HU211201B - Method for pretreatment old papers defibred difficultly - Google Patents

Abstract

The process according to the invention is conventional wet it is difficult to defibrate before the hydropower process wet and coated waste paper they are sorted, chopped (chopped), and baled and shredding (swelling and dispersing) and antifungal agents soaked in water containing min. 12 hours. They are then covered with airtight strech film the bales are stored in a wet condition in a conventional state processing.

Description

SUMMARY OF THE INVENTION The present invention relates to a process for the pretreatment of hard-to-pulverize waste paper using two classes of hard-to-pulverize waste paper. wet-strength and glazed papers can be processed economically and serve as a secondary source of good quality for paper production.

Nowadays, with the gradual depletion of primary raw material sources and the introduction of environmentally friendly processes, the utilization of waste materials as secondary raw materials is gaining importance.

Recycling of waste paper has long been widely used in the papermaking industry, the ultimate goal of which is to obtain high-quality, sufficiently pure fibers.

The most widespread of the known processes are almost exclusive - wet processes, which are essentially so-called. soak and disintegrate (i.e. pulp) the material in hydropulpers for a defined period of time (typically 20-30 minutes). If soaking paper is required for cleaning (decolorization) of the waste water, different chemicals may be added or, depending on the type of waste paper used, the water is heated to facilitate pulping.

Certain types of paper - and our present invention is intended to effectively recycle them - are very difficult to fiberize, so that their processing by known methods is extremely time, material and energy consuming.

The wet strength feature, which means that the wet paper sheet retains some of its original strength - with various condensation resins added to the paper filler, e.g. urea-formaldehyde, melamine-formaldehyde epichlorhydrin, which form plastic bonds with the fibers.

Another class (assortment) of waste paper that is difficult to process is characterized by smooth, coated paper.

The synthetic glazing binders used (polyacrylates, styrene-butadiene latexes, etc.) also form plastic bonds between the fibers and the glazing pigment and prevent moisture penetration and removal of glaze pigments from the fibers. At the same time, CaCo _3's glazed pigmented surface is hydrophobic by nature (difficult to wet).

The application of these types of paper is expanding, and their appearance as waste paper is also increasing.

The conventional wet process involves the decomposition of these materials by heat transfer (soaking in warm water) and addition of chemicals (using alkaline media, dispersing solutions), but even in this case, only high-grade decontamination can be achieved.

There are known attempts to pre-remove or destroy the plastic coating, e.g. M.V. Vanchakov, V.N. Erokmin, M.N. The article by Soviet authors Azurov, entitled "Dry Comminution of Waste Paper" (January 14, 1981), in which paper waste is crushed in a hammer mill prior to hydro-pulping, helps to break down the paper structure.

Also noteworthy is the process known from Hungarian Patent Application No. 195,544, which is one of the most difficult to recycle paper, the so-called. release paper (this is wet-soluble and hydrophobic-silicone coated) by sorting a range of physical properties prior to the conventional wet process, pulverizing it in the known manner and finally grinding it, but this is a general guideline would be applicable to other paper types - it does not provide.

At the time of the present invention, we have aimed to develop an economical process that enables these hard-to-fiber types of paper to be processed in the same technology line with other waste papers.

The essence of the present invention is to realize that the above objective can be achieved economically by initiating the disintegration of the paper structure already during the storage-transport period - thus significantly increasing the processing time compared to the conventional technological time without the need for conventional hydroponfection technology itself. we should change.

Accordingly, the present invention provides a process for recognizing, prior to the conventional wet pulping process, the selected and shredded wet solid and glazed paper assortments, and then min. 12 to 12% by weight and 0.1 to 0.2% by weight of swelling and dispersing agents known per se for 12 hours and min. It is soaked in water containing 10 ppm of antifungal additive, then wrapped with a stretch film and stored until conventional processing.

In a preferred embodiment of the present invention, the soaking water contains 1-2 wt% Na ₂ CO ₃ and 0.1-0.2 wt% Na hexametaphosphate as swelling and dispersing agents.

