COST COMPARISON OF ALTERNATIVE CONSOLIDATION METHODS FOR LARGE SCALE THERMOPLASTIC STRUCTURES

摘要

A number of approaches to consolidation are available or envisioned for thermoplastic prepregmaterials. This study compares the economics of three consolidation processes: (1) traditionalfilm bagging, (2) spray-on silicon membranes, and (3) in situ consolidation without bagging.The comparison was made for large scale sandwich structures manufactured by Automated TapeLayup (ATL), specifically for the production of boat hulls and related framing members up to 60meters in length. A time-based activity cost model was developed with parameters derived fromexperiments, historical data, reports in the literature, and various theories of ship design. Theresults indicate that spray-on membranes are more cost effective than film bagging for vessellengths in excess of about 20 meters. In addition, an in situ or on-line consolidation process iscost competitive with film bagging provided that the material deposition and consolidation rateremains at no less than 50% of the deposition rate for film bagging. Compared to spray-onmembranes, an in situ consolidation process is cost competitive for large vessels (60 m) as longas the deposition and consolidation rate is no less than 80% of the deposition rate used in thespray-on process. Cost savings of up to 10% can be realized over traditional film bagging.