The Experts below are selected from a list of 24 Experts worldwide ranked by ideXlab platform

J. R. White - One of the best experts on this subject based on the ideXlab platform.

  • Photodegradation of polypropylene mouldings containing weld lines : mechanical properties and Surface cracking
    Plastics Rubber and Composites Processing and Applications, 1996
    Co-Authors: M. S. Rabello, J. R. White
    Abstract:

    The photodegradation behaviour of polypropylene (PP) containing weld lines has been investigated. Tensile test bars produced with a double end gated tool using three mould temperatures were compared with single end gated samples made under similar conditions. They were exposed to ultraviolet (UV) radiation in the laboratory for up to 24 weeks, and their mechanical properties and Surface fractography were studied. The deterioration in tensile properties increased with decreasing mould temperature and it was more significant in specimens containing weld lines. This probably results from scission of molecular entanglements at the weld region, but the properties also depend on other factors such as the extent of damage at the Moulded Surfaces. In both single and double end gated injection Moulded PP the pattern of Surface cracks followed the same contours as the flowlines during mould filling, and the concentration of cracks varied with the position along the length of the Moulded Surface. X-ray diffraction indicated that regions of low crack frequency were correlated with regions of low orientation.

Kiyohito Koyama - One of the best experts on this subject based on the ideXlab platform.

  • evaluation of replication properties on Moulded Surface by ultrasonic injection moulding system
    Plastics Rubber and Composites, 2010
    Co-Authors: A Sato, H Sakaguchi, Kiyohito Koyama
    Abstract:

    An ultrasonic injection moulding (UIM) system, which applies ultrasonic waves to injection moulding, as a precision injection moulding technology was developed. Replication properties of the microstructure of the Moulded Surface were evaluated by the UIM system. In particular, the effects of oscillation conditions on the replication ratio of the Moulded Surface were investigated. As a result, the replication ratio of the Moulded Surface was significantly improved in UIM compared with that in conventional moulding. The replication ratio increased when the ultrasonic wave was applied immediately after the resin was filled in a cavity. Results showed that, by applying ultrasonic waves, oscillatory flow was generated inside the cavity and consequently the Surface replication was increased. The Surface replication during packing and holding stages was improved by the oscillatory flow provided by the ultrasonic vibration.

M. S. Rabello - One of the best experts on this subject based on the ideXlab platform.

  • Photodegradation of polypropylene mouldings containing weld lines : mechanical properties and Surface cracking
    Plastics Rubber and Composites Processing and Applications, 1996
    Co-Authors: M. S. Rabello, J. R. White
    Abstract:

    The photodegradation behaviour of polypropylene (PP) containing weld lines has been investigated. Tensile test bars produced with a double end gated tool using three mould temperatures were compared with single end gated samples made under similar conditions. They were exposed to ultraviolet (UV) radiation in the laboratory for up to 24 weeks, and their mechanical properties and Surface fractography were studied. The deterioration in tensile properties increased with decreasing mould temperature and it was more significant in specimens containing weld lines. This probably results from scission of molecular entanglements at the weld region, but the properties also depend on other factors such as the extent of damage at the Moulded Surfaces. In both single and double end gated injection Moulded PP the pattern of Surface cracks followed the same contours as the flowlines during mould filling, and the concentration of cracks varied with the position along the length of the Moulded Surface. X-ray diffraction indicated that regions of low crack frequency were correlated with regions of low orientation.

A Sato - One of the best experts on this subject based on the ideXlab platform.

  • evaluation of replication properties on Moulded Surface by ultrasonic injection moulding system
    Plastics Rubber and Composites, 2010
    Co-Authors: A Sato, H Sakaguchi, Kiyohito Koyama
    Abstract:

    An ultrasonic injection moulding (UIM) system, which applies ultrasonic waves to injection moulding, as a precision injection moulding technology was developed. Replication properties of the microstructure of the Moulded Surface were evaluated by the UIM system. In particular, the effects of oscillation conditions on the replication ratio of the Moulded Surface were investigated. As a result, the replication ratio of the Moulded Surface was significantly improved in UIM compared with that in conventional moulding. The replication ratio increased when the ultrasonic wave was applied immediately after the resin was filled in a cavity. Results showed that, by applying ultrasonic waves, oscillatory flow was generated inside the cavity and consequently the Surface replication was increased. The Surface replication during packing and holding stages was improved by the oscillatory flow provided by the ultrasonic vibration.

Francis Buckley - One of the best experts on this subject based on the ideXlab platform.

  • an ice Moulded Surface from the middle pleistocene of the central north sea
    Near Surface Geophysics, 2012
    Co-Authors: Francis Buckley
    Abstract:

    A collection of seismic datasets, including Ultra-High Resolution 2D, High Resolution 2D and Exploration 3D data, have been compared with geotechnical borehole logs, to investigate a Middle to Late Pleistocene sequence within the Central North Sea (CNS). An Elsterian glacial erosion Surface is interpreted to be overlain by a series of seismo-stratigraphic formations which can mostly be referenced to the accepted stratigraphic model for the area, though with some significant qualifications. Evidence is shown for the presence of at least three grounded ice-sheets within the Middle-Late Pleistocene of the CNS, including a previously unreported, pre-Weichselian, ice-Moulded and lineated Surface. The late and post-glacial history of the CNS is re-constructed by reference to borehole lithological data, compared with seismic textures. It is proposed that a seismo-stratigraphic unit at seabed and named in published sources as the late glacial Forth Fm. is much older, with implications for the prediction of geotechnical properties of the unit elsewhere in the region.