Patent ID: 11919238
Assignee: STRATASYS, INC.
Field: Other special machines (Mechanical engineering)
Classification: CPC B  G | IPC B  G

Claim 20:
21. A method of printing a part with an additive manufacturing system, comprising:
providing a first portion of the part formed of a thermoplastic material, wherein the first portion includes an outer surface, wherein a portion of the outer surface is at a temperature below a material-specific bonding temperature comprising a glass transition temperature for an amorphous thermoplastic material and melting temperature for a semi-crystalline thermoplastic material;
actively pre-heating the outer surface the first portion of the along an upcoming tool path to a temperature at or above the material-specific bonding temperature and below a degradation temperature of the thermoplastic material;
extruding molten thermoplastic material onto the outer surface of the first portion of the part along the pre-heated tool path to form a newly extruded road while the temperature along the pre-heated tool path remains at or above the material-specific bonding temperature and below the degradation temperature, wherein the additional thermoplastic is the same as or different from the thermoplastic material forming the first portion of the part, thereby forming the newly extruded road bonded to the first portion of the part that becomes an additional portion of the part; and
actively cooling the newly extruded road to remove heat imparted by the preheating step and the extruding step such that a thermally stable temperature in a localized region of the newly extruded road is reached, wherein the thermally stable temperature comprises a temperature below the glass transition temperature or below the melting temperature of the thermoplastic material in the newly extruded road and the first portion of the part wherein the steps of actively preheating, extruding and actively cooling are performed in a rapid cyclic fashion in less than ten seconds, and wherein performing said steps of actively preheating and actively cooling in such rapid cyclic fashion results in increased interlayer adhesion between the newly extruded road and the first portion of the part while retaining a dimensional integrity of the part in the localized region.