Failure analysis of polyoxymethylene product using scanning electron microscope, thermal and processing analysis
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The document is about the Indonesian Polymer Journal, Volume 17, No. 1, 2014, which includes articles on polymer synthesis, modification, and characterization. It addresses the failure analysis of polyoxymethylene products and their mechanical properties, highlighting the importance of processing conditions on material performance and structural integrity. The journal also emphasizes the relevance of polymer advancements for researchers and industries in Indonesia.
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REFERENCES
[1]. DuPont, 2008, Problems with Hot Runners.
[2]. DuPont, DuPont™ Delrin® acetal resin
Molding Guide:TechnicalInformation.
[3]. ARCHODOULAKI VM, LUFTL S,
KOCH T, SEIDLER S, Property changes
in polyoxymethylene (POM) resulting from
processing, ageing and recycling, Pol Degrad
Stab, 92 (2007) 2181-2189
[4]. MALLOY RA., Plastic Part Design for
Injection Molding: An Introduction, Hanser
Gardner Publications Inc. (1994)
The authors are grateful to The Center for
Polymer Technology for supporting this project.
ACKNOWLEDGMENTS
Extemalload onthe surfaceofhighly frozen-
in stress part due to improper setting process tend
to form brittle on the surface and layer between
the surface. The inner core part resulted in crack
beginning from the outer surface part and
propagate toward the entire part of thickness
CONCLUSION
Figure 7.Delamination form on the fracture sur-
face, supposed due to layer formation between
the skin and the core.
Figure 6. Different pattern surface fracture
Proven sample.NG sample.
Figure 5. Crack around the gate (bottom) and
(top) ofNG sample.
cooling rate. The setting process also tend to
increase the frozen-in stress orientation on the
surface near to the gate (see Figure 2). This
supposed cause two layers formation, surface part
with highly frozen-in stress orientation (smooth!
brittlesurface-patterncrack); delamination formed
and ductile fracture mode in the inner core part.
This is in accordance to the information received
about the cyclingtime reduction duringproduction
(Figure 7).
Frozen-in stress in microstructure and the
external load applied from outer surface has
resulted in initial crack and propagate to entire
thickness product.
Failure Analysis on PolyOxyMethylene Product Using Scanning Electron Microscope, Thermal and Processing
Analysis (R. Wijaya)](https://image.slidesharecdn.com/failureanalysisofpolyoxymethyleneproductusingscanningelectronmicroscopethermalandprocessinganalysis-160530060628/85/Failure-analysis-of-polyoxymethylene-product-using-scanning-electron-microscope-thermal-and-processing-analysis-8-320.jpg)
Failure analysis of polyoxymethylene product using scanning electron microscope, thermal and processing analysis
- 1. ALAMAT REDAKSI Pusat Penelitian Fisika - LIPI Jalan Sangkuriang / Cisitu No.211152DKomplek LIPI Bandung 40135 Telepon (022) 2503052, 2504826, 2504833, Fax (022) 2503052 e-mail: www.jurnal.lipi.go.id/situs/mpi ?rtajaCa/i POLIMER INDONESIA Indonesian Po(ymer Ioumai Vol. 17, No.1, 2014 ISSN 1410-7864
