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The Chinese National Carbon Fiber Industry Testing Center to be set up in Shandong Province

The Chinese National Carbon Fiber Industry Testing Center to be set up in Shandong ProvinceThe General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China (AQSIQ) has agreed to set up Chinese National Carbon Fiber Industry Testing Center in Weihai City of Shandong Province, China.Thanks to its outstanding mechanical and lightweight properties, carbon fiber is gaining wider application in many sectors. As about 80% of the carbon fibers consumed are imported outside of China, it is listed as one of the top ten strategic new materials in the Chinese national key development plan.Weihai City is the main production base of carbon fibers and composites in China, with more than 200 producers across the supply chain. The National Carbon Fiber Industry Testing Center to be set up in the Harbor Port Carbon Fibre Industrial Park will benefit from the competitive advantages of the city.Academic-industrial partnerships are expected to be strengthened following the establishment of the Center, facilitating the development of carbon fibers in China. Source: China Plastic & Rubber Journal International

Aeyoung Park 2018-01-24

PolyOne to unveil Hammerhead marine composite panels

With a weight savings of more than 50% versus plywood, these continuous-fiber reinforced thermoplastic sandwich panels offer boat manufacturers a lighter, more efficient alternative to traditional marine construction materials.▲ PolyOne to unveil Hammerhead marine composite panelsBeyond weight reduction, Hammerhead panels can improve installation and labor productivity because they replace the typical wood, hand lay-up and vacuum assisted process with a consolidated, ready-to-install panel. Applications range from structural to cosmetic in areas such as bulkheads, decking, ceilings, hatches, covers, cabinetry, fittings, transoms, and stringers. The new panels are currently available through Composites One, a materials distributor to the marine industry.Hammerhead Marine Composite Panels consist of thermoplastics, continuous glass-fiber face sheets, and foam cores. This configuration brings unique characteristics such as improved bondability to various surfaces, enabling thermal lamination to different materials and finishes for increased design flexibility compared with traditional assembly methods.“Boat builders now have an innovative alternative based on strong, lightweight thermoplastic materials that can remove multiple production steps for better quality and economics,” said Matt Borowiec, general manager, PolyOne Advanced Composites.PolyOne Advanced Composites will feature Hammerhead Marine Composite Panels at CAMX.More information: www.polyone.comSource: http://www.jeccomposites.com/knowledge/international-composites-news/polyone-unveil-hammerhead-marine-composite-panels?utm_source=SalesForceMarketingCloud&utm_medium=email&utm_campaign=World+Market+News+N.+721

