An Analysis of the Casting Polymer Mold Wear Manufactured Using PolyJet Method Based on the Measurement of the Surface Topography

An important factor having an impact on the condition of machine parts is their surface topography. For instance, in the production of a molded element in casting or injection molding processes, the surface topography of the molding cavity has a significant impact on the surface condition of the product. An analysis of the wear of a mold made with the PolyJet technique was performed in this work, and we examined the surface topography using the stylus method after casting a wax model of the turbine blade. The surface topographies showed a gradual degradation of the mold cavity surface. After the manufacture of 40 castings, there was a significant deformation of the microstructure of the mold cavity. The maximum height value (Sz) parameter had the most dynamic change from 18.980 to 27.920 μm. Its growth dynamics are mainly influenced by maximum peak height (Sp) rather than the maximum pit height (Sv) parameter. In the case of the root mean square height (Sq) and arithmetic mean height (Sa), their gradual increases can be seen from 2.578 to 3.599 μm and from 2.038 to 2.746 μm. In the case of the value of the skewness (Ssk) parameter, a small positive skew was observed. As for the kurtosis (Sku) values, the distributions are clearly leptokurtic.

Structural investigation of the Plasma Transferred Arc hardfaced glass mold after operation

The paper presents the results of research aimed at detecting the causes of premature wear of molds for glass shaping, manifesting the formation of pits in the Plasma Transferred Arc pad-welds in which the working surface of the mold was shaped. The weld microstructure was tested, the chemical composition was determined in the pad-weld’s cross-section, linear and surface chemical distributions were made in the pad-weld’s cross-section, the surface morphology in damaged areas, and the chemical composition of surface inclusions were examined. The too high temperature of formed glass associated with wettability of the glass of the mold was indicated as the primary cause of premature mold wear.

Lotus-Leaf Inspired Surfaces: Hydrophobicity Evolution of Replicas Due to Mechanical Cleaning and Mold Wear

Inspired from the low wetting properties of Lotus leaves, the fabrication of dual micro/nanoscale topographies is of interest to many applications. In this research, superhydrophobic surfaces are fabricated by a process chain combining ultrashort pulsed laser texturing of steel inserts and injection molding to produce textured polypropylene (PP) parts. This manufacturing route is very promising and could be economically viable for mass production of polymeric parts with superhydrophobic properties. However, surface damages, such as wear and abrasion phenomena, can be detrimental to the attractive wetting properties of replicated textured surfaces. Therefore, the final product lifespan is investigated using mechanical cleaning of textured PP surfaces with multipurpose cloths following the ASTM D3450 standard. Second, the surface damage of replication masters after 350 injection molding cycles with glass-fiber-reinforced PP, especially to intensify mold wear, was investigated. In both cases, the degradation of the dual-scale surface textures had a clear impact on surface topography of the replicas and thus on their wetting properties, too.

The Parameters Optimization for Mold Wear Reduction of the Cross Wedge Rolling

The mold for cross wedge rolling (CWR) is difficult in making, complicated in adjustment and high in costs. It is extremely meaningful to optimize the parameters for wear reduction to extend the mold life. This paper analyzes the influence of the processing parameters on the mold wear based on orthogonal experimental design method and the computer simulation method, which can optimize the parameters in an efficient and simple way. The results show that the rolling process using optimized technological parameters can greatly extend the mold life of the cross wedge rolling.