This invention relates generally to blow molding machines and more particularly to an extrusion head that has an accumulation chamber therein from which thermoplastic material can be discharged intermittently.
Two significant problems presently exist in extrusion heads of the accumulator type, namely, the problem of eliminating the undesirable weld line which occurs in the head when the plastic from the extruder flows in two different paths around the mandrel and comes together to form the melt weld line. The second problem is the problem of down time during changeover of the accumulator head from one color or plastic to another. Present heads pose the continual threat of dead spaces which must be individually purged of residual plastic material before a color change can be effected.
The principal object of this invention, therefore, is to provide an improved accumulator head which emobodies solutions to the above described problems.
USPTO Backgrounds
USPTO Backgrounds