Quick Changeover

Quick changeover techniques. These help to reduce lot sizes and to ahgn them with demand without reducing capacity utilization. 

In cantilever-shaft designs the rollers are located outside the frame (Figure 256). This design is normally used for smaller machines. In many cases such machines are applied for laboratory or pilot work because the location of the rolls allows for easy and quick changeover to different roll surface configurations. 

Flexibility and user friendliness are the key words for many of today s extruders (easy-to-use control systems and displays, quick access for repair, and quick changeover). Several of the new machines feature segmented barrel, the ability to change screw-rotation direction, and the ability to be modified in place, e.g., to compound, to extrude a product or to recycle plant scrap. 

Quick Changeover The ability to change tooling and fixtures rapidly (usually minutes), so that multiple products can be run on the same machine. 

Will the reactions pass through the three-membered onium cation 274 or will 274 quickly changeover into the allyl cation 275, thus leading to the 1,4-addition products (277) ... 

Fig. 4. 150-ton automatic compression press incorporating novel features including easy tool accessibility, quick changeover of top and bottom ejection. (Courtesy of British Industrial Plastics Ltd.)... 

After moving the equipment and ensuring quick changeover capabilities, organizations typically document new procedures for the new layout and train workers on the new production process. In many cases, workers from the affected processes participate in the conversion process. The new layout is also tested and measured against the baselines recorded in step 1 to confirm improvement. 

Nonimpact Printing. Interest is growing ia the use of nonimpact styles because of the quickness of color changeover and the abiUty to iaterface these machines to computer-aided design systems. Two basic types exist drop on demand and constant drop techniques. 

A good diffractometer-spectrograph must function satisfactorily in each role, and it must be built so that the changeover from one to the other is easy, quick, and sure. Unless this is true, two instruments will often be needed where one might have sufficed. The diffractometer should handle either powder samples or single crystals. 

Reverse phase chromatography is finding increasing use in modern LC. For example, steroids (42) and fat soluble vitamins (43) are appropriately separated by this mode. Reverse phase with a chemically bonded stationary phase is popular because mobile phase conditions can be quickly found which produce reasonable retention. (In reverse phase LC the mobile phase is typically a water-organic solvent mixture.) Rapid solvent changeover also allows easy operation in gradient elution. Many examples of reverse phase separations can be found in the literature of the various instrument companies. 

In the short term, more advanced companies meet the overall supply chain demand while simultaneously minimizing the overall costs of inventory, production, and missed sales opportunities. Further, with frozen production periods they avoid unnecessary changeovers, smoothen the whole production, purchasing, and maintenance process, and achieve superior adherence-to-plan and productivity performance. Nevertheless, if required, they can react promptly to unforeseen changes thanks to reduced changeover times, flexible suppliers, and powerful IT tools that adjust the plans quickly. 

Cartridge type These were simple on—line strainers having stainless steel screens positioned in a vessel provided in the sulfur feed line to the burner. A bypass line or a parallel standby unit was also arranged. These could become quickly filled up due to their small capacity to hold the sludge, and frequent changeover was necessary. 

In this process, the melt film contacts (as quickly as possible, vertically or at an angle) the first water-cooled highly polished (to 1 ptm) chrome-plated roll. An air knife can be used its placement parallel to the die makes it possible to press the film smoothly onto the first cooling roll by means of a cold air stream. Lubricant plate-out on the cooling rolls is avoided by operation with contact rolls. At haul-off rates of up to 60 m/min, reel change is carried out by hand. At higher rates, automatic changeover equipment is required. 

Basic Understanding of Quick Change Retrofits of Existing Presses Case study will examine hour a major manufacturer of heavy-duty trucks was able to reduce changeover time by 50% on five major press lines with an expenditure of less than 20,000. 

Average changeover time before quick die change method 90 min... 

Average changeover time after quick die change method 45 min... 

The next step to drive changeover time further down is to implement press and tool modifications with the introduction of new quick change hardware. Figures 4 and 5 summarize before and after quick change retrofits reducing die exchange and clamp time—an average of 49 min down to 3 min. For more detailed information see Ref. 1. 

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