Application Of QFD/TRIZ In The Development Of Honeycomb Sandwich Structural Wooden Acoustic Boards

Wooden acoustic boards (WAB) received extensive attention because of their merits of sound absorption, beautiful color and texture, stereoscopic structure, easy processing, easy to be assembled and so on. There are some problems existed in the development of WAB, such as less of research and development target; lack of communications between the enterprisers and customers of WAB; inadequate structure, shape, sound absorbing and frequency band; preparation and sound absorption mechanism of the new wooden acoustic boards, unabundant product form, thus it is of great significance to develop the new-type WAB.The paper analyzed and developed new-type WAB by integrating Quality Function Deployment (QFD) and TRIZ method. First, it explicited the status and development trends of WAB based on patent analysis and technology evolution law, and revealed the research objectives and development orientations on WAB. Second, it established the Quality House table which reflected the importance degree of WAB technique requirements. Third, it illuminated the technological innovation conflicts of WAB, and found the honeycomb sandwich structural WAB be the solution way of improving the sound absorption performance. Fourth, it designed and fabricated the WAB composed of perforated face board and single paper honeycomb board as sandwich, which demonstrated a good sound absorption in high-middle frequency band. Fifth, it designed and fabricated another type of WAB composed of perforated face board and double-layer paper honeycomb board as sandwich, which demonstrated a high and wideband noise reduction performance. The main conclusions were as follows:(1) The development of WAB went through the following steps:acoustic board of wood strand/cement compositeâ†'hole or groove style WABâ†'Helmholtz resonators type WABâ†'corrugated slot style WABâ†'adjustable sound absorption WAB. Currently, the WAB is in the growth stage, and is in a bottleneck stage.(2) The future evolution of WAB maybe:use of light weight, high strength and low-cost wood plate as substrate; enhancing the decorative performance of face board; combination of sound absorption, sound insulation and heat insulation; changeable style; addition of activated carbon, nano-TiO2and nano silver; improving the local acoustic unit; making into absorption accessories; assembling pulleys on WAB; adding the foldable pieces; splitting the structure or changing the aperture, etc.(3) From the Quality house table of product planning, it could be drawn that the importance of technical requirements for WAB is as follows:sound-absorbing performance and price are the most critical factors, followed by the environmental and decorative performance, while size and installation are comparatively inferior. From the quality house for components configuration, it could be drawn that the sequence of part features and engineering measures for WAB is that:the core material is the primary component, followed by selection of decorative face material.(4) Based on TRIZ, to solve the confliction between improving the perforation percentage and not reducing the strength, it initiated the solutions as, perforated honeycomb sandwich board, reinforced honeycomb sandwich board and adjustable structure board. A solution to solve the confliction between perforating or milling grooves and wasting of wood resources is the selection of paper honeycomb layer as the sandwich of WAB.(5) The single-layer honeycomb sandwich WAB presented a good acoustic absorption performance in medium and high frequency, and the coefficient of noise reduction can reach50%at the following structural parameters:perforation diameter of face board,6mm; perforation ratio of face board,3%; the thickness of honeycomb core board,30mm,40mm or50mm.(6) The double-layer honeycomb sandwich WAB obtained ideal results both on the sound absorption and in the wide frequency range. The noise reduction coefficient (NRC) can achieve60%when selecting the structural parameters as following:anterior honeycomb thickness,10mm; latter honeycomb thickness,20mm; perforation diameter of face board,2-6mm; perforation ratio of face board,3to10%.