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This standard is developed in accordance with the rules given in GB/T 1.1-2020 Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents.
This standard replaces GB/T 11718-2009 Medium density fibreboard. In addition to editorial changes, the following main technical changes have been made with respect to GB/T 11718-2009:
a) “Terms, definitions and abbreviations" is changed (see Clause 3; Clause 3 of Edition 2009);
b) the classification is modified (see Clause 4; 4.1 of Edition 2009);
c) the technical requirements are modified (see 5.2 and 5.4; 5.2 and 5.4 of Edition 2009);
d) the technical requirements for building medium density fibreboard are added (see 5.3.4);
e) the measurement and test methods are modified (see 6.2.2, 6.3~6.15; 6.2.2, 6.3~6.16 of Edition 2009);
f) the inspection rules are modified (see 8.1 and 8.2; 7.1, 7.2.1, 7.2.2 and 7.2.3 of Edition 2009);
g) the inspection time limit is deleted (see 7.2.4 of Edition 2009);
h) the requirements for product marking and packaging are modified (see 9.1 and 9.2; 8.1 and 8.2 of Edition 2009);
i) the calculation of 5% and 95-percentile values are added (see Annex A).
This standard is drafted by reference to but is not equivalent to ISO 16895: 2016 Wood-based panels - Dry-process fibreboard.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this standard shall not be held responsible for identifying any or all such patent rights.
This standard was proposed by the National Forestry and Grassland Administration.
This standard is under the jurisdiction of the National Technical Committee 198 on Wood-based Panels of Standardization Administration of China (SAC/TC 198).
The previous editions of this document are as follows:
——this standard was first issued in 1999 with the serial number of GB/T 11718-1999 and first revised in 2009;
——this is the second revision.
Medium density fibreboard
1 Scope
This standard specifies the terms, definitions and abbreviations, classification, requirements, measurement and test methods, inspection rules, marking, packaging, transportation and storage of medium density fibreboards.
This standard is applicable to dry-process medium density fibreboards.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 2828.1-2012 Sampling procedures for inspection by attributes - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection
GB/T 17657-2013 Test methods of evaluating the properties of wood-based panels and surface decorated wood-based panels
GB/T 18259-2018 Terminology for wood-based panels and their surface decoration
GB/T 19367-2009 Wood-based panels - Determination of dimensions of panels
LY/T 1717-2007 Guide for sampling inspection of wood-based panels
3 Terms, definitions and abbreviations
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 18259-2018 and LY/T 1717-2007 and the following apply.
3.1.1
medium density fibreboard, MDF
board with a density of 0.65~0.80g/cm3, which is made of wood fibres or other plant fibres following the steps of fibre preparation, addition of synthetic resin and pressing under heat-pressure conditions
Note: The density range specified hereof is only for guidance. If the product density is within ±10% of the density range and meets all the property requirements of the specified MDF type, the manufacturer may classify the product into this type. For example, a fibreboard with a density of 0.83g/cm3 may also be called a medium density fibreboard if it meets all the property requirements of the specified type of medium density fibreboard.
3.1.2
general purpose medium density fibreboard
medium density fibreboard for non-furniture or non-structure applications
Example: temporary display boards for exhibitions, partition boards, etc..
[Source: GB/T 18259-2018, 3.2.18, modified]
3.1.3
furniture grade medium density fibreboard
medium density fibreboard for furniture or decoration, which usually needs secondary surface processing
[Source: GB/T 18259-2018, 3.2.19]
3.1.4
load bearing medium density fibreboard
medium density fibreboard used in load-bearing state, usually used for small structural components
[Source: GB/T 18259-2018, 3.2.20]
3.1.5
building medium density fibreboard
medium density fibreboard for general building
Example: Used for window frame, door lining, etc.
