工业折叠门生产厂家按国标标准防火卷帘门必须设置门楣结构，目前普遍使用的是没有门楣的工业折叠门，火灾中阻止不了火势向上形成的强大冲击，烟气通过门楣向外蔓延。
Industrial folding door manufacturers five-sided structure must be set in accordance with the gb standard fire shutter, there is no signage industry at present commonly used folding door, prevent the fire in fire upwards to form strong impact, the flue gas through the lintel spread outward.
门楣处的密封性是防火、防烟的关键所在，若安装没有门楣结构的工业折叠门，则形同虚设。工业折叠门门帘厚度即帘板所用钢板的厚度，目前普遍存在着偷工减料现象，有些厂家送交测试时采用较厚钢板的帘板，取得合格证后，则改用较薄的进行生产。由于在安装现场工业折叠门的帘板厚度不易测量，容易蒙混过关，因此有很多工业折叠门，因门帘厚度都未达到要求，降低使用寿命与耐火时限。在大型门导轨上应有一根能承受高强度的主构件，可是很多厂商用简易的轻型导轨来代替。如遇到火灾，门帘易从导轨脱出，起不到防火作用。
So industrial folding door lintel place the sealing is the key to fire, smoke, if installation without folding door lintel structure of industry, is useless. Industry namely shade fold door curtain thickness plate thickness of the steel plate used, there is a widespread phenomenon of cut corners at present, some manufacturers to test plate is made of thick steel plate in the shade, obtain certificate of approval, please use thinner. Due to the installation site industrial folding door curtain plate thickness is not easy to measure, easy to muddle through, thus there are a lot of folding door industry, due to the thickness of the curtain did not meet the requirements, reduce time limit and service life of refractory. In big door guide rail should be a can withstand the high intensity of main component, but many manufacturers use simple light rail instead. Such as fire, door curtain from guide out easily, not fire.