TWISTING PAPER

Abstract

A twisting paper substrate to be waxed for the production of an opaque waxed paper wrapping, wherein the paper substrate includes a fibrous base, at least one opacifying additive and at least one binder reducing penetration of wax in the fibrous base during the production of the waxed paper substrate by application of wax on the paper substrate, wherein the difference of opacity of the paper substrate before and after Cobb test according to the rizinus Cobb method on one side to be waxed of the paper substrate is most preferably less than or equal to 8 percent.

Claims

1. A twisting paper substrate to be waxed for the production of an opaque waxed paper wrapping, wherein the paper substrate comprises a fibrous base, at least one opacifying additive and at least one binder reducing penetration of wax in the fibrous base during the production of the waxed paper substrate by application of wax on the paper substrate, wherein the difference of opacity of the paper substrate before and after the Cobb test according to the Rizinus Cobb method on one side to be waxed of the paper substrate is less than or equal to 8 percent.

2. The paper substrate according to claim 1, wherein said difference of opacity is less than or equal to 5 percent.

3. The paper substrate according to claim 1, wherein said difference of opacity is fulfilled regardless of the side of the paper substrate chosen for the application of the castor oil.

4. The paper substrate according to claim 1, wherein the at least one opacifying additive comprises TiO.sub.2 or zinc sulfide.

5. The paper substrate according to claim 1, wherein the at least one binder is a water soluble binder, wherein the at least one water soluble binder is selected from PVOH or starch or a mixture of PVOH and starch.

6. The paper substrate according to claim 1, wherein the at least one binder is a water insoluble binder, wherein the at least one water insoluble binder is selected from latex made from polymers and copolymers from several monomers.

7. The paper substrate according to claim 1, wherein the paper substrate comprises a mixture of at least one water soluble binder, wherein the binder is selected from PVOH or starch or a mixture of PVOH and starch, and at least one water insoluble binder, wherein the binder is selected from latex made from polymers and copolymers from several monomers.

8. The paper substrate according to claim 1, wherein the paper substrate comprises at least one softening agent, wherein the at least one softening agent is selected from urea, nitrate, a mixture of urea and sodium nitrate, or an organic plasticizer including sorbitol, sorbitol ether, polyethylene glycol or glycerol.

9. The paper substrate according to claim 1, having a basis weight of less than or equal to 60 g/m.sup.2 according to the standard ISO 536.

10. The paper substrate according to claim 1, having a surface energy higher than or equal to 25 J/m.sup.2.

11. A waxed paper wrapping, comprising the paper substrate according to claim 1 and a coating of wax on at least one side of the paper substrate.

12. The waxed paper wrapping according to claim 11, wherein the wax is present on at least one side of the paper substrate, the wax forming one layer on each of the application side(s) of the paper substrate and penetrating at least partially in the fibrous base.

13. The waxed paper wrapping according to claim 11, wherein the difference of opacity between the paper substrate, before application of wax, and the waxed paper wrapping is less than or equal to 10%.

14. A method for producing a twisting paper substrate to be waxed for the production of an opaque waxed paper wrapping as defined in claim 1, wherein the paper substrate comprises a fibrous base, at least one opacifying additive and at least one binder reducing penetration of wax in the fibrous base during the production of the waxed paper substrate by application of wax on the paper substrate, wherein the binder is applied on at least one side to be waxed of a paper web comprising the fibrous base.

15. A method for producing the paper substrate according to claim 1, wherein the at least one binder is applied on at least one side to be waxed of a paper web comprising the fibrous base.

16. The method according to claim 14, the binder being part of a surface coating composition which is applied on said side to be waxed of the paper web, the surface coating composition being applied on said side in an amount of less than or equal to 5 g/m.sup.2 dry weight.

17. The method according to claim 14, the at least one opacifying additive being mixed to the fibrous base before formation of the paper web.

18. The method according to claim 14 for producing the paper substrate comprising at least one softening agent selected from urea, nitrate, a mixture of urea and sodium nitrate, or an organic plasticizer including sorbitol, sorbitol ether, polyethylene glycol or glycerol, wherein the at least one softening agent and the at least one binder are applied on at least one side to be waxed of the paper web, at the same or at different steps.

19. A method for producing a waxed paper wrapping according to claim 11, comprising: the production of the paper substrate comprising a fibrous base, at least one opacifying additive and at least one binder reducing penetration of wax in the fibrous base during the production of the waxed paper substrate by application of wax on the paper substrate, wherein the difference of opacity of the paper substrate before and after the Cobb test according to the Rizinus Cobb method on one side to be waxed of the paper substrate is less than or equal to 8 percent; and application of the wax on the paper substrate.

20. A method for packaging food, comprising twisting around the food a waxed paper wrapping according to claim 11.

21. A packaged food product comprising a food product and a waxed paper wrapping according to claim 11, twisted around the food product.

22. The packaged food product according to claim 21, wherein the food product is a confectionery food product.

Description

EXAMPLES

Paper Substrates

[0122] The fibrous base is a standard fibrous base used for confectionery application which main characteristics are presented in table 1.

