Classification 4.1 According to the structure, it is divided into a) digital spraying two-layer solid wood composite floor; b) digital spraying three-layer solid wood composite floor; c) digital spraying multi-layer solid wood composite floor. 4.2 According to the surface morphology, it is divided into a) flat digital spraying solid wood composite floor; b) non-flat digital spraying solid wood composite floor. 4.3 According to the formaldehyde emission level, it is divided into a) E0 digital spraying solid wood composite floor; b) ENF digital spraying solid wood composite floor. 4.4 According to whether it is suitable for floor radiant heating, it is divided into a) digital spraying solid wood composite floor for non-floor heating; b) digital spraying solid wood composite floor for floor heating. 4.5 According to whether it is locked and spliced, it is divided into a) locking digital spraying solid wood composite floor; b) tongue-and-groove digital spraying solid wood composite floor. 5 Requirements 5.1 Appearance quality The appearance quality of digital spraying solid wood composite floor shall meet the requirements of Table 1. Table 1 Appearance quality requirements Item Front Back Excellent product Qualified product Tongue and mortise defects are not allowed to exceed 15% of the board length — Edge and corner defects are not allowed Long edge defects are not allowed to exceed 30% of the board length, and the width is not allowed to exceed 5mm, and the thickness is not allowed to exceed 1/3 of the board thickness; short edge defects are not allowed to exceed 20% of the board length, and the width is not allowed to exceed 5mm, and the thickness is not allowed to exceed 1/3 of the board thickness Spraying distortion is not allowed — Color line is not allowed Not obvious — Pattern defect is not allowed — Sand penetration is not allowed — Stains are not obvious The maximum single diameter is not more than 2mm, and each board is not allowed to have 1 — Bottom penetration is not allowed — Indentation and scratches are not allowed The maximum single diameter is not more than 1mm, and each board is not allowed to have 2 — Color halo* is not allowed Not obvious — Blistering of the coating layer is not allowed The maximum single diameter is not more than 0.5mm, and each board is not allowed to have 2 — Pinholes are not allowed The maximum single diameter is not more than 0.5mm, and each board is not allowed to have 3 — Wrinkles are not allowed — Particles are not allowed Not obvious — Leakage of paint is not allowed - Delamination and bubbling are not allowed. Not allowed. Note 1: Other appearance quality requirements shall be negotiated by the supply and demand parties. Note 2: Under normal vision, under natural light, at a distance of 0.4m from the product, it is not obvious if it is not easily identified by naked eye. * This item is not tested for non-vacuum adsorption processes. 5.2 Specifications and Deviations 5.2.1 Specifications The conventional length of digital sprayed solid wood composite flooring is 300mm~2745mm, the width is 60mm~900mm, and the thickness is 8mm~25mm. Products of other specifications and sizes can be produced by negotiation between the supply and demand parties. 5.2.2 Dimension Deviation The dimension deviation of digital sprayed solid wood composite flooring shall meet the requirements of Table 2. Table 2 Dimensional deviation requirements Item Requirements Plane non-planar thickness deviation The absolute value of the difference between the nominal thickness and the average thickness is ≤0.50mm; the difference between the maximum and minimum thickness is ≤0.50mm The absolute value of the difference between the nominal thickness and the average thickness is ≤0.80mm Net length deviation of the surface layer When the nominal length is ≤1500mm, the absolute value of the difference between the nominal length and each measured value is ≤1mm; When the nominal length is >1500mm, the absolute value of the difference between the nominal length and each measured value is ≤2mm Net width deviation of the surface layer The absolute value of the difference between the nominal width and the average width is ≤0.10mm; the difference between the maximum and minimum width is ≤0.20mm Straightness ≤0.20mm Edge straightness ≤0.30mm/m Warpage Warpage in the width direction is ≤0.20%; Warpage in the length direction is ≤1.00% Maximum assembly gap is ≤0.20mm Maximum assembly height difference is ≤0.15mm — Note 1: When the floor is square in shape, the net length deviation of the surface layer shall comply with the net width deviation requirements of the surface layer. Note 2: The dimensional deviation requirements for special products can be negotiated by the supply and demand parties. 