Aeyoung Park 2017-12-18

How glass fiber compounds improve cost-effectiveness

Glass fiber reinforced composites arecost-effective alternatives to traditional metals such as steel and aluminum,offering higher strength-to-weight ratio and better mechanical properties, andare easier to process. The high cost-performance ratio makes them highlydesirable in the electrical & electronics (E&E) as well as automotiveindustries.Lightweight design, including the use of robust yet lightweight materials, has become an imperative in manufacturing, particularly in the automotive industry. Light-weighting helps reduce vehicular CO2 emissions and thus plays a crucial role in enabling manufacturers to adhere to regulatory standards.New level of processability and physical properties▲ Tensile strength comparison of Cremaid and other PA compounds.A new family of compounds from Teknor Apex Company raises the processability and physical properties of glass fiber reinforced polyamide (PA) to a new level, enabling injection molders to take on more demanding metal-replacement applications or replace alternative thermoplastic materials for greater versatility in processing.New Creamid compounds exhibit higher tensile strength and better flow properties compared with standard glass-filled polyamide counterparts, greater dimensional stability, lower water absorption, improved chemical resistance, and enhanced surface aesthetics, according to the US company.In metal-replacement applications, Creamid compounds are frequently formulated for a flexural modulus as high as 21GPa, giving molded parts high dimensional stability. These grades also provide tensile strength up to 260MPa, a property more commonly expected from die-cast aluminum or zinc, and offer significant savings in part weight.When combined with longer tooling life and lower material cost, metal-replacement projects with Creamid polyamides typically produce very high returns on investment for OEMs, according to Brian Rickard, Director of Strategy and Business Development for the Engineering Thermoplastics (ETP) Division of Teknor Apex. The compounds have been successfully used in Europe for automotive air vents, spoilers, fan blades, spring adapters, and key fobs.The processing advantages are also dramatic compared with standard glass-filled PA. For instance, versus a standard 43% glass-filled PA, a 40% glass-filled Creamid compound shows a 68% improvement in spiral flow tests, reaches a 41% lower peak injection pressure, and requires 43% less clamp force.Longer flow length and lower injection pressure translate into a wider processing window, more efficient filling of complex or thin-wall cavities, reduced part warpage, and a possible reduction in the number of gates or knit lines. A lower clamp force also opens the possibility of increasing the number of cavities or running parts in a smaller, less costly molding press.EV brings new opportunitiesThe emergency of electric vehicle (EV) also fueled the demand for lightweight design that improves the driving range. What’s more, an exciting new gamut of design possibilities can be realized. For example, components in battery electric and fuel cell electric vehicles can be fundamentally redesigned for low density polypropylene (PP) compounds due to lower operating temperatures versus internal combustion engine (ICE) powertrains.Components such as tailgates and front end modules can be executed in monomaterial PP solutions that are not only lighter weight, but are more easily recycled. And where metal and higher-cost engineering plastics were once the material of choice for structural elements, PP-based compounds can now be considered for such applications.At the VDI International Plastics in Automotive Engineering Conference in March, polyolefins specialists Borealis and Borouge launched two new grades in the Fibremod range of PP fiber reinforced compounds for interior, exterior, and under- the-bonnet (UTB) automotive parts.The proprietary Fibreod long glass fiber reinforced PP (LGFPP) is known for its good fiber impregnation and flexibility in allowing for use of various PP matrices, andthe production of grades in customized colors, said Borealis.One of the new grades is LGF Fibremod GB416LF with 40% filler content, offering a new solution for a full polyolefin tailgate module as a lower-density replacement solution for conventional metal or engineering polymers.As a high-flow material, Fibremod GB416LF fulfills both emission requirements and mechanical performance criteria. With high quality surface aesthetics, the grade can be used for visible parts. Its sustainability is enhanced not only by its lighter weight, but by eliminating the need for one or more paint layers, or additional aesthetic parts, explained the company.Another new offering, Fibremod GD577SF, is a short glass fiber grade with 50% filler. Apart from strong mechanical properties, the grade provides pleasing surface quality for visible structural parts.As a potential replacement solution for demanding metal and PA applications, GD577SF is suited for a diverse range of exterior, interior and UTB applications, including full plastic front end modules, clutch and gas pedals, external mirror structures, etc.Maximum safety for E&ESafety, in particular fire resistance, is of paramount in E&E applications. Miniaturization of electronics parts places tougher requirements on the material used. Lanxess responded to this trend by introducing two new Durethan flame-retardant PA 6 compounds that are highly reinforced with glass fibers.Marked specimens of the new, halogen-free, flame-retardant polyamide Durethan BKV45FN04 are clamped in a tensile testing machine.They are ideal for components subject to high mechanical load, such as structural parts in industrial machines that must meet flame retardance requirements, and molded case circuit breakers (MCCB).“In addition, they are a substitute for die-cast metals and thermosets, when the high stiffness of these materials is not needed,” said Alexander Radeck, Applications Development Expert in the High Performance Materials (HPM) business unit. “Processors benefit from the high design freedom and cost-efficiency afforded by injection molding.”The first grade, Durethan BKV 45 FN04 is reinforced with 45%-by-weight short glass fibers. Its flame retardance package contains no halogens or red phosphorus. The high-modulus material can therefore also be colored as desired.The material passed the UL 94 test of the US testing organization Underwriter Laboratories (UL), achieving the best classification of V-0 with test specimens just 0.4mm thick.“In the even tougher UL 94-5V test, the compound achieves the best rating of 5VA at just 1.0mm, and that’s entered accordingly on the UL Yellow Card,” continued Radeck.With a CTI A (Comparative Tracking Index, IEC 60112) of 600 volts, the material is highly tracking resistant. Electronic assemblies can therefore be positioned closer together without resulting in shorts or device defects caused by leakage current.Another of the material’s strengths is its high-voltage tracking resistance to DIN EN 60587 and ASTM D2303 (Inclined Plane Tracking, IPT). The test recreates how strongly the insulating capacity of a surface changes at high voltages outdoors when exposed to moisture and soiling.“The Yellow Card lists a good IPT voltage for our material of 1 kilovolt at 60 minutes tracking time. That means it’s also suitable for components used in high-voltage battery systems in electric cars,” explained Radeck.The second new compound from Lanxess is on the verge of market introduction and contains over 50% glass fibers. With a halogen-based flame retardance package, it likewise achieves V-0 (0.75mm) and 5VA classification in UL 94 testing (UL Yellow Card).The high flame retardance is also evident in glow wire testing to IEC 60695-2-12/13. For example, at 775°C, the product easily fulfills glow wire ignition temperature (GWIT) requirements.“With these results, the material is destined for components subject to high mechanical stress, such as in household appliances (IEC 60335-1). It also has great opportunities for use in housing parts and covers of circuit breakers,” said Radeck. The compound’s CTI A tracking resistance is high at 575°C (PLC 0 on UL Yellow Card).With their high glass fiber content, both of the new engineering materials display unusually high stiffness and strength. Durethan BKV45FN04, for instance, has a tensile modulus of 16,000 megapascals (freshly molded).Despite glass fiber reinforcement, the melts of both thermoplastics display high flow properties thanks to EasyFlow technology, according to Lanxess. “Components can therefore be designed with thin walls, complex geometries and relatively long flow paths,” said Radeck.China Plastic & Rubber Journal (CPRJ) - Oct 2017 IssueSource: China Plastic & Rubber Journal By Victor ChengLink: https://www.adsalecprj.com/Publicity/ePub/lang-eng/article-67027862/asid-27/tc-en_CPRJ_EN_20171122/EbookArticle.aspx