TABLE-US-00001 TABLE 1 Fibrous base characterization Fibrous base Standard AVG SD Basisweight (g/m.sup.2) ISO 536-1995 E 40.4 0.1 Tear MD mN ISO 1974-1990 E 302 10 Tear CD mN 298 11 Stiffness MD mN ISO 2493-1: 2010 41.1 6.2 (15-5 mm) ISO 5628-1990 E Stiffness CD mN 20.1 2.5 (15-5 mm) Breaking length MD Km ISO 1924-2-1994 6.81 0.53 Breaking length CD Km 2.42 0.30 Elongation MD % NF EN ISO 1924-2-1994 3.7 0.1 Elongation CD % 9.6 0.7

[0123] Two different surface treatments have been tested, applied each time on both sides of the paper substrate: [0124] A surface coating recipe according to the invention, SP-1. [0125] A surface coating recipe corresponding to a standard recipe SP-2.

[0126] Table 2 presents details of both recipes.

TABLE-US-00002 TABLE 2 coating recipes characterization. Recipe SP-1 SP-2 In composition of the surface Urea 30.73 79.9 layer Nitrate 5.27 13.7 (in % by dry weight) Starch * 2.46 6.4 PVOH ** 46.73 Carboxymethylcellulose*** 10.96 Insolubilizing agent **** 3.85 Solid content target (%) 8% 8% Solid content measured (%) 8.22% 8.30% Viscosity (mPa/s) 92 13 T C. 25 23 pH 7.79 7.85 * Perfectafilm A115 from Avebe ** Celvol 325 from Sekisui Chemical Co, Ltd ***DP 100N from Lamberti **** Cartabond TSI from Archroma Managment GmbH

[0127] A size press has been used to apply the surface treatments on the fibrous bases.

[0128] The conditions were the following: 2 presses at 25 PJ hardness and 4 bars pressure in the nip. Speed was 40 m/min with oven set at 140 C.

[0129] Coatweight is about 2 g/m.sup.2 total dry weight on both sides of each fibrous base.

[0130] In this way, two paper substrates have been produced, each comprising a fibrous base and a surface coating (SP-1 or SP-2).

[0131] Paper Substrates Characterization:

[0132] Table 3 presents the main paper characteristics of these two paper substrates.

[0133] Both paper substrates are twisting paper substrate according to the invention (see table 3 tear, elongation and stiffness values).

[0134] SP coating according to the invention (SP-1) can provide high barrier property to paper while SP-2 is not giving the expected barrier level (see delta opacity after rizinus cobb values of table 3)

TABLE-US-00003 TABLE 3 Paper substrates characteristics Fibrous base SP-1 SP-2 Standards AVG SD AVG SD Basis weight g/m.sup.2 ISO 536-1995 (E) 42.42 0.21 41.41 1.09 Bekk Smoothness Front Side sec ISO 5627: 1995 2421 175 2130.17 144 Bekk Smoothness Reverse Side sec 149.00 5.79 146.20 15.45 Elongation CD % NF EN ISO 1924-2- 10.48 0.86 9.82 0.59 1994 Tear MD mN ISO 1974-1990 (E) 227.40 10.94 269.70 3.79 Tear CD mN 232.00 3.74 271.70 13.28 Stiffness (15-5 mm) MD mN ISO 2493-1: 2010 36.20 4.08 29.60 1.71 Stiffness (15-5 mm) CD mN 19.60 1.84 17.20 1.23 Delta opacity after Front Side % According to the 3.30 1.55 14.40 1.20 rizinus cobb specification Delta opacity after Reverse Side % According to the 3.50 1.99 13.20 0.01 rizinus cobb specification

[0135] Waxed Paper Wrappings

[0136] The paper substrates_have been remoistered with a blend Water/Glycerol/Sorbitol and waxed on both sides with paraffin wax heated at 105-110 C.

[0137] The quantity of wax that is applied ranges between 7 and 8.5 g/m.sup.2 in dry weight.

[0138] Table 4 presents wax coatweights measured inside papers. SP-1 is showing a wax saving of 33% compared to SP-2.

[0139] The amount of TiO2 present in the paper substrate was the same in both cases, and equal to 3.5% of the weight of paper substrate but the difference of opacity before and after waxing is much lower with SP-1 coating, which is a different way to prove lower wax penetration thanks to wax barrier provided by SP-1 coating.

TABLE-US-00004 TABLE 4 Wax saving Fibrous base Standards SP-1 SP-2 Wax coatweights inside paper (g/m.sup.2) 5.05 7.55 Wax saving inside vs. SP-2 (%) 33.11% Opacity before waxing (%) NFQ 03-006 63.55 65.32 Opacity after waxing (%) NFQ 03-006 59.49 53.2 (Measured on waxed samples) Delta opacity after waxing (%) 4.06 12.12

[0140] Therefore coating SP-1 is able to provide suitable barrier to save quantity of wax applied on twisting paper substrates according to the invention.

[0141] Because of this wax saving, less opacifying additive needs to be added in the paper substrate to achieve a given level of opacity of the waxed paper wrapping, which reduces costs.