GB/T 2679.6-2026Corrugating medium - Determination of the flat crush resistance after laboratory fluting (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents".

Drafting.

This document is Part 6 of GB/T 2679.GB/T 2679 has already published the following parts.

---Determination of paper transparency using the diffuse reflectance method (GB/T 2679.1);

---Determination of moisture permeability of thin sheet materials by gravimetric (permeability cup) method (GB/T 2679.2);

---Determination of flat crush strength of corrugated core paper after corrugation in the laboratory (GB/T 2679.6);

---Determination of puncture strength of cardboard (GB/T 2679.7);

---Determination of ring crush strength of paper and paperboard (GB/T 2679.8);

---Determination of short-range compressive strength of paper and paperboard (GB/T 2679.10);

---Qualitative analysis of inorganic fillers and inorganic coatings for paper and paperboard by electron microscopy/X-ray energy dispersive spectroscopy (GB/T 2679.11);

---Qualitative Analytical Chemistry Methods for Inorganic Fillers and Inorganic Coatings in Paper and Paperboard (GB/T 2679.12);

---Determination of pore size in paper and paperboard (GB/T 2679.14);

---Determination of edge crush strength of corrugated cardboard. edge reinforcement method (GB/T 2679.17).

This document replaces GB/T 2679.6-1996 "Determination of Flat Crush Strength of Corrugated Base Paper". Compared with GB/T 2679.6-1996, except for the structure...

Aside from adjustments and editorial changes, the main technical changes are as follows.

a) The term and definition of "flat crush strength index of corrugated core paper" have been added (see 3.2);

b) A sample cutting device was added (see 5.1);

c) The groove patterner has added B-type flutes (see 5.2), and modified the tooth spacing dimensions of the A-type flute groove roller and toothed rack, as well as the comb plate tooth height dimensions.

Requirements (see 5.2, 5.1 of the 1996 edition);

d) Requirements for type B toothed racks and comb plates have been added (see 5.3.2);

e) The requirements for pressure-sensitive tapes and compression testers have been changed (see 5.4 and 5.5, and 5.3 and 5.4 of the 1996 edition);

f) Instrument calibration was removed (see Chapter 6 of the 1996 edition);

g) The sample preparation method was changed (see Chapter 8, 7.2 of the 1996 edition);

h) The test method involving treatment at 65% relative humidity for 60 minutes has been removed (see 8.1 in the 1996 edition);

i) The time and test procedures from corrugation to pressure application have been increased (see 9.2), and the time range for re-humidification after corrugation has been increased (see 9.2).

j) A formula for calculating the flat crush strength index of corrugated core paper has been added (see 10.2);

k) The test report was amended (see Chapter 11, Chapter 10 of the 1996 edition).

This document is modified to adopt ISO 7263-1:2018 "Corrugated core paper – Laboratory determination of flat crush strength after corrugating – Part 1: A-flute".

And ISO 7263-2:2018 "Determination of flat crush strength of corrugated core paper after corrugation in the laboratory - Part 2: B-type corrugation".

This document has undergone significant structural adjustments compared to ISO 7263-1:2018 and ISO 7263-2:2018.The structure of the three documents is as follows.

See Appendix A for a list of changes in the numbering.

The technical differences between this document and ISO 7263-1:2018 and ISO 7263-2:2018, and the reasons therefor, are as follows.

a) The scope has been changed (see Chapter 1) for ease of use;

b) ISO 13820 (see 5.5) has been replaced with the normatively referenced GB/T 22876 to adapt to my country's technical conditions;

c) ISO 186 (see Chapter 6) has been replaced with the normatively referenced GB/T 450, and moved from the references to Chapter 2 to suit my needs.

National technical conditions;

d) ISO 187 (see Chapter 7) has been replaced with the normatively referenced GB/T 10739 to adapt to my country's technical conditions;

e) ISO 536 (see Chapter 8) has been replaced with the normatively referenced GB/T 451.2, and moved from the references to Chapter 2 to accommodate [the new standard].

my country's technological conditions.

The following editorial changes have been made to this document.

---The standard title has been changed to "Determination of Flat Crush Strength of Corrugated Core Paper After Laboratory Corrugation";

---Informative Annex A, "Maintenance of Flexing Rollers (Horizontal)," of ISO 7263-1:2018 and ISO 7263-2:2018 has been removed.