Ms. Park 2017-11-24

DowDuPont Merger Successfully Completed

DowDuPont announced the successful completion of the merger of equals between The Dow Chemical Company and E.I. du Pont de Nemours & Company, effective Aug. 31, 2017. The combined entity is operating as a holding company under the name “DowDuPont” with three divisions – Agriculture, Materials Science and Specialty Products. “Today marks a significant milestone in the storied histories of our two companies,” said Andrew Liveris, executive chairman of DowDuPont. “We are extremely excited to complete this transformational merger and move forward to create three intended industry-leading, independent, publicly traded companies. Our teams have been working for more than a year on integration planning, and -- as of today -- we will hit the ground running on executing those plans with an intention to complete the separations as quickly as possible.” With the merger now complete, our focus is on finalizing the organizational structures that will be the foundations of these three intended strong companies and capturing the synergies to unlock value. With clear focus, market visibility and more productive R&D, each intended company will be equipped to compete successfully as an industry leader,” said Ed Breen, chief executive officer of DowDuPont. The Board of Directors of DowDuPont comprises 16 members – eight directors formerly on the DuPont Board and eight directors formerly on the Dow Board. There are two lead directors: Jeffrey Fettig, who previously served as the lead independent director for Dow; and Alexander Cutler, who previously served as the lead independent director for DuPont. Liveris serves as the executive chairman of the Board and Breen also serves on the Board. Paths to Separation Once each division has its own processes, people, assets, systems and licenses in place to operate independently from the parent company, DowDuPont intends to separate the divisions to stand within their own legal entities, subject to Board approval and any regulatory approvals. The intended separations are expected to occur within 18 months. The intended companies are expected to include:The Agriculture Company that brings together the strengths of DuPont Pioneer, DuPont Crop Protection and Dow AgroSciences and will be headquartered in Wilmington, Delaware, with global business centers in Johnston, Iowa, and Indianapolis, Indiana. The Materials Science Company, to be named Dow that will consist of the businesses comprising the following current Dow operating segments: Performance Plastics, Performance Materials & Chemicals, Infrastructure Solutions and Consumer Solutions (Consumer Care and Dow Automotive Systems; Dow Electronic Materials is intended to go to the Specialty Products Company), as well as DuPont’s current Performance Materials operating segment. The intended Materials Science Company will be headquartered in Midland, Michigan. The Specialty Products Company that will consist of businesses including DuPont Protection Solutions, Sustainable Solutions, Industrial Biosciences and Nutrition & Health, which will integrate the Health and Nutrition business from FMC pending the close of that transaction; as well as Electronic Technologies, which combines DuPont’s Electronics & Communications business with Dow’s Electronic Materials business unit. The intended Specialty Products Company will be headquartered in Wilmington, Delaware. Three Advisory Committees have been established by the DowDuPont Board, chartered to generally oversee the establishment of each of the Agriculture, Materials Science (Dow) and Specialty Products divisions in preparation for the separations. Additionally, each Advisory Committee will develop a capital structure in accordance with the guiding principles set forth in the Bylaws, and designate the future chief executive officer and leadership team of its respective intended company. http://www.kunststoffe.de/en/news/overview/artikel/dowdupont-merger-successfully-completed-4276504.html?et_cid=5&et_lid=5

