| 摘要 |
<p>Soft chairs or other seats are assembled from a hollow shell of flexible, elastic material partially supported by an internal lining of stiffer but also flexible elastic material. The base of the shell is made of a porous material to allow air to be expelled from within the shell and to be replaced by atmospheric air or the shell recovers its shape after use. The components are flexible enough to be deformed or compressed by a person's wt., without complete collapse. Pref. the ratio of the overall ht. (H) of the shell to that (h) of the internal lining is at least 1.6, pref. about 2. Pref. the components are of complementary forms of expanded polyurethane, that of the shell being a 25 PL grade (characteristics density of about 23 kg/m3; elongation to break greater than 220%; closed cell structure), that of the liner being a 30/70 grade (i.e. density of about 28 kg/m3; elongation to break greater than 220%; closed cell structure). Typical, shell and liner are each about 5-10 cm thick, though the liner thickness may diminish towards its upper rim. The base may comprise 150 superimposed layers, the lower being of 30/70 grade and the upper, internal layer being of 24/40 grade (i.e. apparent density 24 kg/m3 and elongation to break being at least 230%). Opt. the shell is covered with a thin dense skin 30-70 microns thick polyurethane pigmented in bulk and lightly bonded to the shell with adhesive.</p> |
