Composite five-door is generally hot composite structure. Mostmanufacturers door core material into two: one for Chinese firtimber; two for the perforated plate.The first Chinese fir timbermanufacturers are most often used in the keel structure, and a lotof people would think as long as the keel is not good, that is coreto do, this is only a one-sided argument that there is hollow keelplace is not good, are jerry-building, is not true. In fact, theuse of the keel is more scientific and reasonable, each object hashis performance, by the surrounding environment factors such astemperature changes, wood will Expansion and Contraction . Keelroom is not easy to deformation, and indeed the whole of the doorcore material is easily deformed, because it does not void; haveone point from a mechanical perspective, the keel structure, reducestress, but also a kind of deformation good measure.??????Material: the majority of manufacturers are used for thesubstrate medium density fiberboard, or MDF. Such a plate is noteasy to crack, good flatness, stable performance. Some clients donot consider the MDF moisture, the general formal large-scalemanufacturers in the kitchen and the back of door pocket makewaterproof paint.