Flame-retardant B1-grade polyurethane foam material for building material accessories as well as preparation method and equipment

The invention discloses a flame-retardant B1-grade polyurethane foam material for building material accessories which is prepared from the following raw materials in parts by weight: a component A composed of 55-65 parts of a flame-retardant polyester, 32-37 parts of a flame-retardant polyether, 3-5 parts of a cross-linking agent, 1-2 parts of a catalyst, 2-5 parts of a foam finishing agent and 10-20 parts of a foaming agent; and a component B composed of 20-35 parts of an isocyanate and 6-8 parts of a flame retardant modifier. The invention also provides a preparation method and equipment thereof. According to the invention, the components, the preparation method and the equipment of the foam material are synchronously improved, so that the flame retardance of the polyurethane foam reaches the B1-level standard, no flame retardant is needed to be added into the combined polyether, and the flame retardance of the material is long lasting. The flame-retardant groups are implanted into isocyanate, so that the c