In the modern manufacturing industry, the role of computer-aided process planning (CAPP) is becoming increasingly crucial. Through the application of new technologies, experience, and intelligence, CAPP is contributing to the automation of manufacturing processes. In this article, the integration of a proposed CAPP system that is named as BKCAPP and G-code generation module provides a completed CAD–CAPP–CNC system that does not involve any manual processing in the CAM modules. The BKCAPP system is capable of automatically performing machining feature and operation recognition processes from design features in three-dimensional (3D) solid models, incorporating technical requirements such as the surface roughness, geometric dimensions, and tolerance in order to provide process planning for machining processes, including information on the machine tools, cutting tools, machining conditions, and operation sequences. G-code programs based on macro programming are automatically generated by the G-code generation module on the basis of the basic information for the machining features, such as the contour shape, basic dimensions, and cutting information obtained from BKCAPP. The G-code generation module can be applied to standard machining features, such as faces, pockets, bosses, slots, holes, and contours. This novel integration approach produces a practical CAPP method enabling end users to generate operation consequences and G-code files and to customize specific cutting tools and machine tool data. In this paper, a machining part consisting of basic machining features was used in order to describe the method and verify its implementation.

To enhance cell adhesion and cell interactions for diverse tissue engineering applications, polycaprolactone (PCL) has been integrated with few biomaterials such as ceramic (i.e. tricalcium phosphate - TCP), hydrogel (i.e. sodium alginate - SA), and synthetic polymer materials (i.e. polyethylene glycol - PEG). Each type of additive material presents typical characteristics, the comparison among these three biomaterial types is currently inadequate. In this study, a 3D printer using direct powder screw extrusion technique was applied for fabricating three types of PCL-based composite scaffolds (namely, PCL-PEG, PCL-SA, and PCL-TCP) which are representative of each type of additive material. The experimental evaluation on the printability, scaffold morphology, surface roughness, hydrophobicity, and cell proliferation of these PCL-based composite scaffolds were compared under the same conditions. The results demonstrated that the additive materials with an amount from 20 wt% have a notable effect on the printability of PCL matrix material and significant enhancement of cell proliferation. The incorporation of PEG with PCL is the most effective choice to increase the hydrophilicity of the scaffold surface. The PCL-SA scaffold provided a more favorable environment for cells at the initial stage, whereas the PCL-TCP scaffold demonstrated superior cell proliferation over time. These findings also demonstrate the feasibility of a direct powder screw extrusion printhead on 3D printing for composite scaffolds in tissue engineering applications.

Polycaprolactone (PCL) is a widely employed biodegradable thermoplastic polymer that finds extensive use in the development of scaffolds for hard tissue engineering, including bone and cartilage regeneration. Different 3D printing methods are available for fabricating PCL-based scaffolds, utilizing various forms of raw materials such as powder, pellets, and filaments. The selection of an appropriate technique for a specific application demands a thorough understanding of the characteristics associated with each method. To ensure standardized and uniform comparisons, this study employs a multi-head 3D printer equipped with three distinct printheads: screw-based extrusion (SBE), filament-based deposition (FBD), and melt-based extrusion (MBE). The performance of these printing techniques is evaluated based on several criteria, including printing speed, printing accuracy, equipment cost, pre-printing time, and waste material generation. Thorough experimentation is conducted to assess the performance and determine the strengths and limitations of each printing technique in scaffold fabrication. The findings of this investigation offer valuable insights and recommendations for selecting an appropriate printing technique tailored to specific requirements in tissue engineering applications.