- 2. REDAKTURPELAKSANA EXECUTIVE EDITORIAL Dra. Sri Pujiastuti, Dra. Rina Ramayanti, Dra, Mirah Yulaili, Yualina Riastuti Partiwi, Indriyanti, M.Sc Penerbit : Perhimpunan Polimer Indonesia (HPI) Terbit pertama kali : Januari 1998. Frekwensi terbit : Enam Bulanan Alamat Redaksi/Editorial Address' Pusat Penelitian Fisika - LIPI JI. Sangkuriang/Cisitu No. 211l54D Kompleks LIPI, Bandung 40135 Telepon : (022) 2503052, 2504826, 2504833, Fax: (022) 2503050 e-mail: www.jumal.lipi.go.id/situs/mpi MITRA BESTARI REVIEWER Dr. Rike Yudianti, LIPJ Dr. Sudaryanto, BATAN Dr. Edy Giri Rachrnan Putra, BATAN Dr. Myrta Karina, LIPJ Ir. Wiwik Pujiastuti, M.Sc, Kemenperin STAF EDITOR EDITORIAL STAFF Dr. Asep Riswoko, BPPT Dr. Emil Budiarto, VI Dr. Eniya Listiani Dewi, BPPT Dr. Darmawan Darwis, BATAN WAKILKETUA Co-CHAIRMAN Dr. Agus Haryono, LIPJ KETUA CHAIRMAN Drs. Sudirman, M.Sc. APU, BATAN DEWAN REDAKSI EDITORIAL BOARD PENANGGUNGJAWAB MANAGING EDITOR Ketua Umum Perhimpunan Polimer Indonesia (HPI) DEWANPENGARAH STEERING BOARD Dr. Suharto, Dr. M. Sugandi Ratulangi, Dr. Ir. A. Zainal Abidin, Dr. Wiwik S. Subowo, Dr. Sunit Hendrana, Dra. Nursyamsu Bahar, M.Sc., Dr. Rochrnadi, Ir. Lies A. Wisojodharmo, Dr. Cynthia L. Radiman, Prof. Basuki Wirjosentono, Ph.D DEWAN PENASEHAT INTERNASIONAL INTERNATIONAL ADVISORY BOARD Prof. Hiroyuki Nishide, Waseda University, Japan Prof. Dr. Takashi Nishino, Faculty of Engineering - Kobe University, Japan Prof. John Forsythe, Monash University, Australia DEWAN PENASEHAT NASIONAL NATIONAL ADVISORY BOARD Prof. Dr. N. M: Surdia, M.Sc., Dr. Roestamsyah, Prof. Dr. Tjia May On, Prof. Dr. Suminar S. Achmadi MAJALAH POLIMER INDONESIA Indonesian Polymer Journal Vol. 17, No.1, 2014 ISSN 1410-7864
- 3. Dewan Redaksi Komentar, kritik dan saran yang membangun atas penerbitan jurnal ini, baik terhadap substansi maupun redaksi, sangat karni hargai Semogajurnal edisikaliini dapatmemberikan manfaat bagi peneliti, pelaku industri dan juga litbang serta perguruan tinggi di Indonesia terkait sintensis, modifikasi, proses dan karakterisasi bahan polimer. Selain artikel terkait sintesis dan modifikasi untuk proses dan aplikasi polimer, karakterisasi khusus dananalisis kegagalan bahanpolimer sangatpenting dilakukanuntuk dapat mempredisikan sifat-sifat bahan polimer tersebut. Peningkatan sifatmekanik untukberbagaiaplikasijuga telah ditunjukkandaribahan komposit polimer dengan memanfaatkan serat alami seperti bambu serta tandan kosong kelapa (empty fruit bunch). Dalam proses pengolahan bahan polimer, penambahan senyawa aditifhidrazin sangat dibutuhkan dalam menentukan viskositas konstan karet sebelum proses pengunyahan (mastication) pengolahan karet mentah. Sedangkan penggunaan perekat dari kopolimer resin akrilik yang meliputi kekentalannya, suhu serta waktu pemanasan dalarn proses penempelan serat nylon 66 terhadap bahan kain kapas telah meningkatkan ketahanan gosok, kekakuan, kekuatan sobek, kekuatan tarik dan mulur kain. Penggunaan polimer untuk kebutuhan penyediaan sumber energi menjadi perhatian yangpentingakhir-akhir ini.Untukitu, sintesispolimerpoliimida yangmemiliki gugus akhir maleat dari maleimid dan bismaleimid dan karakterisasinya telah berhasil dilakukan untuk digunakan sebagai bahan membran elektrolit pada sel bahan bakar penukar proton. Dalam Volume 17,No. 1ditampilkan 1buahartikelterkaitdengan sintesispolimer, 2 buah artikel tentang modifikasi serat alam menjadi bahan komposit dan 2 buah artikel mengenai proses peningkatan kualitas bahan polimer untuk proses lanjutan sertaaplikasi pengunaannya, serta 1buah artikelkhususterkaitkarakterisasisertaanalisisbahanpolimer. KATA PENGANTAR VoL17, No.1, 2014 ISSN: 1410-7864Majalah Polimer Indonesia _R __