Ms. Kang 2017-09-22

Primex Color Compounding & Additives announces new line of thermoplastic elastomers

By : Clare GoldsberryPrimex Color, Compounding & Additives (PCC&A; Jasper, TN), formerly O’Neil Color & Compounding, a supplier of color and polymer solutions for plastics processors, has announced a new line of thermoplastic elastomers (TPEs) for general molding use.PrimeThe Faraprene H300 series of elastomers is intended for general use in a wide variety of injection molded products and adheres well to polyolefin substrates. “Faraprene adds soft touch and grip to many household, industrial and OEM products,” says Technical Director Anthony Montalvo. “It’s a lightweight and durable product that can be custom compounded to meet specific needs, such as color and UV resistance, and comes in a range of hardnesses from 25 to 95 Shore A.” According to Product Manager Lee Pfaffle, PCC&A has produced TPEs for more than 25 years. “This new line is formulated for general use, while our other Faraprene lines have very specific characteristics such as high temperature resistance, abrasion resistance and strength for more demanding applications. We offer a wide range of TPE grades to meet critical performance requirements.” Faraprene H300 features include a soft, flexible feel and grip characteristics, adhesion to PP and PE substrates and easy colorability. UV-resistant grades are available, and drying is not required. PCC&A works with customers during product development and throughout the production cycle to enhance outcomes. As part of the Primex Plastics “One Company,” along with Primex Design & Fabrication, Primex Color offers technical development at the John J. Farber Technology and Innovation Center, centralized quality control, fast delivery from six distribution centers and a single point of contact for the entire process. These resources enhance the ability to identify customer challenges and offer the best solutions. Originally founded in New York in 1957 as Frank V. O’Neil Color, PCC&A, a division of Primex Plastics Corp., operates lines in Garfield, NJ, and Jasper, TN, producing color concentrates, additive masterbatches and specialty compounds. They include high performance custom materials such as TPE/TPO/TPV elastomers, flame-retardant olefins and styrenics, and structural and wear-resistant formulations for injection, extrusion, blowmolding and rotational molding applications. https://www.plasticstoday.com/materials/primex-color-compounding-additives-announces-new-line-thermoplastic-elastomers/133769024756853

Ms. Kang 2017-06-12

Latest Addition to EcoBind™ Family of Ultra-low Emitting Resin Technologies Provides Savings and Su

