Problems along the way of PVC Foam Board Extrusion

screw extruder machine manufacturer

Poor stability will affect the entire board, board will become yellow and the foam sheets'brittleness is large. Insufficient melt strength may cause the cell of foamed sheet becoming bigger and the longitudinal section bulbs much longer. Probably the most direct way to guage whether the melt durability is insufficient would be to press the sheet wrapped in the channel speed roll with your fingers, if the melt durability is excellent, it is possible to look and feel elasticity when pressing. If it is tough to bounce after pressing, then your melt strength is poor. Because there is greater difference between a screw structure and cooling method, it is challenging to determine a reasonable temperature. If you want to get hold of uniform pvc foam board in the foam pipe, there is must ensure good financial strength of PVC materials also. Foaming aid is developed to solve this problem of the foamed document and effectively improve the quality of the foam pipe.

Lubricant is divided into external lubricants and internal lubricants, outer slip is simply conducive to demolding and the surface gloss, if the external slide is much less, it is not easy to control and easy heating, which causes the temperature of confluence core, and there will be the nagging problems in the center of plate, such as a significant bubble, string bubble, yellow, and other concerns. While if the surface of the plate the precipitation of the outer slide isn't smooth; external slide is considerably more, precipitation shall become serious. Inner slide is certainly conducive to the fluidity of melt and plasticization, and then it is difficult to regulate the thickness of construction foam board, if the inner slide is undoubtedly insufficient. If internal slide is too considerably more sufficient, it susceptible to the phenomenon of increased confluence core temperature.

Compared with the above fundamental problems, the process temperature control will be more intuitive, it's the surface problem, if the heat control is not good, it could bring about the emergence of the essential problems. Improving the processing heat, material stabilization period will be reduced, and the nagging challenges of stability will appear; the original lubrication equilibrium will be broken, the general performance may be the lack of the external lubrication, especially exterior lubrication in the later period of time, there is need to improve the volume of external lubrication; the increasing of temperature shall lead to melt strength decreased, cell foam sheet increased, the quantity of cell sheet reduced, the sheet is brittle and an easy task to break; raise the temperatures to reduce the melt strength and reduce the melt viscosity, decreasing of the viscosity decreases dispersing potential, for the screw with poor dispersion, the phenomenon of uneven dispersion sometimes.

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Comments: 1
  • #1

    Notice boards (Friday, 27 May 2016 08:11)

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