Three-Shell Mold for Two-Material Footwear Bottoms

The mold is divided into three separate shells (first shell, intermediate shell, second shell) that can be independently positioned and removed. The intermediate shell is axially spaced from the other two shells, creating distinct molding zones. This segmentation prevents material penetration between zones during cross-linking while maintaining the ability to produce two-color footwear bottoms with sharp division lines.

The intermediate shell acts as a mediator between the first and second shells. It provides a physical barrier that prevents the expandable cross-linkable materials from penetrating into each other during the cross-linking process. The intermediate shell can be selectively removed after molding, allowing the two semi-manufactured parts to be bonded together while maintaining sharp material boundaries.

The mold is segmented into three shells with the intermediate shell axially spaced from the first and second shells. This segmentation allows the intermediate shell to be selectively removed after molding, enabling bonding of two semi-manufactured parts. The segmented structure achieves the desired adaptability while maintaining relative structural simplicity compared to traditional three-platen molds.

The three-shell mold structure serves multiple functions: it molds two different materials simultaneously, prevents material penetration during cross-linking, and enables subsequent bonding of semi-manufactured parts. The injection channels are configured to deliver materials to respective cavities, and the axially spaced intermediate shell provides both molding and separation functions, reducing overall device complexity.

The intermediate shell is axially spaced from the first and second shells, creating distinct molding zones separated by gaps. This axial spacing physically prevents material penetration between zones during cross-linking. The segmented configuration achieves precise material separation without requiring complex positioning mechanisms, as the spacing itself provides the necessary isolation.

The mold structure provides different spatial relationships at different locations: the intermediate shell is axially spaced from the first and second shells at the material delivery zones to prevent penetration, while still allowing close proximity for bonding after removal. This localized quality approach achieves precision where needed without adding overall system complexity.