Consultancy offering vent analysis service
Process & Design Technologies LLC wants you to vent ... just do it properly. The consulting firm in Kenosha, Wis., has patented an apparatus and method for checking mold venting. So now, for the first time, the firm offers the plastics industry venting analysis.
Vent sizes should be based on displacement volume of a mold cavity over time, not just on the likelihood of flash of the material being processed.
The company uses proprietary calculations to determine minimum venting for any part. Its vent-check device also can certify that vents have been installed, are functioning properly and are consistent from cavity to cavity.
Tel. 262-237-2525, email tsch [email protected]
Conair has new types of blender, granulator
Conair Group Inc. has introduced an insulated, high-heat version of its TrueBlend gravimetric blenders that allows makers of PET sheet, strapping and other products to use high levels of recycled material. That flexibility offers significant energy savings and productivity benefits, according to the company.
The high-heat TrueBlend allows processors to keep recycled and virgin materials separated until just before they get to an extruder or molding machine. If contamination is discovered in the regrind, only the regrind stream needs to be cleaned up, so production can continue using 100 percent virgin resin.
Conair said that design also gives users other advantages:
* Blended virgin pellets and regrind fluff, which have significantly different bulk densities and flow characteristics, reach the feed throat of the machine more quickly and have less chance to re-separate during conveying.
* By not allowing the heat input during desiccant drying to dissipate during blending, final processing requires less energy to be added.
In most conventional operations, recycled PET flake is blended with virgin pellets after the flake has been recrystallized and before the material is dried, Gene Flockerzi, vice president of packaging sales, said in a news release.
If contamination is discovered in the recycle stream, it will likely be only after the blended material has been through the drying process, which can take as long as six hours.
The line then has to be shut down while the drying hopper is emptied of material, including both contaminated regrind and uncontaminated virgin pellets. That can take two or three hours, followed by another two or three hours to reload the hopper, followed by another six hours to dry the new material.
The insulated blenders are available in sizes that can handle more than 5,000 pounds an hour.
The company in Cranberry Township, Pa., near Pittsburgh, also now offers three blender-control options for both extruders and injection molding machines. SmartBlend SB-1 and SmartBlend SB-2 offer, respectively, standard and high-end performance control. SB-2 also can be supplied with a software upgrade to add adaptive control of extruder throughput and finished-product dimensions in monolayer extrusion.
Also, the company's new FSG-series granulator has an in-feed section that can handle edge and bleed trim, off-spec rolls or hand-fed materials, making it ideal for grinding thin-gauge film and sheet scrap, Conair said. The granulator is part of a range of new equipment designed to improve productivity and profitability in film, sheet and extrusion coating.
The granulators come in nine sizes, for maximum throughputs from 100-1,600 pounds an hour. They can stand alone or be used as part of an integrated in-line, film-scrap recycling system.
The cutting chamber features three or five knives on an open rotor. The knives are slanted relative to the bed knives, to achieve a scissors-like cutting action for clean and uniform grinding of thin films.
Gneuss gets OK for food-contact process
Gneuss Kunststofftechnik GmbH received a letter of non-objection from the U.S. Food and Drug Administration for recycling PET with the firm's MRS extrusion systems without pre- or post-treatment.
The Bad Oeynhausen, Germany-based company said its process is the first to win FDA approval without pre- or post-treating such as drying, drying under a vacuum or crystallizing.
The letter allows recyclers to use a Gneuss MRS extruder, its devolatilizing system and the rotary melt-filtration system to reprocess up to 100 percent unwashed PET bottle flake, accord- ing to an April 7 news release.
The company credits the large polymer-melt surface area in the multiple-rotation section of the extruder, together with a rapid melt exchange and optimized venting, for the approval.
In the U.S., Gneuss Inc. is based in Matthews, N.C.