Causes of Wrinkling, Vertical Wrinkling and Horizontal Wave Wrinkling Defects in Solvent-Free Composite Rolling and Precise Machine Adjustment Schemes

Wrinkling, vertical wrinkles, and horizontal wave wrinkles are the most common rolling defects in solvent-free composites. The initial adhesion of solvent-free laminating adhesive is weak and the curing process is slow. When the composite film enters the rolling station, it has almost no definite strength, which makes it very prone to wrinkles due to tension, pressure, and deviation in the film path. After aging, it becomes permanently shaped and cannot be repaired, which is a key pain point affecting the appearance of the roll material and the utilization rate of the finished product.

 

The imbalance of tension matching is the primary cause. Solvent-free lamination are highly sensitive to the tension in the three sections of unwinding, traction, and rolling. Insufficient tension at the front end will cause the film layer to relax and wrinkle, while excessive tension will stretch the film material and cause stress wrinkles. Improper settings for high and low speed switching and start-stop buffer parameters will cause instantaneous tension fluctuations, resulting in regular dense horizontal and diagonal wrinkles.

Abnormal conditions of the press roller and the adhesive layer can also cause wrinkles. Uneven pressure of the composite press roller, imbalance in left and right pressure differences, eccentricity of the roller surface, lead to inconsistent tightness of the film surface; low adhesive temperature and high viscosity, poor leveling and wetting, and asynchronous film layer adhesion. At the same time, unreasonable setting of the rolling cone angle, slippage of the air expansion shaft, and deviation of the film surface will cause edge wrinkling and overall roll wrinkling.

 

On-site improvement requires the use of gradient tension settings, stable tension start-stop at low speed, and elimination of instantaneous fluctuations. Calibrate the parallelism of the press roller, balance the composite pressure, improve the fluidity of the adhesive temperature and moisture; match a reasonable rolling cone angle, correct the deviation of the film path. Considering the weak initial adhesion of solvent-free glue, ensure smooth adhesion and tight rolling, which can completely solve the problem of rolling wrinkles and ensure the flat formation of the roll material.