3.1.6
dry conditions
conditions of interior environment or protected exterior environment, under which, the moisture content of the material is equivalent to the moisture content reached where the temperature is 20℃ and the relative humidity is not higher than 65% (or the relative humidity is higher than 65% only in a few weeks of a year)
[Source: GB/T 18259-2018, 2.54]
3.1.7
humid conditions
conditions of interior environment or protected exterior environment, generally under which, the temperature is 20℃, the relative humidity is higher than 65% but not higher than 85%, or the relative humidity is higher than 85% only in a few weeks of a year
3.1.8
humid conditions - temperate
conditions of interior environment or protected exterior environment, under which, the moisture content of materials is equivalent to the moisture content reached where the temperature is 20℃ and the relative humidity is higher than 65% but not higher than 85% (or the relative humidity is higher than 85% only in a few weeks of a year)
[Source: GB/T 18259-2018, 2.55, modified]
3.1.9
humid conditions - tropical
conditions of interior environment or protected exterior environment, under which, the moisture content of materials is equivalent to the moisture content reached where the temperature is 30℃ and the relative humidity is higher than 65% but not higher than 85% (or the relative humidity is higher than 85% only in a few weeks of a year)
[Source: GB/T 18259-2018, 2.56, modified]
3.1.10
high-humid conditions
conditions of interior environment or protected exterior environment, under which, the moisture content of materials is equivalent to the moisture content reached where the temperature is higher than 30℃, the relative humidity is higher than 85%, or where it may be occasionally exposed to water (except water immersion or watering)
[Source: GB/T 18259-2018, 2.57]
3.1.11
exterior conditions
environmental conditions under exterior natural climate conditions
[Source: GB/T 18259-2018, 2.58]
3.2 Abbreviations
For the purposes of this document, the following abbreviations apply.
BL: building
EXT: exterior
F: fungi retardant
FN: furniture (in furniture manufacture, cabinet making, fitments, joinery, bases for surface decorative treatment)
FR: fire retardant
GP: general purpose
HMR: high moisture resistant
I: insect retardant
LB: load bearing
MDF: medium density fibreboard
MR: moisture resistant
MR1: moisture resistant - temperate
MR2: moisture resistant - tropical
REG: regular
4 Classification
Table 1 specifies the MDF classification according to service conditions.
Table 1 UDF classification and type symbols
Type Service conditions Type symbol
General purpose medium density fibreboard Dry conditions MDF-GP REG
Humid conditions MDF-GP MR
High-humid conditions MDF-GP HMR
Furniture grade medium density fibreboard Dry conditions MDF-FN REG
Humid conditions MDF-FN MR
High-humid conditions MDF-FN HMR
Exterior conditions MDF-FN EXT
Load bearing medium density fibreboard Dry conditions MDF-LB REG
Humid conditions MDF-LB MR
High-humid conditions MDF-LB HMR
Building medium density fibreboard Dry conditions MDF-BL REG
Humid conditions - temperate MDF-BL MR1
Humid conditions - tropical MDF-BL MR2
High-humid conditions MDF-BL HMR
5 Requirements
5.1 Appearance quality
5.1.1 Products may be classified into superior products and qualified products according to the appearance quality, among which the quality requirements for sanded surface are listed in Table 2.
Table 2 Quality requirements for sanded surface
Name Quality requirements Permissible range
Superior product Qualified product
Layering, bubbling or carbonizing — Not permitted
Local softness Single area
≤2,000mm2 Not permitted 3 pieces
Defects at edge Width≤10mm Not permitted Permitted
Oil stain or foreign matter Single area: ≤40mm2 Not permitted 1 piece
Indentation — Not permitted Permitted
The same board shall not have two or more appearance defects.
5.1.2 The surface quality of the non-sanded board shall be determined by the supplier and the purchaser.
5.2 Requirements for specification & dimension, dimensional deviation, density, deviation and moisture content
5.2.1 Specification & dimension: generally, the length is 2,440mm and 2,745mm, and the width is 1,220mm and 1,830mm. Special specifications and dimensions shall be determined by the supplier and the purchaser.
5.2.2 See Table 3 for the requirements for dimensional deviation, density, deviation and moisture content.
Foreword i
1 Scope
2 Normative references
3 Terms, definitions and abbreviations
4 Classification
5 Requirements
6 Measurement and test methods
7 Specification limits
8 Inspection rules
9 Marking, packaging, transportation and storage
Annex A (Nominative) Calculation of 5-percentile and 95-percentile values
Bibliography
