Molding lift

By using photoresist as a sacrificial layer or structure, further processes, etching, ion implantation, molding, lift-off, and so on, may be performed. When patterned photoresist finish its roles, it is better to be removed from substrate. There are two kinds of methods to remove photoresist layer, wet type and dry type. Wet type photoresist removal process requires the chemical, PR remover or PR stripper, which can dissolve photoresist. Alternatively, plasma ashing process may remove photoresist This process is called dry process and uses oxygen plasma which oxidizes photoresist layer. 

Acetal resins are also used extensively in transportation, especially automotive. Handles and internal components (gears, gear racks, cables) for window lifts and other similar devices are examples. Most of the appHcations which do not involve painting or plating are below the window line. Many common consumer items are manufactured essentially entirely from acetal resin (eg, disposable lighters) or have critical components molded from acetal resin (eg, hubs and platforms for videocassettes). The properties that make acetal resins useful in industrial appHcations make them useful for internal components, especially mechanical drive systems, of many household appHances. 

The dry ice blaster is an effective and mess-free method for in-place cleaning that eliminates the need to disassemble machinery before it is cleaned. Compressed air propels tiny dry ice pellets at supersonic speeds so they flash freeze and then lift grime, paint, rust, mold, and other contaminants from metal surfaces. Pellets vaporize quickly into the air, leaving no wastewater or solvents, only the soiled contaminant to be swept up. 

Molds can be made from either metallic or nonmetallic materials. Metallic and nonmetallic molds are heated to the same temperature, which can be up to 120°C. Metallic molds are much more heat conductive than molds made from polyurethane or epoxy. When handling the metal molds, clean, heat-resistant gloves must be worn to prevent burning of the skin. The weight of these molds must be taken into account when handling them. Suitable lifting equipment such as a crane, block and tackle, or a forklift must be used. 

Large molds must only be moved by approved lifting gear. The mold should have "eyes" attached of size and number to take the weight of the mold. The weight of the mold should be clearly marked on its side. Certified chains and hooks should be used. The capacity of the chain must be sufficient to take the load applied to it. 

Uses In iron-toning solutions. Fresh ferric ammonium citrate tends to form a layer of mold after a few days. This can be filtered or lifted off. After the first time the mold rarely returns. Notes Both brown and green salts are light-sensitive. Keep well closed and protected from light. 

Figure 2.3 shows the molding cycle of pot-type transfer molding, and Figure 2.4 shows plunger-type transfer molding (sometime called auxiliary raw transfer molding). The taper of the sprue is pot-type transfer is such that, when the mold is opened, the sprue remains attached to the disc of material left in the pot, known as cull, and is thus pulled away from the molded part, whereas the latter is lifted out of the cavity by the ejector pins (Figure 2.3c). In plunger-type transfer molding, on the other hand, the cull and the sprue remains with the molded piece when the mold is opened (Figure 2.4c).

FIGURE 2.3 Molding cycle of a pot-type transfer mold, (a) Molding compound is placed in the transfer pot and then (b) forced under pressure when hot through an orifice and into a closed mold, (c) When the mold opens, the sprue remains with the cull in the pot, and the molded part is lifted out of the cavity by ejector pins. (After Frados, J. ed. 1976. Plastics Engineering Handbook, 4th Ed., Van Nostrand Reinhold, New York.)... 

The opening in Fig. 4.27 is created by raised pads on both the cavity and the core that meet at the vertical shutoff. As the mold opens straight up (as the arrow indicates) the pad on the core will lift off the pad on the cavity at the P/L indicated the core will carry the product along with it. The product will slide off easily when ejected from the core, since there are no hooks to hold it in place. 

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