Potential of Rapid Tooling in Rapid Heat Cycle Molding: A Review

Abstract

Rapid tooling (RT) and additive manufacturing (AM) are currently being used in several parts of industry, particularly in the development of new products. The demand for timely deliveries of low-cost products in a variety of geometrical patterns is continuing to increase year by year. Increased demand for low-cost materials and tooling, including RT, is driving the demand for plastic and rubber products, along with engineering and product manufacturers. The development of AM and RT technologies has led to significant improvements in the technologies, especially in testing performance for newly developed products prior to the fabrication of hard tooling and low-volume production. On the other hand, the rapid heating cycle molding (RHCM) injection method can be implemented to overcome product surface defects generated by conventional injection molding (CIM), since the surface gloss of the parts is significantly improved, and surface marks such as flow marks and weld marks are eliminated. The most important RHCM technique is rapid heating and cooling of the cavity surface, which somewhat improves part quality while also maximizing production efficiencies. RT is not just about making molds quickly; it also improves molding productivity. Therefore, as RT can also be used to produce products with low-volume production, there is a good potential to explore RHCM in RT. This paper reviews the implementation of RHCM in the molding industry, which has been well established and undergone improvement on the basis of different heating technologies. Lastly, this review also introduces future research opportunities regarding the potential of RT in the RHCM technique.

Simulation‐based analysis of weld line strength of glass fiber‐reinforced polymer in injection molding

“…In addition, the appearance of the products significantly influences a consumer's choice 5 . Therefore, several studies have been conducted to improve the strength or appearance, reduce the weld line, and move it to a position where the tensile stresses are low 6–15 . Uyen et al 6 noted that the appearance of the weld line was influenced by the mold temperature.…”

“…Additionally, they indicated that the mold heating temperature affected the appearance during the rapid heating cycle molding process (RHCM). RHCM process is one of the method of improving strength and appearance of weld line 8,9 . Although, mold and melt temperature control is an effective method for improving weld lines, simply increasing the temperature causes other problems such as sink marks and deformation.…”

“…5 Therefore, several studies have been conducted to improve the strength or appearance, reduce the weld line, and move it to a position where the tensile stresses are low. [6][7][8][9][10][11][12][13][14][15] Uyen et al 6 noted that the appearance of the weld line was influenced by the mold temperature. They experimentally confirmed an improvement in the weld line appearance and that the weld line diminished with an increase in the cavity temperature (mold temperature).…”

“…RHCM process is one of the method of improving strength and appearance of weld line. 8,9 Although, mold and melt temperature control is an effective method for improving weld lines, simply increasing the temperature causes other problems such as sink marks and deformation. RHCM can solve this problem by raising the temperature instantaneously and rapidly cooling it down.…”

Deep Drawing of AISI 304 Blanks with Polymer Punches Produced by Additive Manufacturing: Effects of Process Scalability

“…RT is a natural extension of AM; it originated from the need to assess the performance of AM models. To enable performance validation, such models (prototypes) must be produced using the same material and production process used for full-scale production [5,6]. Today, the main application of RT in conventional production processes is in casting, where it is used in complex-shape and net-shape manufacturing [7,8].…”