ES2241408B1 - NEW MATERIAL FROM HIGH QUALITY PRINTED PAPER WASTE AND ITS METHOD OF OBTAINING. - Google Patents

Abstract

New material from waste of high quality printed paper and its method of obtaining. This invention deals with a new material obtained from paper waste and its manufacture. The invention is directed on the one hand to take advantage of a waste that normally goes to landfill, given the difficulty that these residues present in returning to the papermaking cycle, since they have a large number of wet strength loads, which makes them irrepulpable On the other hand, the invention seeks to obtain a new material while minimizing, in its manufacture, chemicals, water and energy. The material obtained aims, therefore, to contribute to the conservation and care of the environment in two ways: in the one of recovering a waste and avoiding its deposition to landfill or its incineration and through the clean production of a new material that tries to take advantage of everything of the residue from which it comes: the fillers, the inks and the fiber that give the new product its properties.

Description

New material from paper waste High quality print and its method of obtaining.

Background Scope

This patent is applicable to waste of paper that due to its characteristics are not recyclable in the paper industry, due to the amount of loads they carry, part of which make them resistant to moisture and therefore difficult to pulp with normal industry pulpers paper bin. It applies to residual papers of graphic industries, and mainly to waste paper printed with printing High quality as the gravure. The graphic industries generate large amount of paper waste that is not admitted by the paper industry for recycling as paper pulp, by problems described above. Specifically the invention is about a new material with high moisture resistance and with character flame retardant, and its manufacturing system from waste Industrial paper gravure printing and usually going to dump.

State of the art

The environmental sensitivity is increasing in society and also in public administrations. This is translates into greater market pressure and also new laws both local, regional, state and international, whose objective is greater control of waste, its generation and Its management and disposal. Strict industries are asked control of waste and its management. This has led to a higher cost of the product due to the cost of managing waste produced, the solution is therefore to get a recycled in the same company or a waste utilization obtaining a high value-added product that saves management and benefit both the company and society.

Industries that generate paper waste They increasingly choose recycling. This recycling is being performing satisfactorily with the newspaper and the paperboard. These products are made of paper that contains few loads and presents an easy repulping. Another problem is the inks, but currently they are already being implemented several methods of deinking that are giving more or less results satisfactory

On the other hand, fiber shortening paper cellulose by partial loss of the degree of polymerization, creates problems of resistance loss and Raw material in recycled paper. This affects losses of quality in recycled paper and also in yield losses of process.

It has been said many times that recycle paper used is not an ecological method since, although it saves virgin pasta (although, due to the need to reinforce the fiber cut with long fiber, it is always necessary), and also due to the need to use chemicals in the treatments of destined and preparation of paper used before pulping, the process waters always require prior treatment before final discharge

Therefore, it can be a problem for a company decide what to do with a difficult paper waste repulped In the literature there are currently some methods to obtain pulp from waste paper, however there is always a loss of resistance in the recovered fiber, a loss of total fiber performance and the problem of Elimination of additives and paper inks.

For the paper industry there is another problem added in the recycling of used paper and is the one to have to add always virgin pulp to the recovered pulp, to obtain a acceptable resistance in the final product, and this makes the price more expensive Process and product.

In some cases mechanical processes are used of flotation and flocculation to separate opposites not paper cellulosics used, such as resins, plastics, polymers, varnishes, coatings, pre and post preparations tincture, or other non-cellulosic products.

Generally all opposites, including the ink particles are removed from the fibers during the defibrillation phase The paper used is treated in a pulper, in alkaline conditions at a temperature of 50º-60ºC to achieve Good defibrillation and get a pulped mass. An alternative to this process is to make this operation cold, then thicken the pulp at a consistency greater than 15%, heat with steam up to 60ºC introducing at this point a destinador and a chemical bleach Then the pulp is left for 2 or 3 hours in a maceration tower without mechanical agitation.

A first difficulty of this technique is that, in heat treatment, all low point substances fusion, they are dispersed in the pulp and can no longer be separated, creating problems later in the paper machinery shutter filters, grilles, valves, pipes, etc.

A second difficulty is that these techniques of Destined are ineffective with modern inks. Currently inks use wet strength resins as a vehicle of fixation on the fiber and with these processes the inks are not separate from the surface of the paper and does not even weaken its adherence.

Another limitation is the impossibility of increasing the temperature of the destined one, since the prolonged treatments of the cellulosic fiber in alkaline medium at temperatures more or less high, produce yellowing of the pulp, especially if there are remains of wood chips between the fragments of the paper.

