Extrusion coating performances of PP/LDPE blends = 폴리프로필렌과 저밀도 폴리에틸렌 블렌드의 압출코팅 성능 연구

Cited 0 time in webofscience Cited 0 time in scopus
  • Hit : 739
  • Download : 0
The performance of PP/LDPE blends in extrusion coating process was investigated in the terms of neck-in and draw-down ability. It is well known that PP alone is not proper because of lower draw-down ability with severe draw resonance in elongational flow. In order to obtain high draw-down ability, PP was blended with LDPE. Strain hardening behaviors was found to be a crucial condition in good extrusion coating performance by blending with LDPE which has long chain branches in our studies. First, PPs having different molecular weight distribution (MWD) were used in this study in order to find out the effect of MWD of PP on neck-in and draw-down ability. To obtain different MWD PP, controlled rheology technique using peroxide was used. It was observed that PP/LDPE blend with narrower MWD exhibits higher draw-down ability with a comparable neck-in value in high draw down ratio. Neck-in and draw-down ability were correlated with shear and elongational properties obtained by several rheological measurements. It is supposed that neck-in is affected mainly by elasticity and shear viscosity in low frequency, and high draw-down ability is affected by low melt strength and strong strain hardening behavior. It is believed that high molecular weight chains of PP in PP/LDPE blend mainly affect to the different result of extrusion coating performance with different MWD. Second, the effect of type of PP on extrusion coating performances was also investigated. Two types of homo PP and two types of random PP having different composition and crystallinity were used as a base PP. They were also treated with same degree of degradation by peroxide to fit the proper MFR for extrusion coating process. PP/LDPE blend incorporated with high comonomer shows high draw-down ability. Neck-in values of four different PP/LDPE blends does not exhibit the dependency on type of PP. From our investigation with several measurements, it is supposed that incorporation with high comonomer affects...
Advisors
Park, O-Okresearcher박오옥researcher
Description
한국과학기술원 : 생명화학공학과,
Publisher
한국과학기술원
Issue Date
2009
Identifier
309258/325007  / 000985001
Language
eng
Description

학위논문(박사) - 한국과학기술원 : 생명화학공학과, 2009.2, [ viii, 101 p. ]

Keywords

blend; extrusion; coating; polypropylene; polyetylene; 블렌드; 압출; 코팅; 폴리프로필렌; 폴리에텔렌; blend; extrusion; coating; polypropylene; polyetylene; 블렌드; 압출; 코팅; 폴리프로필렌; 폴리에텔렌

URI
http://hdl.handle.net/10203/29050
Link
http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=309258&flag=dissertation
Appears in Collection
CBE-Theses_Ph.D.(박사논문)
Files in This Item
There are no files associated with this item.

qr_code

  • mendeley

    citeulike


rss_1.0 rss_2.0 atom_1.0