Paper laminates manufactured using foamed adhesive systems

• US 20070113949A1
• Filed: 01/19/2007
• Published: 05/24/2007
• Est. Priority Date: 09/02/2003
• Status: Active Grant

• Current Assignee: HB Fuller Company
• Original Assignee: HB Fuller Company
• Inventors: Muvundamina, Mutombo
• Granted Patent: US 7,846,281 B2
• Time in Patent Office: Days
• US Class Current: 156/78
• CPC Class Codes: B05B 7/0475 with means for deflecting the peripheral gas flow towards the central liquid flow B05B7/0458 takes precedence
• CPC Class Codes: B29C 44/3446 Feeding the blowing agent
• CPC Class Codes: B32B 2317/12 Paper, e.g. cardboard
• CPC Class Codes: B32B 37/12 characterised by using adhesives
• CPC Class Codes: B32B 37/1292 selectively, e.g. in stripes, in patterns B32B37/0076 takes precedence
• CPC Class Codes: C08L 2666/18 Polyesters or polycarbonates according to C08L67/00 - C08L69/00; Derivatives thereof
• CPC Class Codes: C08L 71/02 Polyalkylene oxides
• CPC Class Codes: C09J 11/04 inorganic
• CPC Class Codes: C09J 129/04 Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
• CPC Class Codes: C09J 5/08 using foamed adhesives
• CPC Class Codes: Y10T 137/2984 Foam control in gas charged liquids
• CPC Class Codes: Y10T 156/1798 with liquid adhesive or adhesive activator applying means

Abstract

Foamed, aqueous adhesive compositions are used to manufacture tissue laminate products including or especially as bathroom tissue, facial tissue, paper towels, and the like. Foaming typically occurs by introducing pressurized gas and adhesive flows in a nozzle chamber on demand, wherein the kinetic energy of the flows is used to provide mixing energy. The adhesive preferably is dispensed as a plurality of discrete, foamed adhesive particles. The foamed adhesive can be used for intralamina bonds, interlaminate bonds, bonding loose sheet extremities, bonding roll to roll, and the like. The invention provides a reliable, straightforward way to accomplish in-nozzle foaming of an adhesive.

Claims

1. A method of making a foamed adhesive, comprising the steps of:

(a) causing one or more flows of an adhesive composition to impact one or more flows of a pressurized gas in a chamber under conditions such that at least portions of the impacting flows mixingly interact to form a foamed adhesive in the chamber, wherein the adhesive composition and the pressurized gas are supplied at a pressure in the range of from about 7 kPa (gauge) to about 70 kPa (gauge); and

(b) dispensing the foamed adhesive from the chamber.

2. The method of claim 1, wherein the adhesive composition incorporates an antimisting agent selected from the group consisting of a borate or boric crosslinking agent, a bentonite, clay, a synthetic layered silicate, xantham gum, derivatives of these, and combinations of these.

3. The method of claim 1, wherein the chamber has an excess volume during at least a portion of the time during which the flows mixingly interact.

4. The method of claim 1 wherein the chamber has an excess volume such that the volume of the one or more flows of adhesive is from about 10% to about 70% of the total volume of the one or more chambers in which foaming occurs.

5. The method of claim 1, wherein the adhesive composition is water-based and comprises at least 50% by weight water based upon the total weight of the composition not including forming gas.

6. The method of claim 1, wherein the adhesive composition comprises an amount of a rheology-modifying agent effective to help provide the composition with shear thinning characteristics.

7. The method of claim 6, wherein the rheology-modifying agent comprises a peptiser.

8. The method of claim 1, wherein the adhesive composition comprises sodium nitrite.

9. The method of claim 1, wherein the adhesive composition incorporates ingredients comprising an aqueous carrier vehicle, adhesive resin, an antimisting agent, a rheology modifying agent, a surface tension modifying agent, and a foaming agent.

10. The method of claim 1, wherein step (a) occurs substantially in the absence of mechanical shear.

11. The method of claim 1, wherein the weight ratio of the one or more adhesive flows to the one or more gas flows is effective to provide a foam having a foam content in the range of from about 10 to about 50 percent.

12. The method of claim 1 wherein the foam is dispensed on one or more plies to form a laminate selected from the group consisting of a toilet tissue, a facial tissue, napkin tissue, and a paper towel.

13. The method of claim 1, wherein step (b) comprises dispensing the foamed adhesive as discrete, independent bodies from the nozzle onto a substrate.

14. The method of claim 13, wherein the foamed adhesive comprises air cells having an average size in the range of from about 20 to about 100 micrometers.

15. The method of claim 1, wherein the flows are independently at a temperature of up to about 30°

C. when introduced into the chamber.

18. A foamed, water-based adhesive composition obtained from the method of claim 7.

16. A method of applying foamed adhesive to a substrate, comprising the steps of:

(a) supplying ingredients comprising an adhesive and a gas to a plurality of nozzle chambers of a nozzle array;

(b) causing at least portions of the adhesive and the gas to mixingly interact in the chambers to form a foamed adhesive in the absence of mechanical mixing; and

(c) dispensing the foamed adhesive from the nozzle array onto the substrate.

17. The method of claim 16 wherein the substrate is a tissue ply.

19. A method of making a foamed adhesive, comprising the steps of:

(a) causing one or more flows of an adhesive composition to impact one or more flows of a pressurized gas in a chamber under conditions such that at least portions of the impacting flows mixingly interact to form a foamed adhesive in the one or more chambers; and

(b) dispensing the foamed adhesive from the chamber, wherein the chamber has at least one inlet through which adhesive is introduced to the chamber and at least one outlet from which foamed adhesive is dispensed from the chamber, and wherein the total opening size of the at least one inlet is less than the total opening area of the at least one outlet.

20. The method of claim 19, wherein the supply pressure of the pressurized gas is about equal to or less than the supply pressure of the adhesive composition.