High‐damping acoustic composites with unique sound insulation feature is reported, demonstrating surprisingly stable soundproof properties over a wide bandwidth of frequency (63–6300 Hz) with good mechanical properties. The extraordinary acoustic properties are attributed to the multiscale synergy of lamellar and hollow structures by multifillers adding. The acoustic composites are designed and fabricated through a low‐temperature one‐time rubber mixing process using nitrile butadiene rubber(NBR), chloroprene rubber (CR) as matrix and mica powder (MP), hollow glass beads (HGB), and montmorillonite (MMT) as multifillers. The soundproof mechanism is discussed in detail. Results indicate that the synergism of damping and sound absorption behaviors in the composition has a considerable impact on the acoustic characteristics, which can be controlled by the blending ratio of NBR/CR matrixes and the multiscale structures of MP/HGB/MMT multifillers. The designed multifillers acoustic composites can adapt to broadband engineering noise control including walls in express train constructions, panels of vessel or aircraft cabins, and large transportation pipelines.

An innovative and effective approach for screw design and optimization has been proposed, derived from multi-field synergy to address a growing challenge affected by the inadequate mixing and thermal management in plasticizing process of extrusion or injection. Dimensionless field synergy equations for incompressible non-Newtonian viscous polymers were established, and subsequently, two new types of screw structures—field synergy torsion element (FST) and field synergy elongation element (FSE)—were designed, fabricated, and validated through both simulation and experiment. Spiral and elongational flows were established in the newly designed screws owing to their unique structures of torsion channel and convergent channel, promoting the shear and stretch ductile deformations of polymer melt, documented to be a meaningful progress on flow patterns generated by conventional screw. A comparative investigation in this work of the newly designed screw with a conventional one showed that the newly proposed screws equipped with FSTs or FSEs performed better mixing and improved heat transfer and thermal uniformity. Multi-field synergy analysis revealed that the spiral and elongational flow enhanced the radial convection, improved the dependence of velocity and velocity gradient fields to facilitate melt stretching deformation as well as the dependence of velocity and temperature gradient fields to achieve heat transfer enhancement.

The ductile forming process of a polymer in a standard screw extruder and pin-barrel extruder, equipped with or without a field synergy elongation screw, was investigated by the finite element method. In order to assess the mixing and heat transfer capabilities of screws, characteristic parameters such as the mixing efficiency, segregation scale, and temperature distribution of different structures were analyzed and compared. The results indicated that the flow pattern of the polymer melt in the extruder was significantly influenced by the screw structure and was improved by the newly designed field synergy screw configuration, which brought a desirable elongational flow to enhance the radial convection. This was attributed to the unique radial wedge-shaped repeated convergence region of the field synergy elongation screw, increasing the synergistic effect between the velocity field, velocity gradient field, and temperature gradient field and thus improving the heat transfer and mixing efficiency. After adding barrel pins, the flow was forced to split, resulting in a more significant stretching effect on the melt. The field synergy effect in the pin mixed region was strengthened, which further increased the heat and mass transfer efficiency of the screw. However, increasing barrel pins could also lead to undesired temperature fluctuation and flow resistance, which have a negative impact on the melt uniformity. This study offers an important reference for optimizing screw structure to obtain strong mixing and heat transfer performances.