以噴霧乾燥法披覆聚乙烯醇或聚甲基丙烯酸甲酯於氧化鋁粉表面

Coating Poly Methyl Methacrylate or Polyvinyl Alcohol on Alumina Powder with Spray Drying

林溪浚(Shi-Jiun Lin)

指導教授 ： 湯華興 ； 嚴孝全

國立臺北科技大學/機電學院/機電整合研究所/碩士(2010年)

https://doi.org/10.6841/NTUT.2010.00488

摘要

在陶瓷雷射燒結快速原型製程中，製造披覆粉末是利用熱風乾燥配合球磨風析法。漿料乾燥成氧化鋁塊後，再利用球磨風析法來收集披覆粉末。在熱風乾燥時，所形成的氧化鋁塊越大，在球磨風析時的生產效率越差。本文之目的是以噴霧乾燥法加上球磨風析方法，生產披覆聚乙烯醇或聚甲基丙烯酸甲酯之氧化鋁粉末。利用經過噴霧乾燥後的粉末較細小，來提升生產效率，並探討披覆後之氧化鋁粉末之性質，以做為往後使用此材料之依據。
使用噴霧乾燥法與球磨風析製程比熱風乾燥與球磨風析製程，有較高之生產效率。以噴霧乾燥法與球磨風析法生產披覆PVA粉末及生產披覆PMMA粉末其生產效率都比現有製程快了3~4倍。由漿料分散性實驗結果得知，添加PVA及添加PMMA漿料都在鹼性(pH10)時有較佳的分散效果，在酸性(pH4)時分散效果最差。由粒徑分析實驗得知，噴霧乾燥後披覆PVA及PMMA粉末的粒徑大部分集中在10μm，再經球磨風析後的披覆PVA粉末平均粒徑為0.653μm、披覆PMMA粉末平均粒徑為0.69μm。從燒失實驗得知經過噴霧乾燥與球磨風析後PVA實際披覆於氧化鋁粉表面為3.272％、 PMMA實際披覆於氧化鋁粉表面為3.337％。由黏度實驗得知，使用經由噴霧乾燥與球磨風析後所生產的披覆PVA或PMMA粉末所調製而成的漿料，其最佳分散效果都位於鹼性(pH10)。從三點抗彎實驗得知，使用經由噴霧乾燥與球磨風析後所生產的披覆PVA及披覆PMMA粉末，所製作之工件其強度分別為430Mpa與421Mpa。

關鍵字

噴霧乾燥 ； 披覆 ； 氧化鋁 ； 聚甲基丙烯酸甲酯 ； 聚乙烯醇

並列摘要

In the rapid prototyping process of Ceramic Laser Sintering, coated-powder was produced by hot air drying with ball mill. Slurry was dried to obtain alumina blocks, ant then the coated-powder was collected with the method of ball mill. In hot air drying, the larger the alumina block is, the lower the efficiency is in ball mill. The purpose of this paper is to coat polyvinyl alcohol (PVA) or poly methyl methacrylate(PMMA) on the surface of the alumina powder by spray drying and ball mill. Spray drying with ball mill can obtain smaller coated-powder than that obtained by hot air drying with ball mill, and can increase the production rate. The property of coated- powder was also studied for future works.
On coated-powder production process, spray drying with ball mill was better than that of hot air drying with ball mill. The efficiency of the former was 3 to 4 times than the latter’s. The result of experiment of slurry dispersion revealed slurry added with PVA or PMMA could achieve a better dispersion in pH10; however, the worse dispersion was obtained in pH4. The result of experiment of particle size analysis revealed the particle size distribution of the powder coated PVA or PMMA by spray drying is concentrated in 10μm. After ball milling, the average particle size is 0.653μm in PVA and 0.69μm in PMMA. The result of experiment of burning out revealed the coating rate was 3.272% and 3.337% for the powder coated with PVA and PMMA respectively. The result of experiment of viscosity revealed, both processes obtained the best dispersion in pH10. The flexural strengths of the specimens fabricated by the powder coated with PVA or PMMA was 430Mpa and 421Mpa respectively.

並列關鍵字

Spray Drying ； Coating ； Poly Methyl Methacrylate ； Polyvinyl Alcohol ； Alumina

參考文獻

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