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Abstract

In this study, the effects of machine direction orientation (MDO) conditions on crystalline orientation, morphology, and mechanical performance of a high-density polyethylene film were investigated. The MDO variables studied were feed speed, stretching temperature, draw ratio (DR) as well as annealing temperature. The type of crystals (spherulites or fibrils) and crystallinity of the films were considered using differential scanning calorimetry. The MDO process increased the film crystallinity by 18% and melting temperature (Tm ) by 5°C. The crystalline phase orientation was measured using Fourier transform infrared and wide angle X-ray diffraction. Stretching noticeably increased the crystalline alignment. The Young’s modulus decreased with increasing extrusion temperature and feed speed and enhanced with rising annealing temperature. However, up to DR = 6, the Young’s modulus decreased with draw ratio whereas it increased beyond DR = 6. Upon drawing, the tear resistance along the machine direction decreased significantly, but the puncture resistance along the normal direction increased drastically. Finally, drawing lowered haze for the films dramatically, hence, improved the clarity significantly.

Keywords

HDPE MDO process orientation modulus haze tear.

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References

Lange, J.

( 2003). Recent Innovations in Barrier Technologies for Plastic Packaging - A Review, Packag. Technol. Sci., 17: 149-158.

Sadeghi, F.

and

Carreau, P.J.

( 2008). Properties of Uniaxially Stretched Polypropylene Films , Can. Chem. Eng. J., 86: 1103-1110.

Schut, J.H.

( 2005). MDO Films, Lots of Promise, Big Challenges, Plastics Technol., 51: 48-53.

Banfa, A.

McFaddin, D.

Beaucage, G.

Merrick-Mack, J.

and

Mirabella, F.M.

( 2007). Integrated Mechanism for the Morphological Structure Development in HDPE Melt-blown and Machine-direction-oriented films, J. Polym. Sci. Part B Polym. Phys., 45: 1834-1844.

Nie, H.Y.

Walzak, M.J.

and

McIntyre, N.S.

(2000). Draw-ratio-dependant Morphology of Biaxially Oriented Polypropylene Films as Determined by Atomic Force Microscopy, Polymer, 41: 2213-2218.

Zuo, F.

Keum, J.K.

Chen, X.

Hsiao, B.S.

Chen, H.

Lai, S.Y.

Wevers, R.

and

Li, J.

( 2007). The Role of Interlamellar Chain Entanglement in Deformation-induced Structure Changes During Uniaxial Stretching of Isotactic Polypropylene, Polymer, 48: 6867-6880.

Tabatabaei, S.H.

Carreau, P.J.

and

Ajji, A.

(2009). Structure and Properties of MDO Stretched Polypropylene, Polymer, 31: 3981-3989.

Ajji, A.

Sammut, P.

and

Huneault, M.A.

( 2003). Elongational Rheology of LLDPE/LDPE Blends, J. Appl. Polym. Sci., 88: 3070-3077.

Tabatabaei, S.H.

Carreau, P.J.

and

Ajji, A.

(2009). Microporous Membranes Obtained from PP/HDPE Multilayer Films by Stretching, J. Membr. Sci., 345: 148-159.

10.

Somani, R.H.

Yang, L.

Zhu, L.

and

Hsiao, B.S.

( 2005). Flow-induced Shishkebab Precursor Structures in Entangled Polymer Melts, Polymer, 46: 8587-8623.

11.

Elias, M.B.

Machado, R.

and

Canevarolo, S.V.

( 2000). Thermal and Dynamic-mechanical Characterization of Uni- and Biaxially Oriented Polypropylene Films, J. Therm. Anal. Cal., 59: 143-155.

12.

Sadeghi, F.

Ajji, A.

and

Carreau, P.J.

( 2007). Analysis of Row Nucleated Lamellar Morphology of Polypropylene Obtained from the Cast Film Process: Effect of Melt Rheology and Process Conditions, Polym. Eng. Sci., 47: 1170-1178.

13.

Sadeghi, F.

Ajji, A.

and

Carreau, P.J.

(2005). Study of Polypropylene Morphology Obtained from Blown and Cast Film Processes: Initial Morphology Requirements for making Porous Membrane by Stretching, J. Plast. Film Sheeting, 21: 199-216.

14.

Alexander, L.E.

(1969). X-ray Diffraction Methods in Polymer Science, Wiley, New York .

15.

Zhang, X.M.

Elkoun, S.

Ajji, A.

and

Huneault, M.A.

(2004). Oriented Structure and Anisotropy Properties of Polymer Blown Films: HDPE, LLDPE and LDPE, Polymer, 45: 217-229.

16.

Ajji, A.

and

Dumoulin, M.M.

( 2000) Rolling and Roll-drawing of Semicrystalline Thermoplastics , In:

Ward, I.M.

Coates, P.D.

and

Dumoulin, M.M.

(eds), Solid Phase Processing of Polymers, Carl Hanser Verlag Publication, Munich.

17.

Sadeghi, F.

Tabatabaei, S.H.

Ajji, A.

and

Carreau, P.J.

(2010). Properties of Uniaxially Stretched Polypropylene Films: Effects of Drawing Temperature and Random Copolymer Content, Can. Chem. Eng. J., (in press).

18.

Strawhecker, K.E.

and

Manias, E.

(2001). AFM of Poly(vinyl alcohol) Crystals next to an Inorganic Surface, Macromolecules, 34: 8475-8482.

Effect of Machine Direction Orientation Conditions On Properties of Hdpe Films

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