National Upholstered Furniture Industry Technology - Sofa Technical Standards

- Jun 11, 2018-

1.0 topic content


   This standard specifies the terms and technical requirements for sofas.


2.0 Application


   All the soft bag components of sofas and other furniture manufactured by our factory and outside processing are applicable.


3.0 reference standard


3.1QB T 1952-2000 "Soft furniture sofas and other furniture soft bag components are applicable.


4.0 Definition of terms


4.1 Sofa: It is made of soft material or metal, etc. It is a flexible seat with back and armrests or without armrests.


4.2 Rule: Lines that are clipped when the fabric is stitched. Commonly known as: open line, sideline.


4.3 Edge: The seat of the sofa, the back and the soft bag around the handlebars. Commonly known as: skirt, side.


4.4. Snake spring: The wire is bent into a continuous S-shaped spring. Commonly known as: curved spring, bow spring.


4.5 Compression A: At the same detection position of the seat surface of the sofa, vertical and downward forces of 4N and 200N are respectively applied, resulting in a displacement difference of the seat surface along the force direction.


4.6 Compression amount B: At the same detection position of the seat surface of the sofa, vertical and downward forces of 40 N and 200 N are respectively applied, resulting in a displacement difference of the seat surface along the force direction.


4.7 Compression amount C: In the same detection position of the seat surface of the sofa, a vertical downward force of 40N and 250N is respectively applied, resulting in a displacement difference of the seat surface along the force direction.


4.8 Loose Momentum: Before the durability test, when the sofa is in the free state, the measured angle between the centerline of the back surface and the base surface is measured at the same measurement site under the preserving conditions after the durability test. The included angle is the backlash.


4.9 Looseness of armrest: Before the durability test, when the sofa is in the free state, the distance between the two fixed points on the same horizontal line at the front of the two armrests, and the durability test, the same two under the preserving conditions. The distance measured between the fixed points is the amount of armrest looseness.


4.10 residual back looseness: After the durability test, under the unloading condition, the measured angle between the back center line and the base surface, and the measured angle between the durability test and the free state, is the residual Loose amount.


4.11 Remaining armrest looseness: After durability test, under the unloading conditions, the distance between the two fixed points measured by the same measuring part 3.10 in the same measuring part and the distance measured in the free state before the durability test is the hand rest. Loose amount.


4.12 front seat width: The widest position of the seat front face in the armrest.


4.13 Seat depth: The distance from the front midpoint of the seat to the line of intersection between the seat and the back front.


4.14 Seat Height: The vertical distance from the front midpoint of the seat to the ground.


4.15 Handrail height: The vertical distance from the highest point of the front of the armrest to the frontal level of the seat surface.


4.16 Back length: The distance from the midpoint of the front edge of the back to the intersection of the back front and the seat surface.


4.17 anticlines: The angle between the front of the back and the horizontal plane.


4.18 seat angle: The angle between the seat surface and the horizontal plane.


4.19 Back Height: The vertical distance from the midpoint of the front edge to the ground.


4.20 Concaveness of the seat surface: The distance between the middle concave point of the seat surface and the midpoint of the front edge of the seat surface to the midpoint of the line of intersection between the front surface of the back seat and the seat surface.


5.0 Product Categories


5.1 Classified by coated fabric


5.1.1 All-leather sofas, except for the bottom of the sofa seat, all use natural animal leather sofas.


5.1.2 The main part of the sofa, the sofa seat, the front of the backrest, the copy of the upper edge and the inner side of the handrail and the upper edge of the handrail, are


Use natural animal leather-covered sofas.


5.1.3 artificial leather sofa, using artificial leather covered sofa.


5.1.4 Regeneration of leather sofas, using recycled leather covered sofas.


5.1.5 Fabric sofas, using wool, linen, cotton and other textile fabric sofas.


5.2 Classification according to front wide sofa


5.2.1 single sofa, sofa for single use.


5.2.2 double sofa, sofa for two people to sit.


5.2.3 Three-seat sofa, sofa for three people to sit on.


5.2.4 combination sofa, composed of multiple units, can be arranged in a certain shape for a number of people sitting sofa.


6.0 specification size


6.1 The main dimensions of a single sofa


   Seat width seat deep seat front high handrail high back length


  >480mm 480-600mm 360-420mm <250mm >300mm


6.2 Sofas with double and double seats are wider and the dimensions are the same as those for single sofas, except for the width of the sofa in accordance with 5.1. Before the seat, the width of the seat is not less than 960 mm and the number of the three persons is not less than 1440 mm.


6.3 Other various types of combination sofas Refer to the corresponding dimensions specified in 5.1.


7.0 Technical Requirements


7.1 Appearance and Sense Requirements


7.1.1 The binding and stretch of the spring should be firm. After rubbing it with hands, there should be no friction and percussion.


7.1.2 The spliced fabric shall be complete in graphic, continuous in pattern, the direction of suede down shall be the same, the fabric shall have no obvious color difference, the edges shall be smooth and straight, there shall be no obvious floating line in sewing, and skipping of stitches shall not be allowed.


7.1.3 The distance between exposed nails and foam nails should be substantially equal, neatly arranged, no burrs, and obvious defects such as flattening and severe paint stripping.


7.1.4 The exposed part of the metal frame shall have no edge.


7.2 Product size limit deviations and shape and position tolerances.


7.2.1 Product Size Limit Deviation


 Front seat, seat, deep seat, front seat, high handrail, high back, high mat


 +8mm +8mm +8mm +8mm +5mm +5mm


7.2.2 The relative difference between the two armrest heights of the same set and the same product is less than 4mm.


7.2.3 The dimension limit deviation of the same part of a sofa or sofa supplied by a combination sofa shall be in accordance with 6.2.1, with positive deviation or negative deviation.