Please note that some content in this document may involve patents. The issuing organization of this document assumes no responsibility for identifying patents.

This document was proposed by the China National Light Industry Council.

This document is under the jurisdiction of the National Technical Committee on Standardization of Paper Industry (SAC/TC141).

Introduction

Paper and paperboard are the main products of the paper industry and are widely used in printing and publishing, packaging, daily life, and special industries.

GB/T 2679 specifies the methods for testing the basic performance indicators of paper and paperboard, which is proposed to consist of 10 parts.

---Determination of Paper Transparency by Diffuse Reflectance Method (GB/T 2679.1). The purpose is to establish a method for determining paper transparency.

---Determination of moisture permeability of thin sheet materials by gravimetric (permeability cup) method (GB/T 2679.2). The purpose is to establish the moisture permeability of thin sheet materials.

Methods for measuring moisture permeability through creases.

---Determination of flat crush strength of corrugated core paper after laboratory corrugation (GB/T 2679.6). The purpose is to establish the laboratory flat crush strength of corrugated base paper.

Method for determining the compressive strength after crease formation.

---Determination of puncture strength of paperboard (GB/T 2679.7). The purpose is to establish a method for determining the puncture strength of paperboard.

---Determination of ring crush strength of paper and paperboard (GB/T 2679.8). The purpose is to establish a method for determining the ring crush strength of paper and paperboard.

---Determination of short-range compressive strength of paper and paperboard (GB/T 2679.10). The purpose is to establish the transverse compressive strength of paper and paperboard.

Measurement method.

---Qualitative analysis of inorganic fillers and inorganic coatings for paper and paperboard by electron microscopy/X-ray energy dispersive spectroscopy (GB/T 2679.11).

The aim is to establish a method for determining inorganic fillers and inorganic coatings in paper and paperboard.

---Qualitative Analytical Chemistry Methods for Inorganic Fillers and Coatings in Paper and Paperboard (GB/T 2679.12). The aim is to establish qualitative analytical methods for inorganic fillers and coatings in paper and paperboard.

Methods for determining inorganic fillers and inorganic coatings in paperboard.

---Determination of pore size in paper and paperboard (GB/T 2679.14). The purpose is to determine the maximum pore size, average pore size, and pore diameter of paper and paperboard.

Methods for determining distribution.

---Determination of Edge Crush Strength of Corrugated Board. Edge Reinforcement Method (GB/T 2679.17). The purpose is to determine the edge crush strength of corrugated board.

Methods for determining edge compensation (edge compensation).

Determination of flat crush strength of corrugated core paper after corrugation in the laboratory

1 Scope

This document describes a method for determining the flat crush strength of corrugated core paper after laboratory corrugation.

This document applies to corrugated core paper.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included.

For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies.

This document.

GB/T 450 Paper and paperboard specimen collection and determination of longitudinal and transverse directions, front and back sides of specimens (GB/T 450-2008, ISO 186.

2002, MOD)

GB/T 451.2 Paper and paperboard - Part 2: Determination of basis weight (GB/T 451.2-2023, ISO 536:2019, MOD) GB/T 10739 Standard atmospheric conditions for the treatment and testing of paper, paperboard and pulp specimens (GB/T 10739-2023, ISO 187.

2022, MOD)

GB/T 22876 Description and calibration of compression testing apparatus for paper, paperboard and corrugated board (GB/T 22876-2008, ISO 13820.

1996, MOD)

3 Terms and Definitions

The following terms and definitions apply to this document.

Under specified conditions, corrugated core paper samples, after being corrugated in the laboratory, are subjected to pressure perpendicular to their surface. Before the corrugations collapse, the samples...

The maximum pressure that can be withstood.

Note. Units are expressed in Newtons (N).

The flat crush strength of corrugated core paper (3.1) is divided by its basis weight.

Note. The unit is expressed in Newton-square-meter per gram (N·m2/g).

4 Principles

After corrugated paper samples of a certain specification are corrugated on a groove tester, they are glued together with tape to form single-sided corrugations, and then compressed on a compression tester.

The flat crush strength of the corrugated core paper is measured until the corrugated core paper is crushed.

5 Instruments