- 4. 11 lndeks Pengarang 41 lndeks Kata Kunci 40 Synthesis and Characterization of Polyimide End Group Maleic as Membrane ofElectrolyte in Proton Exchange Membrane Fuel Cell Sudirman, E. Budianto, E. L. Dewi, R. Yudianti and JOinting 33 Pembuatan Kain Berbulu dengan Metode Mekanik Elektro Statik , Kuntari Adi Suhardjo 20 Failure Analysis on Polyoxymethylene Product Using Scanning Electron Microscope, Thermal and Processing Analysis R. Wijaya, A. Rifathin and B. Afrinaldi 16 Effect of Ultrasonic ation Process from Unbleached Empty Fruit Bunch Pulp Reinforcing with PolyvinylAlcohol Wida B. Kusumaningrum, lsmadi and Sasa Sofyan Munawar 11 Mechanical Properties of Recycled Polypropylene and Bamboos Fibers Composites Kurnia Wiji Prasetiyo, LilikAstari and M Yusram Massijaya 6 Application ofHydrazine Compound to Produce Constant ViscosityRubber Afrizal Vachlepi, Didin Suwardin, Mili Purbaya and Sherly Hanifarianty . 1 Daftar lsi 11 Kata Pengantar (j)aftar lsi ISSN : 1410-7864Indonesian CPofymerJourna{ Vol. 17, No.1, 2014MAJALAH POLIMER INDONESIA
- 5. 16 of 175 °C and 162-173 °C respectively. POM is semicrystalline polymer with 75-85 %degree of crystallinity. As engineeringplastics, PolyOxyMethylene (POM) has two types, homopolymer and copolymerwhich differ slightlyinitsmelting point INTRODUCTION Kala Kunci: Analisis retak, Polioksimetilen,Derajat kristalinitas,Termal ANALISIS RETAK POLIOKSIMETILEN MENGGUNAKAN SCANNING ELECTRON MICROSCOPE, ANALISIS TERMAL DAN PROSES. Analisis retak dilakukan menggunakan Scanning Electron Microscope (SEM) danDifferential Scanning Calorimetry (DSC). Perbandingan karakteristik bahan antara sampel NG dan standar dilakukan. Analisis SEM menunjukkan bahwa permukaanretakan pada sampelNG cenderung lebihmudah patahdibandingkanretakan pada sampel standar.Retakan diduga berasal dari vicinity gate location. Derajat kristalinitas patahan NG adalah 59,6 % lebihrendah dibandingkandengan sampel standard 65,8 %. Tidak ada perbedaan yangjauh antara suhu leleh (164°C) dengan suhu kristalisasi (146 0C).Perubahan danjalur patahan disekitar gate location berpotensi menyebabkan retakan selama proses. Berdasarkan hasil SEM dan DSC, retakan diduga berasal dari setting proses yang tidak tepat yang menghasilkan derajat kristalinitas yang rendah danJrozen-in stress. Beban luar yang diterima juga merupakan salah satu penyebab terjadinyaretakan. ABSTRAK Keywords: Failure, Polyoxymethylene,Crystallinitydegree, Thermal FAILURE ANALYSISON POLYOXYMETHYLENE PRODUCT USING SCANNING ELECTRON MICROSCOPE, THERMAL ANDPROCESSING ANALYSIS.Failureanalysisof PolyOxyMethylene(POM) product were carried out using Scanning Electron Microscope (SEM), DifferentialScanningCalorymetry(DSC) and parameter processrelated factors. Comparationof the failuremode and material propertiesbetween the NG and Provensamplesweretaken. SEM analysis showed that failure surface tent to have more brittle fracture compared with the proven sample failure.The origin of crackwaspredictedfromthe vicinityof gate location. Degreeof crystallinityof failure part was 59.6%, which was lower than the proven products (65.8%). Melting (Tm) and CrystallizationTemperature(Tc)showedno significantdifferences,164°Cand 146°Cformeltingand crystallizationtemperature respectively. Whiteningand molded streamflowwere shown around the gate locationwhich potentiallycaused molded in stress and crack propagation during application in chemicalenvironment.Externalload also found inthe vicinityof crack. Based on the SEM,DSC and process related factor analysis, the failure of product was supposed due to the combination of impropersetting process which resulted in lower degree of crystallinityand frozen-in stress around the gate and external load received have triggered the crack on product. ABSTRACT Accepted: 13December 2013Revised: 13November 2013Received: 19July 2013 R.Wijaya, A.Rifathin and B. Afrinaldi Centerfor Polymer Technology(STP)- BPPT Kawasan Puspiptek;Serpong 15314, TangerangSelatan FAILURE ANALYSIS ON POLYOXYMETHYLENE PRODUCT USING SCANNING ELECTRON MICROSCOPE, THERMAL AND PROCESSING ANALYSIS Vol.17,No.1, 2014, hal: 16-19 ISSN: 1410-7864Majalak Polimer Indonesia
