Aluminum doors and windows of the three windows and doors is the three anti-
(Hereinafter referred to as the official) there is no "two anti-door", 'three anti-door' this argument, only a separate fire doors, security doors, explosion-proof doors, anti-noise doors (or noise doors) Moisture-proof door waterproof doors, insulation doors, etc., the relevant departments of the state to some of the categories of type of inspection, the qualified to give the relevant certificate of approval, and never to a manufacturer or a type of door to test the ' Door ',' three anti-door ',' four anti-door 'and other doors for recognition. The reason is that the National Fire Testing Center on the fire door for type approval, the national complete testing center will no longer be issued on the anti-theft door security certificate, and vice versa. So the official never recognized 'two anti-door', 'three anti-door' this reference.
Then the 'two anti-door', 'three anti-door' and where come from? This reference mainly from the folk saying, 'two defense door'
Generally refers to the steel fire, security door, 'three anti-door' generally refers to the wood fire, anti-theft, anti-noise door.
Anti-theft
This is the basic function of the door, the door can be tamper, the use of general hand tools, 15 minutes can not pry open. Door locks can be anti-drilling, there is a certain scientific and technological content.
Fire protection
The door is made of metal, in the fire, a certain period of time, to prevent the fire and smoke spread, to prevent the spread of fire.
Anti - noise
Door body insulation material, cold and anti-noise, install the three anti-door, you can no longer install ordinary doors.
