Archive for July, 2003

Davis-Standard: Basic Extrusion Seminar October 7 – 8, 2003

Thursday, July 10th, 2003

Davis-Standard will host a seminar on “The Basics of Plastics Extrusion” on October 7 - 8 at its Technical Center in Pawcatuck, Connecticut. The two-day class will cover the fundamentals of extrusion as well as the composition of various polymers and mechanics of essential downstream processes. Topics include extruder components, temperature control, maintenance and screw design. In addition to instruction, course participants will tour Davis-Standard’s laboratory and manufacturing facilities and will have access to polymer process engineers and technical specialists. The fee is $750 per person with a 10 percent discount given for groups of three or more. Course books and materials are included, and class size is limited to promote student/teacher interaction.
For enrollment or more information about Davis-Standard’s seminars and on-site extrusion training, contact Wendy Smith at (860) 599-6119 or at [email protected]

Atlantic Polymers: Self-coloring of ABS by the

Thursday, July 10th, 2003

The coloring of natural color resin during injection moulding - a process now standard with many other plastics - still offers scope for expansion in the case of acrylonitrile-butadiene-styrene (ABS). Slow progress here was due to uncontrollable variations in the natural resin color. Addressing this situation, the Japanese ABS manufacturer Toray and Atlantic Polymers GmbH of Meerbusch/Germany have now developed their ‘batch & resin’ system. For the processor, in-plant coloring of ABS has thus become just as easy as with other polymers, given that all grades of Toray’s ABS base resin, Toyolac, are of a highly uniform light-white base color; the ‘Merbatch’ color masterbatch marketed by Atlantic Polymers has been developed specifically for the Toyolac ABS range and matches these resins ideally due to its high color intensity and compatibility.
The ‘batch + resin’ concept allows processors to cope with increasing cost pressures by cutting on the extra expenditure associated with colored ABS while also simplifying their inventory management. At the same time, they gain flexibility by being able to respond quickly to customers\’ color requests. Color adjustments, too, can be handled speedily since the customer may rely on the direct support of the masterbatch manufacturer’s laboratory.
The ‘batch + resin’ system and the resulting benefits to the processor are key to Toray and Atlantic Polymers in the pursuit of their strategy for expansion in the European ABS market. Other elements include a fast system of distributed supply logistics, powerful customer support and advisory capabilities, plus interesting pricing.

AERT: Fifth production line for wood/plastic composite

Wednesday, July 9th, 2003

Advanced Environmental Recycling Technologies Inc. (AERT), a leader in wood/plastic composites, has brought on stream a new production line at the Company’s Springdale, Ark., headquarters. Line 5 includes a high-output extruder and a high-capacity cooling line. Additional production capacity will be coming on later in the year. AERT converts reclaimed plastic and wood-fiber waste into Weyerhaeuser ChoiceDek outdoor decking systems, MoistureShield door and window components, and MoistureShield CornerLoc exterior trim and fascia components.

Maguire: LineMaster software for film producer

Wednesday, July 9th, 2003

A newly installed yield control system from Maguire has already made possible outstanding product quality and consistency in a three-layer blown film coextrusion line operated by Coextruded Film Technologies [Pty] Ltd. (CFT), according to Bob Boden, managing director of this relatively new producer of polyolefin packaging and industrial films. The yield control system, based on new Maguire (R) LineMaster (TM) software (see accompanying news release), is the latest Maguire technology to be installed in the company’s initial production line, which also includes three Maguire (R) weigh scale blenders (one for each extruder), a Clear-Vu (TM) loader, an LPD (TM) resin dryer, and Maguire (R) Extrusion Control Network (TM) network software.

‘Maguire’s LineMaster system has enabled us to maintain extremely precise layer ratios and to produce rollstock with weights that are virtually identical from one roll to the next,’ said Boden. ‘Our control over layer ratios has resulted in films with consistent heat sealing and mechanical properties-an achievement which has proved invaluable for supplying quality film for high-speed wicketted bag production.’