5.3 Physical and chemical properties The physical and chemical properties of digital sprayed solid wood composite flooring shall meet the requirements of Table 3 and Table 4. Table 3 Physical and mechanical properties requirements Inspection item Unit Requirements Planar non-planar moisture content - ≥5.0%, and less than or equal to the equilibrium moisture content of the wood used Static bending strength MPa Average value ≥30.0, minimum value ≥24.0 Elastic modulus MPa 4000 Immersion peeling - The cumulative length of debonding of any glue layer on any side shall not exceed 1/3 of the length of the glue layer, and the finishing layer shall not peel off. 5 out of 6 test pieces are qualified. Paint film hardness - Superior product ≥3H Qualified product ≥2H Paint film adhesion - Level 4 Surface wear resistance - Abrasion value ≤0.10g/100r, and the 500r pattern is not damaged Abrasion value ≤0.12g/100r, and the 300r pattern is not damaged Surface impact resistance mm Dent diameter ≤13.0 - Table 3 Physical and mechanical performance requirements (continued) Inspection item Unit Requirements Flat surface Non-flat surface Pollution resistance - ≥Level 5 ≥Level 4 Locking force N/mm ≥2.5 (side splicing) ≥2.5 (end splicing) Light fastness (blue wool standard) - Standard grade ≥Level 6 High color retention grade ≥Level 7 Note 1: When using suspended paving, the static bending strength and elastic modulus of the digital sprayed two-layer solid wood composite flooring with the panel perpendicular to the underlying texture and the digital sprayed solid wood composite flooring with horizontal grooves on the back are not tested. Note 2: Only the locking force of the lock digital sprayed solid wood composite floor is tested, and the locking force of the tongue and groove digital sprayed solid wood composite floor is not tested. Table 4 Requirements for the limit of harmful substances Test item Unit Requirement Formaldehyde emission* mg/m3 E0 grade ENF grade ≤0.050 ≤0.025 Soluble heavy metal content Lead mg/kg ≤30 Cadmium ≤25 Chromium ≤20 Mercury ≤20 Total volatile organic compounds mg/m3 ≤0.10 Benzene mg/m3 ≤0.01 Toluene mg/m3 ≤0.02 Xylene mg/m3 ≤0.02 Note: The soluble heavy metal content is tested according to the needs of both the supply and demand parties. *Grading is carried out according to the provisions of GB/T39600-2021. 5.4 Digital sprayed solid wood composite flooring for floor heating The basic quality requirements and harmful substance limit requirements of digital sprayed solid wood composite flooring for floor heating shall comply with the provisions of Table 3 and Table 4 of this document, and the floor heating performance shall comply with the provisions of 5.2 of GB/T41547-2022. 6 Inspection method 6.1 The appearance quality shall be carried out in accordance with the provisions of 6.1 of GB/T18103-2022. 6.2 The specifications, dimensions and deviations shall be carried out in accordance with the provisions of 6.2 of GB/T18103-2022. The warpage test of non-planar digital sprayed solid wood composite flooring shall be based on the back of the floor as the reference surface, and the dimensions of the back shall be inspected. The thickness test shall be based on the relative highest point as the reference thickness. 6.3 Physical and chemical properties 6.3.1 Preparation, size and quantity of test pieces 6.3.1.1 Samples and test pieces shall be extracted from products stored for more than 24 hours after production. 6.3.1.2 Three floorboards shall be randomly selected from the sample as test pieces. Except for the locking force test piece, all test pieces are made from the sample after the mortise and tenon groove is removed. The test piece making position, test piece size and quantity shall be in accordance with the requirements of Table 5. When sawing the test piece, defects shall be avoided. If the floor size is too small to meet the test piece size and quantity requirements, continue to randomly select from the sample until all the required test pieces can be sawed. Table 5 Physical and chemical properties test specimen size and quantity Test item Specimen size/mm Quantity Remarks Moisture content 75.0×75.0 4 pieces Prepared on 2 specimens Static bending strength/elastic modulus 250.0×50.0 6 pieces After 24h, control immersion stripping 75.0×75.0 6 pieces Prepared on 2 specimens Paint film hardness 300.0×board width 1 piece Any piece Paint film adhesion 250.0×board width 1 piece Any piece Surface wear resistance 100.0×100.0 1 piece Any piece Surface impact resistance According to equipment requirements 3 pieces Prepared on 3 specimens Surface pollution resistance 300.0×board width 1 piece Any piece Locking force 100.0×50.0 12 pieces Prepared on 3 specimens, 2 specimens in the vertical and horizontal directions for each specimen Light fastness According to equipment requirements 1 piece Any piece Formaldehyde release 500.0×500.0 When the size of the four samples is insufficient, they can be spliced together to make a test piece, and the number of test pieces is 4. When making the test piece, use a formaldehyde-free adhesive to stick the two test pieces back to back, or use a formaldehyde-free aluminum tape to seal the back of the test piece, and all sides are sealed with formaldehyde-free aluminum tape. Soluble heavy metal content Shape and size are not limited to 2 parts, 0.5g/part Any part Total volatile organic compounds, benzene, toluene, xylene 400.0×500.0 When the size of the two samples is insufficient, they can be spliced together to make a test piece, and the number of test pieces is 2. When making the test piece, use a formaldehyde-free aluminum tape to seal the back of the test piece, and all sides are sealed with formaldehyde-free aluminum tape Note 1: The corners of the test piece should be straight and without broken edges. The allowable deviation of length and width is ±0.5mm. Note 2: When the surface wear-resistant test piece is not wide enough, the same piece of floor should be spliced after removing the tongue and groove, and the height difference should not exceed 0.05mm. Note 3: When the locking force test piece is not wide enough, the test piece size is plate width × 50.0mm. 6.3.2 The moisture content shall be measured in accordance with 4.3 of GB/T17657-2022. The average moisture content shall be expressed as the arithmetic mean of the results of 4 test pieces, accurate to 0.1%. 