Paper for straw production

Abstract

The present invention introduces a paper for straw production with high adhesive application, a pleasant feel on the lips, and optionally the application of a polymer barrier to provide resistance to liquid absorption.

Description

PAPER FOR STRAW PRODUCTION FIELD OF INVENTION

[0001] This document belongs to the field of Chemical Engineering, Paper and Pulp, and corresponds to a paper for the production of straws with the application of high sizing, pleasant sensation to the lips and optionally application of a wet strength agent in the mass or coating with a polymeric barrier to provide resistance to the absorption of liquids. STATE OF THE TECHNIQUE

[0002] There is currently a strong movement worldwide toward replacing fossil-based plastic products with more environmentally friendly, biodegradable materials. The use of straws in the U.S. has reached 500 million a day. The lifespan of a straw is about 15 minutes, while its decomposition time is 200 years for polystyrene and polypropylene, representing about 4% of all plastic waste generated.

[0003] In this context, paper straws gained a foothold in a market that was previously new to the paper world, as it was practically 100% occupied by plastic. The first wave that led to the emergence of this market was driven by global events related to consumer awareness of the waste they generate. Subsequently, the second wave was related to changes in legislation in several countries, including several Brazilian cities, banning the use of plastic straws.

[0004] In Brazil, the city of Rio de Janeiro was the first to ban the use of plastic straws under penalty of fines for non-compliance. A similar initiative was followed by other municipalities such as São Paulo and Piracicaba. Beyond the legislative sphere, there is widespread social pressure toward more sustainable alternatives to plastic straws. In response, fast food and food packaging companies, for example, have already signaled their commitment to replacing their plastic straws with other materials.

[0005] In the case of Brazil, this transformation to paper is being slower than expected, which may be caused, for example, by the sensation of the paper straw on the lips - the lipfeel, since some consumers do not like the sensation of some paper straws when using them.

[0006] Thus, the present invention contributes to the movement to replace plastic straws, and presents the development of paper suitable for straw production, with a pleasant sensation on the lips.

[0007] The paper for straws claimed here arose from modifications to offset paper, typically used for printing, to make it more suitable for the application, particularly regarding its wet strength and roughness. Laboratory studies were conducted on both the papers and the final straws to investigate which parameters (and their values) should be modified to achieve good performance and quality in the final straws, which will be presented below. SUMMARY OF THE INVENTION

[0008] In a first aspect, the present invention provides a paper specifically for the production of white and uncoated straws, optionally with the addition of wet and dry strength agents in its mass or application of coating barrier, have a high bonding application, have no added mineral filler and be made from 100% short fiber cellulose.

[0009] In a second aspect, the present invention provides that the claimed straw paper is made from pumped pulp, to which the following ingredients are added during the preparation of the stock: between 0.5% and 1.5% internal starch; between 0.1% and 0.3% glue; between 0.1 and 0.2% coagulant; between 0.1% and 0.2% silica; and finally, the addition of external starch and microbiological treatment between 0.001 and 0.002%. Additionally, there is the application of 0.2% to 0.3% external starch and 0.02% to 0.03% surface sizing aid during the pressing process in specific machinery. It is noteworthy that the high sizing process is achieved by applying ASA glue between 1.5 and 3.5 kg / ton. Furthermore, the preparation of the pulp to obtain the paper claimed herein also occurs without the addition of bleaches or optical brighteners, polymers, dyes, colorants or additives from Genetically Modified Organisms.

[0010] Optionally, wet strength agents can be added to the paper stock at a rate of 1.5 to 2% and dry strength agents at a rate of 0.1 to 0.4%. The wet strength agent is polyamide-epichlorohydrin (PAE), while the dry strength agent is a polymer blend of cationic polyacrylamide and cationic glycol resins. The wet tensile strength of the paper is 10 to 20% of the dry tensile strength according to the NBR NM-ISO 3781 standard for paper and board.

[0011] In a third aspect, the present invention provides that the paper claimed herein has the bands of weight between 50 and 140 g / m 2 , with its preferred grammage range being between 70 and 120 g / m 2 .

[0012] In a fourth aspect, the present invention provides that the straw paper claimed herein has a Bendtsen roughness of 30 to 600 mL / min, characterizing a better lip feel.

[0013] In a fifth aspect, the present invention provides that the paper for straws claimed herein has a degree of refinement between 400 and 450 CSF, with its preferred range being between 380 and 430 CSF; Cobb rate 120" between 20 and 50 g / m 2 , with its preferred range being between 25 and 40 g / m 2 ; and lateral absorption of a maximum of 0.75%.

