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PRODUCTION • PROCESSING • HANDLING


New technology in polymeric materials has led to the development of an epoxy-based paste grade product that can be applied onto oily, wet and even underwater surfaces, which eases some of the typical surface preparation requirements. Tis material is effective at displacing contaminants from the substrate via a strong electronic affinity with the metallic substrate, which allows the epoxy to penetrate the profile and create a strong mechanical bond even without grit-blasting. Surfaces only need to be prepared to SSPC-SP 11 (power tool cleaning to bare metal).


ALTERNATIVE SOLUTIONS AND THEIR LIMITATIONS Adhesives currently available on the market do not tend to perform well when bonding to oil-contaminated surfaces and substrates in wet or aquatic environments, especially at low temperatures. Commercial surface- tolerant bonding adhesives are slow to cure and have relatively low bond strengths compared to adhesives formulated for dry applications. Traditional acrylic adhesives have longer set times that slow assembly processes and lower impact resistance, resulting in brittle bonds. Tese materials also have a limited shelf life and high odour levels that can cause Health and Safety concerns. Adhesives fall short for use in adverse conditions for a variety of reasons. In two-component adhesive systems, the chemically reactive components needed for


curing generally react low in the presence of water and oil and create poor quality bonds. Light curable adhesives generally require external energy sources; this makes them less desirable from a logistical standpoint. Few thermally cured adhesives result in rapid, high-strength adhesion, and even fewer function in high-moisture environments. Moisture reduces adhesion and low water temperatures reduce exothermic cure for underwater adhesives. As a result, underwater adhesives either cure poorly or require long cure times to obtain sufficient adhesive properties.


LATEST TECHNOLOGY DEVELOPMENT Several market-driven requirements have been identified for a fast curing product with surface tolerance. Tere are instances where surface preparation is an issue and contamination is common, therefore the substrate cannot be fully cleaned or ideally profiled as required for many repair materials. Te desire to minimise downtime and deal with adverse application conditions creates a need for a fast curing, surface tolerant repair material. New technology in polymeric materials has led to the development of the first fast curing epoxy-based, surface tolerant emergency repair metal, called Belzona 1212. Tis material opens new opportunities when ideal surface preparation of the metallic substrate cannot be achieved due to lack of time


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Fig.1. Adhesion of Belzona 1212 to contaminated mild steel surfaces prepared to SSPC-SP11/ISO 8501-01 St3 (power tool cleaned)


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