Methods of stretching wet wipes to increase thickness
View Patent ↗Methods for stretching nonwoven substrate material to reduce the basis weight of the material while maintaining or increasing thickness is disclosed. Additionally, the stretched substrate materials provide the same or improved strength as compared to conventional nonwoven materials and provide a softer feel to the user's skin.
1. A method of stretching a nonwoven substrate material to increase thickness and decrease basis weight of the material, the method comprising:
providing a roll of substrate material, wherein the substrate material comprises about 50% (by weight) cellulosic fibers and about 50% (by weight) thermoplastic fibers;
unwinding the substrate material from the roll;
stretching the unwound substrate material in a cross-direction, wherein the shape of the stretched substrate material is maintained during and subsequent to stretching in the cross-direction;
advancing the stretched substrate material using at least one of an advancing roller and a belt set;
slitting the advanced stretched substrate material;
folding the advanced stretched substrate material;
applying an adhesive composition to an outer surface of the folded stretched substrate material; and
cutting the folded stretched substrate material into discrete sheets and adhesively joining the sheets using the adhesive composition,
wherein, when stretched in the cross-direction by about 50% of the nonwoven substrate material's initial width, the material has a decrease in basis weight of from about 5% to about 33% of its initial basis weight.
2. The method as set forth in claim 1 wherein the substrate material is stretched in the cross-direction by an amount of from about 5% to about 100% of its initial width.
3. The method as set forth in claim 1 wherein the folded stretched substrate material, when stretched in the cross-direction by about 10% of its initial width, has an increased thickness of from about 5% to about 98% of its initial thickness.
4. A method of stretching a spunlace substrate material to increase thickness and decrease basis weight of the material, the method comprising:
providing a roll of spunlace substrate material, wherein the spunlace substrate material comprises about 50% (by weight) cellulosic fibers and about 50% (by weight) thermoplastic fibers;
unwinding the spunlace substrate material from the roll;
stretching the unwound spunlace substrate material in a cross-direction;
advancing the stretched spunlace substrate material using at least one of an advancing roller and a belt set; and
folding the advanced stretched spunlace substrate material,
wherein, when stretched in the cross-direction by about 50% of the nonwoven substrate material's initial width, the material has a decrease in basis weight of from about 5% to about 33% of its initial basis weight.
5. The method as set forth in claim 4 wherein the spunlace substrate material is stretched in the cross-direction by an amount of from about 5% to about 100% of its initial width.
6. The method as set forth in claim 5 wherein the spunlace substrate material is stretched in the cross-direction using a first set of driven belts and a second set of driven belts, wherein the first set of driven belts is configured to contact a first side of the substrate material and the second set of driven belts is configured to contact a second opposing side of the substrate material.
7. The method as set forth in claim 5 wherein the spunlace substrate material is stretched in the cross-direction using at least one roller.
8. The method as set forth in claim 4 wherein the folded stretched spunlace substrate material, when stretched in the cross-direction by about 10% of its initial width, has an increased thickness of from about 5% to about 98% of its initial thickness.
9. The method as set forth in claim 5 further comprising slitting the rolled stretched spunlace substrate material prior to folding the substrate material.
10. The method as set forth in claim 5 further comprising moistening the rolled stretched spunlace substrate material simultaneously with folding the rolled stretched spunlace substrate material.
11. The method as set forth in claim 5 further comprising cutting the folded stretched spunlace substrate material into discrete sheets and adhesively joining the sheets using an adhesive composition.
12. The method as set forth in claim 11 wherein the adhesive composition is applied to an outer surface of the folded stretched substrate material prior to cutting the folded stretched spunlace substrate material.