Until now, designers looking for high strength and stiffness performance properties in high demanding short and long glass filled PP applications have had to make some difficult choices… continue to increase the wall thickness and rib height of the molded part; thus increasing the weight and dimensions of the part, or switch out of PP to a more expensive glass filled nylon material and make do with the added weight and higher costs.
Robert Wick, director of product development explains:
“These new Tension Members (TMs) are essentially continuous fiber reinforced rods that are inserted in the mold and strategically placed at the bottom of a molded rib before the Polypropylene plastic is injected. When a molded part is stressed, it normally fails at the bottom of the rib. By placing these “rods” directly to the bottom of the rib, the force is distributed across the entire rib; thus, dramatically increasing the load capacity and overall stiffness of the molded part.”
In injection molded 5” wide x 18” long x 1” deep panels processed in 40% long fiber glass filled PP, using this patented technology provides flex strength improvements of 72% and flex modulus improvements of 21% without increasing any of the part weight.
In compression molded 8”wide x 18” long x 1” deep panels using the same 40% long fiber glass filled PP, the property improvements are even greater obtaining flex strength improvements of 142% and flex modulus improvements of 50%, again not impacting the part weight.
These tension members are targeted towards large panel applications and parts that may have a slight bend in them. Typical applications would be boards, scaffolding, bins, shelving, pallets, bumper beams, seatbacks, tailgates, and other similar large structures.
“In addition, when these polypropylene TMs are used in conjunction with glass filled PP, the entire part is still completely recyclable because the TMs are also made of thermoplastic PP and glass.”
Tension members are manufactured and sold based on the number of glass filaments within the TM and the overall length of TM. For example, an 8,000 filament (i.e. 8,000 individual strands of fiber) product has an overall diameter of .090” round and sells for around $.034 (i.e. 3.4 cents) per foot at high volume. A 12,000 filament product is .160” in diameter and sells for approximately $.061 (i.e. 6.1 cents) per foot at high volumes. ICP can vary the number of filaments in the TM to meet the application needs and rib size.
Production is done in their Winona, Minesotta site and product is readily available and applications are being sampled and developed.
Companies: Integrated Composite Products, INC.