English
Generally, side feeding is used, and the melt flows symmetrically along the central axis on the overlapping surface of each layer, rather than the traditional cylindrical flow. Its advantages are that the number of layers in the machine head can be arbitrarily combined, the structure is simple, and the temperature of each layer can be controlled separately. This allows for separate control of the temperature of each layer according to the needs of different materials, effectively preventing material decomposition. The layer by layer stacking of the stacked die head allows the melt to flow in each channel, and the change in the number of layers does not affect the size of the inner and outer diameters of the die head. The author believes that due to the flow channel being on a flat or inclined surface, the pressure of the melt cannot be balanced and adjusted, making it difficult to seal the melt and requiring many screws for sealing.
Cone stacking
The design concept of the conical stacking co extrusion head is the same as that of the flat stacking head, except that it adopts a conical modular unit structure, each unit is composed of a pair of short conical modules, and the flow channel is on the conical cylindrical surface. Its body strength is higher than that of the flat stacking head, and it can withstand higher pressure from the melt and has better sealing performance. The conical stacking co extrusion head is divided into two types, namely the upper oblique stacking type and the lower oblique stacking type.
