Views: 56 Author: Site Editor Publish Time: 2022-11-14 Origin: Site
A favorite job, a caring lover, a new house, a dazzling array of furniture is everyone's dream. Among them, wooden furniture is more popular with modern people. But wooden furniture also has a lot of quality problems, need to be careful. Today I will tell you about the quality inspection of wooden furniture need to pay attention to several requirements.
Material requirements for solid wood furniture: If the product is clearly marked as all-rosewood furniture, all parts and components in the product must be made of solid wood furniture, except the backing plate of mirror; If the product is clearly marked as rosewood furniture, the external parts of the product must be rosewood solid wood, and the internal, back and hiding parts of the product can be made of solid wood furniture made of other species. Material requirements for double-pack inlaid frame furniture: The texture of the tree species used on the outside of the product should be similar, and there should be no obvious difference between the same wood species for the glue piece. Needle and broadleaf materials should not be used in the same way. The plywood species used on the outside should be the same, and there is no restriction on the tree species used inside.
Requirements for Appearance
The products after processing are not allowed to have the following defects: parts made of wood-based panels should be edge banked, but not edge banked; There are degumming, bubbling, splicing at the seam and transparent adhesive after the coating material is glued; Joints of parts, joints of tenon holes, plate mounting parts and various supporting parts are loose, unseamed or broken; Product appearance inverted, round lines, rounded corners, there are uneven asymmetrical; There is a pattern line asymmetry after carving or wood processing, the bottom of the shovel is uneven, there are knife marks, sand marks; The surface of the product does not reach the fine light, the inner surface does not reach the fine light, the coarse light parts there are sawing and planing marks.
The products after finishing are not allowed to have the following defects: the whole product or complete set of products have obvious color difference; The surface coating of the product is wrinkled, sticky and paint leakage; The paint film coating has obvious fog light, white, white spot, oil white, flow hanging, shrinkage hole, brush bristles, powder, impurities, scratches, bubbling and peeling; The surface of the soft or hard covering material is concave, pitted, scratched, cracked, broken Angle and edge; The parts of the product that are not coated and the inside of the product are not clean.
After hardware fittings are installed, the following defects are not allowed: missing parts, missing parts with mounting holes; The installation parts are leaky or through-nailing; Inflexible starting of moving parts; The fittings are not firmly installed and loose; With stubble around the mounting hole.
Requirements for dimensions
Furniture size is divided into design size, limit deviation size, beginning and position tolerance size 3:
Design size refers to the size marked on the drawing of the product. Such as the height, width and depth of the product.
The main size, also known as the functional size of the product, refers to the design size of a part of the product, must meet the requirements of the standard size of this part. If the standard in the wardrobe stipulates this part, the standard stipulates that the clearance depth should be greater than or equal to 530mm, and the design size must meet this requirement.
The limit deviation size refers to the difference between the measured value of the product and the designed size of the product. The standard limit deviation is ±5mm for non-collapsible type and ±6mm for collapsible type.
Shape and position tolerance dimensions: warp degree, flatness, adjacent verticality, position difference, drawer swing degree, droop degree, product bottom unevenness and seam 8 items.
Warpage refers to the overall flatness of the surface of the product (component). According to the standard, if the diagonal length L is less than 700mm, the allowable difference is less than 1mm.
Flatness refers to the local flatness of the surface of the product (part) within the range of 0 ~ 150mm. The unevenness stipulated in the standard should be less than 0.2mm.
Adjacent verticality refers to the degree of untorque when the product (component) is rectangular in shape. The standard states that the difference between two diagonal lengths L is allowed to be less than 2mm, and the diagonal length L of the frame is ≥1000mm, and the difference is allowed to be less than 3mm. < 1000mm Allowed difference ≤2mm.
Position difference refers to the distance between a door and a frame, a door and a door, a door and a drawer, a drawer and a frame, and a drawer and a drawer adjacent to two surfaces in a product. According to the standard, the folding distance deviation between the door and the frame, the door and the adjacent surface (the distance not required by the design) is allowed to be less than 2mm, and the distance deviation between the drawer and the frame, the drawer and the door, and the drawer and the adjacent surface (the distance not required by the design) is allowed to be less than 1mm.
