BIOMIMETIC 3D PRINTING MODELING OF WOOD MICROSTRUCTURES AND THEIR WATER ABSORPTION BEHAVIOR

Öz

The cellular structures and material densities of softwood (pine) and hardwood (beech) trees were analyzed using a biomimetic approach, and these properties were adapted to PLA-based composite samples produced using the FDM (Fused Deposition Modeling) method. The novelty of this study lies in the adaptation of the geometric and density-based characteristics of natural wood microstructures into 3D-printed composites through biomimetic principles, and in the comparative analysis of their water absorption, dimensional change, and color variation behaviors.The water absorption, dimensional change, and color change of wood and PLA samples were examined comparatively. As a result, it was determined that the weight and volume of all samples increased in direct proportion to the duration of exposure to water. While the weight change in wood samples was very high (pine 113.13%; beech 81.62%), PLA samples showed minimal volumetric change and weight. When the change in void ratio after water absorption at the cellular level was examined, a shrinkage of 19.26% in pine, 12.98% in beech, 7.77% in PLA50, and 10.9% in PLA70 was observed, leading to the conclusion that water was not retained in the voids but settled into the walls. In the color difference analysis after water absorption, the ΔE values were very high in the wood samples, while they were quite low in the PLA samples. Increasing the PLA ratio positively affected the material's water repellency and dimensional stability. The findings indicate that PLA-based materials may be more resistant to moisture effects and more stable aesthetically.

Anahtar Kelimeler

• Biomimetic
• Bio-Inspired Filling Pattern
• Water Absorption Behavior
• 3D Printing Technology
• Cell Structure.

BİYOMİMETİK YAKLAŞIMLA AĞAÇ MİKRO YAPILARININ 3B BASKI MODELLEMESİ VE SU ALMA DAVRANIŞI

Öz

İğne yapraklı (çam) ve geniş yapraklı (kayın) ağaçların hücresel yapıları ve malzeme yoğunlukları biyomimetik yaklaşımla analiz edilerek, bu özellikler FDM (Eriyik Biriktirme Modelleme) yöntemiyle üretilen PLA esaslı kompozit numunelere uyarlanmıştır. Bu çalışmanın yeniliği, doğal ahşap mikro yapılarının geometrik ve yoğunluk temelli özelliklerinin ilk kez biyomimetik prensiplerle 3B baskı kompozitlerine aktarılması ve bu yapıların su absorpsiyonu, boyutsal değişim ve renk farkı davranışlarının karşılaştırmalı olarak analiz edilmesidir. Ahşap ve PLA numunelerinin su absorpsiyonu, boyutsal değişimi ve renk değişimi karşılaştırmalı olarak incelenmiştir. Sonuç olarak tüm numunelerin suya maruz kalma süresiyle doğru orantılı ağırlık ve hacimlerinin arttığı, ahşap numunelerindeki ağırlık değişimi çok yüksekken (çam %113,13; kayın %81,62), PLA numunelerinin ise minimal hacimsel değişim ile düşük ağırlık değişimi gösterdiği tespit edilmiştir. Hücresel bazda su absorpsiyonu sonrası boşluk oranlarındaki değişim incelendiğinde çamda %19,26, kayında %12,98, PLA50’de %7,77 ve PLA70’te %10,9 luk bir daralma gözlenmiş, bu sayede suyun boşlukta tutulmadığı, çeper içerisine yerleştiği sonucuna ulaşılmıştır. Su absorpsiyonu sonrası renk farkı analizinde, ΔE değerleri ahşap numunelerde çok yüksek iken, PLA numunelerinde oldukça düşük bulunmuştur. PLA oranının artması, malzemenin su iticiliğini ve boyutsal stabilitesini olumlu yönde etkilemiştir. Bulgular, PLA esaslı malzemelerin nem etkisine karşı daha dayanıklı, estetik olarak daha stabil olabileceğini göstermektedir.

Anahtar Kelimeler

• Biyomimetik
• Biyo-İlhamlı Dolgu Deseni
• Su Alma Davranışı
• 3B Yazıcı Teknolojisi
• Hücre Yapısı.

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