Method of co-extruding, co-extrusion die, and extruded articles made therefrom

Patent metadata

Field	Value
Publication number	US-9233500-B2
Application number	US-201113577694-A
Country	US
Kind code	B2
Filing date	Feb 4, 2011
Priority date	Feb 8, 2010
Publication date	Jan 12, 2016
Grant date	Jan 12, 2016

Abstract

A die comprising two die cavities, with each capable of supplying polymeric material, and a distribution plate interposed between at least a portion of each of the two die cavities. The distribution plate has a dispensing edge and a plurality of extrusion channels. First and second extrusion channels extend from entrance openings at the first and second die cavities, respectively, to exit openings on the dispensing edge. The exit openings of the first and second extrusion channels are disposed in alternating positions along the dispensing edge. A method of extruding with such a die and an extruded article made therefrom are also disclosed. The method includes co-extruding a first polymeric composition and a second polymeric composition. The extruded article comprises a plurality of longitudinal first stripes of the first polymeric composition alternating with a plurality of longitudinal second stripes of the second polymeric composition.

First claim

What is claimed is:

1. A die for co-extruding at least a first extrudable polymeric composition and a second extrudable polymeric composition, the die comprising:
a first die cavity in a first die portion;
a second die cavity in a second die portion; and
a distribution plate interposed between at least a portion of the first die cavity and at least a portion of the second die cavity, the distribution plate having a first side forming a boundary of the first die cavity, an opposing second side forming a boundary of the second die cavity, a dispensing edge, a plurality of first extrusion channels, and a plurality of second extrusion channels, with the plurality of first extrusion channels extending from entrance openings at the first die cavity to exit openings on the dispensing edge, the plurality of second extrusion channels extending from entrance openings at the second die cavity to exit openings on the dispensing edge, with the exit openings of the plurality of first extrusion channels and the exit openings of the plurality of second extrusion channels being disposed in alternating positions along the dispensing edge, wherein each of the first extrusion channels comprises two opposite side walls and a joining surface connecting the two opposite side walls, wherein the joining surface of at least some of the first extrusion channels is substantially parallel to the first side of the distribution plate, and wherein each of the first extrusion channels further comprises a rear wall opposite the exit opening and connecting the two opposite side walls, the rear wall being substantially perpendicular to the first side of the distribution plate.

2. The die according to claim 1 , wherein at least some of the first extrusion channels each comprise a reinforcing member.

3. The die according to claim 1 , wherein the two opposite side walls of the first extrusion channels are substantially perpendicular to the first side of the distribution plate.

4. The die according to claim 1 , wherein the exit openings of the first extrusion channels extend from the first side of the distribution plate toward but not all the way to the second side of the distribution plate, and wherein the exit openings of the second extrusion channels extend from the second side of the distribution plate toward but not all the way to the first side of the distribution plate such that a zone of overlap between the exit openings of the first extrusion channels and the exit openings of the second extrusion channels is formed.

5. The die according to claim 1 , wherein the exit openings of the first extrusion channels extend from the first side of the distribution plate to a middle portion between the first side and the second side of the distribution plate, and wherein the exit openings of the second extrusion channels extend from the second side of the distribution plate to the middle portion such that the exit openings of the first extrusion channels and the exit openings of the second extrusion channels do not overlap.

6. The die according to claim 1 , wherein the die further comprises a die lip within 2.5 cm from the dispensing edge.

7. The die according to claim 1 , wherein the first extrusion channels and second extrusion channels have unequal widths.

8. A method of making an extruded article, the method comprising:
providing the die according to claim 1 ;
supplying a first polymeric composition into the first die cavity;
supplying a second polymeric composition, different from the first polymeric composition, into the second die cavity;
extruding the first polymeric composition through the plurality of first extrusion channels and the second polymeric composition through the plurality of second extrusion channels so as to form a flow stream having a width with alternating zones of the first and second polymeric compositions; and
extruding the flow stream out of the die in a longitudinal direction so as to form the extruded article comprising a plurality of longitudinal first stripes of the first polymeric composition alternating with a plurality of longitudinal second stripes of the second polymeric composition, wherein at least some of the longitudinal first stripes have, in a plane perpendicular to the longitudinal direction, a cross-sectional shape comprising substantially parallel opposite sides.

9. The method according to claim 8 , wherein the first polymeric composition comprises an inelastic polymer, and wherein the second polymeric composition comprises an elastomeric polymer.

10. The method according to claim 9 , wherein the second polymeric composition further comprises an inelastic polymer.

11. The method according to claim 8 , wherein at least one of the first or second polymeric compositions is foamed.

12. The method according to claim 8 , wherein the extruded article has opposing major surfaces, the method further comprising co-extruding a third polymeric composition to form a layer on at least one of the opposing major surfaces of the extruded article, wherein the third polymeric composition is different from both the first polymeric composition and the second polymeric composition.

13. The method according to claim 8 , wherein the extruded article has opposing major surfaces, the method further comprising providing projections on at least one of the opposing major surfaces.

14. The method according to claim 13 , wherein the projections are provided on at least some of the longitudinal first stripes, and wherein the projections comprise loop-engaging heads.

15. The method according to claim 13 , wherein the projections are provided on at least some of the longitudinal second stripes and comprise stems without loop-engaging heads.

16. The method according to claim 13 , wherein both the plurality of longitudinal first stripes and the plurality of longitudinal second stripes are provided with projections, the projections of the plurality of longitudinal first stripes being substantially the same height as the projections of the plurality of longitudinal second stripes.

17. The die according to claim 1 , wherein each of the exit openings of the first and second extrusion channels has a minimum width of greater than 1.5 millimeters.

18. The die according to claim 1 , wherein the first extrusion channels and second extrusion channels have unequal depths.

19. The method according to claim 8 , wherein at least one of the longitudinal first stripes has a width unequal to the width of an adjacent longitudinal second stripe.

20. The method according to claim 8 , wherein the extruded article is a film comprising an even number of the longitudinal first stripes of the first polymeric composition comprising an inelastic polymer alternating with an odd number of the longitudinal second stripes of the second polymeric composition comprising an elastomeric polymer such that the longitudinal second stripes are located at least at the first and second lateral edges and at the midline, and wherein at least some of longitudinal second stripes have lines of weakness along their lengths.

Assignees

• Gorman Michael R
• Horns John H
• Ferguson Anthony B
• Rieger Thomas J
• Ausen Ronald W
• Unruh William C
• 3M Innovative Properties Co

Inventors

• Gorman Michael R
• Horns John H
• Ferguson Anthony B
• Rieger Thomas J
• Ausen Ronald W
• Unruh William C

Classifications

• B29C48/21

  the layers being joined at their surfaces · CPC title

• B29K2995/0082

  Flexural strength; Flexion stiffness · CPC title

• Y10T428/15

  Sheet, web, or layer weakened to permit separation through thickness · CPC title

• B29C48/304

  specially adapted for bringing together components, e.g. melts within the die · CPC title

• B29L2031/729

  Hook and loop-type fasteners · CPC title