While Maguire’s Extrusion Control Network controls product thickness by monitoring the weight of raw material metered to the extruder per unit of time and using this data to adjust extruder throughput, LineMaster software provides more advanced control by adjusting both extruder throughput and line speed (length of product per unit of time) to maintain target yield (weight per length of extruded product).
Extrusion Control Enhanced Quality, Saved Material, and Increased Level of Automation

Founded in December of 2000, Coextruded Film Technologies is focused on developing specialized multi-layer polyolefin films. ‘We set up our plant to maximize three capabilities: technological excellence for innovation, quality assurance for customers, and efficient, precision control of all operations by management,’ said Boden. ‘Maguire equipment and systems are at the heart of these capabilities and play a critical role in our current program to institute ISO 9002, EN ISO 14001, and OHSAS 18001. In the meantime, CFT is deliberating the installation of a second, larger three-layer line.’

The current blown film line centers on three 55-mm (2.17-in.) extruders feeding a 300 mm (11.81-in) die and includes oscillating nip, web guide, and tension control. The system is configured to produce film with overall thickness of 10 to 120 microns with three layers of equal thickness. Monthly output is around 70 metric tons (155,000 lb.), according to Boden.

Prior to installing Maguire’s Extrusion Control Network, CFT had set all three extruders to operate at a screw speed of 87 rpm, with the assumption that the three brand-new machines would yield layers of equivalent thickness, according to --- Crittenden, sales manager of Maguire Europe, which worked with CFT to install Maguire systems. ‘Even at identical screw speeds, however, layer thicknesses differ because of differences in the melt indices and bulk densities of the resins and in conditions inside the extruders,’ said Crittenden. ‘Once CFT installed our Extrusion Control Network and set thickness targets at 33% of overall gauge for each layer, they found that screw speeds now varied from one extruder to another to offset resin and process differences and produce layer thicknesses on-target. This increased control also made possible raw material savings that we estimate roughly at 12%.’
Visit the Maguire Products web site: www.maguire.com

Cincinnati: New drip irrigation pipe technology

Tuesday, July 8th, 2003

In cooperation with the American company Drip Research Technology Services USA Ltd., San Diego, California, the Vienna machine manufacturer Cincinnati Extrusion GmbH has developed a new process for continuous production of irrigation pipes. The line concept, a simple, cost-efficient alternative to conventional processes, is of special interest to all markets with a constantly rising demand for irrigation systems. Besides North and South America, this includes Southern Europe, the Middle East, and China.

The development of this new extrusion line concept started with the idea of replacing the so-called “drippers“ placed on the inside of conventional irrigation pipes with a continuous, embossed PE tape. So far, the injection-molded drippers have always been inserted in the course of pipe extrusion, and driven into the pipe just after extrusion through the rear of a crosshead at pre-set intervals. Mechanical insertion of these components requires a sophisticated, high-precision mechanical system. Then, at the end of the pipe extrusion line, a hole is punched into the pipe at the exact spot where the dripper has been fixed.

In new irrigation pipes this dripper is now being replaced by an embossed PE tape with a special kind of embossing that takes over the task of pressure control and ensures that a stable irrigation performance with precise metering of the amount of irrigation water required is maintained. The embossing, and thus the performance of the irrigation system, can be adjusted by simply exchanging the embossing module in the production line.
How the DRIP TAPE LINE works

The complete production line for irrigation pipes with a PE tape inside performs two production steps: first manufacturing of the tape and then pipe extrusion with simultaneous insertion of the tape into the pipe.

The PE tape is extruded with an Alpha 45 single screw extruder and a special die, then embossed directly by a down-stream embossing unit, ready for insertion into the crosshead of a second extruder by means of a special feeding unit. The actual pipe with a 20 mm external diameter and 0.15 to 0.2 mm wall thickness is manufactured on a Proton 60 single screw extruder. Through the specially designed crosshead the tape is fed into the interior of the pipe and then directly welded on in the calibration unit. Next, the pipe is cooled in a full bath cooling aggregate laid out for high-speed extrusion. Then, in the haul-off unit, the holes to release the water are punched into the pipe at precisely defined spots. Finally, the pipe is wound up on an automatic winder.

