One core concept of Industry 4.0 is establishing highly autonomous manufacturing environments. In the vision of Industry 4.0, the product leads its way autonomously through the shopfloor by communicating with the production assets. Therefore, a common vocabulary and an understanding of the domain’s structure are mandatory, so foundations in the form of knowledge bases that enable autonomous communication have to be present. Here, ontologies are applicable since they define all assets, their properties, and their interconnection of a specific domain in a standardized manner. Reusing and enlarging existing ontologies instead of building new ontologies facilitates cross-domain and cross-company communication. However, the demand for reusing or enlarging existing ontologies of the manufacturing domain is challenging as no comprehensive review of present manufacturing domain ontologies is available. In this contribution, we provide a holistic review of 65 manufacturing ontologies and their classification into different categories. Based on the results, we introduce a priority guideline and a framework to support engineers in finding and reusing existent ontologies of a specific subdomain in manufacturing. Furthermore, we present 16 supporting ontologies to be considered in the ontology development process and eight catalogs that contain ontologies and vocabulary services.

Polylactide acid (PLA) is one of the most used plastics in extrusion-based additive manufacturing (AM). Although it is bio-based and in theory biodegradable, its recyclability for fused filament fabrication (FFF) is limited due to material degradation. To better understand the material’s recyclability, blends with different contents of recycled PLA (rPLA) are investigated alongside a coextruded filament comprised of a core layer with high rPLA content and a skin layer from virgin PLA. The goal was to determine whether this coextrusion approach is more efficient than blending rPLA with virgin PLA. Different filaments were extruded and subsequently used to manufacture samples using FFF. While the strength of the individual strands did not decrease significantly, layer adhesion decreased by up to 67%. The coextruded filament was found to be more brittle than its monoextruded counterparts. Additionally, no continuous weld line could be formed between the layers of coextruded material, leading to a decreased tensile strength. However, the coextruded filament proved to be able to save on master batch and colorants, as the outer layer of the filament has the most impact on the part’s coloring. Therefore, switching to a coextruded filament could provide economical savings on master batch material.

In this work, the influence of a modification and fillers on the dimensional stability and warpage of semi‐crystalline polypropylene compounds in screw‐based Large Area Additive Manufacturing is investigated by material characterization and experimental testing. Polypropylene is modified by blending an amorphous polyolefin‐copolymer as well as the addition of three different fillers talc, glass fibers, and hollow glass beads, resulting in eight investigated compounds. A material characterization using Differential Scanning Calorimetry, Thermogravimetric Analysis, thermal conductivity measurements, and pvT‐measurements is carried out. Experimental investigations regarding dimensional stability and warpage deformation during processing are performed. By increasing the crystallization temperature and thermal conductivity from 112.3°C and 0.208 W/(m°C) to 127°C and 0.232 W/(m°C) through the use of a modification and talc, a better dimensional stability during processing is reached. Furthermore, both the modification of the base material and the introduction of talc or glass fibers lead to a significant reduction in the decrease in specific volume during cooling, as determined by pvT‐measurements, thus reducing warpage. The experimentally determined warpage deformation could be reduced by 69% when using 10 wt. % talc‐filler and by 78% when using 10 wt. % glass fibers, compared to the unmodified and unfilled base polypropylene.

The main driver of industry 4.0 is data and information for realizing resilient manufacturing systems through data-based decision-making. This requires the data flow from different machinery and its processing. Therefore, a methodical survey on the logical and technical requirements for enabling an efficient data flow can be beneficial since it fastens the process of establishing the data flow and gives production and software engineers a common understanding of the data’s meaning. Hence, data, related metadata like the unit or the frequency of recordings, and technical information, e.g., the machine’s interface or the communication protocol, are necessary. Based on the classical value stream mapping (VSM) as a lean management tool, the first approach for a methodical gathering of data, value stream mapping 4.0, was established in 2016. Since VSM 4.0 provides technical properties for specifying the data flow, some shortcomings were identified, particularly related to technical information. This contribution introduces the VSM 4.0 plus that solved the identified shortcomings by adding new properties. Compared to VSM 4.0, VSM 4.0 plus offers detailed specifications of data points, includes technical information, e.g., used communication protocols, adds information regarding data processing, and enhances the storage and usage dimension by providing more details. Through the added properties, VSM 4.0 plus allows domain and software engineers more efficient collaboration since all required information for establishing the data flow and its processing are united in one methodology. To verify the practicability, the VSM 4.0 plus was applied within several manufacturing-related use cases.