Cell stretching collapse appears in polyurethane spray foaming

Sprayed foam on vertical surfaces undergoes cell collapse due to gravity stretching. This problem is relatively common in foam molding production and requires comprehensive analysis and solution from multiple aspects of material, process, and equipment.

(1) Process speed aspect: The foam gelling speed is insufficient, Speed parameters affect the synchronization between material flow state and reaction progress. (2) Process factor: Excessive spray thickness makes the foam self-weight too large, causing the lower cells to be stretched, This factor affects the '2079851475616104453 and final quality of the product. (3) Material aspect: Fluctuations in raw material performance indicators or insufficient pretreatment affect molding quality. (4) Process aspect: Control deviation of key process parameters causes the '2079851475616104453 to deviate from optimal conditions. (5) Equipment aspect: Equipment precision and maintenance status affect the stable execution of process parameters.

(1) Implementation measure: Spray thin layers each time (≤25mm), Develop a specific operation plan based on actual production conditions, and verify the implementation effect. (2) Formulation adjustment: Adopt fast-gelling formulations to reduce sagging, Adjust gradually and verify the effect, ensuring that other performance indicators of the product are not affected. (3) Implementation measure: Spray in multiple layers., Develop a specific operation plan based on actual production conditions, and verify the implementation effect. (4) Preventive measure: Establish sound process control standards and a quality inspection system, and regularly review process data for continuous optimization.

This problem requires comprehensive analysis from multiple dimensions of material, process, equipment, and operation, and should be solved by systematically optimizing process parameters and the quality control system.