CS217670B1 - Light card for a washed heavy packing cover cover - Google Patents

Abstract

Cardboard for the outer layer of corrugated cardboard is prepared from a chemical pulp, or a semi-chemical pulp based on hard and soft woods, and a sulphated resinous pulp, with unsorted recovered paper, in the total mixt. ratio of between 2:1:2 and 2:2:1. In an example, the paper pulp is prepd. from a semi-chemical pulp comprising amixt. of 60% hardwood and 40% soft wood refined to 36 deg. SR by a neutral sulphate process and a process of fibrillation, an unbleached resinous sulphate pulp refined to 25 deg. SR, and an unsorted recovered paper refrined to 32 deg. SR in a ratio of 2:1:2. Among the hard woods, oak in particular represents a source of raw material which has not previously been used in papermaking. The invention provides an outlet for this wood in chemical and semi-chemical pulps in corrugated cardboard outer layers.

Description

It is an object of the present invention to provide a carton for a corrugated board liner.

Until now, sulphate coniferous unbleached or bleached pulp has exclusively been used for the production of corrugated board liners. Sulfate coniferous pulp, waste paper, or semi-pulp and softwood pulp as well as tropical wood species (Eucalyptus delupta, Eucal. Cloeziana, Eucal. Grandis, Rucal. Tereticornis) were used for the production of lower grade grades. A mixture of kraft pine pulp and eucalyptus semi-pulp at Australian Papco Manufactures Ltd. was tested for the production of monolayer covering cartons.

A disadvantage of the prior art cartons for the corrugated board covering layer is the use of softwood deficient pulps. The use of additional components of the furnishings is almost always at the expense of the quality parameters of the cartons produced.

The proposed carton for the corrugated board liner is characterized in that it contains pulp or semi-pulp with a yield of 55-70%, based on 20-80% soft and 80-20% hard deciduous pulp, as well as sulphate coniferous unbleached pulp and unsorted waste paper, pvióhl póflier The ingredients in the total mixture are 2: 1: 2 or 2: 2: 1, with hardwood in the mixture of hardwoods up to 2/3 of oak and 1/3 of hardwoods.

Pulp and semi-cellulose prepared by the aforementioned methods and formed by sieving on a paper machine achieve the following mechanical-physical properties:

tear length - 9.0 km, relative overpressure strength - 500 kPa, relative tear strength 620 mN, number of bi-motions 300 within the range of fibrillation milling 30—50 ° SR

Other components of the furnishings are kraft pulp and waste paper. The waste paper may be of inferior quality (eg class P7), characterized by low mechanical-physical parameters, characterized by e.g. a market length of 1750-3800 m, a relative bursting strength of 75-230 kPa, a relative tear strength of 800-900 mN, a number of bipods up to 40 at grinding stages in the range of 17-48 ° SR.

Forming on the paper station respectively.

Cardboard machine using conventional carton manufacturing technology Product received - Cardboard for corrugated board covering by its physico-mechanical values

k. i. 2 aligns the K-0, K-1, K-2 carton of ON 50 2493.

Advantage of the solution. it consists of the use of pulp and semi-pulp from soft and hard deciduous trees, in particular oak, which has so far practically not been used in papermaking. From an economic point of view, oak is a potential source of raw material for the production of semi-pulp and pulp for the production of cartons for the corrugated board covering.

Example 1

From semi-pulp prepared from a mixture of 60% hard and 40% soft deciduous trees, 60% neutralized by a sulphite neutralization process, ground by fibrillation at 36 ° SR, sulphate non-bleached pulp ground at 25 ° SR and unsorted · P7 grade waste paper ground at 32 ° SR In a 2: 1: 2 ratio, a paper stock was prepared from which, after equalization, a carton having a basis weight of 180 g / m 2 was produced by single-layer molding, and the following physico-mechanical parameters were achieved:

