US1949000A

US1949000A - Process for recuperating rosin size already applied to papers

Info

Publication number: US1949000A
Authority: US
Inventors: Yano Shigenari
Original assignee: Yano Shigenari
Current assignee: KNOPF SYSTEMS LLC
Priority date: 1932-09-16
Filing date: 1932-09-16
Publication date: 1934-02-27
Anticipated expiration: 1951-02-27

Description

Patented Feb'. 27, 1934 UNITED V STATES PROCESS FORRECUPERATING ROSIN SIZE ALREADY APPLIED TO PAPERS I Shigenarl Yano, Fulimachi, Fuiix'lm,

Shizuokaken, Japan No Drawing. Application September is, 1932 Serial No. 633,543

2 Claims. (01. 92-1) The present invention relates to a process for recuperatingrosin size already applied to various kinds of papers by means of very simple and easy operation without using chemicals.

5 Hitherto rosin-sized papers have never been produced without damaging the size effect owing to various treatments after drying operation or the latter itself. On this account, when strong size is desired in the .,case of machine-grazed paper, water-finished paper and the like, it is required to apply surface size of animal or vegetable origin. The surface size, however, often decomposes to emit an offensive smell and degrade the appearance of the paper. Moreover, its aprlication requires complicated equipments and raises the cost of production. I

In accordance with the present invention, steam is applied, to the rosin-sized paper before, during 'or after operation of either drying or other various treatments. The simultaneous actions of damping and warming are effected by the simple operation of steaming. The present'proc-' ess of recuperation may be effectively applied to all kinds of papers sized with preparations 5 containing rosin, especially to wrapping paper,

printing paper, Indian paper and the like.

' By the simple and eflective operation of steaming according to the present invention, rosin size contained in papers can be completely recuperated, water-proofing power, writing property, lustre, strength and all other qualities and appearance being remarkably improved. And as expansion and contraction of paper are extremely diminished, the process is especially favourable to print- 5 ing paper. Moreover, quantities of rosin, alum and'other chemicals requisite for preparing size may be reduced to orunder one half by this invention.

In the preferred practie of the invention,

40 steaming is carried outat" 5-95 C. for about 1-30 minutes, usually 2 minutes for most machine-grazed papers, the duration and temperature being varied according to rosin content and kinds of qualities of papers to be treated. The

simplest operation in carrying out the present invention is injection of steam into a chamber containing the paper to be treated. Alternative operations, such as preliminary humidifying and indirect warming, may be adopted. Optimum o temperature varies from 65 C. to 90 C. and

preferable humidity ismore than 90%.

By wayof example, if a water-finished board, which is composed of 80% of bleached sulphite pulp and 20% of ground pulp and sized with a preparation containing 1.5% (to the weight of pulp) of rosin, 2.5% of alum, 1.5% of starch and 25% of clay, is treated inaccordance with the present invention with saturated steam at 55-60 C. for 5, 10, 15 and 30 minutes respectively, maximum and minimum spreading breadths in mm. of ink line of 1.1 mm. original breadth are as follows: 7

0 min. 5 min. 10 min. 15min. 30 min.

Original breadth 1. l 1. l l. l 1. 1 l. 1 Minimum breadth 2. 4 2. 0 1. 6 1. 3 1. 3 Maximum breadth 4. 0 3. 3 2. 6 2. 0 1. 9

And if a paper, which is composed of of ground pulp and 30% of unbleached sulphite pulp and sized with a preparation containing 1.5% of rosin and 4.0% of alum, is treated with saturated steam at 80 0.,

0 min. 5 min. 10 min.

Original breadth.-. l. l l. 1 1. 1 Minimum breadth.. 1. 8 1. 2 l. 2 Maximum breadth- 4. 0 1. 3 1. 3

The steaming process accordingto the present invention may be easily carried out in a continuous operation with paper-making process or various finishing processes.

As already explained hereinbefore, the main object of the invention resides in the recuperation of the rosin size by means of very simple and easy operation, wherefrom many advantages may be derived. Many difllculties and obstructions due to rosin size in paper-making operations may be entirely avoided. As the applied rosin size can be effectively and completely recuperated, even small -quantity of size is sufficient, this fact being especially remarkable in the case of papers which can be'difiicultly sized. In carrying out the present invention the equipment is so simple and the operation is so easy that the cost increased bythe steaming can be sufliciently compensated by the saved cost of chemicals or other materials requisite for preparing rosin size. Moreover, quite differing from surface size, the recuperated rosin size is never decomposed and consequently neither damages the appearance of the paper nor emits a disagreeable odour.

I claim:

1. Process for recuperating the rosin size applied to papers characterized by the fact that rosin-sized paper is submitted to steaming at 55-100 C. whereby the rosin size is simultaneously affected by damping action as well as warm ing action.

2. Process for recuperating rosin size as claimed in claim 1, which comprises exposing the paper to steam and keeping thus treated paper in an enclosed chamber.

SHIGENARI YANO.