Study And Application On Batch Foaming Equipment Of On-line Extrusion

The foam has many excellent performance, such as lightweight, heat insulation, soundinsulation, cushioning, lower price and so on, besides, it has better mechanical properties thanordinary foam and non-foam materials, therefore, it owns wide range of applications, and alsowas regarded as new materials in the twenty-first century.There are two purpose of designing this experiment device, on the one hand, the cellmorphology and quality of batch foaming and continuous extrusion foaming have beencomparatively studied, besides,quality of the extrusion die has been detected, the results ofwhich provided the basis of guiding of the die design; on the other hand, the impact ofdifferent processing parameters, such as screw speed, temperature, pressure, and supercriticalCO2, on the foam diameter and density have been studied. the best combination of processparameters.has been sought besides the device designed factorsThe on line batch foaming autoclave has been developed, including the head die,autoclave, bolts, ball valve and the heating coil. In the process of design, not only combinedthe conventional design method, but also use the modern finite element analysis, for example,used Polyflow to simulate and analysis the pressure distribution and drop rate in the diechannel in order to determine the specific location of the fluid pressure drop, which providedthe theoretical basis of the opening location of the head die.By employing the developed foaming device, We chose polystyrene(PS) as experimentmaterial,the following findings and conclusions made are that:first,in the presentation ofsame processing parameters, compared with traditional extrusion foaming, the foams preparedby online batch foaming device were smaller30-40μm,and cell density were2-3higher.second,The temperature in the batch foaming device, pressure, screw speed andsaturation time all influenced the morphology of foams. The foaming diameter would becomelarger with the increase of temperature between130-150℃,the mean diameter was Increasingfrom32.37μm to84.96μm,With the increase of pressure in the batch foaming device, thedistribution of cell diameter became narrower, the diameter decreased and the cell density increased, the cell quality can be enhanced by extending the saturation time. As the screwspeed increased between3.6r/min-9r/min, the cell diameter increased and the cell densitydecreased.at last the die B is redesigned In the comparison of die A, die B and the developedonline batch foaming device, the quality of cells prepared by the online batch foaming devicewas best followed by die B, die A.Compared with die A,die B can reduce4-10μm of Averagepore size but still need to be further optimized design.