冷冻集装箱检验规范

1、,A) First Shot Blasting,1,Must check if any oil or other contaminate on material surface, oil must be removed by solvnet,2,Blasting and 1st priming quality are as below:, - Blasting density at least at 90 %, - Blasting cleanness at Swedish Standard SA 2.5 3 ( use paint suppliers template samples, fo

2、r comoaration, - Blasting Profile between 25 to 45 microns,3,Shop primer must cover the full surface by average 10 microns of primer, no holiday is allowed, ,B) Cutting and forming,1,Any parts with crack along the formed edges, out of dimension tolerance, incorrect profile or ,mis-alignment during f

3、orming, bending or pressing should be rejected.,2,Burrs at “free” edge like at corner post J bar, front / rear sill lower, bottom side rails, x-members, ,G-neck tunnel rails must be removed,3,Special attention to shearing edges of side panel / lining, roof panel, as it will greatly affect ,TIG butt

4、welding quality,C) Door assembly,1. Aluminum frame installation:,Check the diagonal difference of aluminum frame less than 1mm and all of angle of the ,corners are 90, drill holes through the aluminum frame according to the hole pre-punching ,on the panel and pay attention to the workers shall keep

5、vertical to panel and not damage ,the painting, drilling particals must be removed.,2. Door assembly,1) The nuts shall be tack welded by 2 points of minimum 5mm in size to press plates ,2) The bolts should be protected during welding on of the nuts. Bolts and nuts must not be, welded together,3) Bol

6、ts must be fastened to specified torque to avoid foam leakage.,4) All welding slags and soot must be removed before primer coating.,D) Front and Rear Frame Assembly,1,Gap between corner post, sill / header to conrer casting must be evenly distributed at both ends,and less than 3mm,2,The corner casti

7、ng weld bead size at top corner casting underneath to the header plate should ,be max 4mm. There is a risk of weld bead obstructing the door gasket at that area,3,The gasket contact surface must be kept flush including the 4 corner joint, - 4 corner welding joints protruding beads need to be grinded

8、 in way of gasket,4,Remove welding slag and spatter, eliminate visible weld defect at each individual station,Welding spatters, especially at the area where PVC covers are inserted in main assembly must ,be removed,5,Rear frame diagonal difference must be checked and be kept within 3mm difference,In

9、ternal height and width difference within2mm,E) Base assembly,1,Check b/s rail straightness, alignment must not beyond 3mm,2,Base panel must be equally overlapped on loading x-members.,3,Pay more attention on welding of base panel to G-tunnel rail, b/s rail, omega shape and ,overlap can be found oft

10、en.,4,Grind the welding seam to remove spatters (pay attention to the spatters on welding seam), ,excessive welding bead and dark smoke and some burnt painting shall be ground as well,5,Clean the foaming contact surface by mop and wire brushing to remove welding soot, dust and ,some particles,F) T b

11、oard assembly,1,T bar front end must be burnished to avoid sharp edge damaging USDA cables,2,Must minimize gap between T boards for better TIG welding quality,Welding seams must be free from contamination,3,Any hot cracks especially at end and welds joint, should be solved by reduce welding speed an

12、d, decrease welding current,4,Stringers must be tightly pressed onto T boards before stitch welding, welding soot must be ,removed by wiring brushing,5,Must clean off contamination before flaming and foam bond application.,G) Panel assembly,1,Check and clean oil by solvent before TIG butt wedling,2,

13、make two panels joint together tightly by the screwdriver (the screwdriver sharp edge shall be ,ground to obtuse and can be used only on the top and bottom ends,3,Proper welding parameter must be adopted to avoid undercut or burnt through,4,The diagonal difference of all panels after welding shall b

14、e less than 2mm,5,Welding of side lining to bottom scuff liner, - Jigs must press scuff liner tightly onto side lining, gap is not allowed., - Adjsut welding parameter to avoid undercut or burnt through,6,Spot welding of post / stringer to side panel / roof panel, - Protruding height on post should

15、be 0.50.8mm, to obtain enough strength, - Replace brass templete timely ,7,Side assembly,1) Before top and bottom rails are welded to the side panels, burrs and edges at rail welding , area must be grinded,2) Top/ bottom side rails must be tightly pressed onto side panel while welding, no gap is all

16、owed,3) The side panel should be protected during the welding process against weld spatters,4) The assembled side walls difference in diagonals should be kept within 5mm,H) EP primer application,1) Foaming face should be checked cleanliness by dye ink, standard: higher than #42.,2) Note primer port

17、life is 8 hours, meaning every bucket opened must be used up in 8 hours,3) Base paint, hardener and thinner must be mixed according suppliers instruction, and sufficient, stirring should be taken before using,4) The recommended DFT is 20 microns, should be kept below 30 microns without holiday, , hi

18、gher thickness will lead to weak adhesion and consequently foam de-lamination,5) Foaming can only be done after 8 hours drying. So workers were required to record working time , for every bundle of panels,6) After drying for 8 hours and before foaming, EP primer adhesion strength to panels must be ,

19、 checked. which should be higher than 2.0N/mm2,I) Foam bond YJ-9000 application,1. Foam boand should be applied in webby shape, Coverage should be over 90%,2. 120160g/m2 should be uniformly distributed, either too much or less will deteriorate foam , adhesion either less or too much application will

20、 affection foam adhesion.,J) Foaming,1, Before foaming clean the foaming contact areas by air blowing and no contamination left on panel,2, Ventilation holes on foaming wood mould must be confirmed functional,3, After foaming, remove the foaming mould, and the workers shall pay attention to avoid da

21、mage the ,panel. And put some sealant where the foaming crack from the panels to avoid foaming delamination ,of 2nd foaming,4,Check foaming quality and all of the foaming problems like void and delamination and low density , shall be repaired,5,Check if there is some foaming leakage in the welding s

22、eam and repair these problems,6,Clean off foam leakage at later welding area., 7,Foam density must be checked record regularly, adjust injection volum if necessary.,8,Roof lining stringer must be pressed tightly to lining, must confirm while preparing mould,K) Main assembly,1,ISO dimensions must be

23、guaranteed by stable jigs / fixtures, top / bottom side rails straightness,must be controlled within 3mm.,2,Check the welding area of bottom side rail upper and lower contact area, side panel to both corner ,post, roof panel to top side rail / front / rear header without contamination like primer, f

24、oaming leakage, zinc rich primer, and mask tape etc,3,Roof panel / side panel must be pressed tightly onto rails / corner post while welding.,4,Pay attention to welding quality, the welding seam cannot over the casting and shall avoid pinhole ,and irregular welding,also to remove spatters,L) Painting,1,Box must be checked carefully to remove oil, foam leakage or other contamination before 2nd ,blasting,2,Ensure 2nd blasting quality,3,Ensure the zinc primer D