The most frequently used techniques For paper deinking are: flotation and washing.

In flotation the solution with the fiber a destintar is intimately mixed with air, then a non-ionic solvent and let stand for a while, during this time the air bubbles drag the ink particles up the surface where they are trapped by the solvent once formed the black foam with the trapped ink particles it separates said foam and is treated separately from the rest.

In the washing system, the ink particles well dispersed in the pulp solution, they are separated from the fiber through several cycles of dilution-drained. These cycles are often in the form of a waterfall in countercurrent. The effluents of the first draining sequence concentrate most of the particles of ink but also also contain almost all charges inorganic paper and also fragments of cellulosic fibrils and various pollutants. Therefore these waters must be treated before discharge.

There are other techniques to allocate paper such as they are the use of solvents, but they are rare in the industry of recycled paper.

The US Pat. No. 4,076,578 Puddington et al. remarks that the foundation of the destined one goes through the treatment chemical and thermomechanical pulp and subsequent separation of the ink particles suspended in the solution. Proposes different methods to achieve the objectives of deinking the pulp through the absorption of ink particles in a solid surface and its subsequent desorption. But none of the Methods described is entirely satisfactory.

All these processes need a lot of water and chemicals, often produce losses in the treated product and the resulting effluents have high CODs, electrolytes and inhibitor products. Being therefore difficult treatment in treatment plant.

On the other hand the recovery of used paper to through repulping does not completely solve the problem of addition of virgin pulp, since you always have to add some amount to reinforce fiber resistance loss treated, and also the recycled paper obtained does not have a large quality, especially if it comes from the recovery of printed paper in rotogravure, as the deinking processes must be more drastic due to print quality and loads of wet strength

Furthermore, in all cases where waste paper is repulped, there is the problem of the waste generated and the problem of effluents. M Fritz Zeeb of Voith Cy in French Patent No. 79 19392 suggests eliminating microfibrils and inorganic loads from dewatering washes using a filter press, this generates a solid waste to be managed. A similar solution is also proposed by M. Lothar Pfalzer in TAPPI 63 (9) 1980 pg. 116 with a spin process.

M. Calmanti in French Patent No. 78 29637, simplifies the flotation process by adding only air and therefore eliminating the additional contamination of adding a product chemical to "catch" the ink particles. But nevertheless these remain in the resulting effluents and therefore these must Be treated. Anyway, this process had to be abandoned due to the inefficiency of the single air injection to refloat Ink particles

From what has been seen above, two fundamental problems in the recycling of printed paper: a) the difficulty of the process of repulping and destining of the fiber, b) the obtaining in the process, effluents and waste highly pollutants

Objectives of the invention

The objectives of this invention are to achieve a recycled material from high quality printed paper, avoiding deinking processes and taking advantage of loads and primitive additives of printed paper. This supposes:

to)

Higher use of the original material without losing strength in the fiber for repeated defibrillation treatments and destined

b)

Avoid as much as possible effluents or pollutant residues that need specific treatment by driving end

C)

Recycle a waste that otherwise goes to landfill, assuming this an environmental saving and a saving economic.

Another objective of the invention is to achieve the maximum recycling of treatment waters, through filters to separate the solid parts in suspension. As well as the maximum Energy and chemical savings.

Description of the drawings

Below are detailed each of the elements of figure 1 (flow chart of the method of manufacturing):

1. Waste of printed paper

2. Crusher

3. Macerator

4. Container

5. Pulper

6. Vacuum filter

7. Forced air oven

8. Sedimentator

9. Columns for demineralization by ion exchange resins

10. Solid Waste

11. Water vapor

12. Final product

13. Alkaline solution

14. Acid Dissolution

15. Natural resin

The symbols in the figure are described as continuation:

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Productos químicos 2

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Chemical products

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Vapor de agua 3

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Water vapor

\hskip0.25cm

Línea de flujo del material 4

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Material flow line

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Residuos sólidos 5

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Solid waste

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Agua reciclada 6

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Recycled water

Description of the invention

The details of the manufacturing process, although others can also be applied methods

In fig. 1 a flow chart of the manufacturing method

The printed paper waste (1) is introduced into a shredder (2). Paper fragments are introduced into a macerator (3) with recycled water (at this point water is mixed stream with recycled water from the process). After maceration at room temperature and without stirring, the mixture is brought to a container with possibility of heating and reciprocating movement (4), an alkaline solution (13) is added to pH 9 and raised the temperature up to 50 ° C, after this process the mixture in the pulper (5) and acid (14) is added until pH 5 and a natural resin (15). The material is pulped and filtered under vacuum (6). The filtrate is collected in the settler (8) and the waters supernatants, once demineralized with exchange resins anionic and cationic (9), are introduced again in the cycle. He solid residue (10), is managed separately. Meanwhile the cake obtained in the filter is separated and taken to an air oven forced (7) to dehydrate and cure the final product (12). In this oven there is an emission of water vapor (11).

