Apparatus and methods of making and using heater apparatus for heating an object having two-dimensional or three-dimensional curvature

Heater apparatus for heating an object that has a curved surface in two or three dimensions, comprising:

• a thin, flexible heater mat comprised of fiberglass reinforced silicone solid rubber with an inner surface and an outer surface, said outer surface being spaced radially outward from said inner surface by a thickness of said flexible heater mat, and including an electrically powered heating element embedded in said fiberglass reinforced solid rubber between said inner surface and said outer surface, said inner surface having a size and shape that conforms to an object having a curved surface;
• and
• a thermal insulative jacket comprising silicone sponge or foam rubber, which has a thickness greater than the thickness of the flexible heater mat, molded, cured, and bonded to the outer surface of the flexible heater mat when said inner surface is in said size and shape that conforms to the curved surface of the object such that said silicone sponge or foam rubber has a configuration with a set molecular structure that is elastic, but resilient and biased to said configuration sufficiently such that said silicone sponge or foam rubber returns and maintains said inner surface of the heater mat to and conforming with the curved surface of the object when there is no external force on the heater that deforms the inner surface of the heater mat radially outward away from the curved surface of the object, said silicone sponge or foam rubber having an exposed peripheral surface spaced radially outward from the outer surface of the heater mat by a spatial distance equal to the thickness of the silicone sponge or foam rubber, said silicone sponge or foam rubber also being more resistive to heat conduction than said heater mat and having a thickness such that a 200.degree. C. temperature at said inner surface of said heater mat attenuates to less than 75.degree. C. at said peripheral surface in a room temperature ambient environment, and further wherein after said jacket is bonded to said beater mat, said beater mat and said jacket form interfacing edge faces and a slit such that said heater mat and said jacket are attachable to and removable from the object when external forces are applied to said heater mat and said jacket.

Heater apparatus for beating an object that has a curved surface in two or three dimensions, the heater apparatus being fabricated by a process comprising the steps of:

• forming a thin, flexible, but unstretchable heater mat by positioning an electric heater element between two partially cured, fiberglass reinforced, silicone solid rubber sheets;
• wrapping the two sheets with the electric heater element positioned therebetween around a mandrel that has a surface substantially identical in size and shape to an object having a curved surface;
• and simultaneously applying both radially inward directed pressure and heat to the two sheets and electric heating element wrapped around the mandrel to vulcanize the two sheets together into a unitary heater mat of fiberglass reinforced silicone solid rubber with the electric heater element embedded therein;
• removing the heat and pressure from the heater mat;
• forming an insulative, structure-enhancing jacket around the heater mat by positioning the heater mat still on the mandrel into a mold cavity that has a peripheral size and shape larger than the heater mat on the mandrel;
• mixing a base silicone rubber material with a catalyst that reacts with the base to generate gas, which expands the base material and simultaneously cures the expanding base material into a sponge or foam structure;
• partially filling the mold cavity around the heater element and mandrel with the mixture of base silicone rubber material, and catalyst;
• allowing the base material to expand, cure, and bond around the outer surface of the heater mat on the mandrel in the mold cavity until the mold cavity is filled with expanded silicone sponge or foam structure;
• heating the silicone sponge or foam structure in the mold cavity to cure and then allow the silicone sponge or foam structure to cool;
• removing the cured structure of silicone sponge or foam from the mold cavity;
• and slitting the structure to create a slit or split in the silicone sponge or foam structure with juxtaposed edge faces that can be forced radially apart against an inherent resilient bias of the structural combination of the heater mat and jacket to remove the structure from the mandrel.

A method for creating a heater apparatus for heating an object where the object has a curved surface in two dimensions or three dimensions, comprising the steps of:

• positioning an electric heater element between two partially cured, fiberglass reinforced, silicone solid rubber sheets;
• wrapping said two sheets with said electric heater element positioned there between around a mandrel that has a surface substantially identical in size and shape to an object having a curved surface;
• simultaneously applying both radially inward directed pressure and heat to said two sheets and said electric heating element wrapped around said mandrel to vulcanize said two sheets together into a unitary heater mat with fiberglass reinforced silicone solid rubber having with said electric heater element embedded therein, wherein said unitary heater mat has an inner surface adjacent said mandrel and an outer surface spaced radially outward from said inner surface;
• removing said heat and said pressure from said heater mat;
• positioning said heater mat while still on said mandrel into a mold cavity that has a peripheral size and shape larger than said heater mat on said mandrel;
• mixing a base silicone rubber material with methanol and a catalyst that reacts with said base material to generate gas to expand said base material and simultaneously cure said expanding base material into a silicone sponge or foam structure;
• partially filling said mold cavity around said heater mat and said mandrel with said mixture of base silicone rubber material, methanol, and catalyst;
• allowing said mixture to expand, cure and bond around the outer surface of said heater mat on said mandrel in said mold cavity until said mold cavity is filled with expanded silicone sponge or foam structure surrounding said heater mat;
• heating said silicone sponge or foam structure in said mold cavity to cure said silicone sponge or foam structure;
• allowing said cured silicone sponge or foam structure in said mold cavity to cool such that an insulative, structure-enhancing jacket is formed around said heater mat;
• removing said mandrel with said heater mat and said jacket from said mold cavity;
• and
• slitting said heater mat and said jacket to create a slit or split in said heater mat and said jacket having juxtaposed edge faces that can be forced apart against an inherent resilient bias of the structural combination of said heater mat and said jacket to remove the structure from said mandrel.

