Pengaruh Ukuran Butir, Fraksi Volume dan Penambahan Aseton terhadap Kekuatan Flexural Komposit Papan Partikel Serbuk Gergaji Kayu Sengon-Matrik Polyester

Abstract

Abstrak

Papan partikel dapat digunakan sebagai bahan konstruksi pengganti kayu. Pengaruh ukuran partikel, fraksi volume, dan penambahan aseton pada matrik polyester perlu diketahui kekuatan, regangan, dan modulus/ sifat flexural (bending), serta moda patahannya. Spesimen dibuat dengan cetak tekan dari partikel kayu sengon sebagai penguat dan polyester sebagai matrik. Partikel yang digunakan dengan ukuran mesh 10 dan 20, variasi fraksi volume partikel 30, 32.5, 35, 37.5, dan 40% dengan matrik campuran polyester-aseton dengan variasi penambahan aseton  0, 10, 20, dan 30 ml. Pengujian flexural menggunakan standar ASTM D 1037-99 dan analisa patahan dengan foto makro serta foto mikro untuk analisa struktur partikel komposit. Semakin kecil partikel yang digunakan, dapat meningkatkan sifat flexural karena luas rekatan antara partikel dan matrik semakin besar. Penambahan fraksi volume partikel mesh 20 meningkatkan sifat flexural sampai fraksi volume 37,5% namun pada fraksi volume 40% sifat flexural turun. Peningkatan fraksi volume partikel mesh 10 menurunkan sifat flexural papan partikel. Penambahan aseton menurunkan sifat flexural karena matrik semakin encer sehingga daya rekat polyester semakin berkurang. Patahan komposit papan partikel kayu sengon yaitu patah tunggal yang terjadi pada semua specimen.

Abstract

Particle boards  commonly used as wood replacement construction materials. The investigation of the influence of particle size, volume fraction and addition of acetone on the polyester matrix on their flexural properties and failure modes  has been carried out. Specimens were fabricated by cold press from sengon wood particles as a reinforcement and the polyester as a matrix.  The particles  with mesh sizes of  10 and 20 were used, The composite boards were fabricated with particle volume fraction of 30, 32.5, 35, 37.5, and 40%. Polyester as a matrix was prepared by adding acceton (0, 10, 20, 30 ml) into polyester . The flexural properties was examined in accordance to  ASTM D 1037-99 standard. The microstructure and failure of mode of the the composite were determined by image analysis. The result show that the smaller particles  increase flexural properties because the area of bond between particles and matrix is largerr. The addition of the volume fraction of 20 mesh particles increased the flexural properties to a volume fraction of 37.5% but at a volume fraction of 40% the flexural properties decreased. Increasing the volume fraction of 10 mesh particles decreases the flexural properties of the particle board. The addition of acetone decreases flexural properties because the matrix is more thiner so that the adhesive power of polyester decreases. Single fracture mode was occurred in all specimens being examined.