Example No. one

The paper waste is crushed to a size of 1 square centimeter approximately. The cuts are mixed of the paper with water to a consistency (Kg of paper / Kg total of the mixture) of 5%. They stay submerged overnight room temperature. Then an alkaline solution of sodium hydroxide or any other base, until pH 9 is reached, without virtually decrease consistency. It is heated to 50 ° C with gentle stirring for one hour, after which add acid up to pH 5, 5% by weight of dry matter of a resin natural that can be rosin or other similar style and 4% by weight of dry matter of a metal sulfate which can be hydrated aluminum sulfate, or other sulfate. These substances are add dissolved in the minimum amount of water so as not to lower 4.5% consistency in paper mass. This mass is carried to a pulper or stirred reactor with a rod of cutting blades and with speed up to 3000 r.p.m. You have in this pulper until get a homogeneous pulp that does not sediment (time depends of the mass of processed paper) Once the pulp is achieved, it is left fall into the molding filter that is connected to a vacuum pump of vanes that reaches a pressure of 300 mb. The drain is allowed to drain cake and introduced into a forced air oven at 80 ° C for drying and curing of the product for 3 hours (depending on the efficiency of air circulation and cake size).

The final product presents the following properties:

Water absorption according to UNE 54-027-74 (Cobb 30 method): 31.48 g / m2

Hygrospansivity according to UNE standard 57-097-78: % variation thickness % variation length % variation width 0 0 0.9

Classification of the material according to fireproofing test (standard UNE 23-727-90): M1.

Example No. 2

The paper waste is crushed to a size of 1 square centimeter approximately. The cuts are mixed of paper with demineralized water / recycled water to parts same, up to a consistency (total paper Kg / Kg of the mixture) of 5%. They remain submerged overnight at temperature ambient. Then an acid solution is added, until pH is reached 5, without practically decreasing consistency. It is heated to 40 ° C with gentle rocking for an hour, after which 5% by weight of dry matter is added, of a natural resin that it can be rosin or other similar style and 4% by weight of dry matter, of a metal sulfate which may be sulfate of hydrated aluminum, or other sulfate. These substances are added dissolved in the minimum amount of water not to lose 4.5% of consistency in the mass of paper. This dough is taken to a pulper or stirred reactor with a blade of cutting blades and with speed up to 3000 r.p.m. You have in this pulper until you get a homogeneous pulp that does not sediment (time depends on the mass of processed paper) Once the pulp is achieved, it drops into the molding filter that is connected to a vacuum pump paddles, which reaches a pressure of 300 mb. The drain is allowed to drain cake and introduced into a forced air oven at 80 ° C for drying and curing of the product for 3 hours (depending on the efficiency of air circulation and cake size).

The final product presents the following properties:

Water absorption according to UNE 54-027-74 (Cobb 30 method: 40.1 g / m2)

Hygrospansivity according to UNE standard 57-097-78: % variation thickness % variation length % variation width 3 0 one

Classification of the material according to ignifuquicidad test (UNE 23-727-90): M1.

Claims (8)

1. Procedure for recycling a waste of gravure printed paper with wet strength inks which comprises the following steps:

i)

soaking of waste paper

ii)

pulp of the product obtained in the step i)

iii)

addition of resins and a sulfate metal

iv)

vacuum filtering

v)

stove drying

2. Method according to claim 1, where step i) is done by mixing paper waste with a acid solution 3. Method according to claim 2, where the pH of the solution is between 4.5 and 6. 4. Method according to claim 1 where step i) is performed with an alkaline solution. 5. Method according to claim 4, where the pH of the solution is between 8.5 and 9. 6. Procedure according to any of the previous claims, wherein in step iii) the resin is a Natural resin and metallic sulfate is aluminum sulfate. 7. Product obtainable from the procedure described in any of claims 1 to 6. 8. Use of the product according to claim 7 for the protection of fragile corners of furniture and others objects.