Excessive compression set

After long-term compression, the foam thickness cannot recover. Deformation usually gradually intensifies after demolding, especially in asymmetric structures or parts with large wall thickness differences. This problem causes product dimensions to exceed the tolerance range, affecting assembly accuracy and product function.

(1) Process factor: viscous flow (creep) in the foam causing irreversible deformation; this factor affects the '2079851475616104453 and final quality of the product. (2) Gas removal aspect: after gas escapes from the closed-cell structure, cell walls stick together and bond; gas retention forms internal defects affecting product compactness. (3) Process aspect: uneven cooling causing shrinkage differences in various regions producing thermal stress. (4) Design aspect: asymmetric structure or uneven wall thickness distribution causing anisotropic shrinkage. (5) Material aspect: differences in molecular chain orientation or fiber alignment direction causing different shrinkage in each direction.

(1) Formulation adjustment: increase crosslink density to reduce creep, adjust gradually and verify the effect, ensuring that other performance indicators of the product are not affected. (2) Material selection: use open-cell structure so that gas can freely enter and exit; establish material selection evaluation standards and determine the optimal solution through comparative tests. (3) Design optimization: optimize foam density., combine process simulation analysis or mold trial verification to continuously iterate and improve the design plan. (4) Preventive measures: perform shrinkage and warpage simulation analysis during the product design stage to optimize structure and process plans in advance.

Deformation problems originate from internal stress caused by uneven shrinkage or heating in various parts of the product, and need to be systematically solved from three aspects: structural design, process parameters, and post-treatment.