cured sample surface.

Q

When using machine equipment for sealing, various faults often occur due to components, settings, cleaning, and other reasons. The following methods can be used to quickly troubleshoot and solve them

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A

When using machine equipment for sealing, various faults often occur due to components, settings, cleaning, and other reasons. The following methods can be used to quickly troubleshoot and solve them: 1. When the glue filling equipment is working, the machine head does not move or is not sensitive, which is usually caused by the solidification of glue inside the machine head and the aging of the sealing ring. It is recommended to clean the machine head and replace the machine head sealing ring; 2. After the dispensing of the glue equipment, there may be a leakage of glue from the machine head. At this time, the PTFE sealing ring (white) may have been deformed. It is recommended to clean the machine head and replace the machine head sealing ring; 3. The gear pump of the glue filling equipment has a corner phenomenon, indicating that the skeleton oil seal has aged and needs to be filled with butter and replaced; 4. If the air pressure of the glue filling equipment is too low, the valve cannot be fully opened, the gear pump does not operate at a uniform speed, or there is a blockage in the pipeline, it may cause the flow rate of the glue filling equipment to be unstable. It is necessary to promptly check whether the air pressure and gear pump speed are normal, and whether the pipeline is blocked; 5. If the gluing equipment experiences abnormal heating, please check if the temperature controller parameter settings are correct; 6. If the mixing equipment experiences uneven mixing, it is likely that the mixing motor or capacitor has malfunctioned. Please check the status of the mixing motor and capacitor in a timely manner.