PC toecap can withstand extreme temperatures

Plastics Additives & Compounding January/February 2005

15

NewsAPPLICATIONS

PC toecap can withstand extreme temperaturesInjection moulded LEXANEXL polycarbonate has beenused for the toecaps for arange of protective footwearmade by Bacou-Dalloz. The toecaps, made with aresin supplied by GEAdvanced Materials, affordthe same amount ofprotection as steel toecaps butare much lighter, the companyreports. The shoes aredesigned to be protective evenat sub-zero temperatures andGE says that the impact

strength of Lexan EXL 1414at -40°C is only marginallylower than at normal ambienttemperatures, due to theproprietary siloxanecopolymer technologyincorporated into the resin. The company adds that LexanEXL 1414 also has cold-temperature ductility up to-60°C, improved ultra-violet(UV) stability (thanks to thesiloxane softblock in thepolycarbonate backbone) andgood hydrolytic stability. It

conforms to Blue Angel andTCO99 flame retardancestandards. The resin is said to have goodflow properties, making it easyto fill the multi-cavity hot-runner mould, even in thin-wall areas and its meltviscosity, especially at lowshear rates, is notably lowerthan general purposepolycarbonate, GE claims,adding that Lexan EXL 1414processes well in mostconventional injection moulds

and exhibits excellent releaseproperties, facilitating shortercycle times and improvedproduction. It is said to yieldparts with high knit-linestrength and low residualstresses.The polycarbonate can beinjection moulded andextruded, and is available in awide range of opaque colours,the company reports. Contact:GE Advanced MaterialsWebsite: www.geplastics.com

Nucleating agent helps reduce cycle timeCycle times for moulded gardenfurniture table tops werereduced by 10% whenMilliken’s Hyperform® HPN-68L hyper nucleating agent wasincorporated into thecompound, the companyreports. Milliken says that HartmanGroep, a leading Europeanmanufacturer of gardenfurniture, increased its outputof structural foam table tops bya substantial number over aneight-week period as a result ofusing the nucleating agent inthe polypropylene (PP)compound formulation.The table tops are mouldedusing Corell ResinTechnology®, a patentedinjection mouldingtechnology developed byHartman which producesfully flat tabletops with a highthickness of 20 mm and more,Milliken says. This increasedwall thickness compared toother products can entail long

cycle times. RonaldGeurtsen, head ofproduction atHartman decidedto use Milliken’sproduct to helpreduce these cycletimes and improveproduction.Hyperform HPN-68L can speed upprocessing byoffering extremelyfast crystallizationof the polymermelt, leading to alarge improvementin productivity. Theadditive alsoenhances productquality throughimproved dimensionalstability and physical propertybalance, Milliken reports.When incorporated into themoulding, Hyperform HPN-68L made the cellular foamstructure at its core moreconsistent by narrowing cell

size distribution andeliminating voids, reducingthe reject rate from 3 percentto 2 percent.Hartman is now consideringthe incorporation ofHyperform nucleating agentsinto other products requiring

an improved cycle time. Contact:Milliken ChemicalTel: +32 9 265 1131E-mail:Mady.Hupko@Milliken.comWebsites www.ClearPP.com orwww.millikenchemical.com.

Table tops moulded with Milliken’s nucleating agent.