| 摘要 |
The invention provides a method for encapsulating extrudable materials within an extruded stream of another extrudable material. The produced product is an extruded material that contains one or more different materials embedded within the first material. The boundaries between this first encapsulating material and the material or materials thus encapsulated are well-defined and distinct. In the preferred embodiment, the encapsulated and encapsulating materials are plasticized thermoplastic resins. A stream of the encapsulating material is formed in a first extrusion channel. A plasticized stream of the material to be encapsulated, coated by a coextruded layer of the encapsulating material, is simultaneously formed and travels through a second extrusion channel. At any selected time, a cross-sectional segment of the second stream may be removed from its stream and replaces a similar cross-sectional portion of the stream removed from the first channel. The resulting stream of material extruded from the first channel contains discrete and uniformly shaped units of the second material encapsulated within a continuous stream of the first material.
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