Sealing oriented films

1. A process for sealing a machine direction oriented (MDO) film comprising an LLDPE to a substrate comprising bringing said film and said substrate into contact and subjecting at least a part of the contact area to ultrasound so as to form a seal between said film and said substrate, wherein said substrate is the film comprising an LLDPE and said film is sealed to itself.

2. A process as claimed in claim 1 wherein the seal is formed in the transverse direction.

3. A process as claimed in claim 1 wherein the MDO film has been stretched 4 to 8 times its original length.

4. A process as claimed in claim 1 wherein the UW frequency is 15 to 79 kHz.

5. A process as claimed in claim 1 wherein the film is a multilayer film.

6. A process as claimed in claim 1 wherein ultrasonic welding is effected for 50 to 200 ms.

7. A process as claimed in claim 1 wherein during sealing, the film does not shrink by more than 5% of its length in any direction.

8. A process for the packaging of a product, wherein the product is a heat sensitive product, comprising providing a container having an open end comprising a machine direction oriented (MDO) film comprising an LLDPE;

filling said container with said product by dispensing said product through the open end of the container; and

sealing said container by ultrasonically welding the open end to itself.

9. A process for the packaging of a product, wherein the product is a heat sensitive product, comprising forming a container having an open end from a machine direction oriented (MDO) film comprising an LLDPE;

filling said container with said product by dispensing said product through the open end of the container; and

sealing said container by ultrasonically welding the open end to itself.

10. The product obtained by the process of claim 1 .

11. The product obtained by the process of claim 8 .

12. The product obtained by the process of claim 9 .