Hexion Inc. (“Hexion” or the “Company”) is launching a new EcoBind™ One formaldehyde scavenger product to help particleboard and medium density fiberboard (MDF) producers save on additive costs while meeting CARB Phase 2, EPA TSCA VI and other stringent global emission standards. The EcoBind One scavenger is utilized with standard urea formaldehyde resins to tie up free formaldehyde and eliminate the majority of emissions during panel production and in finished products. This eliminates the use of urea water, which is a significant cost for particleboard and MDF operations. By eliminating the use of urea additives, the Ecobind One scavenger also enhances a panel’s environmental profile. “Hexion has long been a leader in providing innovative and cost-effective solutions to the panelboard industry,” says Mark Alness, Senior Vice President, Americas Forest Products. “The EcoBind One scavenger is another option in our line of EcoBind ultra-low emitting products which customers can choose from, based on the specific performance characteristics they need in their panels and their cost parameters.” The EcoBind One scavenger was specifically designed for the high heat environments typical of MDF and continuous press particleboard production. It can be used with existing equipment and requires no process changes for manufacturers. Hexion’s technical support team will adapt and optimize resin packages utilizing EcoBind One scavengers to specific plant conditions and customer requirements. In addition to the new EcoBind One formaldehyde scavenger resin, the range of EcoBind low-emitting resin technologies for meeting global emission standards such as CARB Phase 2, European EMB and Japanese standards includes: * one-part base UF resin systems with very low mole ratios * base UF resins with scavengers * unique co-reactants For more information, consult with Hexion - Hall 26, Stand F77 - during LIGNA 2017 in Hanover, Germany, May 22-26, or visit http://hexion.com/AM/wood-composite-binders/brand/ecobind-resin-technology/

Ms. Kang 2017-06-12

BASF’s heat-resistant polyamide Ultramid® Endure in the 2017 Alfa Romeo Giulia

Collaboration with ABC Group and Magneti Marelli for innovative parts on the 2.0-liter turbocharger system ▲ Ultramid_Endure_Alfa_Romeo_Giulia BASF is introducing its heat-resistant polyamide Ultramid® Endure in two new powertrain applications on the 2017 Alfa Romeo Giulia: the air intake manifold with integrated charge air cooler and the hot-side turbo duct. As heat under the hood increases, Ultramid® Endure with its high heat-aging resistance up to 220°C enables automakers to achieve engine downsizing and turbocharging without sacrificing performance. The Ultramid® Endure grades offer good processability, excellent weld line strength and are available globally. Hot-side turbo duct by ABC Group made of Ultramid® Endure D5G3 BM BASF collaborated with the automotive supplier ABC Group, Canada, to develop the hot-side turbo duct for the Alfa Romeo Giulia. For this application, ABC Group decided on BASF’s Ultramid® Endure D5G3 BM, a 15 percent glass fiber reinforced blow molding grade, which has a high hose strength and shows good swelling. ABC Group leveraged BASF’s joining technology expertise to optimize the infrared (IR) welding parameters for this part. It was crucial to achieve strong weld lines to ensure the long-term durability of the duct. “After conducting numerous resin trials through molding, welding and rigorous validation testing, we were able to meet the significant demands on this application,” said Mary Anne Bueschkens, CEO of ABC Group. “The part requires many weld connections. Our engineers worked closely with BASF’s material and joining experts to understand the unique requirements, allowing us to fine-tune our IR welding technology, and assuring success of the welding process for this demanding high-temperature duct.” Air intake manifold with integrated charge air cooler by Magneti Marelli made of Ultramid® Endure D3G7 BASF worked with Magneti Marelli, a business of Fiat Chrysler Automobiles (FCA), to develop the air intake manifold with integrated charge air cooler for the Alfa Romeo Giulia. The need for a material to withstand a 200°C continuous use temperature made this air intake manifold a prime candidate for Ultramid® Endure D3G7, a 35 percent glass fiber injection molding grade. The air intake manifold also required an excellent burst pressure performance; therefore, Magneti Marelli needed a material that offered reliable weld strength at elevated temperatures. With BASF’s design, material and processing expertise, Magneti Marelli could achieve the required burst strength and durability for the assembly. “BASF’s technical support was useful for us to ensure the application met the burst requirements,” said Marcello Colli, Product Manager Throttle Bodies at Magneti Marelli. “BASF’s welding experience enabled us to apply this heat-resistant material and meet long-term durability targets.” The Ultramid® Endure grades are suitable for many powertrain applications of the turbocharged system including air intake manifolds, charge-air ducts, resonators, intercooler end caps and throttle bodies. They can achieve long-term service temperatures of 220°C, and withstand peak temperatures of 240°C. The notable heat aging behavior results from an innovative stabilization system by BASF, which greatly reduces oxygen attack on the polymer surface. Further information : www.automotive.basf.com https://www.basf.com/en/company/news-and-media/news-releases/2017/05/p-17-211.html

