Mold changeover

In addition to providing sufficient space for the mold, the press must include space for a pressure box and other elements, such as plug assist plates, cavity isolator plates, trim-in-place die plates, and ejector-ring plates. Water and vacuum lines should be properly located and should be easy to disconnect. Programmable logic controls are needed for adjustment of all rate-dependent ancillary features, such as plug assist, cavity isolator, pressure box, and trim-inplace sequence. Many newer machines are equipped with computer controls that provide for rapid setup after mold changeover. The press platens must allow easy mold removal and installation. 

Mold changeover is often labor intensive. For very large machines, process adjustments may be far above or below floor level. Permanently mounted caged ladders are used for overhead access. Special breathing apparatus is needed for set up of controls that are more than a meter below grade. If the carrousel is far above the operators reach, automatic load and unload features are used. 

Many of the molding processes for RPs employ heat transfer fluids to control the heating of molds. When a continuous supply of fresh air comes into intimate contact with the heat transfer fluid (as when there is constant tool changeover), significant oxidation occurs. Chemically, the result is that some molecules in the fluid are converted to organic acids. In practical terms, the fluid becomes thicker, darker, and more odorous, while heat transfer capability drops dramatically. 

Cooling by means of a controlled quantity of water and consolidation under vacuum using condensers now represents the state of the art. With rapid tool-changing systems, the changeover time can be reduced from the usual 1 to 2 h to 15 to 20 min. Another important means of reducing the processing cost is the use of devices that remove parts from the mold and stack them. 

In the building sector, insulation panels made from PS-E are mostly used. Especially, when small water absorption is required, like perimeter insulation plated in the basement of buildings, these plates are manufactured on shape molding machines. The frequent changeovers of the machine to other plate thicknesses (depending on the number of common insulation plates) are taken into account by changeable molds. 

The changeover is done in the simpiest version by using insert frames, which require a partiai dismantiing of the moid, using hydraulic changes with manually inserted spacers up to electromotively adjustable molds with a balance between thicknesses and parallelism deviations (to guarantee maximum precision [8]) within sectors). 

Changeover The installation of a new type of tool in a metal-working machine, a different paint in a painting system, a new plastic resin and new mold in an injection molding machine, new software in a computer, and so on. 

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