Light transmissive foamed polymer sheet and methods for making the same
View Patent ↗In some embodiments, a foamed polymer sheet comprises: a polymeric material and cells located in the polymeric material. The cells have a size distribution, D 90 of greater than or equal to 300 μm and the sheet has a light transmission of greater than or equal to about 5%. In another embodiment, the cells have an average diameter, as measured along a major axis, of about 1 mm to about 4 mm, and the sheet has a light transmission of greater than or equal to about 5%. In another embodiment, a method of making a foamed polymeric sheet comprises: combining a blowing agent with a polymeric material to form a mixture, nucleating bubbles in the mixture, and cooling the mixture. The mixture is at a sufficient temperature and the cells have a sufficient cell size such that the sheet has a light transmission of greater than or equal to 10%.
1. A foamed polymer sheet, comprising:
a polycarbonate sheet having a first side and a second side;
foam cells located in the polycarbonate sheet, wherein the foam cells have a size distribution, D 90 of about 0.3 mm to about 2.5 mm;
a first cap layer disposed on the first side; a second cap layer disposed on the second side; and wherein the first cap layer and/or second cap layer comprise a UV absorber;
wherein the foamed polymer sheet has a light transmission of greater than or equal to about 5%.
2. The sheet of claim 1 , wherein the light transmission is about 30% to about 60%.
3. The sheet according to claim 1 , wherein the light transmission is greater than or equal to 10%.
4. The foamed polymer sheet of claim 1 , wherein a thickness of the foamed polymer sheet is about 8 mm to about 32 mm.
5. The foamed polymer sheet of claim 4 , wherein the thickness is about 10 mm to about 16 mm.
6. An article comprising the foamed polymer sheet of claim 1 , wherein the article comprises at least one of naturally lit structures, sunroofs, canopies, shelters, windows, and stadium roofing.
7. The foamed polymer sheet of claim 1 , wherein the cells comprise closed cells.
8. The foamed polymer sheet of claim 1 , wherein the first cap layer and the second cap layer each comprise a thickness of less than or equal to about 200 micrometers.
9. The foamed polymer sheet of claim 1 , wherein the first cap layer and/or the second cap layer are co-extruded with the sheet.
10. The foamed polymer sheet of claim 1 , wherein the first cap layer and/or the second cap layer have a thickness of less than or equal to about 200 μm.
11. The foamed polymer sheet of claim 10 , wherein the thickness is about 20 μm to about 200 μm.
12. The foamed polymer sheet of claim 11 , wherein the thickness is about 30 μm to about 100 μm.