Continuous automatic operation

Since one of the ultimate objectives of the RIM process, for its major market of automotive exterior part production, was a cycle time of 2 minutes or less, a great deal of effort was applied to mold construction and design. Continuous automatic operation of a molding station without interruption required improvements in mold release and mold surface technology. Originally, mold preparation following a shot was required due to the buildup of external release agents, which were necessary to enable easy removal of the part from the mold. 

In order to avoid the tedious bridging of the plug, attempts have been made to replace the wire with a conductive path created by sprayedon metal and more recently by forming a metal layer through vacuum depositing. On the other hand, it is now possible to perform wirebridging in continuous automatic operation. ... 

The two procedures primarily used for continuous nitration are the semicontinuous method developed by Bofors-Nobel Chematur of Sweden and the continuous method of Hercules Powder Co. in the United States. The latter process, which uses a multiple cascade system for nitration and a continuous wringing operation, increases safety, reduces the personnel involved, provides a substantial reduction in pollutants, and increases the uniformity of the product. The cellulose is automatically and continuously fed into the first of a series of pots at a controlled rate. It falls into the slurry of acid and nitrocellulose and is submerged immediately by a turbine-type agitator. The acid is deflvered to the pots from tanks at a rate controlled by appropriate instmmentation based on the desired acid to cellulose ratio. The slurry flows successively by gravity from the first to the last of the nitration vessels through under- and overflow weirs to ensure adequate retention time during nitration. The overflow from the last pot is fully nitrated cellulose. 

Process or heating plant may have controls ranging from manual operation with some processes supervised by interlocks to semi-automatic and fully automatic operation. Deciding factors will include temperature of operation, frequency of ignition, degree of operator supervision, and rating of the plant. For example, boiler plant, both steam and water, will invariably have automatic control whereas tunnel kilns operated continuously at high temperature are unlikely to require it. 

The dipping processes are of three basic types (1) continuous lengths of strip, wire or tube pass through the molten coating metal (2) semimanufactured products such as cut tube lengths or sheets are dipped into the molten metal in batches in specially designed and automatically operated plants and (3) fabricated products are dipped into the molten metal. 

The primary advantage of fluidized bed reactors, however, is that they permit continuous, automatically controlled operations using reactant-catalyst systems that require catalyst regeneration at very frequent intervals. Fluidized bed operation permits one to easily add or remove the catalyst from the reactor or the regenerator. Regeneration can be accomplished by any convenient procedure, but the... 

The equipment is designed so as to permit continuous and automatic operation, and the resultant molten calcium carbide is withdrawn from the furnace and allowed to cool, whereupon it solidifies to a dense gray solid. 

A submerged-arc process is commonly used for welding stainless steels and carbon steels when an automatic operation is acceptable. The electrode is a continuous roll of wire fed at an automatically controlled rate. The arc is submerged in a granulated flux which serves the same purpose as the coating on the rods in the shielded-arc process. The appearance and quality of the submerged-arc weld is better than that obtained by an ordinary shielded-arc manual process however, the automatic process is limited in its applications to main seams or similar long-run operations. 

Continuous Expression Equipment Continuous ejqiression equipment has the advantage of large capacity and automatic operation. Compared to batch ejqiression equipment, lower pressure is used to squeeze the cake in the continuous ejmression equipment. As a result, the cakes are not as dry as those from the batch eq)ression devices. 

Protection against loss of data due to power failure. The microprocessor and digital clock are provided with reserve power supplies, which ensures that, if the normal mains supply should fail, the timing continues uninterrupted and there is no loss of data from the RAM. After restoration of the normal supply following a power failure, the time, date and stored data are recorded by the output equipment and normal automatic operation is resumed. Recharging of the reserve power-pack also takes place when the operation from the mains supply is restored. No reserve supply is required by the PROM, whose memory contents are unaffected by disturbances to the mains. 

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