Ms. Kang 2017-06-12

What You Need to Know About Drying Specialty Nylons

PPA is being used more frequently by molders for demanding high-heat applications in automotive and other markets. While in the nylon family, it does not dry quite like nylon. Follow these tips. William Hamm technical development engineer, Solvay Specialty Polymers Edgar Benjamin technical development engineer, Solvay Specialty Polymers Basic chemistry dictates that the strength of molded parts partly derives from the entanglement of the long polymer chains that comprise the base resin. Hygroscopic engineering resins, such as PBT, PET, PC and nylons, all absorb ambient moisture that can effectively shorten their polymeric chains and adversely affect performance in both the mold and the end part. The aliphatic amine molecule of nylons, in particular, lacks the aromatic ring directly on the molecule’s nitrogen atom, which makes them particularly susceptible to picking up moisture. If excess moisture is not removed, the presence of heat and pressure during molding can cause hydrolysis, which degrades the polymer or causes chain scissions that produce excessive outgassing, splay marks, or discoloration and compromise the physical integrity of the finished part. ▲ Specialty resins such as Amodel PPA absorb less moisture than aliphatic nylons such as nylons 6 and 66, and do so at a slower rate. Yet PPA is still considered hygroscopic and requires proper drying prior to processing. A number of specialty resins, such as polyphthalamide (PPA), have significant amounts of aromatic character in their polymeric backbone, which causes them to absorb less moisture than aliphatic nylons like nylons 6 and 66, and do so at a slower rate. The diffusion coefficient for water in some grades of Solvay’s Amodel PPA, for instance, is approximately 20% that of nylon 66 at 73°F (23°C). Put another way, PPA generally will not absorb more than 1.5% of its weight in moisture, while nylon 6 can hold up to 7%. Yet PPA resins are still considered hygroscopic and require proper drying prior to processing. It is important to emphasize that there is more at stake here than simply getting unwanted moisture out. There is such a thing as drying a resin too much. Ultimately, the aim is to ensure maximum polymer performance, which is especially important if your design calls for a specialty polymer like PPA. This also applies to less hygroscopic specialty resins like polyamide-imide (PAI) and even non-hygroscopic polymers, like polyphenylene sulfide (PPS). Although PPS is hydrolytically stable, pellets may pick up some surface moisture during shipping or storage that may result in cosmetic defects, such as surface streaks or splay marks on injection molded parts or severe bubbling or streaking in extruded profiles. Further, surface moisture can vaporize into steam within the barrel of an injection molding machine, creating internal pressures that force nozzle drool. Lastly, it is important to remember that many mineral fillers are hygroscopic and can make reinforced compounds more susceptible to moisture-driven drool even if the base resin is stoutly non-hygroscopic. ▲ Proper drying of PPA is critical to maintain mechanical and aesthetic performance in demanding applications, such as this automotive exhaust-gas recirculation valve. ROLE OF DRYING EQUIPMENT & TECHNIQUE The first step toward optimal drying of hygroscopic resins is to prevent moisture absorption in the first place. Amodel PPA, for example, is shipped with less than 0.15% moisture in vacuum- sealed, aluminum-lined containers that prevent moisture ingress. Once opened, it is critical to reseal packaging containers as quickly and as tightly as possible. Many suppliers provide tools to help molders gauge how long they should dry a resin based on how long its container has been open. Equally important is that bags should be opened individually and immediately loaded into a hopper dryer. Opening several bags to allow air conveyors to transfer the resin to the hopper as needed allows the resin to pick up moisture. When loading resin from large containers, it is best to cut just enough of the foil liner to fit an air- conveyor wand into the package, and then reseal the foil around the top of the wand. Only dried air—as opposed to “shop air”—should convey resin. More exacting applications may require measurement of resin moisture content prior to molding. Karl Fischer titration, which uses a moisture-reactant chemical, offers an efficient, rapid, and highly precise method for determining water content in resins. Gravimetric moisture analyzers, while less precise than titration, may