ThesisOpen AccessMetadata saja
2024•Skripsi, Thesis, Disertasi, dan Tugas Akhir
ANALYSIS OF THE EFFECT OF HOLDING TIME IN THE INJECTION MOLDING PROGRES ON THE HARDNESS OF HDPE AND PP MATERIALS Abstract Injection molding is a method of forming thermoplastic materials where the material that melts due to heating is injected using a plunger into the mold. Holding time in the heat treatment process is one of the processes carried out with the aim of obtaining a high hardness value from a material. The purpose of this research was to determine the printing procedure with holding time and determine the effect oh holding time on defects, depreciation and hardness oh HDPE and PP. The measurement results at a holding time of 18 seconds produced an average hardness level of 57.13 shore D, while at a holding time of 20 seconds the average hardness level of the test object was 54.26 shore D. Depreciation using an injection molding machine at a holding time 18 seconds the average was 0.06%, while for a holding time of 20 seconds the average was 0.045%. There were 3 material defects that occur in HDPE and PP materials, namely short shot, flashing, and sink mark defects.
ThesisOpen AccessMetadata saja
2023•Skripsi, Thesis, Disertasi, dan Tugas Akhir
.Pada konversi motor bakar ke motor listrik salah satu komponen penting adalah bracket yang berfungsi sebagai dudukan motor listrik BLDC. Bahan bracket umumnya adalah baja karbon, salah satu metode untuk meningkatkan sifat baja karbon dengan perlakuan panas dan pendinginan. Pada penelitian ini bertujuan untuk mengetahui pengaruh perlakuan panas pada plat baja terhadap kekerasan dan struktur mikro. Eksperimen yang dilakukan pada penelitian ini yaitu perlakuan panas dengan variasi media pendingin oli dan udara. Setelah dilakukan eksperimen kemudian dilakukan di uji kekerasan brinell dan uji metalografi pada spesimen. Hasil yang diperoleh dari spesimen non treatment memilki nilai kekerasan yaitu 138 kgf/mm2. Spesimen heat treatment dengan pendingin oli memiliki nilai kekerasan yaitu 168,2 kgf/mm2 dan spesimen heat treatment dengan pendingin udara memiliki nilai kekerasan yaitu 132,2 kgf/mm2. Bisa disimpulkan bahwa nilai kekerasan dilakukan heat treatment dengan pendingin oli paling tertinggi yakni 168.2 kgf/mm2. Hal ini ditunjukkan dengan perubahan struktur mikro yaitu martensit, dikarenakan adanya efek pendinginan cepat. In converting a combustion motor to an electric motor, one of the main components is the bracket which functions as a mount for the BLDC electric motor. The bracket material is generally carbon steel. One method to improve the properties of carbon steel is by heating and cooling. The research aimed to determine the effect of heat treatment on steel plates on hardness and microstructure. The experiment carried out in this research was heat treatment with a type of oil and air-cooling media. After carrying out test, the next step was to carry out Brinell hardness tests and metallographic tests on the specimens. The test results obtained from non-treated specimens had a hardness value of 138 kgf/mm². The heat-treated specimen with oil cooling had a hardness value of 168.2 kgf/mm², and the heat-treated specimen with air cooling had a hardness value of 132.2 kgf/mm². From the test results, it can be concluded that the hardness value of heat treatment with oil cooling obtained the highest value of 168.2 kgf/mm². It was indicated by changes in the microstructure, namely martensite, due to the rapid cooling effect.
