Browse Prior Art Database

Molding Compound

IP.com Disclosure Number: IPCOM000202242D
Publication Date: 2010-Dec-10
Document File: 2 page(s) / 20K

Publishing Venue

The IP.com Prior Art Database

Abstract

A novel method of converting a sheet molding compound (SMC) into a bulk molding compound (BMC)is described. The method comprises the making of a molding material by forming an elongated tubular shaped compound from sheet material which can then be processed into a three dimensional molding material. The process can take advantage of the recycling of off-cut material, scrap material and surplus SMC materials by using this method to produce a viable material for use in making molded parts.

This text was extracted from a Microsoft Word document.
This is the abbreviated version, containing approximately 52% of the total text.

 

MOLDING COMPOUND

ABSTRACT

A novel method of converting a sheet molding compound (SMC) into a bulk molding compound (BMC) is described.  The method comprises the making of a molding material by forming an elongated tubular shaped compound from sheet material which can then be processed into a three dimensional molding material.  The process can take advantage of the recycling of off-cut material, scrap material and surplus SMC materials by using this method to produce a viable material for use in making molded parts.

In the manufacture of fiber reinforced resin products, a sheet molding compound (SMC) is frequently used.  Sheet molding compounds generally consist of a mixture of a thermosetting resin or a thermoplastic resin or a combination of the two, a catalyst if required, a chopped fiber reinforcement and often a particulate filler.  The reinforcement can be a commercially available carbon, fiberglass, polyamide or other organic fiber or a natural fiber such as cotton or jute or the like or a combination of fibers.  In most cases the resin and chopped fibers are sandwiched between films of plastic. This forms a laminated sheet that is typically wound into a roll form for storage and shipping.  At the time of use, the plastic films are removed and the laminated sheet is cut into blanks or plies of a desired shape and size. Generally, most end use applications require multiple plies of the laminated sheets. The plies are molded under heat and pressure to form a cured composite part.

Frequently, the properties of a SMC molded material can be advantageously used in a specialized composite part. However, the two dimensional configuration of the material often prohibits this due to the potential molded composite part constraints of space and size.  In this case, the SMC can be cut or chopped into smaller dimensional pieces and utilized as a conventional bulk molding compound (BMC). This is an additional processing step which is often performed by the molder.  The conversion of a SMC to a BMC can burden the molder with additional labor, additional cost and the need for specialized chopping equipment.  A solution to this conversion step is to supply the molder with a sheet molding compound composition in the form of a three dimensional BMC.

To convert SMC to a different configuration of molding compound, it is proposed that the SMC be chopped into small dimensional components as the initial step in the conversion process. Full width material can be used as a starting material.    Advantage can be taken to also recycle off-cut scrap material, waste material or surplus material as the starting material to yield a viable molding compound product...