Ulster University Logo

Ulster Institutional Repository

Improving the optical characteristics of a polycarbonate visor for use in a fencing mask

Biomedical Sciences Research Institute Computer Science Research Institute Environmental Sciences Research Institute Nanotechnology & Advanced Materials Research Institute

Holmes, R, Goddard, NJ, Singh, K and Mohr, S (2001) Improving the optical characteristics of a polycarbonate visor for use in a fencing mask. Sports Engineering, 4 . pp. 225-231. [Journal article]

[img]
Preview
PDF (Fencing Mask Paper) - Published Version
551Kb

URL: http://www3.interscience.wiley.com/journal/120135899/abstract?CRETRY=1&SRETRY=0

DOI: 10.1046/j.1460-2687.2001.00068.

Abstract

A Fencing mask with a transparent polycarbonate visor has recently been introduced which replaces the conventional metal mesh mask. The visor is constructed using two polycarbonate sheets, one forming the structural layer and the other a removable scratch plate. This multilayer system has inherent disadvantages with regard to optical transmission, since the intensity of reflected light is related to the difference in refractive index of the materials. As such, a large step change in refractive index leads to greater reflective losses, thereby lowering the intensity of transmitted light. The magnitude of this reflective loss may be calculated using the Fresnel equations.Light scattering and the appearance of a `ghost' image are a manifestation of the Fresnel re ̄ections. Light re ̄ected at one surface undergoes internal re ̄ection and thus appears to originate in a different optical plane. Since there are re ̄ective losses at every interface, it is essential to reduce the re ̄ectivity at each step.Results presented here show that the optical properties of an air-filled multilayer system offer substantially lower transmission than a liquid-filled structure. Modelling of this simple modification to the existing mask design has been shown to increase the theoretical transmission of light by a minimum of 7%, with experimental work substantiating these findings.

Item Type:Journal article
Faculties and Schools:Faculty of Computing & Engineering
Faculty of Computing & Engineering > School of Engineering
Research Institutes and Groups:Engineering Research Institute > Nanotechnology & Integrated BioEngineering Centre (NIBEC)
ID Code:937
Deposited By:Dr Richard Holmes
Deposited On:23 Nov 2009 13:47
Last Modified:18 Aug 2011 11:46

Repository Staff Only: item control page