Molding machine types

The profiles were formed from the granulates with an injection molding machine type ARBURG-420 Ml000-25 All rounder. For flie tests the actual injection at speed of 10 cm Vs was used with addition at speed of 15 cmVs, injection temperatures 195/200/210/210 °C and blend injection time was slightly lower than for iPP itself... 

Requirements Mold/Machine/ Periphery Mold type (e.g., normal, stack and multicomponent molds) Machine type (injection molding machine) Connection and periphery systems... 

All these type assembly methods usually require the same time to perform as placing inserts in the mold, but they also lower IMM time. There are several other means of accomplishing the desired result that depend on the circumstances at hand. In any event, conventional molded-in inserts usually prove costlier. There are highly automatic injection molding machines available designed just for insert molding that will reverse the cost. 

Injection molding is not new. A patent was issued in 1872 for an injection-molding machine for camphor-plasticized CN, celluloid. Almost all of the machines used today are reciprocating or two-stage screw types. Both types employ a reciprocating Archimedean-like screw similar to that of a screw extruder. A few are of the plunger type. 

Two systems have been used in injection molding machines to melt and inject the polymer. The most commonly used types use a reciprocating screw, which has many... 

William Willert filed a patent on the in-line, now more commonly known as the reciprocating screw injection molding machine in 1952. In 1953 Reed Prentice Corp. was the first to use Willert s invention, building a 600-ton machine. The patent was issued in 1956. By the end of the decade almost all the injection molding machines being built were of the reciprocating screw type. 

The EZ-Track system can also be used to count good parts, diverted parts, packed cases, etc. Downtime is measured automatically and can be classified into an unlimited number of causes. Once production data is collected, there is an extensive set of Web-based reports that can incorporate trend charts, tabular reports, pie charts, and Pareto charts. Finally, it is possible to interface the EZ-Track system to ERP/MRP systems via an advanced SQL database that is open, fully documented, and ODBC-compliant. Not only is the EZ-Track system scalable from small to large numbers of molding machines and other types of cyclical manufacturing equipment, it also can play an important role in sending real-time production data to company-wide ERP/MRP systems. 

The type of molding machine available has an important influence upon the blow opening system used. Some machines, for instance, use needle blowing exclusively. Hollow needle insertion at the mold parting line is considered when a very small opening is required that may even need closing or if the hollow object must be blown up on the side, e.g., on carousels with a series of molds. 

The conventional and slightly modified injection molding machines (IMMs) are used to produce different types of foams (Chapter 4). 

This type of extrusion blow molding machine uses something called a shuttle machine to get all the parts in place. Alternatively, a rotary machine, illustrated in Figure 14-61, can be used. Rotary extrusion blow molders are used in high volume applications, as in the production of laundry detergent bottles. 

The third and most successful approach was accomplished on a wheel-type blow molding machine. Unlike the shuttle machine where only gravity acts on a downward extruded parison, a wheel machine draws or pulls the parison from the die. This allows extension in the extrusion direction and the opportunity to thin down the barrier layer and reorient the mica platelets. 

Fluoropolymers can be injection-molded in plunger or ram-type equipment but a screw machine works best with this family of plastics. The screw-type injection molding machines have a number of advantages including those listed in Table 6.23. Various components of screw-type machines for processing fluoropolymers are described in this section. 

Table 6.23. Advantages of Screw-Type Injection Molding Machine...

Cyro produces a family of acrylic-based resins Acrylite , Cyrolite and XT). All types of injection molding machines can be used to mold these blends. If reciprocating screw machines are used, the screw compression ratio should not exceed 3.5 (to avoid material breakdown). Injection temperature should be the lowest at which the part will fill. Since the material has sparkling clarity, great care should be taken to avoid contamination. 

Figure 11.5 Schematic diagram of a piunger-type injection molding machine. (From Weir, C.L, Introduction to Molding, Society of Plastics Engineers, CT, 1975. With permission.)...

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