According to a preferred embodiment of the invention, 10 ppm biocide (active ingredient: 2-bromo-4-hydroxyacetophenone) is added to the soaking water to prevent fungal growth.

It is advantageous to introduce a perforated tube to the middle of the bale to facilitate wetting of the paper bale and thereby inject anti-fungal and antifungal additives.

It is also very advantageous that, after injection, a vacuum pump is applied to the inside of the bale by means of a vacuum pump through a perforated tube entering the paper bale. This promotes wetting and increases capillary action. The created air thinning should preferably be 0.05 x 10 ⁵ N / m ² .

In the process according to the invention, the pulping of the waste paper is preferably carried out with a tear fan.

HU 211 201 Β

Swelling and dispersing agents are understood as meaning e.g. products containing the following active substances:

NaOH

Na ₂ CO ₃

Na tripolyphosphate Na hexametaphosphate

By antifungal additives we mean e.g. products containing the following active substances:

2-Bromo-4-hydroxyacetophenone methylene bis thiocyanate and 2-thiocyanomethylthiobenzothiazole

3,5-Dimethyl-tetrahydro-1,3,5-thiadisin As shown above, the process of the present invention has the advantage of extending the time required to recover the secondary fibers. The dismantling of the paper structure does not begin at the place of processing (that is, at the paper mills), but at the waste collector, and in hermetically sealed, stretch-wrapped bales, the fibers swell and decompose during wet storage. paper structure with wet-solid or glazed pigment.

The effectiveness of the method is enhanced by applying vacuum technology or injecting fluid into the center of the paper bale.

By its very nature, the preparatory process can be organically adapted to the known technology and can be used or omitted at any time.

Without limiting the claims, a specific embodiment will now be described:

1. Raw Material Printed Wet Solid Beer Label Paper.

2. Tear the raw material into 1-15 cm ² pieces in a tear fan.

3. From the torn pieces of paper, make a bale of cm x 60 cm x 90 cm in a batch press.

4. Place the bale in a soak water filled with a crane using a crane.

The soaking water contains 1% w / w Na ₂ CO ₃ and 0.15% w / w Na hexametaphosphate swelling and dispersion additive and Busan 90 D biocide containing 10 ppm 2 bromo-4-hydroxyacetophenone active ingredient, injected through a perforated tube injected into the bale. system.

5. Insert a perforated tube connected to a suitable vacuum pump into the center of the bale and maintain a vacuum of 0.06 x 10 ⁵ N / m ² for 15 hours to aid in saturation.

6. Lift out the bale using a crane and wrap it with airtight foil.

The prepared stock was used for experimental paper production, producing paper with a weight of 60-100 g / m ² , 60% whiteness, a content of 500 pcs / m ² and an average breakage of 3 km, which are suitable for making less demanding brochures and weekly papers. to make environmentally friendly products.

Claims (6)

PATIENT INDIVIDUAL POINTS 1. A method of pretreatment of hard-to-fibrous waste paper, in particular wet and greaseproof waste paper, by separating and crushing these waste paper grades by baling selected and crushed waste paper assortments prior to the conventional wet process, and then known for at least 12 hours on their own. and 0.1-0.2% by weight of water in a water-repellent swelling and dispersing agent and at least 10 ppm of fungicide additive and so stored for conventional processing. Process according to claim 1, characterized in that the soaking water contains 1 to 2% by weight of Na ₂ CO ₃ as 0.1-0.2% by weight of Na-hexamethphosphate or other surfactant as a swelling and dispersing agent. Process according to claim 1 or 2, characterized in that 10 ppm of 2-bromo-4-hydroxyacetophenone or other active compound biocide is added to the soaking water as an antifungal agent. 4. Referring to 1-3. A method according to any one of claims 1 to 3, characterized in that a perforated tube is introduced into the bale of waste paper and injected into it by the additives that promote shear and fungus. 5. Method according to one of Claims 1 to 3, characterized in that air permeation is produced by vacuum pumping through the perforated tube at a value of at least 0.05 x 10 ⁵ N / m ² inside the bale. 6. Method according to any one of claims 1 to 3, characterized in that the waste paper is shredded with a tear-off fan.