HUT75845A - Method for recycling of paper wastes - Google Patents

Abstract

In the process according to the invention, a multilayer paper sheet is produced by replacing the primary and / or secondary fiber in the starting fiber suspension with 10-100% by weight of the pulp slurry, paper waste resulting from the production of waste paper, and the starting suspension is known to be acid or neutral. in the medium, the flocculant is added to promote the retention. “2 From this prepared slurry, a sheet of paper with a thickness of from 5 to 50 layers with a weight of 450-5000 g / m is made on a plate machine.

Description

The present invention relates to a process for the utilization of paper sludge, in which a multilayer paper sheet is produced using paper sludge produced in paper mills.

In paper mills, the filler and some of the fibers in the various types of paper are deposited in the effluent water and then deposited as a paper slurry using a suitable apparatus, having a dry matter content of 35-45%. The resulting paper waste is a problem and its disposal is solved. Known procedures between the combustion (Szucs A .; Merchant Cs .; Isépy Zs .;

Badacsonyi B .: PAPER INDUSTRY, No. 3 86-90, 1994), in which the heat content of the organic matter content of the sludge is utilized. The disadvantage of the process is the water content of the sludge is 55-65%. Alternatively, it is used in the manufacture of bricks (Kirsten K .; Zellstoff und Papier, pp. 83-84, 1978). Hungarian Patent No. 171903, entitled "Process for making heat insulation material, especially for pipe insulation - from paper sludge", also applies to the preparation of heat insulation material. Some solutions favor agricultural utilization (Alpert, I.T., et al., Pulp and Paper 127-129.p. 1982), which aims to improve soil strength.

The abovementioned uses do not, or only slightly, take into account the filler content of the paper sludge.

It is an object of the present invention to provide a process which utilizes the mineral content of the paper sludge, i.e. the filler in the sludge, together with the organic matter content of the paper sludge.

The present invention relates to the use of paper sludge for the production of paperboard.

According to the present invention, this object is solved by replacing the primary and / or secondary fiber used in the production of the paper board with 10-100% by weight of paper sludge.

In conventional paperboard production processes, primary fibers (bleached or unbleached cellulose) and / or secondary fibers (raw materials obtained by pulping of waste paper) are used as starting materials.

Another aspect of the process of the present invention is that the paper sludge used contains from 0 to 90% by weight of a mineral, also known as a filler.

FIELD OF THE INVENTION The present invention relates to a process for utilizing paper sludge by preparing a multilayered paper slab comprising 10 to 100% by weight of the primary and / or secondary fiber in the initial fibrous slurry, which is a waste disposal problem during papermaking. the initial fiber suspension is glued in an acidic or neutral medium and a flocculating agent 2 is added to facilitate retention. By this method, it is advisable to make a sheet of 450-5000 g / m sheet of paper, 5-50 layers of paper, which can be used for the production of book covers, letter covers, paper-coated boards and tables, coasters and trays, boxes, crates, seals, toys, calendars.

Advantages of the process according to the invention:

the. ) utilizes paper sludge, which is a waste disposal problem,

b. ) replaces the expensive cellulose used as a raw material in conventional paperboard production processes,

c. The multilayer paper sheet produced by the process of the present invention satisfies market requirements.

• · «

In a preferred embodiment of the process, the paperboard is made up of 50% secondary fiber and 50% paper sludge in the composition of the slurry, the paper sludge being composed of 20% organic matter and 80% mineral matter.

The paper pulp thus prepared is mixed with 1.5% glue based on the absolute dry matter of the pulp, the pH is adjusted to 5-5.5 with aluminum sulfate and the material density is maintained at 1.5-2%. Prior to administration to the plate, 0.05% flocculant is added to the pulp so that the residence time of the flocculant is

Do not exceed 10-15 seconds. From the two suspensions thus prepared, the sheet machine is used to make a sheet of paper weighing 1500 g / m.

The invention will now be described in more detail by way of examples.

Example 1 "" 2

A 450 g / m sheet was prepared on a laboratory sheet with the composition of 20% secondary fiber and 80% paper sludge. The paper sludge contained 10% organic matter and 90% mineral matter. The suspension was glued in an acidic medium with modified pine resin dispersion and adjusted to pH 4.5 with aluminum sulfate.

Properties of the disk thus produced:

- sheet weight 445 g / m

- 0.73 g / cm

- tensile strength of 15.8 MPa

- moisture content 6%

Characteristics of a paper sheet made from 100% secondary fiber under the same conditions:

- sheet weight

- leaf density

- tensile strength

- moisture content

453 g / m 0.68 g / cm '14.2 MPa%

- 5 Example 2

A slurry was prepared in a semi-industrial Dutch with 20% bleached cellulose, 10% secondary fiber and 70% paper sludge. The paper sludge contained 100% organic matter. The pulp was glued with AKD in sem2 media and a 1300 g / m sheet was made on an experimental paper machine.

Properties of the disk thus produced:

1312 g / m 0.72 g / cm '9.8 MPa 5%

- sheet weight

- leaf density

- tensile strength

- moisture content

Example 3

A sheet weighing 5,000 g / m was prepared on a Rapid-Köthen sheet former with a composition of 30% secondary fiber, 30% unbleached sulphiteululose and 40% paper sludge. The paper sludge contained 100% minerals.

0.05% flocculant was added to the suspension to facilitate retention.

The properties of the paperboard thus produced are as follows:

sheet weight 4956 g / m Back density 0.83 g / m strength 15.3 MPa humidity 5.3 %

Properties of 50% Secondary Fiber and 50% Unbleached Sulphite Cellulose Sheet Under Similar Conditions:

sheet weight 5012 g / m Back density 0.78 g / cm strength 14.6 MPa humidity 4.9 %

Example 4

Under operating conditions, a 6% slurry was prepared in a 6 m Dutch with 60% paper sludge and 40% secondary fiber. The paper sludge is composed of 50% organic matter and 50% mineral. Sizing was performed in a neutral medium at pH 7.2. From this slurry, a plate weight plate of 2300 g / m was prepared on a plate machine.

Properties of paper sheet:

- leaf weight 2304 g / m

- Childhood 0.83 g / cm

tensile strength 12.1 MPa

- moisture content 5,8%

Example 5

The slurry was prepared according to Example 4, except that the slurry was composed of 50% unbleached sulfate pulp and 50% paper sludge. The paper sludge contained 30% filler and 70% fiber.

Disk Properties:

- sheet weight

- leaf density

- tensile strength

3200 g / m 0.68 g / cm @ 14.6 MPa moisture content 7.3

Claims (2)

Claims 1.) A process for utilizing paper sludge, comprising preparing a multilayer paper board in an ab-known manner by gluing the initial fiber suspension in an acidic or neutral medium, adding a flocculant to facilitate retention. wherein the primary fiber and / or secondary fiber in the initial fiber suspension is replaced by 10-100% by weight of paper slurry based on the weight of the fiber suspension. 2. The process according to claim 1, wherein the paper slurry contains 1-90% by weight of mineral material. The process of claim 1, wherein the paper slurry containing 100% by weight of organic material is used. 1-3. The process according to claim 1, characterized in that the bleached and / or unbleached cellulose is primary, i.e., In l L · 1-4. The method of claim 1 f-og-α-R as-j-a-as? characterized in that the cellulose produced in the < RTI ID = 0.0 > < / RTI > m, row number 5-50 Láhcttiκ -