Method to produce a laminated textile product
The present invention pertains to a method to produce a laminated textile product, the product comprising a primary carrier sheet with yarns that form a pile on the front surface thereof, and a secondary carrier sheet adhered to the back surface of the primary carrier sheet, the method comprising providing a lick roller having a mass of molten polymer adhesive at its outer circumference, transporting the primary carrier sheet along the lick roller while its back surface is in contact with the outer circumference of the roller at a contact site, thereby transferring a layer of adhesive to the back surface of the primary carrier sheet, and bringing the secondary sheet in contact with the layer of adhesive to adhere the secondary sheet to the back surface of the primary carrier sheet to produce the laminated textile product, wherein downstream of the contact site between the primary carrier sheet and the lick roller, before the secondary sheet is contacted with the layer of adhesive, cobwebbing of the adhesive between the primary carrier sheet and the lick roller is induced.
1. A method to produce a laminated textile product, the product comprising a primary carrier sheet, the primary carrier sheet having front and back surfaces with yarns that form a pile on the front surface thereof, and a secondary carrier sheet adhered to the back surface thereof, wherein the method comprises the steps of:
(a) providing a lick roller having a mass of molten polymer adhesive at an outer circumference of the lick roller,
(b) transporting the primary carrier sheet along the lick roller while the back surface thereof is in contact with the outer circumference of the lick roller at a contact site thereby transferring adhesive to the back surface of the primary carrier sheet,
(c) inducing cobwebbing of the adhesive between the primary carrier sheet and the lick roller downstream of the contact site between the primary carrier sheet and the lick roller before the secondary sheet is contacted with the adhesive by forming a continuously present row of multiple parallel strands of the adhesive along a length of the lick roller with the strands extending perpendicular to the lick roller in a spider web-like fashion and having a macroscopic length and width,
(d) breaking the strands of adhesive by moving the primary carrier sheet away from the lick roller to thereby cause separate strands of the adhesive to be present at the back surface of the primary carrier sheet, and
(e) bringing the secondary sheet into contact with the separate strands of adhesive on the back surface of the primary carrier sheet to adhere the secondary sheet to the back surface of the primary carrier sheet and thereby produce the laminated textile product.
2. The method according to claim 1 , wherein the primary carrier sheet is a fibrous sheet with yarns stitched therein to form the pile on the front surface and loops of yarns at the back surface of the primary carrier sheet.
3. The method according to claim 2 , which further comprises heat treating the primary carrier sheet to bond the yarns to the primary carrier sheet by contacting the back surface of the primary carrier sheet with a surface of a hot body to at least partly melt the loops of the yarns to create a mass of molten yarn material at the back surface of the primary carrier sheet before the polymer adhesive is applied to the back surface.
4. The method according to claim 3 , wherein the heat treating of the primary carrier sheet is practiced by providing the surface of the hot body at a relative speed with respect to the back surface of the primary carrier sheet.
5. The method according to claim 1 , wherein the adhesive is transferred to the back surface of the primary carrier sheet in an amount between 100 and 600 g/m 2 .
6. The method according to claim 1 , further comprising guiding the primary carrier sheet as a continuous web over a guiding roller directly preceding the lick roller, wherein the guiding roller is a bowed roller having an outer roller surface in contact with the pile.
7. The method according to claim 1 , wherein the adhesive has a viscosity of less than 500 Pa·s at 150° C.
8. The method according to claim 7 , wherein the adhesive has a viscosity of between 1 and 100 Pa·s at 150° C.
9. The method according to claim 8 , wherein the adhesive has a viscosity of between 5 and 55 Pa·s at 150° C.
10. The method according to claim 1 , wherein the adhesive is semi-crystalline.
11. The method according to claim 10 , wherein the adhesive has a crystallinity between 1 and 50%.
12. The method according to claim 11 , wherein the adhesive has a crystallinity between 5 and 35%.
13. The method according to claim 1 , wherein the temperature of the polymer adhesive at the contact site is between 120° C. and 160° C.
14. The method according to claim 1 , wherein the transport speed of the primary carrier sheet with respect to the lick roller is at least 4 m/min.
15. The method according to claim 4 , wherein the heat treating of the primary carrier sheet is practiced by providing the surface of the hot body as a stationary object and transporting the primary carrier sheet along the hot body.