GB/T 12626.1-2009Hardboard - Part 1: Definitions and classification (English PDF)

Foreword

GB/T 12626 "wet hardboard" is divided into nine sections.

--- Part 1. Definitions and classification;

--- Part 2. Common requirements for all board types;

--- Part 3. Specimen Samples and measurements;

--- Part 4. General plate for use in dry conditions;

--- Part 5. Common plate under wet conditions of use;

--- Part 6. ordinary plate under high humidity conditions of use; Ordinary plate under outdoor conditions of use;.

--- Part 8. under dry conditions using carrier plate;

--- Part 9. humid conditions bearing plate used. This section GB/T Part of 112,626. This portion of the reference ISO /DIS27769-1.2008 "wet fiberboard classification" (Wood-basedpanels-Wetprocess fibreboard-Part 1. Classifications) in hardboard section. This part is GB/T 12626.1-1990 "hardboard" of Amendments. This Part replaces GB/T 12626.1-1990. This section compared with the GB/T 12626.1-1990 main technical changes are as follows:

--- Increase in terms. dry conditions, wet conditions, high humidity conditions, outdoor conditions, general plate used in dry conditions, in the tide Under ordinary conditions of wet plate used in ordinary plate under high humidity conditions, the common plate under outdoor conditions used in Under dry conditions using carrier plate, bearing plate in humid conditions of use; and GB/T 12626.2-1990 APPENDIX A modification of the contents after joining the section;

--- Increase in the classification by points and surface processing status by zoning. This part by the State Forestry Administration. This part of the National Standardization Technical Committee centralized wood-based panels. This section is responsible for drafting units. China Forestry Science Institute of Wood Industry. Participated in the drafting of this section. Dunhua Danfeng forestry fiberboard limited liability company, Yichun City, Heilongjiang Province friendship and fibreboard plant in Henan Province Ltd. Xinxiang Tyrone system board. The main drafters of this section. Fan Yang, Qu Yan Chun, Wang new, Rencheng Bin, Debris, Pan Yulin. This section was first released in October 1980, in December 1990 the first amendment, this is the second revision. Wet hardboard Part 1. Definitions and classification

1 Scope

Part 1 of China's series on wet process hardboard, carrying the definitions and the classification on which the other parts rest. Hardboard is made by breaking wood down to fibre, forming it into a mat in water and pressing it hot: the lignin in the wood softens and bonds the fibres, so the classic wet process board needs little or no added adhesive - which is why it behaves differently from the dry process fibreboards it is often confused with, and why it has a separate series of standards. This part specifies the definitions and the classification of wet process hardboard, and it applies to the boards falling within the definition it gives. The classification is what the rest of the series depends on and what a purchaser is actually choosing between: the separation by density and by the process, and within that the board types distinguished by their intended service conditions - the standard boards for dry interior use, and the boards treated or made for humid conditions or for load bearing use, which are different products with different requirements even though they look the same. Getting that classification right is the practical value of a short standard like this one: a board specified by the wrong type is the commonest failure in the material, because a hardboard made for dry interior use will swell, lose thickness and lose strength permanently once it takes up water, and no amount of surface finishing prevents it. The definitions clause fixes the terms the whole series then uses - the board itself, the process, the density classes and the surface conditions - so that Part 2, which sets the requirements common to all types, and Part 3, which sets the sampling, can be written without ambiguity. Issued on 30 September 2009 and in force since 1 December 2009, it replaces GB/T 12626.1-1990.

GB/T 12626 provisions of this part of the wet hardboard definition and classification. This section applies to

3.1 defined wet hardboard.

2 Normative references

The following documents contain provisions which, through reference

GB/T 12626 in this section constitute provisions of this section. For dated reference documents Member, all subsequent amendments (not including errata content) or revisions do not apply to this section, however, encouraged to reach under this section Parties to research agreement to use the latest versions of these documents. For undated reference documents, the latest versions apply to this section.

GB/T 18259 artificial board and surface decoration term

3 Terms and Definitions

GB/T 18259 and established the following terms and definitions apply GB/T 12626 in this section.

3.1 Wood or other plant fiber as raw material, molding mat high moisture content of 20%, and is mainly the use of his inherent viscosity fibers The combination of adhesive properties make fiberboard having a density greater than 800kg/m3.

3.2 Wood fiber as raw material wet hardboard.

3.3 Non-wood plant fiber as raw material wet hardboard.

3.4 In addition to the year only a few weeks away, keep the ambient air temperature is 20 °C, the air relative humidity at less than 65%.

3.5 In addition to the year only a few weeks away, keep the ambient air temperature 20 °C, between 65% to 85% relative humidity in the air condition.

3.6 In addition to the year only a few weeks away, keep the ambient air temperature of 20 °C, the air relative humidity at 85% or Occasionally there is a risk of flooding (not including being immersed in water or washout) conditions.

3.7 Exposed to outdoor weather conditions, to withstand rain, sun and air pollution conditions. * * *