6.3.3 The static bending strength and elastic modulus shall be measured in accordance with 6.3.4 of GB/T18103-2022. If there is a mute pad on the back, it shall be removed before testing. 6.3.4 Immersion stripping shall be measured in accordance with 6.3.2 of GB/T18103-2022. 6.3.5 The hardness of the paint film shall be measured in accordance with 4.58 of GB/T17657-2022. 6.3.6 The adhesion of the paint film shall be measured in accordance with 4.57 of GB/T17657-2022, with a cutting spacing of 2mm. 6.3.7 The surface wear resistance shall be determined in accordance with the provisions of 4.47 of GB/T17657-2022, with the number of revolutions being 100r and the result being accurate to 0.01g/100r. For flat digital sprayed solid wood composite flooring, continue grinding to 500r to observe whether the pattern is damaged. For non-flat digital sprayed solid wood composite flooring, continue grinding to 300r to observe whether the pattern is damaged. 6.3.8 The surface impact resistance shall be determined in accordance with the provisions of 4.53 of GB/T17657-2022. The impact height is 1m, and each specimen is impacted once. 6.3.9 The surface pollution resistance shall be determined in accordance with the provisions of 4.44 of GB/T17657-2022, and the pollutants are black coffee and 10% citric acid. 6.3.10 The locking force shall be determined in accordance with the provisions of 6.3.10 of GB/T18103-2022, with 3 groups of side and end locking force test specimens each. 6.3.11 The color fastness to light shall be tested in accordance with the provisions of 4.31 of GB/T17657-2022. The test piece and a set of blue wool standards (blue wool standard level 6 for standard grade; blue wool standard level 7 for high color retention grade) shall be exposed together. When the color difference between the exposed and unexposed parts of the blue wool standard reaches level 4 of the gray scale sample card, the exposure shall be terminated. The corresponding color changes of the test piece and the blue wool standard shall be compared in the rating light box. The color fastness to light grade of the test piece shall be the number of the blue wool standard showing similar color change. 6.3.12 The formaldehyde emission shall be tested in accordance with the provisions of GB18580, and the formaldehyde emission shall be accurate to 0.001 mg/m3. 6.3.13 The soluble heavy metal content shall be tested in accordance with the provisions of GB/T33042-2016. Among them, the sample preparation and heavy metal element extraction shall be carried out in accordance with the provisions of 6.2 and 7.2 of GB/T33042-2016 respectively. 6.3.14 Total Volatile Organic Compounds, Benzene, Toluene, and Xylene 6.3.14.1 The test method for the release of total volatile organic compounds, benzene, toluene, and xylene shall be carried out in accordance with the provisions of Appendix A.5 of HJ571-2010. 6.3.14.2 Calculation of mass concentration: Calculate the mass concentration of each component according to formula (1): (1) Where: ρm——mass concentration of the sample to be analyzed, mg/m3; mF——mass of volatile organic compounds collected by the sampling tube, mg; mb——mass of volatile organic compounds in the blank tube, mg; V——sampling volume, L. 6.3.14.3 Calculation of mass concentration under standard conditions: Convert the mass concentration in 6.3.14.2 into the mass concentration under standard conditions according to formula (2): (2) Where: ρc——mass concentration of the sample under standard conditions, mg/m3; ρm——mass concentration of the sample under standard conditions, mg/m3; T0——thermodynamic temperature under standard conditions, 273K; T——the sum of the temperature (t)℃ at the sampling point during sampling and the thermodynamic temperature under standard conditions, (t+273)K; p0——atmospheric pressure under standard conditions, 101.3kPa; p——atmospheric pressure at the sampling point during sampling, kPa. 6.3.14.4 Requirements for calculation of mass concentration of organic compounds: Carry out in accordance with the provisions of Appendix A.6.1.3 of HJ571-2010. 6.3.14.5 Calculation of mass concentrations of total volatile organic compounds, benzene, toluene and xylene: Calculate the sum of the mass concentrations of each organic compound in standard state obtained in 6.3.14.3 as the mass concentration of total volatile organic compounds (ρχ); calculate the mass concentration of benzene in standard state according to 6.3.14.3 as the mass concentration of benzene; calculate the mass concentration of toluene in standard state according to 6.3.14.3 as the mass concentration of toluene; calculate the mass concentration of xylene in standard state according to 6.3.14.3 as the mass concentration of xylene. 6.3.15 Physical and chemical properties of digital sprayed solid wood composite flooring for floor heating The basic quality and harmful substance limit test of digital sprayed solid wood composite flooring for floor heating shall be carried out in accordance with the provisions of 6.3.1 to 6.3.14 of this document; the floor heating performance test shall be carried out in accordance with the provisions of 6.2 of GB/T41547-2022. 