Mold material sprayed-metal

The actuator contains the final orifice and a finger pad or mechanical linkage for on—off control. The spray pattern is largely affected by the constmction of the actuator, particularly by the chamber preceding the orifice. Actuators are often termed mechanical breakup and nonmechanical breakup depending upon the complexity of this chamber. Mechanical breakup actuators are of more expensive two-piece constmction. Actuators are usually molded from polyethylene or polypropylene the breakup insert may be almost any material, including metal. 

Thermoforming is one of the major processes used to produce prototype parts that may be made other ways, such as injection molding. Many materials are used to produce molds that are serviceable for a few to a few himdred parts. Traditional mold materials include wood, plywood, hard plaster such as Hydrocal (US Gypsum), and medium density fiberboard. Sprayed and cast white metal are used on occasion. 

Diffuse or scattering samples can have many appearances or compositions. Materials such as ceramic tiles, packed powdered metal salts or polymers, painted chips, simple molded plastics, or more esoteric materials such as plasma-sprayed metals or sintered porous polymers, are all successfully used as standards for diffuse reflectance. 

Sprayed Metal Molds. Molds made by spraying molten metal onto a master until a shell of predetermined thickness is achieved. The shell is then removed and backed up with plaster, cement, casting resin, or other suitable material. Used primarily as a mold in sheet forming process. 

Deductive mold materials are removed to form the desired shape. Inductive mold materials are built up to form the desired shape. Hardwoods, fiberboard, and industrial plaster are examples of deductive materials, which under certain circumstances can also be used inductively. Syntactic foam, thermoset plastics, papier mache, and sprayed white metals are normally considered to be inductive materials. 

After cooling, the final part is removed and the mold is recharged with resin. Since the mold surfaces are often complex, processors commonly apply mold release agents to allow the part to demold. Mold release agents are lubricants that coat the metal surface with a waxy material preventing the polymer from adhering to the mold s surface. Examples of mold release agents include silicone sprays or olefin based waxes. 

The investigation was begun after complaints that the pumps became blocked over time. Pumps typically deliver a low pressure, fine droplet-sized mist at a controlled dose rate. Good control of the dose rate and spray pattern requires precision molding of the components and consistent performance of these components when they are in contact with the drug product for extended periods and over a wide range of ambient temperatures. These components are made of thermoplastic, elastomeric, and metallic materials. The pump actuator and its elastomeric check valve are vital components. Their relative position is shown in Figure 10-3. 

Also, glass, thermoplastics, composites and ceramics (metal molds sprayed with a refractory material) can be molded by this method. 

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