Some standard content:
QB/T2379-1998
This standard is proposed by the Industry Management Department of the State Bureau of Light Industry. This standard is under the jurisdiction of the National Sewing Machine Standardization Center.
The drafting units of this standard are: Sewing Machine Factory No. 4 of Shanggong Co., Ltd. and Shanggong Co., Ltd. The main drafters of this standard are: Wu Meifang and Zhou Yuzhu. 425
1 Scope
Light Industry Industry Standards of the People's Republic of China
, Tables
Industrial Sewing Machines
QB/T2379—1998
This standard specifies the technical requirements, test methods, marking, packaging, transportation and storage of industrial sewing machine tables. This standard applies to industrial sewing machine tables (hereinafter referred to as "tables"). 2 Referenced Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard was published, the versions shown were all valid. All standards are subject to revision. Parties using this standard should explore the possibility of using the latest version of the following standards. GB/T153.2-1984 Grading of coniferous sawn timber GB/T1931-1991 Method for determination of moisture content of wood GB/T5851~—1986 Specification of test pieces for blockboard GB/T5852—1986 Determination of moisture content of blockboard GB/T5854—1986 Determination of shear strength of glue layer of blockboard Technical conditions for decorative laminates with thermosetting resins GB/T 7911. 1—-1987
GB/T 9846. 4—1988.
Plywood General technical conditions for ordinary plywood GB/T 9846. 11-1988
Determination of moisture content of plywood
GB/T 9846.12—1988
Determination of bonding strength of plywood
GB/T124711990Tolerance and fit of wooden partsGB/T 16469—1996
3 Definitions
Sewing machine packaging
This standard adopts the following definitions.
3.1 Top panel
The layer of board below the thermosetting resin decorative board (hereinafter referred to as "decorative board"). 3.2 Back panel
The other back panel of the table top to which the decorative board is attached.
3.3 Main surface
The surface of the table top directly seen by the user, generally refers to the top surface of the table top, the surrounding sides and the front of the drawer. 3.4 Frame blockboard structure tabletop (hereinafter referred to as "frame blockboard tabletop") The four sides of the frame are all made of whole wood, the middle core board is made of wood boards, the two surfaces are solid boards with glued wood veneers, and the surface is a tabletop with decorative boards.
3.5 Multi-layer plywood tabletop (hereinafter referred to as "plywood tabletop") is a tabletop with multi-layer boards glued together and decorative boards pasted on the surface. Approved by the State Bureau of Light Industry on May 14, 1998
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Implementation on March 1, 1999
4 Product classification
4.1 Type
QB/T2379--1998
Tabletops are divided into two categories according to their structure: frame blockboard tabletops and multi-layer plywood tabletops. 4.2 The external dimensions of the tabletop are shown in Appendix A.
5 Technical requirements
5.1 Materials
5.1.1 The materials used should not have defects such as skin inclusions, worm holes, dead knots, cracks, resin capsules, decay and deterioration, and defects that affect strength. 5.1.2 The moisture content of wood should not be greater than 18%. 5.1.3 The plywood used should meet the requirements of Class III (moisture-resistant) plywood second-class materials specified in GB/T9846.4. 5.1.4 The material of the inner and outer frames of the frame-type blockboard table should meet the requirements of first-class materials specified in GB/T153.2. 5.1.5 The veneer decorative board of the table should meet the requirements of second-class materials specified in GB/T7911.1. 5.1.6 The adhesive should be urea-formaldehyde resin glue or an adhesive with the same performance. 5.2 Appearance quality
5.2.1 The main surface of the table should be free of stains, and the other surfaces should be free of obvious stains. 5.2.2 The surface of the decorative board is not allowed to have defects such as dry and wet spots, indentations, small bubbles, cracks and uneven color. 5.2.3 After the processing of the table top veneer decorative board, the saw cut cracks should be evenly chamfered and trimmed. The residual crack width should not exceed 2mm, the crack length should not exceed 5mm, and there should be no more than two places. 5.2.4 The decorative board should be flat after gluing, and its flatness error should not exceed 0.3mm in any 70mm×18mm range. 5.2.5 The flatness error of the table surface should not exceed that specified in Table 1. Table 1 Table surface flatness tolerance value
Length L
>700～1000
>1000～1200
5.2.6 The four sides and inner frame edges of the table are not allowed to have board surface delamination. Tolerance value
5.2.7 The paint coating on the surface of the table frame, drawer panel, head support, etc. should be flat and smooth, with uniform color. There should be no defects such as missing paint, paint contact, peeling, cracking, shelling, blistering and obvious impurities. 5.2.8 The scale scale should comply with the international legal measurement units, and the trademark and scale position should be correct and should not be damaged. 5.2.9 The inner frame of the table, the outer surface of the drawer, the belt groove and the back plate should be painted, and there should be no burrs or defects that affect the appearance. 5.2.10 The back plate should be made of a whole single plate, and there should be no serious defects that affect the strength and appearance. Some defects such as wormholes and small cracks are allowed and should be repaired completely. bzxz.net