Makroform: 6-layer polycarbonate sheet in new widths

Tuesday, July 8th, 2003

In the second half of 2003, the new Makrolon® multi longlife 6-layer polycarbonate sheet will also be available as 980 and 1200 millimetre-wide sheet. Makroform offers the additional widths to respond to the high demand for the new, highly heat-insulating sheet. The sheet entered the market in January 2003 in a standard width of 2100 millimetres. As in the standard width, the new sheet widths will be available in a thickness of 16 and 20 millimetres in transparent and opal white.

Users of the 6-layer polycarbonate sheet particularly value its outstanding heat insulation, high cold-bending radius, and extremely high impact resistance. Compared to standard sheet of the same thickness, the new Makrolon® multi longlife 6-layer polycarbonate sheet is a clear energy saver, as it helps to save up to 25 % energy – this corresponds to 5 litres heating oil per square meter per year, or 5.5 cubic meters natural gas per square meter annually. High sales illustrate that the new sheet offers a great value for money.

Thanks to their light weight, the sheets can be easily installed even on large surfaces and light substructures - a factor that has a significant impact on the construction cost. Its high cold-bending radius lends the sheet to special designs, such as cupolas. As all Makroform products with longlife coating, the new polycarbonate sheets boost absolute weather resistance. The 6-layer sheet is particularly recommended for roofing of residential and industrial buildings.

Clariant: Innovating in coatings

Monday, July 7th, 2003

The Latin American Coatings Show takes place on 16th and 17th July 2003 in Mexico City/Mexico. Together with its partner, Eckart GmbH (Website: www.eckart.de), Clariant’s Pigments & Additives Division is showing new developments for paints, printing inks and other coatings on Stand 50. Highlights include innovative waxes and light stabilizers. The focus will also be on high performance colorants for coatings and products for high quality printing inks.
Further information on products and help in selecting raw materials can be found at http://pa.clariant.com . The Product Finder, an interactive search system can be queried according to area of application such as ‘Coatings’.

EDI: Flat die with unique ‘sculpted’ design

Monday, July 7th, 2003

A new type of flat extrusion die that differs in shape dramatically from conventional dies enables film, sheet, and coating processors to improve productivity and product quality by eliminating a longstanding tradeoff between gauge uniformity and streamlined melt flow, it was announced at NPE 2003 by Extrusion Dies Industries, LLC (EDI), which is exhibiting at Booth 4561.

Called the Contour Die because it has a tapered, ’sculpted’ shape instead of the standard block-like configuration, the new system exhibits die-body deflection that is uniform across the width of the die yet avoids the sacrifice of melt-flow streamlining incurred by earlier ‘constant-deflection’ dies, according to John A. Ulcej, executive vice president of engineering and technology. Ulcej cited these specific benefits:

. Rapid achievement of target gauge. The key advantage of uniform die body deflection is a reduction of the time required to adjust the gauge profiling system. ‘Operators can achieve target gauge several minutes sooner after startup or changes in extrusion rate,’ Ulcej said.

. Low levels of polymer degradation. ‘The superior flow of the Contour Die compared with that of earlier constant-deflection dies is particularly valuable for those running heat-sensitive polymers like PVC,’ noted Ulcej, ‘and for most polymers it provides greater assurance of good-quality product and less likelihood of lip buildup or gels.’

. Fast purges. Streamlined flow helps to speed purges for color or product changes.

. Low levels of scrap. All three improvements cited above manifest themselves in terms of reduced scrap generation.

‘We anticipate that users of the Contour Die will achieve significant reduction in scrap,’
Ulcej said. ‘With conventional dies, scrap is often the major penalty paid for non-uniform die body deflection, as well as for flow hang-ups or dead spots in the manifold. This new die reduces or eliminates both causes of excessive scrap.’

While manufacturers running heat-sensitive polymers or requiring frequent product changeovers are obvious beneficiaries of the Contour Die, Ulcej noted, ‘virtually every processor of film, sheet, or coatings can use this new system to improve productivity and quality.’

