Processes for In-Mold coating systems for molding, and products formed therefrom
Disclosed are processes for In-Mold coating of a substrate. The processes include: introducing a curable composition to a mixhead at a first elevated pressure, the curable composition comprising a first polymeric component and a second polymeric component, the introducing of the curable composition to the mixhead comprising mixing the first and second polymeric components by impingement to form an intermediate composition; introducing the intermediate composition to a secondary mixer, the introducing of the intermediate composition to the secondary mixer comprising mixing the intermediate composition to form a coating composition; and introducing the coating composition into a mold containing a substrate to form a curable coating on a surface of the substrate.
1. A system comprising:
a mixhead in communication with a first body, the mixhead configured to receive a curable composition at a first elevated pressure, the curable composition comprising a first polymeric component and a second polymeric component, the mixhead configured to mix the first and second polymeric components by impingement to form an intermediate composition;
a channel comprising a secondary mixer and a dump well, and having a channel volume;
the secondary mixer positioned between the mixhead and a cavity positioned in the first body, the secondary mixer configured to receive the intermediate composition and to mix the intermediate composition to form a coating composition; and
the cavity configured to receive a substrate, to receive the coating composition, and to form a curable coating on a surface of the substrate from the coating composition,
wherein the dump well is configured to increase the channel volume and to limit improperly mixed curable composition from reaching the cavity.
2. The system according to claim 1 , wherein the secondary mixer is a peanut mixer, wherein the mix of the intermediate composition to form the coating composition is a kinetic mix.
3. The system according to claim 1 , wherein the secondary mixer is partially formed in a mold and partially formed in the substrate.
4. The system according to claim 1 ,
wherein the mixhead is configured to receive the curable composition at a second pressure less than the first elevated pressure to form a non-homogenous mixture.
5. The system according to claim 4 , wherein the dump well comprises the secondary mixer.
6. The system according to claim 4 , wherein the dump well comprises at least two channels.
7. The system according to claim 4 , wherein the dump well is positioned between the mixhead and the secondary mixer.
8. The system according to claim 4 , wherein the secondary mixer is positioned between the dump well and the mixhead.
9. The system according to claim 1 , where the first polymeric component comprises an isocyanate-reactive group and the second polymeric component comprises a polyisocyanate.
10. The system according to claim 9 , wherein the isocyanate-reactive group comprises a polyol.
11. The system according to claim 1 , wherein the first elevated pressure is at least 1600 psi.
12. The system according to claim 1 , wherein the coating composition is homogeneous.
13. The system according to claim 1 , further comprising the curable coating configured to form a cured coating on the substrate having a thickness between 50 micrometers and 100 micrometers.
14. The system according to claim 13 , wherein the cured coating thickness is between 80 micrometers and 100 micrometers.
15. The system according to claim 13 , wherein the cured coating is substantially free of defects.
16. The system according to claim 13 , wherein the curable coating composition is cured:
at a mold temperature of 75° C. to 105° C.; and
fora period between 10 and 90 seconds.
17. The system according to claim 1 , further comprising:
at least two channels positioned between the mixhead and the cavity, the at least two channels configured to facilitate conveyance of the coating composition to the cavity.