5.2.11 Metal accessories shall not be rusted.
5.3 Processing requirements
5.3.1 The decorative board and the surface board shall be firmly glued. Debonding is not allowed within 25mm along the edge of the table board. Debonding in other parts shall not exceed three places, and the area of each debonding shall not exceed 900mm2. 5.3.2 The surface board of the plywood table board shall be a whole single board, with the front side facing outward. The middle layer shall be glued with veneers with staggered parallel and horizontal grains, and end splicing is not allowed. 5.3.3 The surface board of the frame-type blockboard table board shall be a whole single board, and the middle layer shall be closely matched with blockboard. The connection parts with the machine head, frame, motor, etc. shall not be in the gap.
5.3.4 Weather resistance After the test in accordance with 6.3.4, it shall meet the following requirements: a) The wood shall be free of defects such as cracks, peeling and warping; b) The paint film surface shall not damage the color and have obvious peeling and other defects; 427
c) Metal accessories shall not rust.
5.4 Mechanical dimensions and fit
OB/T 2379
—1998
5.4.1 The dimensions and tolerances of the tabletop should comply with the requirements of the product drawings. 5.4.2 The dimensions of the tabletop and the machine head assembly should comply with the requirements of the product drawings. If the tolerance is not specified, it shall be selected according to h17 and s17 in GB/T12471. 5.4.3 The dimensions of the tabletop belt groove, machine head support, motor installation, etc. shall comply with the requirements of the product drawings. If the tolerance is not specified, it shall be selected according to h17 in GB/T12471.
The drawer and guide rail should be flexible.
5.5 Physical properties
The moisture content of the frame-type blockboard tabletop should not be greater than 18%. 5.5.1
The static bending strength of the frame-type blockboard tabletop should not be less than 24MPa. 5.5.2
The shear strength of the glue layer of frame-type blockboard decks shall not be less than 1MPa. The moisture content of plywood decks shall not exceed 18%.
5.5.5 The gluing strength of plywood decks shall not be less than 0.8MPa. 5.5.6 The static bending strength of plywood decks shall not be less than 30MPa. 6 Test methods
6.1 Materials
6.1.1 This standard 5.1.1 Visual inspection under natural light. 6.1.2 The moisture content of wood shall be inspected in accordance with the provisions of GB/T1931. 6.1.3 The inspection of second-class materials of Class III plywood shall be inspected in accordance with the provisions of GB/T9846.11 and GB/T9846.12. 6.1.4 The surface board of the deck and the inner and outer frames of the frame-type blockboard deck shall be visually inspected after cutting. 6.1.5 The quality of decorative panels shall be inspected in accordance with the provisions of GB/T7911.1. 6. 1.6 The performance of adhesives shall be determined in the physical performance test. 6.2 Appearance quality
The oil stains and stains on the tabletop shall be visually inspected under natural light. 6.2.2 The surface quality of decorative panels shall be visually inspected under natural light. 6.2.3 The burst length of the saw cut of decorative panels shall be measured with a vernier caliper with an accuracy of 0.02mm and a measuring range of 0~125mm. 6.2.4 The flatness of decorative panels after gluing
Place a 70mmX18mm×18mm gauge block on any surface of the tested piece and then measure with a feeler gauge. 6.2.5 Flatness error of the table surface
Use a 1m long steel ruler to place it on the diagonal part of the table surface, and then use a feeler gauge to measure the maximum gap between the side of the steel ruler and the table surface. The maximum gap between the two diagonals is taken as the flatness error. During arbitration, it can be directly measured with a dial indicator. The method is as follows: Place the measured piece on a flat plate with two adjustable supports and one fixed support, adjust the three farthest points on the measured surface so that the three points are at the same height as the flat plate, and then use a dial indicator to measure at any position about 10mm from the edge of the measured piece. The difference between the maximum and the minimum is taken as the flatness error. 6.2.6 Delamination of the four sides and inner frame of the table
Visually inspect or tap with fingers, and check with ears.
6.2.7 The paint film coating is flat and smooth, with uniform color, without defects such as missing paint, paint contact, and peeling. Use a sample for visual comparison. 6.2.8 Visually determine the scale, trademark and ruler position. 6.2.9 The coating and burrs of the inner frame of the table, the outer surface of the drawer, the belt groove and the backboard shall be visually inspected. 6.2.10 The quality of the table and backboard shall be visually inspected. 6.2.11 The rust of metal accessories shall be visually inspected. 6.3 Processing requirements
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6.3.1 The bonding firmness of decorative panels
QB/T 2379.-.-1998
Judgment shall be made by finger tapping and ear listening. The debonding area shall be calculated by measuring the product of its length and width with a steel ruler. 6.3.2 The quality of the surface board of plywood shall be visually inspected. 6.3.3 The surface board, back board and middle layer of the framed joinery board table shall be visually inspected after cutting. 6.3.4 Weathering resistance
6.3.4.1 Weathering resistance test
Place the specimen in a thermostatic humidifier with a temperature of (35±2)℃ and a humidity of (30±5)%r·h. Place it for 24 hours and then take it out. Visually inspect its condition.
