The present invention relates to a method for the production of plastic footwear (10; 100) of the “full plastic” type by means of moulding using a polyurethane mixture (M; P). The method comprises the steps of: —providing a mould (20) having a mould cavity (22) defined by at least two impressions (28, 30) and designed to receive a shoe last (24) so as to define, when the mould (20) is closed, an interspace (26) having the shape and dimensions of the plastic footwear (10; 100) to be produced; —spraying a polyurethane mixture (M, P) onto said at least two impressions (28, 30) of the mould cavity (22); —inserting the shoe last (24) inside said mould cavity (22); —closing the mould cavity (22) so that the sprayed polyurethane mixture (M, P) occupies said interspace (26); —opening the mould (20), once at least the demoulding time (td) for the sprayed polyurethane mixture (M, P) has lapsed, such that the sprayed polyurethane mixture (M, P) has solidified inside the interspace (26) forming said plastic footwear (10, 100); —extracting the shoe last (24) from the mould cavity (22); —removing the plastic footwear (10, 100) from the shoe last (24).

The present invention relates to a method for the production of plastic footwear (10; 100) of the “full plastic” type by means of moulding using a polyurethane mixture (M; P). The method comprises the steps of: —providing a mould (20) having a mould cavity (22) defined by at least two impressions (28, 30) and designed to receive a shoe last (24) so as to define, when the mould (20) is closed, an interspace (26) having the shape and dimensions of the plastic footwear (10; 100) to be produced; —spraying a polyurethane mixture (M, P) onto said at least two impressions (28, 30) of the mould cavity (22); —inserting the shoe last (24) inside said mould cavity (22); —closing the mould cavity (22) so that the sprayed polyurethane mixture (M, P) occupies said interspace (26); —opening the mould (20), once at least the demoulding time (td) for the sprayed polyurethane mixture (M, P) has lapsed, such that the sprayed polyurethane mixture (M, P) has solidified inside the interspace (26) forming said plastic footwear (10, 100); —extracting the shoe last (24) from the mould cavity (22); —removing the plastic footwear (10, 100) from the shoe last (24).

A method for micro-molding a polymeric membrane and including pouring a predetermined volume of curable polymer unto a micro-fabricated mold having a post array with pillars, and overlaying the polymer with a support substrate. A spacer, such as a rubber spacer, is placed in contact with the support substrate and a force is applied to an exposed side of the spacer to compress the support substrate and the polymer together. While applying the force, the polymer is cured on the mold for a predetermined time period and at a predetermined temperature to form a polymeric membrane having a pore array with a plurality of pores corresponding to the plurality of pillars of the post array. The polymeric membrane is removed from the support substrate.

A method for micro-molding a polymeric membrane and including pouring a predetermined volume of curable polymer unto a micro-fabricated mold having a post array with pillars, and overlaying the polymer with a support substrate. A spacer, such as a rubber spacer, is placed in contact with the support substrate and a force is applied to an exposed side of the spacer to compress the support substrate and the polymer together. While applying the force, the polymer is cured on the mold for a predetermined time period and at a predetermined temperature to form a polymeric membrane having a pore array with a plurality of pores corresponding to the plurality of pillars of the post array. The polymeric membrane is removed from the support substrate.

A closing device for a mold group with two half-molds extends along a main axis and has a device body mountable to one of the two half-molds, and a closing group having a closing element rotatable about a rotation axis between a closing position, in which the two half-molds are lockable and an opening position, in which the two half-molds are releasable. A movement group housed in the device body and engaged with the closing group to rotationally move the closing element has a stem movable along the main axis and transmission members for transforming linear motion of the stem into rotatory motion of the closing element. A command group has a command plate engaged with one command end of the stem and a metal sealing bellows engaged with the command plate. A position of the metal sealing bellows corresponds to an axial position of the command plate and of the stem.

A closing device for a mold group with two half-molds extends along a main axis and has a device body mountable to one of the two half-molds, and a closing group having a closing element rotatable about a rotation axis between a closing position, in which the two half-molds are lockable and an opening position, in which the two half-molds are releasable. A movement group housed in the device body and engaged with the closing group to rotationally move the closing element has a stem movable along the main axis and transmission members for transforming linear motion of the stem into rotatory motion of the closing element. A command group has a command plate engaged with one command end of the stem and a metal sealing bellows engaged with the command plate. A position of the metal sealing bellows corresponds to an axial position of the command plate and of the stem.

A closing device for a mold group with two half-molds extends along a main axis and has a device body mountable to one of the two half-molds, and a closing group having a closing element rotatable about a rotation axis between a closing position, in which the two half-molds are lockable and an opening position, in which the two half-molds are releasable. A movement group housed in the device body and engaged with the closing group to rotationally move the closing element has a stem movable along the main axis and transmission members for transforming linear motion of the stem into rotatory motion of the closing element. A command group has a command plate engaged with one command end of the stem and a metal sealing bellows engaged with the command plate. A position of the metal sealing bellows corresponds to an axial position of the command plate and of the stem.

A closing device for a mold group with two half-molds extends along a main axis and has a device body mountable to one of the two half-molds, and a closing group having a closing element rotatable about a rotation axis between a closing position, in which the two half-molds are lockable and an opening position, in which the two half-molds are releasable. A movement group housed in the device body and engaged with the closing group to rotationally move the closing element has a stem movable along the main axis and transmission members for transforming linear motion of the stem into rotatory motion of the closing element. A command group has a command plate engaged with one command end of the stem and a metal sealing bellows engaged with the command plate. A position of the metal sealing bellows corresponds to an axial position of the command plate and of the stem.

A mold for building coating products obtained from composite liquid mixtures is described. The mold includes a base plate, having a plurality of through holes; and a die, configured for incorporating the base plate therein. On the upper surface of the die there are a plurality of shapes of the front surface in negative of each coating product to be manufactured and a molding grid open at the upper part, configured to be pressure applied above the die. The molding grid has side walls which define the perimeter edges of each coating product. Between the molding grid side walls separate bowls are formed for containing a single coating product. Each side wall is inclined at an acute angle with respect to a vertical plane, to confer to each side wall a sharp-pointed and tapered shape from top towards bottom with respect to the entire mold for facilitating the extraction of the finished coating products.

A single-acting, full return clamp (10) holds first and second objects, such as mold portions, in a compressive clamping relationship. A body (12), for attachment to the first object, has a housing (22) with first and second end plates (16, 18). A shaft (26) moves axially in the body and rotates about an axis of the body. A shaft end (32) outside of the housing bears against the second object in a first condition and disengages from the second object in a second condition, where the shaft end is lifts away from the body, and rotates relative to the axis. A spring (40) in the housing applies compressive force on the shaft in the first condition. A piston (74), in the housing near the first end plate when the device is in the first condition, moves axially against the spring force to move the shaft while in the second condition.