A heater assembly, comprising:

• a plurality of heater apparatuses, each heater apparatus including:
• a heater mat including a heat producing material in a flexible, but substantially unstretchable solid material matrix that has a first edge and a second edge with an inner surface extending between said first edge and said second edge and an outer surface spaced outward from the inner surface and extending between said first edge and said second edge with the solid material matrix separating the outer surface spatially from the inner surface, said mat being formed in a shape that wraps said inner surface around a space, which space has a periphery that is defined by said inner surface, said first edge and said second edge being in substantially juxtaposed relation to each other, further wherein said heat producing material in each heater apparatus in the heater assembly is connectable in electrical parallel to the heat producing material of each other heater mat in the heater assembly and is electrically connectable to a source of electric power;
• and
• a jacket formed around and bonded in immoveable relation to the outer surface of the heater mat, said jacket comprising a resiliently stretchable and compressible material containing cells of gas dispersed throughout a matrix of solid material, wherein said material is less dense, more elastic, more compressible, less thermally conductive, and thicker in cross-sectional dimension than said heater mat and is resiliently resistive to both compression set and compression to a sufficient extent that said material yields and strains in compression to accommodate separation of said first edge and said second edge from each other as an external force is applied to move said first edge and said second edge apart from each other such that said heater apparatus returns to and maintains said first edge and said second edge in substantially juxtaposed relation to each other after removal of such external force.

A method for fabricating a heater apparatus for heating an object where the object has a curved surface in two dimensions or three dimensions, comprising the steps of:

• positioning an electric heater element between two partially cured, fiberglass reinforced, silicone solid rubber sheets;
• wrapping said two sheets with said electric heater element positioned there between around a mandrel that has a surface substantially identical in size and shape to an object having a curved surface;
• simultaneously applying both radially inward directed pressure and heat to said two sheets and said electric heating element wrapped around said mandrel to vulcanize said two sheets together into a unitary heater mat of fiberglass reinforced silicone solid rubber with said electric heater element embedded therein;
• removing said heat and said pressure from said heater mat;
• positioning said heater mat while still on said mandrel into a mold cavity that has a peripheral size and shape larger than said heater mat on said mandrel;
• mixing a base silicone rubber material with a catalyst that reacts with said base to generate gas to expand said base material and simultaneously cure said expanding base material into a silicone sponge or foam structure;
• partially filling said mold cavity around said heater mat and said mandrel with said mixture of base silicone rubber material and catalyst;
• allowing said mixture to expand, cure and bond around the outer surface of said heater mat on said mandrel in said mold cavity until said mold cavity is filled with expanded silicone sponge or foam structure surrounding said heater mat;
• allowing said cured silicone sponge or foam structure in said mold cavity to cool such that an insulative, structure-enhancing jacket is formed around said heater mat;
• removing said mandrel with said heater mat and said jacket from said mold cavity;
• and
• slitting said heater mat and said jacket to create a slit or split in said heater mat and said jacket having juxtaposed edge faces that can be forced apart against an inherent resilient bias of the structural combination of said heater mat and said jacket to remove the structure from said mandrel.

A method for fabricating a heater apparatus for heating an object where the object has a curved surface in two dimensions or three dimensions, comprising the steps of:

• creating a unitary heater mat of fiberglass reinforced silicone solid rubber that has a first surface and a second surface and includes an electric heater element enclosed substantially within said fiberglass reinforced silicone solid rubber;
• wrapping said unitary heater mat around a mandrel, wherein said mandrel has an surface substantially identical in size and shape to an object having a curved surface, such that said first surface of said unitary heater mat is adjacent said surface of said mandrel;
• positioning said unitary heater mat while still wrapped around said mandrel into a mold cavity that has a peripheral size and shape larger than said unitary heater mat on said mandrel;
• mixing a base silicone rubber material and a catalyst that reacts with said base material to generate gas to expand said base material and simultaneously cure said expanding base material into a silicone sponge or foam structure;
• partially filling said mold cavity around said unitary heater mat and said mandrel with said mixture of base silicone rubber material and catalyst;
• allowing said mixture of base silicone rubber material and catalyst to expand, cure and bond around said second surface of said unitary heater mat on said mandrel in said mold cavity until said mold cavity is filled with expanded silicone sponge or foam structure surrounding said unitary heater mat;
• allowing said cured silicone sponge or foam structure in said mold cavity to cool such that an insulative, structure-enhancing jacket is formed around said unitary heater mat;
• removing said mandrel with said unitary heater mat and said jacket from said mold cavity;
• and
• slitting said unitary heater mat and said jacket to create a slit or split in said unitary heater mat and said jacket having juxtaposed edge faces that can be forced apart against an inherent resilient bias of the structural combination of said unitary heater mat and said jacket to remove said structural combination from said mandrel.