Market Length - Late .8.0 km - Across 4.5 km Tear strength - Late 2100 mN - Across 2500. mN Overpressure strength 700 kPa Bending strength (K-M 8N) - Late - 1400 bends - Transversal - 600 bends

Example 2

Of semi-solids prepared from a mixture of 75% hard broadleaves containing 40% oak, 10% cedar, 15% beech, 10% maple and 25% soft broadleaves containing 16% poplar, 9% willow by a neutral sulphate process in a yield of 65%, ground by a fibrillation method at 40 ° SR, from kraft coniferous unbleached pulp ground to 23 ° SR. and unsorted collection. paper of class P7 ground to 35 ° SR in a 2: 2: 1 ratio was prepared paper pulp. After equalization, the paperboard was made by single-layer molding and covered with a basis weight. 180 g / m2 with the following physico-mechanical parameters:

Market Length - Late 9.5. km. - Across 5.5 km

Tear strength - Later 2200 mN - Transversal 2600 mN Burst strength 750 kPa

Fortress. deflection (K-M 8N) along 1600 bends

Hospodářská. the applicability of the invention on a global scale lies in the possibility of higher use of broadleaves. woods processed by mechanical-chemical methods, which are currently presented by 29.4% of deciduous trees a

70.6% coniferous trees. From a global perspective, oak wood mass supplies in mixed temperate forests and northern areas of humid subtropical forests represent! 10—11% of all deciduous wood mass.

Claims (2)

2 is compared to carton type K-0, K-1, K-2 according to ON 50 2493. The advantage of the present solution lies in the use of pulps and semi-cells from soft hardwoods, especially oak, which until now has practically not been used in paper production. For example, from semi-cell prepared from a mixture of 60% hard and 40% soft deciduous trees, a neutral-sulphate process with a yield of 60% fibrillated to 36 ° SR paper pulp from which, after leveling, a carton having a basis weight was produced by a single-layer molding, a paper stock of a weight of 25% SR and an unsorted collecting paper of class P7 ground to 32 ° SR in a 2: 1: 2 ratio. tensile strength - 180 g / m2, with the following physico-mechanical parameters being acheived: Market length - Longer 8.0 km - 4.5 km across Tear strength - Later 2100 mN - Cross 2500 mN Flow strength 700 kPa Bending strength (KM 8N) - Later - 1400 number of bends - Cross - 600 number of bends Example 2 From semi-cells y prepared from a mixture of 75% hardwoods containing 40% oak, 10% cedar, 15% beech, 10% maple and 25% softwood deciduous trees containing 16% topofa, 9% willow by a method of neutral-sulfuric acid extraction of 65%, eluted by fibrillation The pulp was prepared at 40 ° SR, kraft conifer non-bleached pulp 23 ° SR, and ungraded grade P7 pulp, ground at 35 ° SR, in a 2: 2: 1 ratio. After leveling, the paperboard was made with a single-ply molding sheet of a weight of 180g / m 2 with the following physico-mechanical parameters: Market length - Later 9.5 km— Cross 5.5 km Tear strength - Later 2200 mN - Cross-section 2600 mN Flow Strength 750 kPa Bending Strength (KM 8N) along the 1600fold The economic applicability of the invention worldwide is the possibility of higher use of deciduous trees processed by mechanical-chemical methods which are currently presented at 29.4 % deciduous trees and 70.6% coniferous trees. From a worldwide perspective, the oak wood stock in the mixed temperate forests and northern areas of subtropical wet forests represents 10-11% of all woody leafy wood. SUBJECT OF THE INVENTION A carton for a cover layer of corrugated cardboard, characterized in that it comprises cellulose or semi-cell with a yield of 55-70% consisting of a mixture of 20-80% hard and 80-20% softwood, furthermore a sulphate-non-bleached pulp and unsorted waste paper, the total mixture is 2: 1: 2 or 2: 2: 1. 2. Cardboard for the corrugated cover layer of point 1, characterized by the fact that in the volume of hardwoods it is under 2/3 represented by cubes and 1/3 are hard hardwoods.