Alternative polyolefin composite veil/compatibilizing mat material

#The present invention relates generally to improving surface smoothness, surface hardness, and compatibilizing polyolefin or polyolefin composite materials to functional polymers. A method of producing such materials from a polyolefin/polyolefin composite substrate that is topologically/mechanically bonded to a reinforcing mat formed from reinforcing fibers and thermoplastic polymer powder is described.

#Plastic sheet materials made from polyolefin or polyolefin composite materials are widely used in the manufacture of molded articles. Such materials suffer from bonding issues, little to no surface abrasion resistance, coupled with composite form process issues. Accordingly, when used for certain applications such as, for example, high impact paneling, woven fiberglass/polyolefin materials have a tendency to develop sink marks that many consumers find detrimental to their aesthetic appearance. It should also be appreciated that polyolefin and polyolefin composite materials are often difficult to adhere or bond to other materials. This can limit the application of these materials particularly where decorative attributes are required.

#A need is therefore identified for a way to effectively provide surface enhancements and improved bondability to polyolefin and polyolefin composite materials. Preferably, the fiber reinforcement will be accomplished in a manner that not only provides increased strength and rigidity when employed with straight polyolefin materials but also compatibilizes the polyolefin and polyolefin composite materials for better bonding to other materials and also functions to provide smoother surfacing and a wider range of decorative possibilities. The present invention successfully achieves these goals while also minimizing the application of heat to the polyolefin/polyolefin composite material prior to molding into the final product shape. Thus, a number of important properties including surface energy, surface smoothness, and improvements in impact, flexural and tensile strengths of straight polyolefin materials can be achieved.

#The accompanying drawing incorporated in and forming a part of the specification, illustrates several aspects of the present invention and together with the description serves to explain the principles of the invention. In the drawing:

#FIG. 1 is a schematical cross sectional view showing a first embodiment of the compatibilized polyolefin/polyolefin composite material of the present invention; and

#FIG. 2 is a schematic cross sectional view showing a second embodiment of the compatibilized polyolefin/polyolefin composite material of the present invention.

#Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawing.

#Reference is now made to FIG. 1 schematically illustrating one possible embodiment of the compatibilized polyolefin/polyolefin composite material of the present invention. The material 10 includes a polyolefin/polyolefin composite substrate 12 and a reinforcing mat 14.

#The polyolefin/polyolefin composite substrate may, for example, be made from high density polyethylene, polypropylene, polybutylene, mixed with various chemical additives such as heat stabilizers, UV stabilizers, metal deactivators, and the like possibly combined with grafted species that incorporate acrylic acid or maleic anhydride to promote the bondability of the polyolefin to whatever glass fiber form is employed. Composite forms may include injection moldable grades, extrusion-compression molded long fiber grades, GMT forms as for example an Azdel® type product, or in a woven roving form as for example a Twintex® product grade.