Presented by: De Carlo Livio Supervisor: Scheubel Maud Section: EN/MME-MM

23 May 2011De Carlo Livio  Recall  Stereomicroscope observations  Presentation of Sefar straws delivered in March 2011  Presentation of tensile test results (without weld, without coating,…)  Elongation discussion  Presentation of JINR straws delivered in May 2011  Summary of the observations Summary

23 May 2011De Carlo Livio Recall  Improvement in the weld manufacturing by Sefar (from September to December 2010)  JINR straws delivered in January 2011 have the similar behaviour to Sefar straws delivered in December 2010  Hypothesis: Correlation between the mechanism of the failure and the value of the elongation and the reduction of the cross-section in the weld Variation of the cross-section and the melted area on a short distance

23 May 2011De Carlo Livio Stereomicroscope observations Chemical treated side: Line in the middle of the welds Coating side: Sefar welds delivered in March 2011

23 May 2011De Carlo Livio Stereomicroscope observations Before the tensile test: Line in the middle After the tensile test: Line Failure Sefar welds delivered in December x Magnification 50x Magnification

23 May 2011De Carlo Livio Sefar straws delivered in March 2011 Samples SEFAR MARCH 2011 (8 samples) Sefar December 2010 (8 samples) Length (µm)635,4-719,4777,5-985,3 Thickness (µm)60,2-78,550,1-75,4 Melted area (%)40,0-54,136,2-53,3 100x Magnification

23 May 2011De Carlo Livio Method of sampling Sample AASample BB 4x Sections comparison Piece of straw 2 cm

23 May 2011De Carlo Livio Comparison of the cross-section in a short distance Cross-sectionA (%)B (%)Difference (%) SM148,653,95,3 SM242,940,02,9 SM354,146,08 SM451,044,5 6,6 Accuracy10 Cross-sectionA (µm)B (µm)Difference (µm) SM1681,2700,219 SM2656,4635,421 SM3710,7686,224,5 SM4710,1719,49,3 Accuracy15 Cross-sectionA (µm)B (µm) Biggest difference (µm) SM160,6-72,362,5-73,14,7 SM261,5-70,260,2-72,53,2 SM361,8-75,364,2-78,53,1 SM460,2-75,360,3-75,310,0 Accuracy8 MELTED AREA: LENGTH: THICKNESS: Cross-section A:Cross section B:

23 May 2011De Carlo Livio Comparison of the cross-section in a short distance Samples Before tensile test (µm) After tensiletest (µm) ElongationFailure SM1 A681,2738,156,9 Outside the weld SM1 B700,2711,010,8 Inside the weld SM2 A656,4648,1/ Outside the weld SM2 B635,4694,058,6 Outside the weld SM3 A710,7720,39,6 Outside the weld SM3 B686,2760,874,6 Outside the weld SM4 A710,1804,194 Inside the weld SM4B719,4745,626 Inside the weld Length: -> No correlation between the value of the elongation in the weld and the mechanism of the failure -> Same observation regarding the reduction of the thickness

23 May 2011De Carlo Livio Tensile test results for Sefar straws delivered in March SamplesThickness (mm) Width (mm) Load max (N) Strength max (Mpa) Failure SM1A in the clamps SM1B in the weld SM2A in the clamps SM2B in the clamps SM3A in the clamps SM3B in the clamps SM4A in the weld SM4B in the weld SM in the weld Average Standard deviation17.31 SamplesThickness (mm)Width (mm) Load max (N) Strength max (Mpa) Failure SM in the weld SM in the weld SM in the weld SM in the weld SM in the weld SM in the weld SM in the weld SM in the weld SM in the weld SM in the weld Average Standard deviation28.72 NORM ISO Graphic for SM6-SM10 Welds Tensile test with the ‘old’ tensile test machine:Tensile test with the ‘new’ tensile test machine:

23 May 2011De Carlo Livio Tensile test results Hostaphan RNK 2600 with coating SamplesThickness (mm) Width (mm) Load max (N) Strength max (Mpa) Average Standard deviation6.92 SamplesThickness (mm) Width (mm) Load max (N) Strength max (Mpa) Average Standard deviation4.02 No welded and transversal direction:No welded and longitudinal direction (roll direction): Sefar delivered in March: Test with the weld in the longitudinal direction SamplesThickness (mm)Width (mm)Load max (N)Strength max (Mpa) Average Standard deviation10.32

23 May 2011De Carlo Livio Tensile test results Comparison between straws welded with coating and without coating (Hostaphan RNK 2600) SamplesThickness (mm) Width (mm) Load max (N) Strength max (Mpa) Average Standard deviation4.36 Without coating:With coating: SamplesThickness (mm) Width (mm) Load max (N) Strength max (Mpa) Average Standard deviation3.06

23 May 2011De Carlo Livio Elongation (Tests performed on Sefar samples delivered in March) By the tensile test results: Measures of the elongation by pictures visualization: Samples 1 234Average Elongation (mm) 4,4/103,33/104,34/104,26/104,08/10 Percentage of elongation 44,033,343,442,640,8 Maximum strength (MPa) 172,6161,5172,0176,4170,6 Samples Initial distance -> Final distance (mm) Elongation (mm) Percentage of elongation Number 16->8,12,135,0 Number 26->7,71,728,3 Number 36->8,22,236,6 Number 46->8,52,541,7 Average2,135,0

23 May 2011De Carlo Livio Elongation conclusions -> Difference of about 5% between the two methods =>Extensometer is useful but not applicable in our case -> Even if an elongation of 35 % is calculated for these 4 samples, some samples have less than 10% of elongation Graphic for SM1-SM5

23 May 2011De Carlo Livio JINR straws delivered in May Stereomicroscope observation Chemical treated side Coating side Optical microscope observation Sefar welds delivered in December Dubna welds delivered in January

23 May 2011De Carlo Livio Dimensions Samples JINR MAY (3 samples) Sefar March (8 samples) Length (µm)686,9-709,2635,4-719,4 Thickness (µm)33,1-84,5 60,2-78,5 Melted area (%)40-45,940,0-54,1

23 May 2011De Carlo Livio Tensile test results SamplesThickness (mm) Width (mm) Load max (N) Strength max (Mpa) Average65.44 Standard deviation20.64

23 May 2011De Carlo Livio Summary of the observations  Straws from Sefar delivered in March 2011: Good welding aspect High values of tensile strength except for a few samples (Some dispersion in the tensile test results) No significant variation in the dimension of the cross- section and the melted area on a short distance No correlation between the mechanism of failure and the value of the elongation in the weld: Elongation and reduction of section are unpredictable

23 May 2011De Carlo Livio Summary of observations  No significant difference in the tensile strength results between PET films welded with and without coating  Elongation is difficult to determinate with accuracy because of the size of the samples and the tensile test machine errors  Straws from JINR delivered in May 2011: Welding aspect not as good as last JINR delivered in January 2011 Low values of tensile strength Only one straw was studied, need more investigations…