7 Inspection rules 7.1 Inspection classification Product inspection is divided into factory inspection and type inspection. 7.1.1 Factory inspection Factory inspection is conducted in batches, and the inspection items include appearance quality, specification size and deviation, moisture content, impregnation peeling, paint film hardness, paint film adhesion, surface wear resistance, and surface impact resistance. 7.1.2 Type inspection Type inspection items are all items specified in 5 of this document. In normal production, type inspection should be conducted at least once a year. Type inspection should be conducted in any of the following situations: a) When there are major changes in raw materials and production processes; b) When production is resumed after a suspension of more than 3 months; c) When new products are put into production or converted; d) When the quality supervision department proposes type inspection requirements. 7.2 Batch grouping Products of the same shift, same specification, and same type are considered a batch. 7.3 Sampling method and judgment principle 7.3.1 General rules For product quality inspection of digital sprayed solid wood composite flooring, samples should be drawn according to regulations from products of the same type, specification, and type. The drawn samples should be inspected one by one, and the samples are counted by piece. 7.3.2 Appearance quality shall be in accordance with the provisions of 7.2.2.1 of GB/T18103-2022. 7.3.3 Specifications, dimensions and deviations shall be in accordance with the provisions of 7.2.2.2 of GB/T18103-2022. 7.3.4 Physical and chemical properties 7.3.4.1 The sampling plan for physical and chemical properties is shown in Table 6. Sufficient samples shall be drawn from the samples that have passed the appearance quality inspection for physical and chemical performance inspection. If a certain indicator of the initial inspection sample is unqualified, re-inspection is allowed once, and double samples shall be drawn from the same batch of products for re-inspection of the unqualified items. After re-inspection, all qualified items are judged as qualified; if one item is unqualified, it is judged as unqualified. Table 6 Sampling plan for physical and chemical properties Unit: block Number of finished products submitted for inspection Number of initial inspection samples Number of re-inspection samples ≤1000 3 6 ≥1001 6 12 Note 1: Formaldehyde emission, total volatile organic compound emission, benzene, toluene, and xylene test samples are sampled separately according to product specifications. Note 2: If the sample specifications are too small and the samples drawn according to the above plan cannot meet the inspection requirements, the number of samples can be appropriately increased. 7.3.4.2 Determination of inspection results: a) If the arithmetic mean of the moisture content, elastic modulus, and locking force of the floor sample meets the requirements of 5.3 of this document, the moisture content, elastic modulus, and locking force of the floor sample are judged to be qualified, otherwise they are judged to be unqualified. b) If the average value of the static bending strength of the floor sample meets the requirements of 5.3 of this document, and the minimum value is not less than 80% of the value specified in the standard, the static bending strength of the floor sample is judged to be qualified, otherwise it is judged to be unqualified. c) When the immersion peeling, paint film hardness, paint film adhesion, surface wear resistance, surface pollution resistance, light fastness, formaldehyde emission, soluble heavy metal content, total volatile organic compound emission, benzene, toluene, and xylene of the floor sample all meet the requirements of 5.3 of this document, the above performance of the floor sample is judged to be qualified, otherwise it is judged to be unqualified. d) When the maximum value of the surface impact resistance of the floor sample all meets the requirements of 5.3 of this document, the surface impact resistance of the floor sample is judged to be qualified, otherwise it is judged to be unqualified. 7.4 When the comprehensive judgment of the sample appearance quality, specification size and deviation and physical and chemical performance test results all meet the requirements of the corresponding grade, the batch of products is judged to be qualified, otherwise the batch of products is unqualified. 8 Marking, packaging, transportation and storage 8.1 Marking Important information related to the product should be marked on the product or packaging. Including: manufacturer, address, product name, implementation standard, production date, trademark, specification, model, category, grade, formaldehyde emission limit mark, quantity, and other precautions such as rain protection, moisture protection, and sun protection. 8.2 Packaging Products should be packaged according to product category and specification when leaving the factory. The packaging should ensure that the products are protected from bumps, scratches and stains. Packaging requirements can also be negotiated by both the supply and demand parties. 8.3 Transportation and storage During transportation and storage, products should be stacked flat to prevent stains, moisture, rain and exposure. When storing, they should be stacked according to categories, specifications, colors, grades, etc. Appropriate labeling, storage and protection should be done. ?