be more suitable for a manufacturing setting. These devices comprise a sensitive weigh scale embedded within a benchtop drying oven to measure how much weight the resin loses during drying. While relatively fast and inexpensive, gravimetric analysis is not moisture-specific. So, its measurement may be distorted by the evaporation of other volatile components in the resin. The range of options for drying resin is even more diverse, but they take one of three approaches: heat, chemical desiccation, or vacuum pressure. All are suitable for drying specialty resins. • Hot-air dryers are the most effective in removing surface moisture and therefore are suitable for non-hygroscopic polymers such as polyolefins, polystyrene, and PVC. • Desiccant dryers have long been the workhorse for drying resins that absorb moisture, and generally include some configuration of a moisture-removal filter or bed that recycles dry air through the system in a closed loop. Single-bed desiccant systems are adequate as long as the desiccant is replaced as necessary, but dual-bed systems allow regeneration of one bed while the other is drying. Another variation incorporates a rotor that exposes different sections of a rotating desiccant wheel to process air, regeneration or cooling. Rotating or wheel designs absorb moisture at a more constant rate than a conventional desiccant bed, which helps to minimize spikes in dewpoint or temperature. • Low-pressure or vacuum dryers heat pellets just enough to dislodge moisture from the resin’s molecular structure, and then draw it off under vacuum. These systems can dry resins in a fraction of the time it takes other dryers, thereby saving energy and minimizing the prospect of discoloration from heat. Regardless of the technique, the key metric for effective drying is dewpoint, which equates with ambient moisture. That is, the lower the dewpoint, the less moisture there is in the air inside the dryer. The ideal dewpoint for drying most resins, including PPA, is -40°F/°C. As long as the dryer’s dewpoint remains fixed, however, time and temperature can be used to calculate when the resin is adequately dry for processing. This may vary from polymer to polymer. For PPAs, the drying time and temperature depends on the moisture content of the resin, the size of the hopper dryer used, and the throughput of the molding process. To determine the proper drying temperature, divide the capacity of the hopper dryer (in lb or kg) by the rate of resin consumption (in lb/hr or kg/hr). This will determine how long the material should remain inside the dryer, which in turn determines the drying temperature. Figure 1 shows recommended drying time and temperature for Solvay’s Amodel PPA resins when their sealed shipping container is opened. For most uses, the specified dryness is 300 ppm (0.03%) for Amodel PPA resin. However, this specification may be tighter for some applications, such as extruded monofilament, which requires the resin to be extremely dry. As previously mentioned, it is possible to overdry PPA and other resins, thereby solid- stating the material or increasing its molecular weight. This typically leads to increased viscosity or lower flow, which may result in short shots, increased pressure required to fill, and inconsistent processing. It is best to find the equilibrium temperature where uniform moisture can be maintained without over drying. The low-end tolerance for Amodel PPA is 100 ppm (0.01%) moisture content. Once a resin has been adequately dried, it is important to maintain relatively constant moisture levels throughout the molding run to ensure process and part uniformity. Melt viscosity is influenced by the amount of moisture in resin. More moisture equates with a lower melt viscosity (see Fig. 2). Moisture levels upwards of 0.15% can cause cosmetic problems such as splay or silver streaking on the surface of a molded part. Higher levels can lead to hydrolysis, and result in a significant reduction in mechanical properties. This is clearly an issue for any molder. But it underscores the importance of proper drying techniques when specifying specialty resins like PPA, which are often selected for the most demanding applications. ABOUT THE AUTHORS: William Hamm and Edgar Benjamin are both technical development engineers in Solvay’s Specialty Polymers global business unit in Alpharetta, Ga. They bring nearly 50 years of combined experience in polymer technology. Contact: 770-772-8200; William.hamm@solvay.com and edgar.benjamin@solvay.com; solvay.com; http://www.ptonline.com/articles/what-you-need-to-know-about-drying-specialty-nylons

Ms.Kang 2017-05-15