Topic 1: paper
Type of paper
-Paper for packing: tissue paper, oil/water proof paper
-High quality printing paper: book, calendar etc.
-Cardboard: laminated paper which increase the thickness and reinforced the strength of paper product/paper box.
-Corrugated card-board: gift box and shipped carton
Special test
-Visual check and hand feel the paper surface matched to the submitted sample.
-Smell test: If any bad smell existed, samples should be sealed into polybag and take back to office for reference.
-Humidity check (4-7% for printing paper): Visual check and hand feel the paper, if the humidity is too high, please seal the samples into polybag and take back to office for reference.
-Weight of paper/㎡: weight of paper should be not less than submitted sample or specification.
Defect
-different weight of paper used
-high humidity of paper
-wrong pages of book/note book
-press mark on paper
-wrinkle of paper
-detached of laminating of cardboard
-deformed of paper box
-color variation
-torn of paper
-color stain of paper
Topic 2: natural material (Bamboo and rattan)
Product
Rattan chair/desk/sofa, bamboo blind(curtain), bamboo blanket, bamboo chopsticks, bamboo floor board
Manufacturing process
-Bamboo and rattan------sterilization------coloring------woven-------spraying/painting
-Bamboo and rattan------sterilization------carbonization------lamination by pressing------surface polishing------spraying/painting
Special test
-Moisture content: normal spec 7-16%(included)
-split check: split bamboo or rattan to check any insect inside it.
-For chair/desk/sofa loading test(normal 135kg/seat for chair and sofa, 100kg for desk/table)
-stability check: put product on flat surface and no wobble(plug gauge≤2mm)
Defect
-Mould
-knot
-insect bore/hole
-crack
-protruded of nail end
-uneven thickness or width of bamboo or rattan strap
-broken of strap
-split of strap
-the trimming end of strap appeared at using panel
-wobble base
-great color shade (slight color variation of strap was accepted caused by different degree of absorption of dying.)
Topic 3: Plastic (polymeric material)
Type of plastic
-Thermoplastic
Can form upon the application of heat and pressure
Can be continually reformed with further application of heat and pressure
-Thermoset
Can form upon the application of heat and pressure
Can’t be continually reformed with further application of heat and pressure
Commonly used plastic
ABS Acrylonitrile-utadiene-styrene（丙烯腈-- 丁二烯 - 苯二烯）
PE Polyethylene（聚乙烯）
PP Polypropylene（聚丙烯）
PS Polystyrene(聚苯乙烯)
PVC Polyvinyl chloride(聚氯乙烯)
PMMA Polymeric Methyl Methacrylate（聚甲基丙烯酸甲酯）（压克力）
Molding method
-plastic Injection: a process of heating thermoplastic
-plastic extrusion: form product like tube, power wire
-plastic blow: form hollow article like plastic bottle
- Compression Molding: form flat article like film, plastic slice
-thermoforming: form into various shape article like dolls, drinking cup
Defect for injection
-embedded dirt
-gate flash(gate mark)
-white patches on surface
-silver mark
-uneven color
-short shot
-flow mark
-white texture
-jetting mark
-matt surface
-burn mark
-warpage/deformed
-shrinkage
-sink mark
-over/under dimension
-flashing
-discoloration
-weld line
-drag mark
-scratch mark
-delamination
-poor transparence
-brittle
-air bubble
-crack mark
-torn of product
-hole on product
Topic 4: Metal
Manufacturing process
-stainless steel---punched---trimming(rotate with steel ball 抛丸工艺)---polishing and finishing
-metal material---die casting---finishing---painting or electroplating
Special test
-Hardness check for steel after anneal process by Rockwell hardness(normally used)( 洛氏硬度计)
-Stainless steel tested by magnet: some stainless steel could be attracted by magnet and most of stainless steel could not be attracted by magnet
-Thickness & diameter of metal tube of desk/chair Thickness of metal part
-Weight of metal product
Defect
For stainless steel:
-rusty
-pin hole(sandy hole)
-press mark
-double punch
-flash mark at the edge of parts
-the metal surface not flat
-dent mark
-scratch mark
For die casting(铸造)
-short shot
-the surface not smooth
Topic 5: Metal welding
Method
-resistance welding 电阻焊(spot welding, shielded welding)
-soldering welding 锡焊
-gas welding 气焊
Special Test
-water leakage check to check whether the welded seam completed or not (. soldering welding)
-Dynamic or static loading check according the actual using of product
-destroyed test by pulling and check the welded performance(. spot welding)
-pull the welding parts with moderate force on each inspected samples
Defect
-sharp at the welding point caused by improper finishing.
