Granted Patent B2

US 8,563,102 · App. 12/857,977 · Granted Oct 22, 2013

Abstract

Claims (34)

1. A bag or pouch for containing flowable material, made by a process comprising the steps of:

(I) providing a monofilm, said monofilm comprising a flowable material packaging film comprising at least a resin blend of:

(a) from about 33 wt % to about 80 wt % of at least one ethylene-C 4 to C 10 -α-olefin interpolymer having a melt-index of from 0.4 to 1.5 g/10 min (190° C., 2.15 kg), and a density of from 0.900 to 0.916 g/cm 3 ; and

(b) from about 67 wt % to about 20 wt % of at least one propylene-based heterogeneous interpolymer of propylene with ethylene, or of at least one propylene-based heterogeneous of propylene with ethylene and butene, said propylene-based heterogeneous interpolymer comprising:

(i) from about 71 mol % to about 86 mol % propylene, and

(ii) from about 29 mol % to about 14 mol % ethylene or ethylene and butene,

wherein said propylene-based heterogeneous interpolymer has an overall weight average molecular weight (M W ) of at least about 400,000, a xylene soluble phase of not less than 30 wt %, with the xylene soluble phase having a M W of at least about 275,000, and

wherein said propylene-based heterogeneous propylene-based interpolymer has a density of from 0.875 to 0.91 g/cm 3 ;

wherein said monofilm has a Hot Tack Initiation Temperature in the range of from about 100° C. to about 140° C. and a Hot Tack Strength of not more than about 5 N/inch in the temperature range of about 100° C. to about 150° C., when fabricated at a thickness of about 50 μm and tested using a JB Instrument Hot Tack Tester set at a 0.5 second dwell, 0.2 second delay time, 40 psi seal bar pressure, and 250 mm/second peel rate; and

wherein said monofilm has a flex crack resistance such that it develops 5 or less pinholes per 300 cm 2 in 10,000 cycles of Gelbo Flex testing as measured according to ASTM F392;

(II) forming said monofilm into a tubular member;

(III) heat-sealing longitudinal edges and then filling said pouch with flowable material;

(IV) heat-sealing a first transverse end of said tubular member to form a pouch; and

(V) sealing and cutting through a second transverse end of said tubular member to provide a filled pouch; said tubular member being filled continuously or intermittently; wherein said upper transverse seal is the bottom seal of the next pouch to be formed and filled;

and

wherein said monofilm has a thickness of from about 20 to about 150 μm.

2. The bag or pouch as recited in claim 1 , wherein said monofilm is sterilized.

3. A bag or pouch for containing flowable material, made by a process comprising the steps of:

(I) providing a multilayer film, said multilayer film comprising a flowable material packaging film comprising at least a resin blend of:

(a) from about 33 wt % to about 80 wt % of at least one ethylene-C 4 to C 10 -α-olefin interpolymer having a melt-index of from 0.4 to 1.5 g/10 min (190° C., 2.15 kg), and a density of from 0.900 to 0.916 g/cm 3 ; and

(b) from about 67 wt % to about 20 wt % of at least one propylene-based heterogeneous interpolymer of propylene with ethylene, or of at least one propylene-based heterogeneous interpolymer of propylene with ethylene and butene, said propylene-based heterogeneous interpolymer comprising:

(i) from about 71 mol % to about 86 mol % propylene, and

(ii) from about 29 mol % to about 14 mol % ethylene or ethylene and butene,

wherein said propylene-based heterogeneous interpolymer has an overall weight average molecular weight (M W ) of at least about 400,000, a xylene soluble phase of not less than 30 wt %, with the xylene soluble phase having a M W of at least about 275,000, and

wherein said propylene-based heterogeneous propylene-based interpolymer has a density of from 0.875 to 0.91 g/cm 3 ;

wherein said multilayer film has a Hot Tack Initiation Temperature in the range of from about 100° C. to about 140° C. and a Hot Tack Strength of not more than about 5 N/inch in the temperature range of about 100° C. to about 150° C., when fabricated at a thickness of about 50 μm and tested using a JB Instrument Hot Tack Tester set at a 0.5 second dwell, 0.2 second delay time, 40 psi seal bar pressure, and 250 mm/second peel rate; and

wherein said multilayer film has a flex crack resistance such that it develops 5 or less pinholes per 300 cm 2 in 10,000 cycles of Gelbo Flex testing as measured according to ASTM F392;

(II) forming said multilayer film into a tubular member;

(III) heat-sealing longitudinal edges and then filling said pouch with flowable material;

(IV) heat-sealing a first transverse end of said tubular member to form a pouch; and

(V) sealing and cutting through a second transverse end of said tubular member to provide a filled pouch; said tubular member being filled continuously or intermittently; wherein said upper transverse seal is the bottom seal of the next pouch to be formed and filled;

and

wherein at least one layer of said multilayer film has a thickness of from about 20 to about 150 μm.

4. The bag or pouch as recited in claim 3 , wherein said multilayer film is sterilized.

Assignments (10)