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Hollow Glass Microspheres Dispersion Improvement: A Technical Approach for Themoset Resin Composites

IP.com Disclosure Number: IPCOM000239379D
Publication Date: 2014-Nov-03
Document File: 3 page(s) / 1M

Publishing Venue

The IP.com Prior Art Database

Abstract

Hollow glass microspheres (HGM) are low density performance additive that gives a lot of benefits to thermoset composites. Thermoset resins (TR) are largely used in RTM process that is a mechanical process using a closed mold system that requires low viscosity thermoset resin to fill the mold. Some cases the flotation of HGM can occur. In this work was investigated some thixotropic agents that could prevent this phenomenon in very low addition.

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Hollow Glass Microspheres Dispersion Improvement: A Technical Approach for Themoset Resin Composites

Abstract:

Hollow glass microspheres (HGM) are low density performance additive that gives a lot of benefits to thermoset composites. Thermoset resins (TR) are largely used in RTM process that is a mechanical process using a closed mold system that requires low viscosity thermoset resin to fill the mold. Some cases the flotation of HGM can occur. In this work was investigated some thixotropic agents that could prevent this phenomenon in very low addition.

Introduction

Hollow glass microspheres (HGM) commercialized as 3MTM Glass bubbles can provide innovative users with new and unique material and design solutions. They render polymers with lower density which is crucial in weight sensitive industries such as in transportation and aerospace. They reduce total systems costs and shipping costs for parts. In addition to weight reduction, they reduce warpage and excessive shrinkage of molded or extruded plastics which helps reduce scrap and rejects. Glass bubbles have a neutral impact on carbon footprint of finished plastic parts which helps environmental sustainability during the use period of the part.

HGM are geometrically isotropic fillers with an aspect ratio of one and have intrinsically low surface areas due to sphericity. This is the main reason why they can be incorporated at very high volume loadings compared to inorganic particles and still exhibit acceptable viscosity for further polymer processing and shaping operations. Fillers with high geometrical anisotropy are more efficient for reinforcing composites compared to glass bubbles. Glass bubbles, when used along with other reinforcing fillers, can provide excellent weight, performance, processing and dimensional stability characteristics.

Resin Transfer Molding (RTM) is a mechanical process using a closed mold system. Catalyst and resin are pumped in under pressure from two separate containers into a closed mold containing glass reinforcement, usually continuous strand mat. The resin is pumped into the mold until excess resin escapes through vent tubes placed at the far end of the flow pattern. The system is then allowed to cure for a specific period of time after which the mold is opened and the part is removed. RTM requires low viscosity resin, typically less than 250 cps, which can be pumped easily and readily fills the mold and wets the glass.

Thermoset resins (TR) are largely used in RTM. They have several properties of filling and reinforcement and a broad range of characteristics and uses. The TR's are the first-class matrix for general purpose and are very used for mass produced composites with a good technical level, generally with glass fiber reinforcement. They are found in applications as: shipbuilding, bus, trucks, automotive and railway bodies, tanks, etc.

HGM is an excellent additive for providing weight reduction when incorporated into TR for production of...