Key to Constant Deflection: ‘Engineer the Die from the Inside Out’

The manifold of a flat extrusion die is a flow channel that is machined between the upper and lower halves, or bodies, of the die and whose function is to develop uniform flow and to distribute the melt to its final product width. Die-body deflection is caused by the pressure of the molten polymer that the extruder continuously charges into the manifold. Multiplied across the entire area of the manifold, this pressure (typically in the range of 1000-4000 p.s.i., or 70-280 kg per sq. m) generates thousands of pounds of force, enough to deflect heavy steel die bodies.

This deflection is non-uniform in a die with a standard coathanger manifold (so-called because its back walls, on either side of the melt entry port, are positioned at an angle to the die exit rather than parallel to it, forming two sides of a triangle). The result of this non-uniformity is a tendency for center flow to be too heavy and flow at the ends to be too light; operators need several minutes to correct for this problem in order to achieve an acceptable product. In the interval, substantial scrap is generated.

Previous designs for constant-deflection dies solved this problem with manifolds that had straight backlines, parallel to the die exit, but they did not provide the degree of flow streamlining available with a coathanger manifold. Melt flowing through such dies stood a greater chance of encountering hang-ups or dead spots that cause polymer degradation and retard purges for color change.

‘In designing the Contour Die, we started with a standard coathanger manifold and engineered the rest of the die around it,’ Ulcej said. ‘Since there is a pressure gradient across the width of the manifold from the center to the ends, we built in extra die-body thickness where the force was greater and did the reverse where there was less force. The result is a sculpted configuration that is smaller and tapered at the ends.’

In developing the new die, EDI employed sophisticated three-dimensional engineering software and computerized manufacturing systems, including a five-axis machining center. ‘These capabilities enabled us to turn die manufacturing upside-down,’ Ulcej said. ‘Instead of starting and ending with two steel rectangles because it is easier to build conventional dies that way, we had the freedom to design the die in a way that would optimize its performance.’

For more information: [email protected]

Maguire: New blender-based yield control

Thursday, July 3rd, 2003

Gravimetric blenders powered by new LineMaster (TM) software from Maguire Products, Inc. raise extrusion yield control to a new level of simplicity and accuracy and enable processors to enhance product consistency, save on raw material, shorten setup times, and reduce scrap, the company announced at NPE 2003 (Booth 9101). The yield control system has already been used commercially-see accompanying news release on blown film producer Coextruded Film Technologies for an example.

The new technology makes advanced yield control available without need for large, complex, and costly hardware systems such as loss-in-weight blenders, according to B. Patrick Smith, vice president of marketing and sales. ‘It is now possible to achieve consistent accuracy in material consumption and product quality using nothing more elaborate than the Maguire (R) Weigh Scale Blender,’ Smith said. ‘The simplicity, ease of use, and low cost of this system have made it by far the most widely used blender in the world, yet its precision and reliability also make it eminently suitable for governing the entire extrusion process with unvarying accuracy.’

The LineMaster system combines advanced blender controller software with Maguire’s Gravimetric Gateway (TM), or ‘G2,’ software for integrating blenders in a computer controlled network. This integrated system makes it possible for the blender controller to adjust two critical process parameters simultaneously.

In standard extrusion control, the blender controller automatically adjusts only one parameter-extruder speed-to achieve a manually set target throughput (weight of raw material processed per unit of time). Somewhat more advanced is a basic type of yield control, in which the controller once again automatically adjusts only extruder speed, but does so by first calculating target throughput on the basis of two manually set parameters: target line speed (length of product per unit of time) and target yield (weight per length of extruded product). In contrast with these systems, the LineMaster system simultaneously adjusts both throughput and line speed to achieve target yield, providing complete control of the process.

‘Until the advent of our LineMaster technology, the vast middle ground of extrusion processors have had to choose between cumbersome and costly loss-in-weight yield control systems or very basic forms of extrusion control,’ said Smith. ‘Now any extrusion processor armed with our software can lock in desired product yields via simple connections between a standard Maguire blender and the extruder-screw and hauloff-speed controls. Once set up, this system quickly establishes control over the amount of material per length of product, without need for prolonged setups in which operators must optimize speed settings.’

