In the ''blow filler'' indeed the pneumatic pressure is generated directly from the user of the pen that must blow (from this the name comes from) inside the barrel through a special hole drilled on the bottom of the same. The pressure thus generated compresses the internal sac and allows the subsequent filling of the pen. | In the ''blow filler'' indeed the pneumatic pressure is generated directly from the user of the pen that must blow (from this the name comes from) inside the barrel through a special hole drilled on the bottom of the same. The pressure thus generated compresses the internal sac and allows the subsequent filling of the pen. |