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Wiwiek Utami Dewi
Lembaga Penerbangan dan Antariksa Nasional (LAPAN)
Aerospace Engineering Chemical Engineering, Chemistry & Bioengineering Computer Science & IT Mechanical Engineering Physics

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Effects of Bleeder Schedule to Fiber Mass Fraction and Composites Surface Topography on Wet Lay-up Manufacturing Process Wiwiek Utami Dewi
Jurnal Teknologi Dirgantara Vol 19, No 1 (2021)
Publisher : National Institute of Aeronautics and Space - LAPAN

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30536/j.jtd.2021.v19.a3572

Abstract

The thermal protector materials of the rocket’s motor are made by a wet lay-up manufacturing process. Since the fiber mass fraction of the product is low, several experiments were conducted to solve this problem including changing the type of the epoxy resin and selecting the most suitable bleeder schedule. Bleeder cloth application results in increasing the fiber mass fraction. The fiber mass fraction of thermal protector material manufactured by hand lay-up can reach a maximum of 56,78%, whereas vacuum bagging can reach a maximum of 66,43%. Peel ply and breather fabric combination are the best bleeder schedule for the hand lay-up method meanwhile perforated release film and breather fabric are the best bleeders for the vacuum bagging method. Composite surface topography obtained from peel ply is visible on the surface. The imprints of the nylon peel ply weave are visible through SEM analysis. Meanwhile, the surface topography obtained from the perforated release film is not visible. The vacuum bagging method helped reduce the number of voids and ductile polymer fractures from the composite surface. This paper recommends peel ply usage in the thermal protector manufacturing process to replace the sanding or filling method that the author use nowadays.
DEKOMPOSISI TERMAL PROPELAN KOMPOSIT BERBASIS AMONIUM PERKLORAT/HYDROXY TERMINATED POLYBUTADIENE (AP/HTPB) (THE THERMAL DECOMPOSITION ANALYSIS OF AMMONIUM PERCHLORATE/HYDROXYTERMINATED POLYBUTADIENE (AP/HTPB) COMPOSITE SOLID PROPELLANT) Wiwiek Utami Dewi; Yulia Azatil Ismah
Jurnal Teknologi Dirgantara Vol. 14 No. 1 Juni 2016
Publisher : National Institute of Aeronautics and Space - LAPAN

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30536/j.jtd.2016.v14.a2944

Abstract

Thermal decomposition process of AP/HTPB solid propellant type RUM, 450 and 1220 were investigated by DTG60 (Differential Thermogravimetric) with operational parameters: temperature 30 – 400oC, nitrogen flow rate 50 ml/min, and heating rate 2.5 C/min. Thermal decomposition analysis will be the first step of decomposition kinetics research in determining life time of the propellant. TGA curve of propellant RUM was found to be two staged meanwhile the thermal decomposition of propellant 450 and 1220 has become one staged. The DTA curve/thermogram of propellant RUM show the formation of intermediate product before full-length decomposition. Unlike propellant RUM, DTA curves of propellant 450 and 1220 do not show the formation of intermediate product. Decomposition process of propellant 450 and 1220 accelerate by Al presence. The difference between AP modal on propellant 450 and 1220 show insignificance effect to the amount of decomposition energy consumption. ABSTRAKProses dekomposisi termal propelan padat AP/HTPB jenis RUM, 450 dan 1220 telah dianalisis menggunakan Differential Thermogravimetric 60 (DTG) dengan parameter operasi: suhu 30 - 400⁰C, atmosfer nitrogen berlaju alir 50 ml/menit, dan laju pemanasan 2,5⁰C/menit. Analisis dekomposisi termal adalah langkah awal penelitian kinetika dekomposisi propelan dalam menentukan life time propelan. Kurva TGA menunjukkan bahwa propelan RUM mengalami proses dekomposisi dua tahap sedangkan propelan 450 dan 1220 mengalami proses dekomposisi satu tahap. Kurva DTA/ termogram proses dekomposisi propelan RUM menunjukkan adanya pembentukan produk intermediate sebelum akhirnya terdekomposisi sempurna. Berbeda dengan propelan RUM, termogram propelan 450 dan 1220 tidak menunjukkan terbentuknya produk intermediate. Proses dekomposisi propelan 450 dan 1220 terakselerasi oleh keberadaan Al. Perbedaan modal AP pada propelan 450 dan 1220 ternyata tidak begitu berpengaruh pada nilai konsumsi energi proses dekomposisi.
EVALUASI KINETIKA DEKOMPOSISI TERMAL PROPELAN KOMPOSIT AP/HTPB DENGAN METODE KISSINGER, FLYNN WALL OZAWA DAN COATS - REDFREN Wiwiek Utami Dewi
Jurnal Teknologi Dirgantara Vol. 15 No. 2 Desember 2017
Publisher : National Institute of Aeronautics and Space - LAPAN

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30536/j.jtd.2017.v0.a2635

Abstract

Decomposition of propellant Mechanism and kinetics have been investigated by using DTG/TA with three different methods: Kissinger, Flynn Wall Ozawa and Coats & Redfern. This research aims to determine decomposition kinetic parameters of LAPAN’s propellant. The propellants have different composition of Al and AP modal. RUM propellant consist of AP/HTPB. 450 propellant consists AP/HTPB/Al (bimodal). Meanwhile 1220 propellant consists of AP/HTPB/Al (trimoda). Thermal analysis takes place at 30 – 400oC and nitrogen atmosphere flow rate is 50 ml/min. The result according showed that propellant was decomposed by F1 mechanism (random nucleation with one nucleus on the individual particles). Activation energy of propellants are in range between 100.876 – 155.156 kJ/mol meanwhile pre-exponential factor are in range between 4.57 x 107 – 3.46 x 1012/min. Activation energy (E) as well as pre-exponential factor for 1220 propellant is the lowest among the others. AP trimodal application generates catalytic effect which decreases activation energy. 1220 propellant is easier to decompose (easier to react) than RUM and 450 propellant. AbstrakMekanisme dan kinetika dekomposisi propelan telah diinvestigasi menggunakan DTG/TA dengan tiga jenis metode yang berbeda yaitu Kissinger, Flynn Wall Ozawa dan Coats & Redfern. Penelitian ini bertujuan untuk mengetahui parameter kinetika dekomposisi propelan LAPAN. Propelan yang digunakan memiliki perbedaan komposisi Al dan jenis moda AP. Propelan RUM adalah propelan AP/HTPB. RX 450 adalah AP/HTPB/ Al (bimoda). Sementara itu, RX 1220 adalah AP/HTPB/ Al (trimoda). Pengujian termal berlangsung pada suhu 30 - 400oC dan atmosfer nitrogen berlaju alir 50 ml/menit. Hasil penelitian mengungkapkan bahwa semua jenis propelan terdekomposisi dengan mekanisme F1 (nukleasi acak dengan satu nukleus pada partikel individu). Energi aktivasi propelan berkisar antara 100,876 – 155,156 kJ/mol sementara faktor pre-eksponensial berkisar antara 4,57 x 107 – 3,46 x 1012/min. Energi aktivasi (E) dan faktor pre-eksponensial (A) RX 1220 adalah terendah dari ketiga sampel. Penggunaan jenis AP trimodul menciptakan efek katalitik yang menurunkan besarnya energi aktivasi. Propelan RX 1220 lebih mudah terdekomposisi (lebih mudah bereaksi) daripada propelan RUM dan RX 450. 
Co-Authors Yulia Azatil Ismah