- 6. 17 approximately 10mg,placed intoalumina crucible. The alumina crucible was then placed in Thermal Gravimetry Analysis (TGA) instrumentation. The test is conducted under temperature program as follow: Firstly the sample was heated up from temperature of 50 to 600 DC under nitrogen gas. The temperature was held at 600 DC for 5 minutes nitrogen gas environtment. The temperature was then continuing heated up until 900 DC under oxygen gas. The rate of heating was 10 DC per minute, and the nitrogen/oxygen gas flow rate was 50 mL per minute. After measurement was completely finished the TGA-thermograms were analyzed. DSC821-Mettler Toledo was used to measure the thermal properties ofthe samples such as melting point, glass transition temperature, thermal history, degree and the growth' of crystallinity. The test was conducted according to ASTM D 3418-2003. Sample was cut and weighed approximately 20 mg, placed into Al crucible. The Al-cruble was then placed in DSC sample chamber. The test is conducted under nitrogen gas environment with temperature program of "heating-cooling-heating" as follow: the temperature program was started from 30 to 200 "C, then cooled down to -100 °C and finally heated up to 200 °C. The rate of heating was 10 -cper minute, and the nitrogen gas flow rate was 50 mL per minute. After the test was completely finished the DSC-thermograms were analyzed. Figure 2. FTIR test results of NG and proven samples i I ~' -,- ._ The failure POM product was received as failured-part applied in motor cycle. To identify the main material, possible degradation and semi quantitatively analysis the material composition, we used FT-IR-Bruker Tensor 27, ATR method. Placed the sample on ATR crystal. Touched the sample surface perfectly on the crystall by setting down the stainless steel tip. Samples analysis were carried out by OPUS software (Figure 2). To measure the material composition. The test was carried out in accordance to ASTM 1131-1998. Sample was cut and weighed EXPERIMENTAL METHOD Figure 1. Frozen-in orientation (top) and poten- tial shrinkage near to the gate (bottom) t Edge p.le ~I I '>:~I/ :/'_____ POM are generally processed in injection molding with special runner system. Hot runner types are commonly applied in POM. Wrong selection of runner type could result in loss of pressure during process. Toovercome the pressure reduction, operators usually increase the temperature. Unfortunately this could severe the material to degradation. The melt entering the cavity will form orientation during fillingphase. And melt adjacent tothemoldwillfreeze:firstandleadtohighinterfacial shear stress between the melt and the solid layer. This frozen-in orientation will continue to develop during holding pressure in order to compensate for volume shrinkage, particularlynear the gateregion of the part (Figure 1). However, fast cycle time during production is required. Those process parameters influentthemicrostructureofpartwhich also affect the properties and performances. In this paper, we analyzed the effect of settingprocess tothermalproperties as contribution ofpotential causes of failureby observing the crack pattern on the failed surface. Failure Analysis on PolyOxyMethylene Product Using Scanning Electron Microscope, Thermal and Processing Analysis (R. Wijaya)