[0014] In a sixth aspect, the present invention provides the following morphological aspects of the short fiber cellulose used to manufacture the paper for straws claimed herein:

[0015] - Weighted Average Length Lc (n) ISO [mm] from 0.6 to 0.9;

[0016] - Fines from 4% to 9%;

[0017] - Wall thickness from 1 to 3 pm;

[0018] - 15 to 30 million fibers / gram;

[0019] - Coarseness of 4 to 8mg / 100m.

[0020] Finally, in a final aspect, the present invention provides an optional application of a barrier based on an aqueous polymeric dispersion, which provides water resistance properties and a pleasant material sensation when the straws come into contact with the lips (lipfeel). BRIEF DESCRIPTION OF THE FIGURES

[0021] Figure 1: Illustrative diagram of straw formation in a market machine.

[0022] Figure 2: Market straws evaluated in lateral and surface absorption tests. DETAILED DESCRIPTION OF THE INVENTION

[0023] We will now refer in detail to the various embodiments of the present invention, of which one or more examples are shown from the experimental descriptions below. Each example is provided by way of illustration of the present invention and should not be construed as a limitation thereof.

[0024] First Prototypes

[0025] The first straw formation tests were performed on a machine adapted from tubes, which resemble the shape of straws. From these tests, it was observed that the glue / adhesive used plays a very important role in the functional integrity of the straws (Figure 1).

[0026] Evaluation of Lateral and Surface Absorption of Selected Straws

[0027] Table 1 below highlights the comparison of the straws produced with other straws on the market, which can also be seen in Figure 2. superficial of the straws

[0028] Wet stiffness

[0029] We sought to develop a technique to analyze the rigidity of paper and straws after contact with liquids. This was called "wet stiffness." It was assumed that the higher a straw's wet stiffness at a given point in time, the greater the likelihood of it not breaking during use, while also providing greater comfort to consumers. The comparative results are presented in Table 2 below for the samples analyzed. Table 2: Wet stiffness of straws. Methodology: Immersion in liquid for 15 minutes.

[0030] Based on this information and wet stiffness analyses, inputs were sought for paper production to strengthen this characteristic and, consequently, the final straws.

[0031] Different chemical products were analyzed at varying dosages to achieve lower lateral absorption and greater wet stiffness. The recycling / repulpability criteria of the proposed solutions were also evaluated.

[0032] After these analyses, it was decided to adopt high sizing (hard size) with ASA glue to reduce lateral absorption and increase rigidity, as it presents an interesting gain in these properties and is repulpable.

[0033] Modifications Made to the Process / Recipe

[0034] As previously stated, the straw paper claimed here is a modification of conventional offset base paper.

[0035] In short, the following modifications were made to make conventional printing paper suitable for use in straws:

[0036] - Removal of carbonate / mineral filler, primarily calcium carbonate, to comply with RDC-88 / 2016. In one of the legislation's analyses, the material (paper or final straw) comes into contact with a liquid simulating acidic beverages, a 3% acetic acid solution. The reaction between the calcium carbonate present in the material and the acetic acid leads to the formation of calcium acetate, which, if not limited, exceeds the total migration limit. This removal process is performed at the beginning of production by cleaning the machine's water system. Subsequently, calcium carbonate is also eliminated throughout the production process.

[0037] - Use only cellulose that does not contain residual carbonate / mineral filler / optical brightener.

[0038] - Increase glue dosage to a maximum of 2.5 kg / ton, preferably between 1.8 and 2 kg / ton. Frequent attention to the accumulation of glue in the system is necessary to prevent it from coming loose and increasing the soiling of the paper.

[0039] Base recipe

[0040] Based on the tests and recipe adjustments carried out, a base recipe was arrived at as specified in Table 3 below:

[0041] Finally, the product specifications below were indicated (Table 4): Table 3: Technical specifications of straw paper.

[0042] In short, the paper straws claimed here, and consequently the straw itself, offer significant technical advantages over other paper straws currently available in the state of the art. Particularly noteworthy are their moisture resistance, non-peeling sensation when in contact with the mouth, and compliance with the required sustainability certifications.

[0043] Addition of resistance agents

[0044] Optionally to the base recipe specified above, it is possible to add wet and dry strength agents to the paper mass during its manufacturing process.

