Improvement of the Shock Absorption Ability of a Face Guard by Incorporating a Glass-Fiber-Reinforced Thermoplastic and Buffering Space

Abstract

This study aimed to evaluate the shock absorption ability of trial face guards (FGs) incorporating a glass-fiber-reinforced thermoplastic (GF) and buffering space. The mechanical properties of 3.2 mm and 1.6 mm thick commercial medical splint materials (Aquaplast, AP) and experimental GF prepared from 1.6 mm thick AP and fiberglass cloth were determined by a three-point bending test. Shock absorption tests were conducted on APs with two different thicknesses and two types of experimental materials, both with a bottom material of 1.6 mm thick AP and a buffering space of 30 mm in diameter (APS) and with either (i) 1.6 mm thick AP (AP-APS) or (ii) 1.6 mm thick GF (GF-APS) covering the APS. The GF exhibited significantly higher flexural strength (64.4 MPa) and flexural modulus (7.53 GPa) than the commercial specimens. The maximum load of GF-APS was 75% that of 3.2 mm AP, which is widely used clinically. The maximum stress of the GF-APS only could not be determined as its maximum stress is below the limits of the analysis materials used (<0.5 MPa). Incorporating a GF and buffering space would enhance the shock absorption ability; thus, the shock absorption ability increased while the total thickness and weight decreased.

Air Permeability, Shock Absorption Ability, and Flexural Strength of 3D-Printed Perforated ABS Polymer Sheets with 3D-Knitted Fabric Cushioning for Sports Face Guard Applications

“…The ABS materials exhibited greater flexural strengths than that of the AP material. A core material with a higher flexural strength will diffuse impacts more effectively [ 17 , 46 ]. This was confirmed by the results of the ML measurements in this study.…”

Mandibular Condylar Fracture in a Professional Soccer Goalkeeper: How to Achieve Early Return-to-Play—A Case Report

“…15,16 The face guard is mainly composed of 2 layers of hard thermoplastic material and soft cushioning material to provide shock absorption properties. 4,8,15,16 The inner layer reduces the impact force and spreads it over a wider area. 4 Polymethyl methacrylate, polytrimethyl hexamethylene terephthalamide, Kevlar, and carbon fiber (Torayca, Toray, Tokyo) are used for the outer surface of face guards for professional soccer players.…”

Use of the fiberglass reinforcement method in thermoplastic mouthguard materials to improve flexural properties for enhancement of functionality

“…Other studies stated that reinforcing thermoplastic denture base resin by impregnating it with fiberglass is a useful method to improve overall mechanical properties, yielding higher elastic modulus and improved flexural properties with satisfactory reinforcing effects 26,27) . Studies by both Abe et al 18) and Wada et al 19) proved that in the case of sports protective equipment made using thermoplastic core materials for faceguards, reinforcing with fiberglass results in improved flexural properties and better shock absorption capabilities. Using such a procedure also might lead to a decrease in the total thickness and weight of the faceguard to lower values than for one that is commercially or conventionally custom-made.…”

“…Reinforcing thermoplastic material with fiberglass is a frequently used and unique technique to increase the shock absorption ability of protective sports equipment such as face guards. Reinforcing face guard thermoplastic material with fiberglass already has proved very effective at improving shock absorption ability and decreasing the total thickness and weight of the material 18,19) . A first, this study evaluated the effect of fiberglass reinforcement of conventional mouthguard materials (EVA and PO) on their flexural properties to develop a high functionality for mouthguards.…”

“…In another study, Ihara et al performed a delamination test on PO and EVA materials, which showed that both materials had good adhesive strength 21) . Shock absorption ability and flexural properties of fiberglass-reinforced thermoplastic material for face guards have already been evaluated 18,19,22) . However, adding different materials like fiberglass cloth to the thermoplastic material used for fabrication of mouthguards, then testing its flexural properties and adhesive strength, has not yet been investigated.…”