Apparatus for making a spunbond web from filaments

An apparatus for making a spunbond web, the apparatus comprising:

• means for heating polypropylene having an average isotactic sequence length of at least 65 to an onset temperature of at least 120°;
• a spinneret having a nozzle plate forming a plurality of nozzle holes homogeneously distributed across the entire nozzle plate and connected to the means for heating for receiving the heated polypropylene and extruding filaments of the heated polypropylene through the homogeneously distributed nozzle holes such that the filaments travel in a flow direction and are spaced apart homogeneously in a direction transverse to the flow direction;
• a monomer suction device downstream of the spinneret and through which the homogeneously spaced and extruded filaments move in the flow direction;
• a cooling chamber downstream of the monomer suction device and divided into upper and lower cooling compartments through which the filaments move in the direction after exiting the monomer suction device;
• blower means for
• feeding cool process air into the cooling chamber to cool the filaments in the compartments thereof,
• sucking a portion from the upper cooling compartment and into the monomer suction device at a volumetric flow rate VM, and
• feeding another portion of the process air from the upper compartment at a volumetric flow rate V1 into the lower cooling compartment;
• control means connected to the blower means for setting the flow rates relative to each other such that a volumetric flow-rate ratio VM/V1 is 0.1 to 0.3;
• a stretcher downstream of the lower cooling compartment for receiving and stretching the filaments therefrom;
• and
• a deposition device downstream of the stretcher for receiving the stretched filaments.