Lubricant Pellets Cut Scrap & Cycle Times
Internal lubricants for a variety of thermoplastics are newly available in a 100%-active pellet form from Axel Plastics Research Laboratories, Woodside, N.Y. MoldWiz pellets come in several resin-specific formulations that contain no binders or fillers. Use levels are as low as 0.25%.
Precision Plastic Injection molders can tumble or dry blend these pellets with resin or feed them directly at the throat-an advantage over messy powders. For compounders, they are said to be useful in masterbatches because they improve dispersion of color, fillers, and other additives. MoldWiz internal lubricants reportedly improve resin flow at lower temperatures, helping to shorten cycles and reduce flow marks and knit lines on molded parts. The lubricants also do not leave any residue on molded parts, eliminating the need for cleaning before plating or other secondary processes, Axel says.
More Long-Fiber Pellets For EMI Shielding
The Incoshield family of long-fiber nickel concentrates for EMI/RFI shielding has been expanded to include three new masterbatches of ABS, nylon 6, and PBT. Previous grades are based on nylon 12, PC, PEI, PPS, and acrylic. Supplied by Inco SPP, Wyckoff, N.J., Incoshield concentrates contain 60% by weight nickel-coated long carbon fibers. These concentrates are dry blended with resin before being injection molded into housings for computers, electronics, and communications equipment.
FR Agent Doesn’t Get Steamed at a Little Heat
A new synthetic, halogen-free flame retardant gives up its water of hydration endothermically at higher temperatures than familiar alumina trihydrate. Basic Aluminum Oxalate (BAO) from Alcoa Industrial Chemicals, Bauxite, Ark., extends the processing range of aluminum-based flame retardants up to 625 F, versus around 392 F for ATH and 540 F for magnesium hydroxide. Price is about $1/lbÑmuch higher than for ATH and competitive with Mg(OH)2.
Like ATH, BAO has a white color, high brightness, and low toxicity. But the low soda content of BAO means less impact on electrical properties of wire and cable, Alcoa claims. BAO reportedly can provide UL 94V-0 ratings to a wide range of resins at loadings of 40-63%. Its specific gravity is 2.2. Available mean particle sizes are 0.3 to 2.7 microns.