- 7. Figure 4. DSC test results ofNG (a) and proven (b) samples on cooling phase after first heating '---';"::;';';;"j , _______ _.'._H.__ ,'_"' __ . ..,_.__ _._ __ ,_.._' .. ~: I " to ~,(;~. ! ....~ ..,. .~--.....--.......~-----"":;-;.;~=.~~-·-=·,·~--""""u=·~=,:=,;~~.:;;::~:.;.~- ~-::::;i:'!~;~~_,.:... _-6l"l.'Ii ,)'U~'.ll':<;;:.~ . :.;.~ / ! :1(a) --_ .._----,._-------, :___ ._" .1 Figure 3. DSCtest results ofNG (a) and proven (b) samples on heating phase --_.•._---------.. '" ,., "" ..._.",,';j : ~'"':'...:...:"._-;=-~--.._--- ...~--.-.-~.-.-.-------."-.'--.-----.--..-. ~ ._..._( -.•_..- , :.!:-<"",~,-, 18 Degree of crystalinity of the NG sample showalittlebitlower(Figure3),whilecrystalization rate is higher and the crystal distribution (which indicates the size of crystaline) is lower than the proven one. (Figure 4) Figure 5 shows crack that occured near to the gate. Smoothlbrittle pattern of crack found on the cracksurfaceofNG sample. Ontheotherhand, the fracturepattern of proven sample showedmore ductile (see Figure 6). Crack supposed initially occured from the outer to the inner surfaces and wascaused by the extemalload.Thiswas shownwithwhiteningcircle- like defect on outer surface (see Figure 4). Lower degree of crystallinitywhich isfound on the NG sample is usually related to high the Test Methods Proven sample NG sample FTIR, polymer type Polyoxymethylene Polyoxymethylene TGA, % polymer 100 99.99 DSC Heating phase Melting point (OC) 164.51 164.06 Delta H (Jig) 156.1098 149.6349 Crystallinity (%) 65.8 59.6 Cooling phase Temp ofCrytalline 145.80 146.45 CCC) Crystalline rate 0.31 0.29 (min) Crystalline distr 0.38 0.32 (min) Table 1. Comparative test results of NG and proven samples. .No significance differences on spectra of NG and proven samples. Both show the POM materialaccordingto OPUS softwareanalysis.No degradation is indicated both samples. Table 1 shows the results of FT-IR, TGAand DSC. RESULTS AND DISCUSSION ScanningElectron Microscopy JEOL JSM- 6510LA was applied to observe the fracture surface in order to see the crack initiation and propagation. Inorderto analyze the root causesof failure, the comparative method between the failure and the new proven product are carried out on the test results. VoL17, No.1, 2014, hal: 16 -19 ISSN: 1410-7864Majalah Polimer Indonesia
- 8. 19 REFERENCES [1]. DuPont, 2008, Problems with Hot Runners. [2]. DuPont, DuPont™ Delrin® acetal resin Molding Guide:TechnicalInformation. [3]. ARCHODOULAKI VM, LUFTL S, KOCH T, SEIDLER S, Property changes in polyoxymethylene (POM) resulting from processing, ageing and recycling, Pol Degrad Stab, 92 (2007) 2181-2189 [4]. MALLOY RA., Plastic Part Design for Injection Molding: An Introduction, Hanser Gardner Publications Inc. (1994) The authors are grateful to The Center for Polymer Technology for supporting this project. ACKNOWLEDGMENTS Extemalload onthe surfaceofhighly frozen- in stress part due to improper setting process tend to form brittle on the surface and layer between the surface. The inner core part resulted in crack beginning from the outer surface part and propagate toward the entire part of thickness CONCLUSION Figure 7.Delamination form on the fracture sur- face, supposed due to layer formation between the skin and the core. Figure 6. Different pattern surface fracture Proven sample.NG sample. Figure 5. Crack around the gate (bottom) and (top) ofNG sample. cooling rate. The setting process also tend to increase the frozen-in stress orientation on the surface near to the gate (see Figure 2). This supposed cause two layers formation, surface part with highly frozen-in stress orientation (smooth! brittlesurface-patterncrack); delamination formed and ductile fracture mode in the inner core part. This is in accordance to the information received about the cyclingtime reduction duringproduction (Figure 7). Frozen-in stress in microstructure and the external load applied from outer surface has resulted in initial crack and propagate to entire thickness product. Failure Analysis on PolyOxyMethylene Product Using Scanning Electron Microscope, Thermal and Processing Analysis (R. Wijaya)