Putting one or two vents between the feed throat and die is a good way to remove moisture, trapped air, and other volatiles from melted plastic as it moves through an extruder.
Your Business in Brief - January 2002
Bimetalix Joins With SpirexBimetalix of Sullivan, Wis., a producer of bimetallic single- and twin-screw barrels, has become a division of Spirex Corp., Youngstown, Ohio.
Your Business Outlook - January 2002
Over a dozen processors already foam wood-fiber composites and an equal number are experimenting with it. Foaming with wood cuts resin cost and weight in half and brings design advantages. But it also requires particular know-how in materials formulation and extrusion hardware.
Food and consumer packaging was the focus of new developments in polyolefins and styrenics, while automotive was the main target for new engineering materials.
The Internet investment bubble may have burst, and some twenty-something ex-billionaires may have moved back in with their parents, but the "dot-com thing" is definitely not over.
High-speed packaging systems dominated thermoforming news in Dusseldorf. A new shallow-draw, servo-driven system promises to make formed PP deli lids competitive with injection molded LLDPE. Other new machines use electric servo motors to speed forming of PS, PE, and PET packaging.
The October show in Dusseldorf saw an onslaught of new all-electric and hybrid-electric presses, with modular designs, new clamping styles, and new sizes available from an ever-growing range of suppliers.
This K show demonstrated the continuing evolution toward higher torque, screw speed, and throughput rates in twin-screw compounders. There were also new developments for reducing wear when processing filled compounds and new processes available for license to compound wood and paper fibers with plastics. There were even some improvements in backflushing screen changers.
It doesn’t matter whether you extrude blown or cast film, sheet, pipe, profiles, or foam—the K 2001 show held something exciting and unexpected that will open your eyes to new possibilities.
Processors of rigid PVC pipe, window profiles, siding, fencing, and doors can save money and speed compound mixing by using a new grade of white mineral oil as an external lubricant in place of the usual paraffin wax.
Energy efficiency and production cost savings were dominant themes of the blow molding exhibits at K 2001. A handful of new all-electric machines aroused intense interest, though they are aimed primarily at niche markets. And in two-stage (reheat) PET stretch-blow molding, the focus was on boosting output per cavity.
Recently formed alliances of fuel-cell start-up companies and engineering-polymer suppliers are already bearing fruit. Their research is coming up with new ion-conducting plastic films for use in Proton Exchange Membrane (PEM) fuel cells. These novel membranes are said to generate electric current more easily, operate across a broader temperature range, and cost less than the incumbent materials, which are mainly sulfonated fluoropolymers.
A new metallocene catalyzed, very-low-density polyethlyene (mVLDPE) from ExxonMobil Chemical Co., Houston, reportedly offers the excellent toughness associated with mLLDPE plus lower heat-seal temperatures and other advantages over conventional Ziegler-Natta VLDPEs or ULDPEs for flexible packaging.
Foamed Films Find New Niches
Thin polyolefin foams have been made for decades for decorative ribbons, wire wrap, and sleeve-type labels.
Laser Welding Comes of Age
Laser welding is gaining acceptance as a specialized method for joining plastic parts that are sensitive (e.g., contain circuit boards), involve complex geometries, or have strict cleanliness requirements (medical devices). So far, most of this activity has taken place in Europe.
A Big Player in Niche Markets
One route to success in custom molding is to offer customers as many process and technology options as possible at diverse locations.