Production of molded laminated articles, particularly soles for footwear

A method for the production of molded laminated articles in a mold having a mold cavity comprising the steps of:

• placing in the mold cavity a layer of a vulcanisable rubber constituting a moldable first material in contact with a surface thereof so as to be molded by the surface;
• injecting into the mold cavity foamable second material to fill the remainder of the cavity;
• wherein the foaming of the second material generates pressure therein as it is confined within the mold cavity;
• and
• molding the first and second materials to form a laminated article with adjoining attached layers of vulcanised molded first material and foamed molded second material;
• wherein molding of the first material against the mold surface employs pressure produced by the foaming of the second material.

A method for the production of a boot or shoe comprising a molded laminated sole attached by molding to an upper comprising the steps of:

• placing in a mold cavity of a mold a layer of a heat vulcanisable rubber material;
• drawing a vacuum between the layer and a tread surface of the mold that is to mold an outer tread surface of the boot or shoe so as to bring the layer into contact with the mold tread surface;
• closing the mold cavity with a boot or shoe upper to which the sole is to be molded;
• injecting into the mold cavity foamable polymerisable polyurethane material to fill the remainder of the cavity;
• the polymerisation reaction of the polyurethane material being exothermic and the foaming thereof generating pressure therein as it is confined within the mold cavity;
• and
• molding the heat vulcanisable rubber material and the foamable polymerisable polyurethane material together to form a laminated sole with an outer tread layer of heat vulcanised rubber material molded against the mold tread surface and the remainder of foamed polymerised polyurethane material attached by the molding to the boot or shoe upper and to the outer tread layer;
• wherein vulcanisation of the heat vulcanisable rubber material employs heat produced by the exothermic reaction of the foamed polymerised polyurethane material and molding of the heat vulcanisable rubber material against the mold surface employs pressure produced by the foaming of the foamed polymerised polyurethane material.

A method for the production of a molded laminated sole for attachment to a boot or shoe comprising the steps of:

• placing in a mold cavity of a mold a layer of a heat vulcanisable rubber material;
• drawing a vacuum between the layer and a tread surface of the mold that is to mold an outer tread surface of the sole so as to bring the layer into contact with the mold tread surface;
• closing the mold cavity and injecting therein foamable polymerisable polyurethane material to fill the remainder of the cavity;
• the polymerisation reaction of the polyurethane material being exothermic and the foaming thereof generating pressure therein as it is confined within the mold cavity;
• and
• molding the heat vulcanisable rubber material and the foamable polymerisable polyurethane material together to form a laminated sole with an outer tread layer of heat vulcanised rubber material molded against the mold tread surface and the remainder of foamed polymerised polyurethane material attached by the molding to the outer tread layer;
• wherein vulcanisation of the heat vulcanisable rubber material employs heat produced by the exothermic reaction of the foamed polymerised polyurethane material and molding of the heat vulcanisable rubber material against the mold surface employs pressure produced by the foaming of the foamed polymerised polyurethane material.