Machinery company injection molds wood-filled PP part

In what could be an industry-first, Wilmington Machinery and partners have successfully injection molded a 30% wood-filled polypropylene part. The part was molded on a specially designed 375 ton, two-stage injection molding machine.
According to a report published by Omnexus, the process involved careful drying, melting in a low shear extrusion apparatus, and a high-pressure, fast-fill injection unit capable of achieving fill-times in a fraction of a second with shot sizes of 3 to 5 lb.
The polypropylene/pine-filled material was supplied by North Wood Plastics Inc.; while an additives package including stabilizers, lubricants and foaming agents was supplied by Reedy International
The 375-ton machine used to mold the wood-filled part is located at Wilmington’s Foam Laboratory at the company’s North Carolina headquarters. Wilmington says it sees immediate opportunities for applications in the furniture industry for seat and back pieces requiring stapling and mails, deck boards and other marine and building products.