Nonwoven moldable composite and method of manufacture

A method of manufacturing a heat stabilized, shaped, nonwoven composite material which resists shrinkage during thermoform molding, said method comprising:

• forming a batt by dry blending a mix of first fibers and second thermoplastic fibers, said second fibers having a melting point lower than that of said first fibers and comprising approximately 40-80 percent by volume of said batt;
• needlepunching said batt to form a nonwoven porous structure of intermixed first and second fibers;
• passing heated fluid through said nonwoven structure to heat said nonwoven structure to a temperature below the melting point of said first fibers yet sufficiently high to melt said second thermoplastic fibers to form a liquefied thermoplastic resin;
• compressing said heated nonwoven structure to flow said melted resin and encapsulate said first fibers, said resin displacing approximately 80-90 percent of the entrapped air in said nonwoven structure;
• cooling said compressed nonwoven structure to form a moldable composite material having substantially reduced air voids therein, said first fibers being sized such that said composite material is capable of substantial elongation upon thermoform molding;
• and
• thermoform molding said moldable composite material into said shaped nonwoven molded composite material.

A method of manufacturing a nonwoven moldable composite material comprising the steps of:

• forming a batt by blending bicomponent fibers, such fibers comprising a higher melting point core material covered by a thermoplastic lower melting point sheath material;
• consolidating said batt into a nonwoven porous structure by needlepunching or stitch bonding the same;
• heating the consolidated nonwoven structure to a temperature below the melting point of said core material and above the melting point of said sheath material to substantially liquefy said sheath material and form a thermoplastic resin therefrom;
• compressing said heated nonwoven structure to flow said liquefied resin to displace air voids in said nonwoven structure;
• and
• cooling said nonwoven structure to form a composite material having substantially reduced air voids therein, said composite material being substantially free from shrinkage when subjected to a subsequent thermoforming molding operation.

A method of manufacturing a nonwoven moldable composite material comprising the steps of:

• forming a batt by blending a mix of first fibers and second thermoplastic fibers, said second fibers having a melting point lower than that of said first fibers and comprising approximately 40-80 percent by volume of said batt;
• needlepunching or stitch bonding said batt into a nonwoven porous consolidated structure, said first fibers being thoroughly intermixed with said second fibers;
• heating said nonwoven structure to a temperature below the melting point of said first fibers and above the melting point of said second thermoplastic fibers to substantially liquefy said second fibers and form a thermoplastic resin therefrom;
• positioning a covering material against at least one surface of said heated nonwoven structure and simultaneously compressing and laminating said cover material to said nonwoven structure during compression, said resin acting as an adhesive to achieve said lamination, and said compression causing said liquefied resin to flow and displace air voids in said nonwoven structure and encapsulate said first fibers;
• said lamination and compression being achieved by moving said heated nonwoven structure and covering material between a pair of pinch rollers maintained at a temperature below the melting point of said resin and spaced to create sufficient closure pressure against said heated nonwoven structure and covering material to cause the molten resin in said nonwoven structure to redistribute within the matrix of first fibers in said nonwoven structure as well as to adhere said covering material to said nonwoven structure;
• and
• cooling said nonwoven structure to form a moldable composite material having substantially reduced air voids therein, yet still porous, said cooling being provided at least in part by said pinch rollers being maintained at said temperature below the melting point of said resin, and said moldable composite material being resistant to shrinkage when subjected to subsequent thermoform molding.

A method of manufacturing a nonwoven moldable composite material comprising the steps of:

• forming a batt by blending a mix of first fibers and second thermoplastic fibers, said second fibers having a melting point lower than that of said first fibers and comprising approximately 40-80 percent by volume of said batt;
• needlepunching or stitch bonding said batt into a nonwoven porous consolidated structure, said first fibers being thoroughly intermixed with said second fibers;
• heating said nonwoven structure to a temperature below the melting point of said first fibers and above the melting point of said second thermoplastic fibers to substantially liquefy said second fibers and form a thermoplastic resin therefrom;
• said nonwoven structure being heated by utilizing hot air impingement to force hot air through said nonwoven structure to thoroughly liquefy said second thermoplastic fibers;
• compressing said heated nonwoven structure to flow said liquefied resin to displace air voids in said nonwoven structure and encapsulate said first fibers, said nonwoven structure being compressed between two pinch rollers maintained at a temperature below the melting point of said second fibers to assist in solidifying said resin while simultaneously redistributing said resin within the matrix of first reinforcement fibers of said nonwoven structure;
• and
• cooling said nonwoven structure to form a moldable composite material having substantially reduced air voids therein, yet still porous, with said first fibers encapsulated by said resin, said composite material being resistant to shrinkage when subjected to subsequent thermoform molding.

A method of manufacturing a heat stabilized, moldable nonwoven material which resists shrinkage during thermoforming, said method comprising;

• forming a batt by dry blending a mix of first fibers and second thermoplastic fibers, said second fibers having a melting point lower than that of said first fibers and comprising approximately 40-80 percent by volume of said batt;
• needlepunching said batt to form a nonwoven porous structure of intermixed first and second fibers;
• passing heated fluid through said nonwoven structure to heat said nonwoven structure to a temperature below the melting point of said first fibers yet sufficiently high to melt said second thermoplastic fibers to form a liquefied thermoplastic resin;
• compressing said heated nonwoven structure to flow said melted resin and encapsulate said first fibers, said resin displacing approximately 80-90 percent of the entrapped air in said nonwoven structure, said heated nonwoven structure being compressed by passing it between a pair of pinch rollers maintained at a temperature below the melting point of said melted resin and spaced to provide sufficient closure pressure to redistribute the molten resin within the matrix of first fibers;
• and
• cooling said compressed nonwoven structure to form a moldable composite material having substantially reduced air voids therein, the temperature of said rollers assisting in the cooling of said compressed nonwoven structure, said first fibers being sized such that said composite material is capable of substantial elongation upon thermoform molding.