Apparatus and Method for Producing Embossed Film
Disclosed herein are embossing lines and methods for their use. In one embodiment an embossing line comprises: an embossing belt disposed about a heating roll and a chill roll, a joining roll disposed between the heating roll and the chill roll, and a pre-embossing heater disposed between the joining roll and the heating roll such that the substrate film can be heated by the pre-embossing heater prior to the embossing belt contacting the heating roll. In another embodiment, a film making process is disclosed.
1 . An embossing line, comprising:
an embossing belt disposed about a heating roll and a chill roll;
a joining roll disposed between the heating roll and the chill roll such that the joining roll can dispose a substrate film on the embossing belt prior to the embossing belt contacting the heating roll; and,
a pre-embossing heater disposed between the joining roll and the heating roll such that the substrate film can be heated by the pre-embossing heater prior to the embossing belt contacting the heating roll.
2 . The embossing line of claim 1 , further comprising a cooling apparatus comprising a cooling jet and a vacuum conduit, wherein the cooling apparatus is disposed such that an embossed film can be cooled.
3 . The embossing line of claim 1 , further comprising a belt heater disposed between the chill roll and the joining roll such that the embossing belt can be heated prior to the joining roll.
4 . The embossing line of claim 1 , further comprising an idler roll positioned such that the substrate film can be supplied to the joining roll at an acute angle.
5 . The embossing line of claim 4 , wherein the acute angle is greater than or equal to about 15°.
6 . The embossing line of claim 5 , wherein the acute angle is greater than or equal to about 30°.
7 . The embossing line of claim 6 , wherein the acute angle is greater than or equal to about 45°.
8 . An embossing line, comprising:
an extruder capable of extruding a polymer melt onto a nip section between an embossing drum and a compression drum to form an embossed film; and,
a cooling apparatus capable of cooling the embossed film, wherein the cooling apparatus comprises a cooling jet and a vacuum conduit.
9 . A film making process, comprising:
disposing a substrate film and a support film on an embossing belt to form a supported film;
heating the supported film to form a heated supported film;
introducing the heated supported film into a first nip section; and,
forming an embossed film, wherein the embossed film comprises surface features.
10 . The process of claim 9 , further comprising heating the embossing belt prior to disposing the substrate film and support film on the embossing belt.
11 . The process of claim 9 , wherein the substrate film is heated above its glass transition temperature.
12 . The process of claim 9 , further comprising:
blowing a cooling media at a surface of the embossed film;
removing heat energy from the embossed film with the cooling media to form a warmed media; and,
applying a vacuum to at least a portion of the warmed media.
13 . The process of claim 9 , wherein the substrate film comprises a polycarbonate.
14 . The process of claim 9 , wherein the support film comprises a polyethylene terephthalate
15 . The process of claim 9 , further comprising producing the embossed film at a rate of greater than or equal to about 10 feet per minute, wherein the surface features comprise a replication percentage of greater than or equal to about 90%.
16 . The process of claim 15 , wherein the rate is greater than or equal to about 20 feet per minute.
17 . The process of claim 16 , wherein the rate is greater than or equal to about 30 feet per minute.
18 . An film making process, comprising:
extruding a polymer melt onto a nip section formed by an embossing drum and a compression drum;
forming an embossed film, wherein the embossed film comprises surface features;
blowing a cooling media at a surface of the embossed film;
removing heat energy from the embossed film with the cooling media to form a warmed media; and,
applying a vacuum to at least a portion of the warmed media.
19 . The process of claim 18 , further comprising producing the embossed film at a rate of greater than or equal to about 10 feet per minute, wherein the surface features comprise a replication percentage of greater than or equal to about 90%.
20 . The process of claim 19 , wherein the rate is greater than or equal to about 20 feet per minute.