ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract In injection-moulded parts, the degree of orientation (anisotropy) varies over the cross-section. Normally, such parts exhibit a layered structure, with a biaxially oriented surface layer (stretching of the flow front during mould filling), a highly oriented shear zone, and a core region with a relatively low orientation. This paper describes a novel method to show the different morphological zones by studying the occurrence and structure of fibres formed during injection moulding of certain incompatible blends, in the present case a mixture of high-density polyethylene and a technical lignosulphonate grade (Wanin S). The polyethylene fibres formed during processing of this composite were ribbon-shaped in the surface layer (biaxial orientation), while they had a normal appearance in the shear zone. Only relatively few fibres were found in the core region. A qualitative agreement was found when the fibre character in the various layers was compared with orientation data from thermal shrinkage measurements, as obtained with pure polyethylene samples (test bars).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00540392
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