SCIGRIP adhesives qualified for composite bonding processes with Ferretti

SCIGRIP (Durham, NC, US) announced June 12 its methacrylate adhesives were approved for use in Ferretti's moulding yard.

SCIGRIP and its Italian distributor Mastikol (Turin, Italy) have been working together with the Ferretti Group (Forlì, Italy) with the aim of qualifying Lloyds approved SG230 HVA to improve production efficiencies through smarter composite bonding processes.

According to SCIGRIP, one of the parameters that has the most impact on the structural and quality performance of manufactured components is bonding, which often has challenging requirements. In order to consolidate the construction process, as well as implement a new production line, Ferretti and Mastikol explored the possibility of replacing polyester-based adhesives with SCIGRIP’s methacrylate adhesives, and following collaboration and a period of testing and validation, SCIGRIP methacrylate adhesives were approved for use in Ferretti's moulding yard.

The production lines at the M&S Composite Manufacturing Yard – Ferretti’s assembly department – are based on the concept of bonding together structural elements that are built off-site to maximize repeatability in the building stages, resulting in shorter production cycle times. The yard requires the high performance structural bonding (in terms of both mechanical bond strength and fatigue performance) offered by SCIGRIP’s MMA adhesives, when bonding the fibre-glass hull shell and the structural elements, specifically those of the engine room and other key load bearing parts, that are laminated off-line. Adopting a solid and reliable process and using materials that were independently certified for marine use were key requirements for the bonding process.

The product specified by Mastikol was SCIGRIP’s Lloyd’s approved SG230 HVA adhesive, supplied in 189-L drums.   This high viscosity, thixotropic adhesive can also be applied in void free bead sizes up to 80mm in thickness without sagging or any reduction in bonding performance.  Different hardener speeds were supplied allowing customized working times to match the required joining times.

Given the large bonding surface area, it was necessary to use an application system that dispenses a large quantity of product in the shortest possible time. Mastikol and SCIGRIP also specified a special drum extruder to dispense the product. The large drum product format makes it possible to apply the product without any production stoppage time for changing the drums and using a machine optimizes the accuracy of the component mixing.

Further optimization of the production process is being studied for the future, which will reduce the surface preparation stage and make full use of another feature of SCIGRIP’s SG230 HV adhesive: its high capacity to adhere to smooth, gel-coated and moist surfaces makes it possible to avoid/reduce preliminary abrasion of the composite.

This will further reduce the production cycle time, while also reducing the production of dust that is often produced by this sanding and grinding.