Methods for deinking UV prints

Patent metadata

Field	Value
Publication number	US-11560672-B2
Application number	US-201917042506-A
Country	US
Kind code	B2
Filing date	Feb 21, 2019
Priority date	Mar 29, 2018
Publication date	Jan 24, 2023
Grant date	Jan 24, 2023

Abstract

The present invention aims to develop a technique for efficiently preparing deinked pulp from prints made with UV-curable inks. According to the processes for preparing deinked pulp of the present invention, high quality deinked pulp can be obtained by performing the steps of: disintegrating printed waste paper containing UV prints in water to give a waste paper slurry; and applying a mechanical process to the waste paper slurry using a rotary disintegrator.

First claim

The invention claimed is:

1. A process for preparing a deinked pulp, comprising the steps of:
disintegrating printed waste paper containing UV prints in water to give a waste paper slurry; and
applying a mechanical process to the waste paper slurry having a solids content of 0.5 to 5.0% by weight using a rotary disintegrator;
wherein the rotary disintegrator comprises stationary blades and rotating blades, so that inks can be detached/pulverized from a waste paper pulp when a feed stream passes between the stationary blades and the rotating blades, and
wherein the rotating blades have a blade width of 1.0 to 10 mm, and the stationary blades have a blade width of 0.3 to 2.0 mm.

2. The process of claim 1 , comprising removing inks to the outside by flotation before the step of applying a mechanical process.

3. A process for making paper, comprising converting a raw material containing the deinked pulp prepared by the process of claim 1 into paper.

4. A process for making paper, comprising converting a raw material containing the deinked pulp prepared by the process of claim 2 into paper.

5. The process of claim 1 , wherein the rotating blades have a blade width of 1.2 to 5.0 mm, and the stationary blades have a blade width of 0.5 to 1.4 mm.

6. The process of claim 1 , wherein the rotating blades have a conical shape.

7. The process of claim 1 , wherein the mechanical process is applied at 5 to 80° C.

Assignees

• Jujo Paper Co Ltd

Inventors

• Koizumi Hirohiko
• Takayama Masato
• Yoneshige Seiki
• Goto Shisei

Classifications

• D21B1/327

  using flotation devices · CPC title

• D21C5/025 Primary

  De-inking · CPC title

• D21C5/02

  Working-up waste paper (mechanical part D21B1/08, D21B1/32) · CPC title

• D21B1/32

  of waste paper · CPC title

• Y02W30/64

  Paper recycling · CPC title