-undercut (咬边)
-lack of fusion（未熔合）
-overlap（焊瘤）
-excessive penetration（塌陷）
-root concavity（根部凹陷）
-incomplete penetration（未焊透）
-burn through（烧穿）
- surface crack（表面裂纹）
-porosity（密集气孔）
-gas hole(气孔)
-cracking（裂纹）
-gas cavity in surface（表面气孔）
-arc pit（弧坑）-指焊缝表面或背面局部的低于母材的部分
-slag inclusion（夹渣）
- arc scratch(电弧擦伤)
-misalignment(错边)
-welding splash(焊接飞溅)
-twist(扭曲)-焊接过程中因为应力导致的材料变形
Topic 6: Metal surface treatment
Method
-electroplating
-polishing/finishing
-lacquering
-oil and rusty removed
-plastic coating
-painting/power spraying and heating
-heat treatment
Special Test
-hardness check(for metal after heat treatment)
-cross hatching test(百格测试)(standard: peeled area≤10%)
-hardness of paint test
Defect
For electroplating
-color stain
-electroplating peeled off
-black spot
-bubble inside(电镀层里有空气或聚集着电镀液，形状与离层差不多，一般以小面积形状出现)
-plating burn(电镀烧焦)
-pitting(镀件微小的漏镀部分,如针孔一样大小)
-matted surface(表面黯淡)
-rough surface(表面粗糙)
-haze surface(气化分子象云雾状积于产品表面)
-scratch
-void of electroplating(漏镀)
-brass show(漏黄)-没镀上铬，淡黄色的镍层暴露，通常发生在镀件的边缘和孔位四周
-chromes rain(铬渍)-产品电镀后，铬液没清洗干净，渗出后浸蚀产品表面而产生的缺陷
-crack-由于电镀层厚度太厚引起
For finishing and polishing
-rough surface
-the surface not flat
-pin hole
For lacquering
-uneven thickness of lacquering
-lacquering drip
For plastic coating
-torn of plastic coating
-scratch of plastic coating
-press/dent of coating
For painting/powder spraying
-painting peeled off
-under-spraying/over-spraying of painting
-paint drip
-uneven paint thickness
-dirty on painting
-bubble inside painting
-paint damp
-paint abrasion
-paint adhesion
-yellowish painting
-matted painting
-missing spraying
-poor painting
For heat treatment
-the hardness below the requirement
Topic 7: fabric
Method
-die cut
-scissors cut
-cut with heat
Defect of cutting
-deformed of fabric caused by improper position for cutting
-shift of pattern/printing on fabric caused by improper position of cutting
-frayed edge of fabric by poor cutting of fabric
-burn mark on fabric by careless when cut with heat
-cutting mark
Fabric defect
-coarse yarn
-snagging yarn
-broken yarn
-fly yarn
-fault fabric
-color variation
Topic 8: fabric stitching and embroidery
Method
Single stitches, double stitches, back track stitches, quilt stitches(绗缝-用长针缝制有夹层的纺织物，使里面的棉絮等固定), over-lock（锁边）, piping, binding and embroidery
Manufacturing process
Fabric---cutting---stitching---over-lock/quilt stitching/piping/binding
Defect
-broken stitches
-run off/ skipped stitches
-loose stitches
-incomplete stitches
-open seam
-improper seam density
-crooked stitches
-loose thread of embroidery
-gap at the embroidery
-double stitches
-poor stitching
Topic 9: wood
Manufacturing method
-lathe(车床加工)
-milling(平磨)
-drilling(钻孔)
-groove and tongue(开槽和榫舌)
Manufacturing process
Wood material---cutting into proper shape---groove and tongue cutting---assembly of parts---precise cutting---surface finishing---lacquering---polishing
Special test
-Moisture content check (normal standard ≤16%)
-Split check: split the wood to check if there is insect inside the wood.
-assembly check
defect
-Mould
-knot/death knot
-insect bore/hole
-crack
-protruded of nail end
-surface not smooth/rough surface
-gap between joint of parts
-splinter
-hi-low of assembly parts
-dent mark
-scratch mark
-cutting mark
-great color shade (slight color variation of strap was accepted caused by different degree of absorption of dying.)
Topic 10: ceramic/glass
Method
Rotate mold(转模)
Ceramic: Grinding of clay---metal removed---mixed with formula---molding---
glazing---assembly with decorate---burn---stuck with pattern printed film---burn---grinding of base
Glass: Grinding material---mixed with formula---glass liquid---molding--- anneal---grinding edge
Special test
-water leakage test
-stability check
-thermal shock test for glass: putting in hot water(50℃ relative to cool water, example: cool water 20℃, so hot water should be 70℃)10mins, then put into cool water 10mins, no crack or broken
-broken glass test for tempered glass: the glass fragment not sharp and hurt hand when touching.
-transportation drop test
Defect
For both:
-crack
-chipped edge
-broken
-deformed
-wobble base
-warpage
-black spot
-uneven wall thickness
-sandy surface
-dirty/impurity inside material
-part line
-assembly of decorative not properly or slanted
-gap at joint of decorative
-the wall surface not flat
-incomplete of pattern
-wrong position of pattern
For ceramic:
-incomplete glazing
-uneven glazing
-glaze dripping
-burn mark
For glass:
-flow mark
-bubble inside glass
-broken bubble inside glass
Topic 11: printing/painting/coloring
Method
-silk screen printing, tempo printing(移印)，spraying, hand painting, hot stamped, dying
-before the surface coating, it should be treated properly such as oil or grease removed. Otherwise the strength of paint adhesive would be reduced.
-General terms for printing:1 color(C) printing, 2 colors printing, 4colors printing
Manufacturing process
The treated object---oil or grease removed---printing/painting/hot stamped---heat to enhance the adhesive strength of paint
Special test
Tape and rub test
Defect
-double printing
-smeared
-scratch mark
-incomplete printing
-out of register(套印不准)
-over spraying/under spraying
-uneven painting/printing
-paint peeled off
-poor painting/printing
-color stain
-dirty/impurity inside painting/printing
Topic 12: small part
Method
-small part cylinder
Topic 13: electronic concept
Checking Method
-battery voltage checking
check the voltage of battery included in the product
-battery compartment fitting test
Check the client’s particular battery that can be fitted into the battery compartment properly and also maintain the normal operational of product performance.
-current check
Check the operation and/ standby(备用) current complied with the client’s requirement.
-polarity check
Check the polarity of battery placement marked inside the battery and specified on the instruction which same as the actual installation of battery.
-reliability check
Check the reliability of a electronic product after for a long time operation.
-adapter check
Ensure the DC and AC current supply not functioned at the same time.
