Blow molding origin

Haemonetics Bowl Technology. Haemonetics disposable bowl technology has evolved from the original plasma separation chamber. The two principal shapes of bowls are the Latham bowl and the blow-molded bowl (Fig. 4). 

Table 11.8 Screw Geometry for a 152.4 mm Diameter Screw for a High-Speed Blow-Molding Process Running an HOPE resin (Original Design). The Screw had an L/D of 33 and a Barrier Melting Section...

Figure 13.14 Simulated axial pressure and temperature profile for the original blow-molding screw at a rate of 156 kg/h and a sorew speed of 12 rpm, for a specific rate of 13.0 kg/(h-rpm)...

An important development in screw design was the barrier screw. The primary reason for a barrier screw is to eliminate the problem of solids bed breakup for more efficient melting. They have been around for over a quarter century. Original developments were for extrusion, but latter they were used to solve problems in injection and blow molding. There are many different patented barrier screw designs that under the broad claims of the Geyer or Uniroyal U.S. Patent No. 3,375,549 that expired in 1985.3>143... 

Cases III and IV are of direct interest to the packaging industry. Case IV, in fact, relates directly to monomer migration in blow-molded bottles. Daniels and Procter have treated simultaneous diffusion of VCM into the environment and into the package contents over a time scale sufficient to invalidate the assumption of independent diffusional processes at each of the bottle wall boimdaries. Over relatively short time periods, approximately half of the VCM originally sorbed in the bottle wall tends to diffuse into the environment and be swept away while the crther half (in the inside half of the wall) tends to diffuse into the package contents and increase its VCM content. Such a simultaneous process increases the VCM concentration at the... 

During stretching flow, material is drawn from one cross-sectional area to another. This type of flow dominates fibre, film, blow molding, and vacuum forming processes (57). Let us assume that a filament of a molten polymer is hauled off under a force F (see Fig. 13.40). Taking the die of the extruder as the origin of the reference frame, the cross-sectional area A of the filament... 

Originally, the commercial PC resins were linear polymers with high shear viscosity and low melt strength, thus difficult to process in operation involving extensional flows, viz. blow molding stretching, foaming. Several years ago branched PC (bPC) became available. The resin is usually blended with linear PC at the ratio that on the... 

Injection and blow molded products based on inhibited PE and PP produced by the Northern Instruments Corp. (USA) have become world standard for anticorrosion plastic containers. Similar plastic products modified by VCI are manufactured by the German companies Rose Plastic and Brangs and Meinrich [20]. Another original sort of inner packages for small diameter metal tubes is a tube strip. Tube strips are extruded PE tubings inserted into metal tubes to protect their interior surfaces from corrosion [21]. 

This particular pipe is useful in repair (relining) of sewage system without necessity of dismantling but by blow molding new liner inside the original pipe. 

Blow molding is a stretching process in that the material, which is first injection molded or extruded into a parison, is expanded to fill out the cavity. The ratio of the surface area of the expanded surface to that of its original surface is referred to as the blow ratio, which can be determined by... 

The Hyatt brothers did Uttle to advance polymer science but they did influence the development of Charles Burrough s compression sheet molder and blow molding press. They also utilized H. Brewley s extruder. The latter was developed originally in 1845 for the extrusion of shellac and gutta percha (8). 

In blow molding, one of the parameters used in the BUR (blowup ratio). The BUR is defined as the ratio of the final radius to the original radius. Would it be possible to obtain a value of unity for BUR for certain temperatures and values of the dimensionless ratio ttR AP/ixappGj where Ro is the original radius, AP the pressure inside the parison, Q the volumetric fiow rate, and Xapp the apparent viscosity of the polymer ... 

Blow molding is a collective term for the manufacture of hollow thermoplastic products, characterized by the principle that a preform is blown to its desired shape in a blow mold. Blow molds have their origin in the glass industry. 

For the economic manufacture of seamless hollow articles made of plastic materials, the well-known procedures for blow molding and rotational molding can be used. In the origins of rotational molding, PVC or plastisols were used for the manufacture. Since "industrialization of rotational molding in the 1950s, PE is the most widely used processed material. PE is available in different densities and qualities, dry blended and compounded, ultraviolet-(UV)stabilized, electrically conductive, and phosphorescent. Other common materials are PVC, as well as PP, PA 6, PA 12, and PC. All of the RAL colors are feasible and even colors that imitate natural colors are possible (e.g., stone, terracotta, etc.). 

The ram pushes the accumulated material through the die head to form the parison as a shot. This type of machine is obsolete however, there are machines of this type out in the industry still in use. The extruder or plasticizer is stationary and can continuously feed heated plastic into the accumulator. The extruder may be programmed to stop when the die is filled to a predetermined volume and then start again after the parison is extruded. The extruder speed is adjusted to fill the accumulator at the proper rate so the parison is extruded almost immediately after the blow mold has opened and the product ejected. Fig. 13.8 is a photo of an original product blow molding machine of this style of equipment. 

Though the nylons originally were developed for their fiber-forming characteristics, their first commercial application was for toothbrush bristles, and shortly thereafter they were used for women s stockings. Not only are they drawn into monofilament and spun into fiber they are extruded into film and tubing, blow-molded into bottles, injection-molded... 

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