Importance Of Pultrusion Mold Pressure

There are many process failure and pultruded product defects are caused by the lack of internal pressure in pultrusion mould. When the problem occurs, most of people will check whether there is problem on the raw material, the formulation is wrong, or the temperature is not inappropriate, etc. We can’t say one reason effects the production, in fact, a variety of factors that affect each other, adjust the formulation and process parameters can also affect the pressure inside of the pultrusion mould. However, if we can fully realize the importance of the inner pressure of pultrusion mold, and know how to increase the pressure within the mold, the problem will be solved much easier.

The movement in the pultrusion mold is equivalent to a slider that is bonded by a multi layer bond, sliding on the smooth surface of the mold. Resin in the mold will have the process of increasing the temperature in the mold, and gradually complete curing process. From the gel to the complete curing process, the adhesion between the layers is gradually increasing. When the resin is not completely cured, the strength of the resin is very low, so the adhesion between the layers is not high, then if the mold pressure is not enough, it will cause the failure of inter layer shear. Even if there is no shear failure, due to the surface of the product and mold surface can’t be tightly attached to glide, which will cause the surface finish of the product lacking of gloss.

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