Dear Mr Hang ! It is very nice to hearing you from USA come to
VietNam (PVTEX company ) as consultant of textile service
.Regarding to lab for testing filament part (POY/DTY ), I would
like to introduce the list of ourtesting filament which include
testing method, instrument, standard specification of POY, DTY
products were published. First of all, testing methods of POY &
DTY. We test properties of POY and DTY according to standard in the
world. Denier of POY, DTY : JISL 1073 : 1999Tensile of POY, DTY :
JISL 1073 : 1999Unevenness of POY : JISL 1073 : 1999Boiling water
shrinkage of DTY : JISL 1073 : 1999Crimp of DTY ( crimp contraction
& crimp stability ) : ASTM D 4031OPU of POY/DTY : instrument
instruction.Interlace of DTY : instrument instructionNumber of
filaments : JISL 1073 : 1999Besides , all of instruments for
measuring filament include :1. Auto-Wrap reel (DL-3208 )- Korea :
denier of filament2. Instron 3343 (3343)- USA : tensile of
filament3. Unevenness tester ( Ket-80V/C )- Keisokki Japan : U% of
POY4. Analytical balance (HR-202i )- AND- Japan : the weight of
yarn5. Entanglement Counter (EC-4 )-Osaka -Japan : interlace of
DTY6. Spin finish testing ( OPU- 500 )-Technomac Korea : OPU of
POY/DTY7. Extraction instrument China (manual testing with ethanol
) : OPU of POY/ DTY8. Thermal bath (BW-1010H) Korea : boiling water
shrinkage of DTY9. Kin Write Machine Eiko-Korea : knitting DTY10.
Crimp tester-modification of TEXTECHNO machine- VietNam : crimp of
DTY
The third is specification of POY/DTY were published. I will
give you in the meeting For testing filament (POY/DTY), I have many
trouble with method, result, analyse report.Some method of tesing
filament still do not via any standard , only machine instructions.
These are OPU of filament, interlace of DTY. Does it necessary
follow any standard ?Do you have any document about testing
procedure of OPU POY & DTY ? For dye up take of DTY in the lab,
we lack of method, standard. Do you have any experience about this
? If you do not mind, pls send the documents related to this area
?With calculation after testing, we do not have clear documents .
Hence, I would like to ask you more clear about calculation. One of
these is M 0.8. It has too much meaning to understand. For example,
you can in PVTEX specification of DTY OPU= M 0.8 is grade AA. M=
2-3.5. If we measure 6 bobbins of DTY, the oil content of these
bobbins from 2-0.8=1.2 to 3.5 + 0.8 = 4.3 . They are OK. Another
way, if the aim of process engineer is OPU of DTY is 2.5. That
means when we measure, the OPU has to from 2.5-0.8 to 2.5 +0.8. If
any bobbin outside of this range (1.7; 3.2 ), it is not OK. If 6
DTY bobbins were tested, the results are the first one =2.3, 2.4,
2.5, 3.1, 3.2, 3.3.We caculate average of this group = (2.3 + 2.4 +
2.8 + 3.1 + 3.2 + 3.3 )/6=2.85The range (-)= 2.3-2.85 = -0.55The
range (+)=3.3 -2.85 = 0.55 After that, we compare first all results
of oil pick up belong 2-3.5. it is acceptable.Then the range =
(-0.55 ; 0.55 ) belong (-0.8 ; 0.8 ). It is also
acceptable.Finally, M is average value of oil pick up which we test
in the group. Normally, the process engineer set up parameter order
to achived the range from 2-3.5. If we measure oil content, the
average is 2.2 . All of bobbins results are from 1.4 to 3. It is
acceptable, it is grade AA. Any value is outside 1.4 to 3, it is
not acceptable.Can you choose one of them ? What is correct ?Until
now, after testing , we get the results . Then we compare the value
with standard and evaluate the value. They belong grade AA, A, BWe
have no tool to jugde all test result is correct or not ?
reliability of test results ? What other application of CV, Q95%,
S, range ? Does lab need a tool for quality control ? Does it
statistic quality control ?These queries really need you answer. I
hope we will discuss more effectiveness in the meeting.Best
regardsQuynh Trang(Lab physical engineer )