6.3.4.2 Humidity resistance test
Humidity resistance test must be carried out after the drought resistance test. Place the specimen in a thermostatic humidifier with a temperature of (35±2)℃ and a humidity of (90±5)%·h. Place it for 24 hours and then take it out. Visually inspect its condition. 6.4 Dimensions and fit
6.4.1 The outer dimensions of the tabletop shall be measured with a 2m tape measure. 6.4.2 The inner frame dimensions of the tabletop shall be measured with a steel ruler or special measuring tool with an accuracy of 0.5mm. 6.4.3 The width of the table belt groove, the head support and the motor positioning dimensions shall be measured with a steel ruler with an accuracy of 0.5mm. 6.4.4 The flexibility of the drawer and the guide rail shall be checked by hand. 6.5 Physical properties
6.5.1 The permanent content of the frame-type blockboard table shall comply with the provisions of GB/T5852. 6.5.2 The static bending strength of the frame-type blockboard table shall be tested in the following manner. 6.5.2.1 Sample sampling method
a) Samples shall be taken at the specified position of the table, and the sample thickness shall be the thickness of the finished product; b) The specified length of the sample is the length of the table, the width is b=100mm, and there shall be no defects on the surface. 6.5.2.2 Test method
Place the sample as shown in Figure 1, the support span 1 is the distance between the two sides of the frame, the force P is at the center of the two supports, the load shall be increased evenly, the speed shall not be greater than 40kN/min, and the classification number accuracy shall be 5N.
Figure 1 Schematic diagram of static bending strength test method
Calculation method is carried out according to formula (1):
Where: α—-static bending strength, MPa (accuracy is 0.01MPa); P specimen failure load, N;
1——-two-point span, mm#
b---—specimen width, mm;
h specimen thickness, mm.
QB/T2379—1998
6.5.3 The shear strength of the adhesive layer of the frame-type fine board table is carried out according to the following method. 6.5.3.1 Sample sampling method
a) Samples are taken at the specified position of the table (see Figure 2), and the sample thickness is the thickness of the finished product; b) The specified size of the sample is 130mm×25mm, and there is no surface defect. The test piece production method is in accordance with 1.2.3 of GB/T5851-1986.
Schematic diagram of sampling position of static bending strength test sample
Schematic diagram of sampling position of adhesive layer shear strength test sample 200
Figure 2 Sampling position of static bending strength adhesive layer shear strength 6.5.3.2 The test method shall comply with GB/T5854. 6.5.4 The moisture content of multi-layer plywood table shall comply with GB/T9846.11. 6.5.5 The bonding strength of multi-layer plywood table shall comply with GB/T9846.12. 6.5.6 The static bending strength of multi-layer plywood table shall comply with 6.5.2. 7 Marking, packaging, transportation and storage
7.1 The table shall be wrapped with kraft paper and tied with fine hemp rope, and packed one piece at a time. If it is packed in a carton together with the rack, there should be a pad between the rack to prevent scratching the table.
7.2 The finished product must be marked with the model, packing date and manufacturer code. 7.3 Transportation and storage shall comply with 7.2 of GB/T16469--1996.5 The bonding strength of multi-layer plywood table tops shall comply with the provisions of GB/T9846.12. 6.5.6 The static bending strength of multi-layer plywood table tops shall comply with the provisions of 6.5.2. 7 Marking, packaging, transportation, storage
7.1 The table tops shall be wrapped with kraft paper, tied with fine hemp rope, and packaged one piece at a time. If they are packaged in cartons together with the racks, there should be pads between the racks to prevent scratches on the table tops.
7.2 The model, packing date, and manufacturer code must be marked on the finished product before it is shipped. 7.3 Transportation and storage shall comply with the provisions of 7.2 in GB/T16469--1996. 430
HiKAoNiKAca5 The bonding strength of multi-layer plywood table tops shall comply with the provisions of GB/T9846.12. 6.5.6 The static bending strength of multi-layer plywood table tops shall comply with the provisions of 6.5.2. 7 Marking, packaging, transportation, storage
7.1 The table tops shall be wrapped with kraft paper, tied with fine hemp rope, and packaged one piece at a time. If they are packaged in cartons together with the racks, there should be pads between the racks to prevent scratches on the table tops.
7.2 The model, packing date, and manufacturer code must be marked on the finished product before it is shipped. 7.3 Transportation and storage shall comply with the provisions of 7.2 in GB/T16469--1996. 430
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