In cast film production, thickness uniformity serves as a core indicator for evaluating product quality, which directly determines the optical properties and downstream processability of films. Cast film machines form films via melt casting and rapid cooling, so their thickness control performance requires systematic assurance covering die design through cooling processes. Relying on its in-house R&D center for casting equipment, Nanjing sumino Precision Machinery Co., Ltd. guarantees consistent film thickness through multiple production links.

The precision die lays the foundation for thickness uniformity. The geometric design of internal die flow channels, surface finish, and precision of lip adjusting mechanisms directly affect the melt distribution uniformity across the full width. Nanjing sumino Precision adopts a coat-hanger flow channel design integrated with automatically adjustable die lips and high-precision actuators, maintaining even melt flow velocity and pressure distribution at the die outlet to underpin thickness regulation. Once the on-line thickness gauge detects deviations, the die lips can conduct automatic fine-tuning to realize closed-loop thickness control.

Cooling technology acts as a critical guarantee for thickness consistency. After exiting the die, the melt must make rapid contact with the cooling roll for solidification. Temperature uniformity and surface finish of cooling rolls, together with the configuration of air knife systems, influence film cooling rate and internal stress distribution, thereby impacting thickness uniformity. Cast film machines manufactured by Nanjing sumino Precision are equipped with mirror-finished roll sets featuring independent zoned temperature control paired with stable air knife systems, enabling homogeneous cooling of films under high-speed operation.

Optimization of process parameters delivers sustained thickness accuracy. Tuning process parameters including temperature profile, extrusion speed and cooling conditions is equally vital. Nanjing sumino Precision supplies full-set technical solutions ranging from raw material testing to production commissioning, assisting customers in establishing suitable process windows for specific materials and keeping film thickness tolerances within desired ranges. Through systematic coordination of dies, cooling systems and process parameters, cast film machines can continuously produce high-quality films featuring uniform thickness and stable performance.