Method for producing structural injection molded parts using lost motion movement between a mold and surrounding cutting blade

A method of forming a structural injection molded part comprising the steps of:

• providing a mold assembly including a female mold defining a concavity and a male mold defining a convexity sized to fit within the concavity of the female mold to define a mold cavity corresponding to the shape of the part to be molded;
• positioning a substantially non-stretchable, reinforcing material over the concavity of the female mold;
• clamping said material around the periphery of said mold cavity;
• thereafter moving said male mold convexity into said female mold concavity to position said reinforcing material in said mold cavity while selectively controlling the clamping pressure to allow the material to selectively slip past the clamping interface to allow said male mold convexity to move into said female mold concavity;
• injecting resin into said mold cavity to produce a structural injection molded part;
• wherein,
• said clamping step includes selectively varying the clamping pressure around the clamped peripheral interface to provide a varying clamping force as measured around the clamping interface.

A method of forming a structural injection molded part comprising the steps of:

• providing a mold assembly including a female mold defining a concavity and a male mold defining a convexity sized to fit within the concavity of the female mold to define a mold cavity corresponding to the shape of the part to be molded;
• positioning a substantially non-stretchable, reinforcing material over the concavity of the female mold;
• clamping said material around the periphery of said mold cavity with a plurality of individually adjustable clamping segments;
• thereafter moving said male mold convexity into said female mold concavity to position said reinforcing material in said mold cavity while individually controlling the clamping pressure exerted by each segment to allow the material to selectively slip past the clamping interface to allow said male mold convexity to move into said female mold concavity;
• and
• injecting resin into said mold cavity to produce a structural injection molded part.

A method of forming and cutting a structural injection molded part comprising the steps of:

• providing a mold assembly including a female mold defining a concavity and a male mold defining a convexity sized to fit within the concavity of the female mold to define a mold cavity corresponding to the shape of the part to be molded;
• positioning a closed loop cutting blade in surrounding relation to one of said molds;
• positioning reinforcing material over the concavity of the female mold;
• moving said male mold convexity into said female mold concavity to position said reinforcing material in said mold cavity;
• thereafter moving said cutting blade relative to said one mold to trim said part;
• injecting resin into said mold cavity to produce a structural injection molded part;
• wherein,
• said one mold and said cutting blade are part of and movable with a common die set assembly with a lost motion drive connection between said one mold and said cutting blade, and said trimming step is accomplished by lost motion movement between said one mold and said cutting blade after said male mold has been moved into said female mold.