NGHIEN Cflu-TRAODOI \ijc JGHiEN cu-u A N H HU-ONG C U A CAC T H O N G S CdNG NGHE FDM OtN QUA TRINH LIEN K^T SAN P H A M DU-aC TAO BANG VAT Ll6U POLYLACTIC-ACID (PLA) EXPERIMENTAL INVESTIGATIONS ON INFLUENCE OF IMPORTANT FDM PROCESS PARAMETERS ON OF BONDING PROCESS POLYLACTIC ACID (PLA) PARTS Nguyin Minh Hieu, POSTS Thai Thi Thu Ha Phong Thi nghiem Trgng diem Quoc gia Dieu khien so va Ky thuat He thong, TrUdng Dai hoc Bach Khoa, Dai hoc Quoc gia TP Ho Chi Minh TOM TAT Bdi bdo ndy trinh bdy nghien citu dnh hudng cua cdc thong so cong nghe quan nhu ddy ldp vd nhiet dim den qud trinh lien ket chi tiet bdng vat lieu Polylactic Acid (PLA) dUdc chi'tao tii cong nghe FDM SiC dung Matlab-Simulink de thUc hien tinh todn mo phong vd phdn tich cdc dnh hudng ndy Tii khoa: Tao mdu nhanh FDM; Qud trinh lien ket; Matlab-Simulink; Polylactic Acid ABSTRACT This paper presents experimental investigations on influence of important process parameters such as: Extruder temperature and layer thickness on of bonding process of FDM for PLA (Polylactic acid) parts These influences have been calculated and analysed by using software Matlab-Simulink And then, we use practical method to value simulated result by test specimen Keywords: Rapid prototyping; Matlab-Simulink: Fused Deposition Modelling (FDM); Bonding PLA plastic TAP CHl C O KHl V I £ T NAM, S6 12 nam 2013 filament; NGHIEN ClJfU-TRAODOl GIOI THIEU CHUNG Cdng nghe tao mau nhanh theo phfldng phdp bdi dap vdt lieu dang phat trien rat manh vdi nhieufludiem noi bat hdn so vdi qua trinh cat gpt d nhflng phfldng phap truyen thdng Cd rat nhieu cdng nghe tao mau nhanh lam viec theo nguyen ly bdi ddp vat Ueu theo tflng ldp md ndi bat hdn ca la cdng nghe FDM (hinh 1) Uen ket FDM Id rat quan trpng Cac thdng s6 qua trinh anh hfldi^ tdi Uen ket sdn pham FDM bao gdm: Nhiet dp dun, nhiet dd bao quanh mdu, chieu day ldp, dfldng kinh mieng dim va tdc dd dun .Trong cdc thdng sd nay, nhiet dp dun vd chieu day ldp Id hai thdng sd quan trpng anh hfldng rat nhieu tdi viec hinh thdnh va gia tang Uen ket 2.2 Qua trinh lam ngupi FDM De nhanh chdng tao san pham dfla thi trfldng thi viec tinh toan va thiet ke can phai Phfldng trinh dflpc sfl dung de tinh toan nhanh hdn nhflng van dap flng day du cac yeu qua trinh 1dm ngupi dflpc the hien theo cdng thflc cau ky thuat ma quan trpng nhat la sfl lien ket ben (1), theo [2] : chi tiet 7-= 7"^ -f- (ro-r^)e-'"* (1) Trong bdi bao cung tien hanh nghien cflu Trong dd: anh hfldng cua cac thdng so cdng nghe nhfl dp day ldp va nhiet dp dun den qua trinh lien ket • T: La nhiet dp cua sdi dun tai t > 0; • T^: La nhiet dp bao quanh mau; CO sd LY THUYET • T^: Nhiet dp cua spi dun tai t = 0; • x: La chieu dai spi dun, x = vt vdi v la van toe dau 2.1 Gidi thieu ve cac thdng sd cdng nghe cua dun va t la thdi gian qua trinh tao mau nhanh FDM • m dflpc tinh bang cdng thflc sau: Nguyen ly lam viec cua he thdng FDM dfldc the hien d hinh l - o / ? - l (2) Cdc he so a va p la nhflng h$ sd phu thu6c vao tinh chat vat lieu, hinh dang cua spi dim va dflpc dinh nghia nhfl sau: k pCv /? = pCAv (3} (4) • h: Ld he sd truyen nhiet ddi lflu, ta chon h = 50 (W/m^oC) [3]; • k: La dp ddn nhiet, doi vdi vat heu mau Id PLAta cdk=0.198(W/m.oC)[5]; Hinh 1: Nguyen ly he thong FDM • p: La khdi Iflpng rieng vd doi vdi vat lieu mSula PLA ta cd p = 1250 (kg/m') [6]; Vi cdc san pham FDM la ket qua cua qud • C: La nhiet dung rieng, ddi vdi vdt lieu mau la trinh lien ket cac ldp vdi dd dp ben cua PLA ta cd C = 2221.3 (J/Kg "C) [5]; nd phu thupc rat nhieu vdo cdc lien ket nen • A: La dien tich mat cat ngang spi dun; viec xem xet cdc yeu td anh hfldng tdi qud trinh • P: La chu vi mat cat ngang spi dun TAP CHi CO KHi VIET NAM, Sd 12 nam 2013 o NGHIEN COU - TRAO D O I • f = e-" -' a=107.23»10' • T la nhiet dp tham chieu, T = 170°C K, = 0.0285 « Y la toe trum cua dong nhua, ta chon y = 100 (1/s) a = 1.219 n = 0.19465 Hinh 2: Mat cdt ngang dang elip ciia mot sdi dun, [2] • r la ban kinh ban dau cua sdi dun dUOc tinh theo Dien tich A va chu vi P cua mat cat ngang hinh elip cua sol dim dUdc tinh toan bcfi cac phuong trinh sau: (5) A = Tiab (6) k = (7) a-vb (10) — P 2.4 Suf dung Matlab-SimuUnk de tinh toan va phan tich qua trinh lien ket v6i vat lieu mau la PLA va chieu day 16p O.Smm [4] 2,4.1 Qud trinh Idm nguoi Trong \ diipc dinh nghia la: -b congthutc; r = Trong bai nay, cac gia tri a / b cua mat cat ngang spi dun lan lUpt la 0.36mm / 0.18mm va 0.32mm/ 0.16mm doi v6i mau thii nghiem co chieu day 16p la 0.5mm va 0.25mm Qua trinh lam ngupi cua mau CO chieu day ldp 0.5mm vdi nhiet dp dim thay doi d cac gia tri 195°C-200°C-205°C-215°C-220"'C dflpc the hien d hinh sau: 2.3 Qua trinh li«n kft FDM Viec ph6ng doan lien ket gifla cac spi dun diipc thUc hien bang each sif dung phUcfng trinh (8),theo[118([31: 6' = r ~ ' ^ cos8sin6(^2-cose :^ (8) Trong d6: • T: La sdc cang be mat vat lieu, d6i vdi vat lieu mau la PLA ta c6 F = 0.05 (N/m) [6] • r): La dp nhdt dpng hpc cua vat li^u mdu, dpi vdi v^t li^u mJu l i PLA ta cd dp nhdt dflpc the hien theo phflpng trinh sau: [7] !> = fcf Trong d6: • (t: L4 d$ nhdt cua PLA d nhiet dp T; • n : Li nhdt tinh ciia PLA, n^ = 3668; (9) Hinh 3: Qud trinh lam nguoi cua mdu cd chieu ddy ldp 0.5mm Nhan xet ve k^t qua lam ngupi (hinh 3); Khi nhiet dp dim tang tii 195°C den 220°C thi thdi gian ket tinh cua spi dim tang tfl 11.7 den 12.7 giay (nhiet dp ket tinh cua nhUa PLA la 58''C [6] Hon nfla, thdi gian ma nhiet dp cua spi dun cao hon 152°C (nhiet dp ndng chay cua nhUa PLA [6] cung tang tfl 1.1 cho den 2.0 giay '^ TAP CHl CO KHl V I £ T NAM, S6 12 nam 2013 NGHIEN CUTU-TRAO Ddi 2.4.2 Qud trinh lien ket Qua trinh lien ket cua mdu cd chieu day ldp 0.5mm vdi nhiet dp dun thay doi d cac gia tri 195''C-200"C-205