This study aims to develop a recyclable, economical, and flame-retardant composite material using polypropylene, beech flour, tetrabromobisphenol A bis (TBBPA), and antimony trioxide (ATO). Flame-retardant additives (TBBPA and ATO) were initially added into polypropylene at different rates, and masterbatch (MB) samples were produced by the extrusion method. Subsequently, different percentages of wood flour (10%, 15%, 20%, 25%, and 30%) along with 60% MB were added to the polypropylene to create wood–polymer composites (WPC) using the injection method. The TBBPA, ATO, and wood flour were introduced through side-feeding hoppers during injection to ensure a homogeneous distribution within the WPC. Physical, thermal, and mechanical tests were conducted on the WPC samples. Additionally, TGA, FTIR, and SEM analyses were performed. The results indicated that the optimal ratios for TBBPA and ATO additives were 20% and 10%, respectively. It was observed that increasing the wood flour content in the WPC samples led to enhanced density, water absorption, hardness, impact, and abrasion resistance. Conversely, MFI, bending strength, and tensile strength decreased with higher wood flour content. It was observed that WPC samples exhibited flame resistance up to 725 °C. The produced WPC materials can be used in flooring applications, interior furniture, decorative wall panels, and aesthetic structural elements due to their fire behavior, good mechanical properties, low water-absorption rates, and aesthetic appearance.

This study examined the drilling performance of five polymer composite systems: three natural fiber (jute, flax, hemp) composites with aluminum particle-reinforced epoxy, one glass fiber-reinforced composite with the same matrix, and an unreinforced aluminum particle-filled epoxy (Al–epoxy). Drilling experiments were performed at spindle speeds of 1500 and 3000 rpm with feed rates of 50, 75, and 100 mm/min in order to evaluate the effect of cutting parameters on the drilling performance. Cutting zone temperatures were measured using thermocouples embedded within the drill bit’s cooling channels, while thrust forces were recorded with a dynamometer. Additionally, hole exit damage and inner hole surface roughness were evaluated to assess machining quality. The results showed that increasing spindle speed reduces thrust forces due to thermal softening of the matrix, whereas natural fiber-reinforced composites generally exhibit higher thrust forces and slightly rougher inner hole surfaces compared to synthetic counterparts. During drilling, the measured thrust forces ranged from 320 to 693 N for the glass fiber-reinforced specimen and from 335 to 702 N for the Al–epoxy specimen, while for natural fiber-reinforced composites the thrust force values were 352–679 N for hemp, 241–719 N for jute, and 571–732 N for flax specimens. Synthetic specimens (glass fiber and Al–epoxy) exhibited comparable cutting temperature ranges (288–371 °C and 248–327 °C, respectively), whereas natural fiber-reinforced composites showed higher and broader temperature ranges of 311–389 °C for hemp, 368–374 °C for jute, and 307–379 °C for flax specimens. The overall results indicated that lower forces were generated during the drilling of synthetic glass fiber-reinforced composites, while among natural fiber-reinforced plastics, flax fiber-reinforced composites stood out by exhibiting a balanced machining response.

A composite material can be defined as a combination of two or more materials that provide better properties than the material used alone. Composite materials can be preferred because of their many advantages – for example, they are stronger and lighter compared with conventional materials. Usage of fibre-reinforced composite structures has increased in industries such as automotive, marine transportation, civil engineering, sporting goods, medical equipment and prosthetic devices.

Bu çalışmada, organik takviye malzemelerinin polilaktik asit (PLA) ile oluşturulan kompozit malzemeler üzerine yapılan çalışmalar incelenmiştir. Organik takviye malzemeler, doğal lifleri, güçlü, hafif ve düşük ağırlıkta, yüksek özgül mukavemete sahip, ucuz, çevre dostu ve doğada biyolojik olarak parçalanabilir özelliklerde olduğundan polimer matrisli kompozitlerde kullanımı yaygındır. Biyo çözünür polimerler teknolojik gelişimin çeşitli alanlarında çok büyük önem teşkil etmektedirler. Bu konudaki çalışmalar gün geçtikçe yaygınlaşmaktadır. Biyo çözünür polimerlerden biri olan PLA medikal alanında, paketleme ve ambalaj alanında, çevresel uygulamalarda, tekstil uygulamalarında oldukça etkin bir şekilde kullanılmaktadır. Genel olarak organik takviyeli kompozitler; lifler, odun, sisal, kenevir, keten, kenaf, bambu, kayısı çekirdeği kabuğu vb. bitki kaynaklı doğal malzemelerden elde edilmektedir. Bu çalışmada, PLA polimer matrisine organik malzemelerin takviyesi ile üretilen kompozit malzemelerin mekanik özellikleri, üretim teknikleri, takviye elamanlarının PLA matrisi üzerine etkileri, ilave edilen takviye oranları, ara yüz malzemelerin etkileri üzerine yapılmış çalışmalar incelenerek, elde edilen bulgular ve sonuçlar derlenmiştir.