To address quality issues in laminated glass production with EVA, we can consider the following steps:
Optimize the lamination parameters: The lamination parameters for EVA laminates can be fine-tuned in an experimental way, especially when inserts are added in the laminate. The temperature, time, and vacuum conditions during the lamination process should be adjusted based on the specific case, such as the curing system, laminate complexity, and laminate size. Ensure proper curing of EVA: It is essential to ensure that the EVA interlayer is properly cured during the lamination process. If the EVA is still very flexible or easily sticks to the surface during edge trimming, it indicates that the EVA was not properly cured. More attention should be devoted to optimizing the process in such cases. Prevent degumming: Degumming is a common issue in laminated glass production with EVA. It can occur when the heating temperature is not high enough or the keeping time is not long enough for the EVA film to melt and react completely. Increasing the heating temperature or the keeping time can help prevent degumming. It is also important to use EVA film within its shelf life and ensure the quality of the EVA film. Ensure proper cooling of laminated glass: Cooling the laminated glass too fast can lead to quality issues. It is recommended to avoid opening the oven door to help with cooling until the temperature of the laminated glass is lower than 75 degrees Celsius. Additionally, it is important to avoid hot laminated glass touching cold water. Placing wood blocks between the laminated glasses can help ensure well-proportioned cooling. Trimming and post-processing: Trimming of EVA can be done using a heated knife, which can ease the work of the operator. However, it is important to ensure that the EVA is properly cured and not too soft during edge trimming. EVA spills from the edges can be removed by trimming, and any sticking strips of EVA on the outer surface of the glass pane can be removed using isopropanol or acetone. Regular equipment cleaning is also important to prevent contamination. Consider the advantages and disadvantages of EVA compared to PVB: EVA and PVB are two commonly used interlayer materials for laminated glass. EVA has advantages such as lower water vapor transmission rate, lower water absorption, and lower cost compared to PVB. However, it is important to consider the specific requirements of the application and the properties of the interlayer material when choosing between EVA and PVB. Perform adhesion assessment: Adhesion assessment is an important aspect of quality control in laminated glass production. The Pummel test is commonly used to assess adhesion in the laminated glass industry. However, the test conditions need to be adjusted for EVA laminates, as the classic Pummel test at -18°C may not give accurate results. Cooling the laminate at lower temperatures can be considered to obtain comparable results.
These steps should help address some of the quality issues in laminated glass production with EVA. It is important to note that the specific parameters and techniques may vary based on the equipment and materials used, so it is recommended to consult the manufacturer’s guidelines and conduct thorough testing and optimization for each specific case.