0

Full Content is available to subscribers

Subscribe/Learn More  >

Evaluation of Mechanical Properties at the Knit Line Interface in a Complex Multi-Cell PVC Extrusion

[+] Author Affiliations
J. J. Grudzinski, R. Fischer, R. L. Talaga, V. Guarino

Argonne National Laboratory, Argonne, IL

A. Pla-Dalmau, J. E. Fagan, C. Grozis

Fermi National Accelerator Laboratory, Batavia, IL

Paper No. IMECE2014-40217, pp. V014T11A048; 8 pages
doi:10.1115/IMECE2014-40217
From:
  • ASME 2014 International Mechanical Engineering Congress and Exposition
  • Volume 14: Emerging Technologies; Engineering Management, Safety, Ethics, Society, and Education; Materials: Genetics to Structures
  • Montreal, Quebec, Canada, November 14–20, 2014
  • Conference Sponsors: ASME
  • ISBN: 978-0-7918-4963-7
  • Copyright © 2014 by ASME

abstract

In order to form internal cells in PVC extrusions, the die requires an insert or internal member that the material flows past. These inserts are supported to the outer die structure by so-called spiders that pass through to the outer wall of the extrusion die. The extruded material must separate and then recombine as it passes over the spider. The material must then form a bond at this interface shortly before exiting the die. These interfaces are referred to as knit-lines. In a recent project involving a large and complex PVC extrusion, difficulty was encountered in developing these knit lines within the webs of the extrusions. Upon visual inspection, these interfaces appeared to be without bond over portions of the cross section. However, mechanical testing in the worst knits revealed that bonding had occurred with the knit providing 85% of the bulk material strength although without supporting any significant ductility. At the same time, knits at different parts of the extrusions showed ductility comparable with the base material. Altering the process variables showed a means for improvement in the webs but this was limited by other constraints. In this work we describe the character of the knitlines and the resulting mechanical properties along with the testing methodology.

Copyright © 2014 by ASME

Figures

Tables

Interactive Graphics

Video

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In