No abstract

Three-dimensional (3D) printing technology provides advanced technical support for designing personalized bone tissue engineering scaffold. In this study, two porous diffusing models, namely, average and layered perforated cylindrical scaffolds, were designed for bone tissue engineering scaffold. The designed models were fabricated by liquid crystal display mask stereolithography printing. Structural design and finite element mechanical analysis were conducted. 45S5 bioglass was selected as the raw material for preparing the printing inks for bone tissue engineering scaffolds. By adjusting the viscosity and temperature of the slurry, the maximum proportion of 45S5 bioglass (40 wt%) was added into the photosensitive resin for preparing 3D printing slurry. Our results indicated that an optimized sintering condition includes the debinding rate (0.5°C/min), and temperature raising rate (5°C/min) and sintering temperature (1100°C) were proposed to sinter 45S5 bioceramic scaffolds. The amorphous 45S5 bioglass showed good crystallization after sintering, and the scaffold porous structure showed good integrity. Micropores were observed in the struts which interconnected with each other. Moreover, the porosities were tested as 57% and 45% with a uniform pore distribution. The shrinkage rate was about 10% during sintering process due to binder burning and crystallization shrinkage. The compressive strength of the sintered scaffold was 0.71 ± 0.048 MPa and 2.13 ± 0.054 MPa, respectively, which are consistent with the finite element mechanical analysis simulation results. In conclusion, the layered perforated 45S5 bioglass scaffold shows good mechanical properties and porosity, indicating that it could be a promising candidate for bone tissue engineering.

Purpose – In a mixed flow production environment, interactions between production planning and scheduling are critical for mixed flow distributed manufacturing management. The purpose of this paper is to assist manufacturers in achieving real-time ordering and obtaining integrated optimization of shop floor production planning and scheduling for mixed flow production systems. Design/methodology/approach – A double decoupling postponement (DDP) approach is presented for production dispatch control, and an integrated model is designed under an assemble to order (ATO) environment. To generate “optimal” lots to fulfil real-time customer requests, constant work in progress (CONWIP) and days of inventory dispatching algorithms are embedded into the proposed DDP model, which can deal with real-time ordering and dynamic scheduling simultaneously. Subsequently, a case study is conducted, and experiments are carried out to verify the presented method. Findings – The proposed DDP model is designed to upgrade a previous CONWIP method in the case study company, and the proposed model demonstrates better performance for the integration of production planning and scheduling in mixed flow manufacturing. As a result, the presented operation mechanism can reflect real-time ordering information to shop floor scheduling and obtain performance metrics in terms of reliability, availability and maintainability. Research limitations/implications – The presented model can be further proliferated to generic factory manufacturing with the proposed logic and architecture. Originality/value – The DDP model can integrate real-time customer orders and work in process information, upon which manufacturers can make correct decisions for dispatch strategies and order selection within an integrated system.

flexsim7.0 software is conducted to testify the proposed model and mechanism. The simulation results show that the improved solutions are achieved with the indicators of inventory quantity control, customer order fulfillment, and cycle time reduction.

Access to this document was granted through an Emerald subscription provided by emerald-srm:464745 [] For AuthorsIf you would like to write for this, or any other Emerald publication, then please use our Emerald for Authors service information about how to choose which publication to write for and submission guidelines are available for all. Please visit www.emeraldinsight.com/authors for more information. About Emerald www.emeraldinsight.comEmerald is a global publisher linking research and practice to the benefit of society. The company manages a portfolio of more than 290 journals and over 2,350 books and book series volumes, as well as providing an extensive range of online products and additional customer resources and services.Emerald is both COUNTER 4 and TRANSFER compliant. The organization is a partner of the Committee on Publication Ethics (COPE) and also works with Portico and the LOCKSS initiative for digital archive preservation. AbstractPurpose -In a complex semiconductor manufacturing system (SMS) environment, the implementation of dynamic production scheduling and dispatching strategies is critical for SMS distributed collaborative manufacturing events to make quick and correct decisions. The purpose of this paper is to assist manufacturers in achieving the real time dispatching and obtaining integrated optimization for shop floor production scheduling. Design/methodology/approach -In this paper, an integrated model is designed under assemble to order environment and a framework of a real time dispatching (IRTD) system for production scheduling control is presented accordingly. Both of the scheduling and ordering performances are integrated into the days of inventory based dispatching algorithm, which can deal with the multiple indicators of dynamic scheduling and ordering in this system to generate the "optimal" dispatching policies. Subsequently, the platform of IRTD system is realized with four modules function embedded. Findings -The proposed IRTD system is designed to compare the previous constant work in process method in the experiment, which shows the better performance achievement of the IRTD system for shop floor production dynamic scheduling and order control. The presented framework and algorithm can facilitate real time dispatching information integration to obtain performance metrics in terms of reliability, availability, and maintainability. Research limitations/implications -The presented system can be further developed to generic factory manufacturing with the presented logic and architecture proliferation. Originality/value -The IRTD system can integrate the real time customer demand and work in process information, based on which manufacturers can make correct and timely decisions in solving dispatching strategies and ordering selection within an integrated information system.