[0045] The wet strength additive used in papermaking has a chemical base composed of polyamide-epichlorohydrin (PAE) resin. This additive improves paper's wet strength and is widely used in consumer paper products such as paper towels, napkins, and packaging. It is added to the paper stock at a rate of 1.5 to 2%.

[0046] The dry strength additive used in papermaking has a chemical base of cationic polyacrylamide polymers and cationic glycol resins. These components help improve paper dry strength and offer flexibility in formulating dry strength programs for different paper grades. It is added to the paper stock at a rate of 0.1 to 0.4%.

[0047] Barrier Application

[0048] Another option for obtaining the straw paper claimed here is to add a barrier to the paper obtained from the base recipe presented above.

[0049] In short, it is possible to apply a coating based on polymeric aqueous dispersion, which provides water resistance properties.

Claims

CLAIMS 1. Paper for straw production characterized by being an uncoated white paper, with or without barrier application, having a high sizing application, no addition of mineral filler and being made from 100% short fiber cellulose.

2. Paper for producing straws, according to claim 1, characterized by the fact that it is produced from pumped cellulose, in which the following ingredients are added in the preparation of the mass: - Between 0.5% and 1.5% internal starch; - Between 0.1% and 0.3% of glue; - Between 0.1 and 0.2% coagulant; - Between 0.1% and 0.4% silica; - Addition of external starch for microbiological treatment between 0.001 and 0.002%.

3. Paper for producing straws, according to any one of the preceding claims, characterized in that there is optionally the addition of a wet strength agent and a dry strength agent in the preparation of the mass.

4. Paper for producing straws, according to claim 3, characterized in that the wet strength agent is added in a proportion of between 1.5 and 2%.

5. Paper for producing straws, according to claim 3, characterized in that the dry strength agent is added in a proportion between 0.1 to 0.4%.

6. Paper for producing straws, according to claims 3 and 4, characterized in that the wet strength agent is a polyamide-epichlorohydrin (PAE) resin.

7. Paper for producing straws, according to claims 3 and 5, characterized in that the dry strength agent is a mixture of cationic polyacrylamide polymers and cationic glycoxylated resins.

8. Paper for producing straws, according to any one of claims 3 to 7, characterized in that the wet tensile strength of the paper is 10 to 20% of the dry tensile strength according to standard NBR NM-ISO 3781 for paper and cardboard.

9. Paper for producing straws, according to claims 1 to 3, characterized by the additional application of 0.2% to 0.3% of external starch and 0.02% to 0.03% of surface sizing aid during the process in specific machinery (speed sizer).

10. Paper for producing straws, according to claim 1, characterized in that the high gluing is applied by applying ASA glue between 1.5 and 3.5 kg / ton.

11. Paper for producing straws, according to claim 1, characterized by having a grammage range between 50 and 140 g / m 2 .

12. Paper for producing straws, according to claim 5, characterized by preferably having a grammage range between 60 and 120 g / m 2 .

13. Paper for producing straws, according to any one of the preceding claims, characterized by having a Bendtsen Screen roughness of 30 to 600 mL / min.

14. Paper for producing straws, according to any of the preceding claims, characterized by the fact that it presents better contact with the lips.

15. Paper for producing straws, according to any one of the previous claims, characterized in that it is prepared without the addition of bleaches or optical brighteners, polymers, dyes, colorants or additives from Genetically Modified Organisms.

16. Paper for producing straws, according to any one of the previous claims, characterized by having a degree of refining between 380 and 450 CSF, with its preferred range being between 380 and 430 CSF.

17. Paper for producing straws, according to any one of the previous claims, characterized by having a Cobb 120" rate between 20 and 50 g / m 2 , with its preferred range being between 25 and 40 g / m 2 .

18. Paper for producing straws, according to any one of the previous claims, characterized by presenting lateral absorption of a maximum of 0.75%.

19. Paper for producing straws, according to claim 1, characterized in that the short fiber cellulose has the following morphological characteristics: - Weighted Average Length Lc(n)ISO [mm] from 0.6 to 0.9; Fines from 4% to 9%; - Wall thickness from 1 to 3 pm; - 15 to 30 million fibers / gram; - Coarseness of 4 to 8mg / 100m.

20. Paper for producing straws, according to claim 1, characterized by optionally presenting a barrier application based on aqueous polymeric dispersion.

21. Paper for producing straws, according to claim 20 , characterized by the polymer dispersion-based barrier providing water resistance and a pleasant material sensation when the straws come into contact with the lips.

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