Drawer swing degree, droop degree, refers to the accuracy of the drawer and the frame. The standard stipulates that when the drawer is pulled out of 2/3 of the depth, the swing degree should be less than 15mm and the droop degree should be less than 20mm.
The unevenness of the product's bottom foot refers to the smoothness of the product's bottom foot on the ground. The standard states that the unevenness should be less than 2mm.
Splitting refers to the matching gap between the external opening and closing parts of the product and the frame, called splitting. The standard states that the maximum splitseam shall not exceed 2mm and 1.5mm.
Wood moisture content requirements
The standard states that the wood moisture content should conform to the area where the product is located, with an annual average wood equilibrium moisture content of + W1%. The region where the product is located refers to the standard value of the annual average wood balanced water content + W1% in the region where the product is located when the product is inspected. When ordering products, the distribution unit shall specify in the order contract any additional requirements on wood moisture content. Wood moisture content requirement is the most important index of wood furniture quality. There is a big difference between the annual average wood balance moisture content in the south and the north, which is generally 16% ~ 18% in the south, 12% ~ 14% in the north, and about 15% on average in the south and the north. Even in one region, there are great changes in the rainy and dry seasons, winter and summer.
Particleboard, MDF technical requirements
GB4897-85 particleboard technical requirements stipulate that the free formaldehyde release of particleboard shall not exceed 50mg for every 100g of particleboard. MDF technical requirements: physical performance index, ex-factory moisture content should be 4% ~ 13%; The average density of each plate shall not exceed ± 10% of the nominal density; The swelling rate of water absorption thickness shall not exceed 12%. The amount of formaldehyde released in the plate shall not exceed 70mg per 100g weight.
Physical and chemical properties of paint film
The physical and chemical properties of the film coating are measured in 8 items: liquid resistance, wet and heat resistance, dry heat resistance, adhesion, wear resistance, cold and hot temperature resistance, impact resistance and gloss.
Liquid resistance measurement, refers to the furniture surface paint film contact with a variety of possible liquid, can play a chemical reaction determination. The standard allows slight discoloration or noticeable discoloration impressions.
The determination of humidity and heat resistance refers to the determination of the changes caused by the paint film on the surface of furniture when it touches 85℃ hot water. The standard allows for nearly complete ring or ring marks and slight discoloration in the test area.
The determination of dry heat resistance refers to the determination of the change caused by the paint film on the surface of furniture when the contact temperature is 70℃. The standard specifies a nearly complete ring or ring mark and slight variation in the test area.
The determination of adhesion refers to the determination of the bonding strength between the paint film and the substrate. The standard allows the film to flake intermittently or continuously along the cut marks.
The determination of wear resistance refers to the determination of the strength of furniture surface paint film against wear. The standard states that after 2000 RPM wear, the paint film is allowed to be locally visible white.
Temperature resistance measurement, refers to the furniture surface paint film in the temperature 60℃ and temperature below -40℃ state, after the periodic test, the paint film caused by the change. The standard rules do not allow cracks, bubbling, obvious loss of light and discoloration and other defects.
Impact resistance measurement refers to the determination of the impact resistance of furniture surface paint film to foreign objects. The standard allows slight cracks on the surface of the film, usually 1 ~ 2 ring cracks or arc cracks.
The measurement of gloss refers to the ratio of the amount of positive reflected light on the surface of the film to the amount of positive reflected light on the surface of the standard plate under the same condition. According to the standard, the raw light of the film surface is 70% ~ 79%, the polishing is 65% ~ 74%, the filling hole matte is less than 14%, and the display hole matte is 25% ~ 35%. The physical and chemical properties of the paint film on the surface of dark rare hardwood furniture are also specified.
Mechanical property requirements of products
Furniture mechanical properties test items, table strength, stability and durability test; Bench strength, stability and durability test; Cabinet strength, stability and durability test; Bed strength and durability test.
Strength test includes static load test and impact test. Static load test refers to the strength test that the product may encounter under heavy load conditions. Impact test refers to the simulation test of the strength of the product under the condition of accidental impact load.
Stability test refers to the simulation test of the ability of chair and bench furniture to withstand the load in daily use and cabinet furniture to withstand the load or no load in daily use.
Durability test refers to the simulation test of the fatigue strength of the product under the condition of repeated use and repeated loading.