| 摘要 |
PURPOSE:To improve an internal loss and make it possible to make an acoustic pressure frequency characteristic flat by laminating or soaking a thermoplastic resin onto or into a compound material where synthetic pulp and synthetic fiber are mixed and by metling synthetic pulp to bind fiber. CONSTITUTION:Synthetic pulp consisting of high-density polyethylene and acrylic fiber are mixed with rate 1:1 to form a compound material of an approximately 40g/m<2> scale. This compound material is caused to include emulsion consisting of ionomer resin and is dried, and after that, synthetic pulp is melted to form an edge material of an approximately 60g/m<2> scale. Elastic modulus E of this edge material is 4.5X10<9>dyn/cm<2>, and the internal loss is tandelta=0.10. Normally, a paper edge has elastic modulus E of 12X10<9>dyn/cm<2> and an internal loss of tandelta=0.04. Thus, this edge material has no air-permeability and has a large internal loss, so that the acoustic pressure frequency characteristic of the speaker can be made flat. |