Three yield-control configurations are possible with the LineMaster system, in each of which 1) the blender is connected to the downstream speed control and automatically adjusts it to maintain line speed; and 2) the desired yield is entered by the operator. The three configurations vary according to which other parameter is to be set as a target by the operator:

Line speed.
Blender calculates required extruder throughput based on pre-set line speed and yield and automatically adjusts the extruder speed control.

Extruder throughput.
Blender calculates required line speed based on pre-set throughput rate and yield and automatically adjusts the extruder speed control.

Extruder speed.
Blender calculates required line speed based on pre-set extruder speed and yield and automatically adjusts downstream speed control.

Gain-in-Weight Blending and Advanced Software Are Keys to Precision Yield Control

Mounted directly over the throat of an extruder, a Maguire (R) Weigh Scale Blender controls raw-material metering by weighing each recipe batch. Recipe ratios can be varied from 0.01 to 100% with simple thumb-wheel settings. In operation, the blender sequentially dispenses all ingredients, in their targeted recipe proportions, from separate hopper bins into a weigh chamber (hence the term ‘gain-in-weight’). From the weigh chamber the batch falls into a mixing chamber, then is fed directly into the extruder. In subsequent batches, small corrections are made automatically. Added to this precise information about the weight of each batch (in grams) is information about the exact time (in tenths of a second) required for each batch to be consumed by the process.

These data enable the blender to adjust the speed of the extruder screw to maintain a targeted throughput rate. To carry out coordinated, simultaneous adjustments of both line speed and throughput to ensure maintenance of targeted product yield, the blender must be used in combination with G2 software.

Teknor Apex: Plasticizer-free vinyl compounds eliminate volatiles

Thursday, July 3rd, 2003

Chemistry that combines polyvinyl chloride (PVC) and polyolefin elastomers (POEs) has yielded a new series of flexible vinyl compounds that perform better than conventional plasticized PVC at high and low temperatures and avoid problems caused by plasticizer volatilization or migration, it was announced today at NPE 2003 by Teknor Apex, Vinyl Division (Booth 9755). The FreeFlex (TM) 4002 series includes four grades with Shore A hardness ratings of 81, 82, 85, and 90.

‘While a degree of plasticizer loss is acceptable in many applications for flexible vinyl, the resulting falloff in mechanical properties, though typically marginal, has limited or prevented use of conventional compounds in applications that demand outstanding performance at temperature extremes or after outdoor exposure,’ said industry manager Philip Morin. ‘Because the flexibility of FreeFlex compounds is inherent in their elastomeric component, products manufactured from them avoid embrittlement and provide as-new performance after prolonged service under such challenging conditions.’

Potential applications include hose and tubing and sheet products such as tank and pond liners, added Morin. ‘FreeFlex compounds are particularly promising for applications involving transport or containment of fluids that have a chemical affinity with conventional plasticizers,’ he said, ‘or in parts for assemblies in which plasticizer migration can mar the surface of adjacent components.’

The new compounds will be priced approximately 40 to 80% higher than high-performance conventional vinyl with low-extractible, low-volatility polymeric plasticizers.

FreeFlex Products Are The First Fruits of a Major Compounding Innovation
The technology underlying new FreeFlex compounds involves 1) use of high-performance new-
generation POEs that typically are immiscible with PVC, and 2) development of proprietary compatibilizer chemistry enabling Teknor Apex to alloy them with PVC. ‘Unlike plasticizers, the POEs in FreeFlex compounds stay permanently blended with PVC,’ said technical manager Maryellen Cox, ‘making possible material systems that remain fully homogeneous throughout their end-use service life.’

Plasticizers typically constitute a third of flexible vinyl compounds by weight and vary in their rates of extractability.

The FreeFlex 4002 series is just the first in a broad range of compounds anticipated as a result of the new PVC/POE technology, according to Cox. ‘In comparison with plasticizer additives, our elastomeric alloy components make possible greater retention of elongation upon heat aging, greater resistance to embrittlement at very low temperatures, superior electrical properties as reflected by a lower dielectric constant, and improved chemical resistance. We intend to develop a range of other PVC/POE alloys, all of them designed to expand the applicability of PVC to product areas where conventional vinyl does not meet existing requirements.’
Visit the web site: www.teknorapex.com.