System and method of making an in-mold clear-coated composite
A plastic product covered with a clear coating which is applied through an in-mold coating process. Covalent bonds hold the clear coating and the plastic substrate together, and the clear coating is capable of resisting delamination and of inhibiting fading of a pigmented surface underlying the clear coating. A preferred in-mold coating method of preparing a plastic part with a clear-coat surface includes the steps of (a) providing a mold, (b) heating the mold, (c) providing an unpigmented first-reactant/solvent mixture, (d) providing an unpigmented second-reactant/solvent mixture, (e) mixing the first-reactant/solvent mixture and the second-reactant/solvent mixture to form a clear-coat mixture, (f) spraying the clear-coat mixture onto the heated mold surface, (g) providing a pigmented third-reactant/solvent mixture, (h) providing a fourth-reactant/solvent mixture, (i) mixing the third-reactant/solvent mixture and the fourth-reactant/solvent mixture to form a pigmented mixture, (j) spraying the pigmented mixture, during the open time of the clear-coat mixture, onto the clear-coat mixture previously sprayed onto the heated mold surface, (k) applying, over the sprayed pigmented mixture, a substrate-forming material, so as to create an uncured preform, and (l) allowing the preform to cure so as to form a substrate having a clear-coat surface.
1. An in-mold coating method of preparing a plastic part with a clear-coat surface, the method comprising:
providing a mold having a mold surface having a predetermined degree of finish;
heating the mold to a temperature between approximately 40 degrees Celsius and approximately 95 degrees Celsius;
providing an unpigmented first-reactant/solvent mixture;
providing an unpigmented second-reactant/solvent mixture;
mixing the unpigmented first-reactant/solvent mixture and the unpigmented second-reactant/solvent mixture to form a clear-coat mixture;
spraying the clear-coat mixture onto the heated mold surface, the clear-coat mixture having an open time on the heated mold surface;
providing a pigmented third-reactant/solvent mixture;
providing a fourth-reactant/solvent mixture;
mixing the pigmented third-reactant/solvent mixture and the fourth-reactant/solvent mixture to form a pigmented mixture;
spraying the pigmented mixture, during the open time of the clear-coat mixture, onto the clear-coat mixture previously sprayed onto the heated mold surface;
applying, over the sprayed pigmented mixture, a substrate-forming material, so as to create an uncured preform; and
allowing the preform to cure so as to form a substrate having a clear-coat surface with substantially the predetermined degree of finish;
wherein the clear-coat mixture and the pigmented mixture are sprayed in an amount to form a total coating layer thickness substantially between 3.0 to 4.0 mils DFT.
2. An in-mold coating method of preparing a plastic part with a clear-coat surface, the method comprising:
providing a mold having a mold surface having minimal surface roughness;
heating the mold to a temperature between approximately 40 degrees Celsius and approximately 95 degrees Celsius;
providing an unpigmented first-reactant/solvent mixture;
providing an unpigmented second-reactant/solvent mixture;
mixing the unpigmented first-reactant/solvent mixture and the unpigmented second-reactant/solvent mixture to form a clear-coat mixture;
spraying the clear-coat mixture onto the heated mold surface, the clear-coat mixture having an open time on the heated mold surface;
providing a pigmented third-reactant/solvent mixture;
providing a fourth-reactant/solvent mixture;
mixing the pigmented third-reactant/solvent mixture and the fourth-reactant/solvent mixture to form a pigmented mixture;
spraying the pigmented mixture, during the open time of the clear-coat mixture, onto the clear-coat mixture previously sprayed onto the heated mold surface;
applying, over the sprayed pigmented mixture, a substrate-forming material, so as to create an uncured preform; and
wherein the clear-coat mixture and the pigmented mixture are sprayed in an amount to form a total coating layer thickness substantially between 3.0 to 4.0 DFT.
3. The method according to claim 2 , wherein the mold may be opened to permit spraying onto the mold surface; wherein the mold is closed after the pigmented mixture is sprayed onto the clear-coat mixture; and wherein the substrate-forming material is injected into the closed mold.
4. The method according to claim 2 , wherein a barrier formulation is applied on the sprayed pigmented mixture so as to create an unreinforced barrier layer; wherein the substrate-forming material includes a polymeric-matrix-forming material and reinforcing components and is applied over the barrier layer; and wherein the preform is cured so as to form a composite with a reinforced substrate and a clear-coat pigmented surface.
5. The method according to claim 4 , wherein the reinforcing components include fibers.
6. The method according to claim 2 , wherein the unpigmented first-reactant/solvent mixture and the pigmented third-reactant/solvent mixture include polyol as a reactant, and wherein the second-reactant/solvent mixture and the fourth-reactant/solvent mixture include isocyanate as a reactant.
7. The method according to claim 6 , further comprising:
(a) mixing the unpigmented first-reactant/solvent mixture and the unpigmented second-reactant solvent mixture to form the clear-coat mixture having a total volume fraction of solids substantially between 0.30 and 0.60; and
(b) mixing the pigmented third-reactant/solvent mixture and the fourth-reactant solvent mixture to form the pigmented mixture having a total volume fraction of solids substantially between 0.30 and 0.60.