Processing methods rotational molding

Important processing methods injection molding, blow molding, rotational molding, extrusion, foam molding, compression molding, transfer molding... 

Typical processing methods - blow molding, blown film extrusion, cast film extrusion, extrusion, extrusion coating, injection molding, rotational molding ... 

Rotational molding creates a wide variety of plastic products that cannot be made effectively, efficiently, or economically by other means. What sets this method apart from others is that it can create thin-walled, hollow parts that exhibit no weld lines or scarring from ejector pins and from the process itself. It also has the advantage of having little scrap and minimal molded-in stresses, due to the low pressure and low shear rate characteristics of the process. Finally, it can be used to make parts that are very large which would be impossible to manufacture by other methods. 

The validity of Frenkel s model is limited to Newtonian flow and can only be used to predict the early stage of the coalescence process, when the diameter of the two spherical particles remains nearly unchanged. The inadequacy of a Newtonian model in describing the coalescence of polymers was also demonstrated in other studies, as reviewed by Mazur, and has led to the development of models as well as alternative methods for the characterization of the coalescence behavior of polymers for rotational molding applications.Based on theoretical and experimental analyses of the coalescence phenomenon, the material properties of primary interest in the evaluation of resin coalescence behavior in rotational molding have been identifled as the resin viscosity, surface tension, and elasticity. 

Aside from PTFE and PCTFE, copolymers of TFE and a few other fluorocarbon polyuners are processed by melt-processing methods. Commercial fluoropolymers that have found application in chemical processing industries include PFA, FEP, ETFE, ECTFE, and PVDF. These plastics are fabricated into parts by common techniques such as injection molding, transfer molding, blow molding, compression molding, rotational molding, and extrusion (Table... 

Method of processing electrostatic spray coating, fluidized bed coating, rotational molding, slush molding ... 

POs are processed using virtually every known thermoplastic conversion method. In some applications, such as film, pipe, or rotational molding, POs are the dominant materials in others, such as the injection or compression molding of highly reinforced composites, they are only starting to show their value. In summary, there are currently five major application sectors that consume the most POs ... 

---