Granted Patent B2

US 10,343,323 · App. 15/324,933 · Granted Jul 9, 2019

Abstract

Claims (23)

1. A method for processing polyethylene terephthalate (PET), the method comprising:

supplying a PET raw material;

determining a target moisture level based on an intrinsic viscosity of the supplied PET raw material and a targeted intrinsic viscosity of the PET raw material after plasticization;

drying the PET raw material to the target moisture level;

plasticizing the PET raw material; and

injecting the plasticized PET into a mold,

wherein the target moisture level is between 60 ppm and 250 ppm to generate a hydrolysis of the PET raw material during plasticization resulting in a controlled drop of the intrinsic viscosity of the PET raw material during plasticization.

2. The method according to claim 1 , wherein the targeted intrinsic viscosity is set between 0.70 dL/g and 0.76 dL/g.

3. The method according to claim 1 , wherein the supplied raw material has an intrinsic viscosity of between 0.80 dL/g and 0.85 dL/g.

4. The method according to claim 1 , wherein the drying is performed at 150° C. or below.

5. The method according to claim 1 , wherein the drying is performed using drying air having a dew point of −40° C. or higher.

6. The method according to claim 1 , wherein the drying is performed using a residence time of the PET raw material in a dryer of between one and four hours.

7. The method according to claim 1 , wherein the plasticized PET raw material is injection-molded to form a container preform for a container.

8. The method according to claim 7 , wherein the container is a bottle.

9. Method A method for forming a bottle comprising using polyethylene terephthalate (PET), the method comprising:

supplying a PET raw material;

drying the PET raw material to a target moisture level;

plasticizing the PET raw material;

injecting the plasticized PET raw material into a mold,

the target moisture level is between 60 ppm and 250 ppm to generate a hydrolysis of PET raw material during plasticization of the PET raw material resulting in a controlled drop of an intrinsic viscosity of the PET raw material to provide a preform of a bottle; and

producing the bottle using blow molding, wherein the bottle has a wall thickness of less than 100 microns over at least 50 percent of a surface of the bottle.

10. The method according to claim 9 comprising filling the bottle with a still beverage.

11. The method according to claim 1 , wherein the drying is performed using a residence time of the PET raw material in a dryer of between one and three hours.

Assignments (6)