7.2.4 product shape and position tolerances.


 Part Size Limit Shape Symmetry Difference Thickness


  Back <1000 <8


           >1000 <10


 Block <1000 <8 <5


          >1000 <10


 Symmetric Handrails <1000 Maximum Error <8


7.2.5 The deviation of the unevenness of the sofa bottom foot should not exceed 2mm.


7.3 material requirements


7.3.1 The interior racks are not limited by the tree species, but they must not affect the structural strength of the sofa. The old timbers can be used after being cut and processed.


7.3.2 External wooden materials


7.3.2.1 In a product or a set of products, wood of the same tree species should be used, and the wood color and texture should be similar. Needle and hardwood materials must not be mixed.


7.3.2.2 Wood with defects such as through cracks, insects, rot, dead knots, and resin sacs shall not be used, and any twill grade exceeding 20% may not be used.


7.3.2.3 Other minor wood defects, such as cracks, blunt edges, etc., may be used after repair processing without affecting the structural strength and appearance of the product, and may not be used without repair processing.


7.3.3 Metal Material


7.3.3.1 The plain carbon steel and low-alloy structural steel sheets used in products shall meet the requirements specified in the relevant standards.


7.3.3.2 The thickness of the wall of any round bar or profiled pipe of a stressed part shall not be less than 1.2 mm.


7.3.3.3 All kinds of pipe materials are not allowed to have cracks, overlapping seams, and the misalignment of pipe joints is not allowed.


7.3.4 All kinds of spring steel shall not be less than 65mn steel or No. 70 steel, and all springs and ferrous metal fittings shall be treated for rust prevention.


 Item Performance (Volume) Density Tensile Strength Kpa Compression Set %


Technical requirements >25Kg/m >100 <5.0


7.3.5 The blankets of felt (cloth), batting, cotton felt, brown felt, etc. shall be dry, sanitary, free of mildew and spoilage, and free of sediment and metal inclusions. The use of waste spacers is not allowed. If the use of recycled liner material should be specified in the product mark.


7.3.6 Coated fabric


     a) Leather should meet the following requirements


Thickness mm Tear strength N/mm Elongation at break% Color Frictional fastness Compression set %


 >1.5 >3.5 <80 >4.5/3.5 (dry, wet) <5.0


     b) Textile-covered fabrics such as artificial leather, cotton suitable for sofas, rough linen, etc. shall meet the qualification requirements of the corresponding standards.


7.4 Product Mechanical Performance Requirements


   Note: This section does not use non-framed sofas


7.4.1 The number of durability tests shall be greater than 60000. When the durability test passes, the seat and back fabric shall be intact and not damaged. The litter has no obvious displacement, the spring has no inclination, there is no broken spring, there is no looseness in the joint between the spring and the skeleton, the bandage is not damaged, and the skeleton has no permanent looseness or breakage.


7.4.2 After the product has been subjected to a permanent test, the displacement of each experimental part shall be specified. (See the table below)


7.5 paint film and plating layer physical and chemical performance requirements.


7.5.1 Strength requirements for seams of wrapping fabrics


     The strength of stitching seams of various coated fabrics is not more than 2mm.


7.5.2 The physical and chemical properties of the paint film on the surface of wooden parts shall comply with the requirements of the First Schedule.


7.5.3 The physicochemical properties of the metal surface baking paint, spray coating, electroplating layer, etc. shall comply with the requirements of Schedule 2.


7.6 product appearance and sensory requirements.


               Project Technical Requirements


           Looseness behind the surface <2


          Remaining looseness behind the surface <1


          Armrest looseness mm Single <30, Double and Double <15


        Armrest remaining looseness mm Single<30, Double and Double<15


             Compression amount a mm >55


             Compression b mm 30-40


7.7 paint film and plating layer physical and chemical performance requirements.


7.7.1 Strength requirements for seams of wrapping fabrics


   All kinds of cladding surface refurbishment stitching seam opening degree is not more than 5mm.


7.7.2 The rationalization performance of paint film on the surface of wooden parts shall comply with the requirements of Schedule 1.


7.7.3 The physicochemical properties such as baking on the surface of the metal, spraying, electroplating, etc. shall comply with the requirements of Schedule 2.


7.8 Appearance and Sensory Requirements


7.8.1 Abnormal sound


   Freehand pressure on the seat and back should be free of abnormal metal friction and impact.


7.8.2 Textile fabrics


7.8.2.1 The spliced fabric pattern should be complete, the direction of the pile hair is the same, and the fabric should have no significant color difference.


7.8.2.2 The fabric should be free from scratches, stains, and oil.


7.8.2.3 The fabric should have no residue.


7.8.3 Leather and Artificial or Regenerated Leather Fabrics:


    There should be no color difference between leather and artificial or regenerated leather fabrics. The surface is free from cracks, breakage, and greasy feel.


7.8.9.2 All kinds of decorative parts shall be tightly and firmly installed, and shall not be loosened. The installation shall be positively symmetrical.


7.8.9.3 The metal and all types of springs and hardware fittings inside the product shall be rust proofed and shall not be rusted.


8.0 acceptance, marking, packaging, transportation, storage.


8.1 The finished product shall be checked and accepted by the quality inspection department according to this standard.


8.2 The finished product shall have a qualified mark and production date.


8.3 The finished product should be cushioned or packaged during transportation to prevent heavy pressure damage and rain.


8.4 The finished product should be kept dry, ventilated, prevented from contamination, and not exposed to the sun during storage; cushioning should be added during stacking to prevent pressure loss