Celcon POM UV90Z Stereo Speaker Grille - Hi Polymers

APPLICATION SHEETCelcon® Acetal CopolymerGrade UV90Z / UV270ZAutomotive Stereo Speaker GrilleTypical Related ApplicationsRequiring Heat Resistance;Ultraviolet Light Stability;Colorability; Impact Strength:■ Automotive door handles andwindow cranks■ Seat belt release buttons andretractor covers; visor brackets;clips■ Irrigation sprinkler heads■ Drapery rods and hardware■ Window shades, blindscomponents■ Cellular phone housingsProblemIn the past, when automotive stereo speaker grilles weremade from metal, there were many steps in manufacturingincluding stamping, assembly, painting, and attaching ascrim cloth. In an effort to reduce manufacturing steps andsignificantly lower the cost, auto makers began consideringplastics including polycarbonate (PC), modified polyphenyleneoxide (PPO), acylonitrile-butadiene-styrene (ABS),polypropylene (PP), and Celcon ® acetal copolymer (POM).Material EvaluationThe plastic used for speaker grilles must have excellentultraviolet (UV) light stability to resist both color fading andmechanical property degradation over years of exposure tosunlight. Heat distortion temperature (HDT) is an importantconsideration, especially when the speaker grilles are mountedhorizontally near the front windshield or rear windowbecause the temperature can reach as high as 250°F in theseareas. High impact strength is another important materialcharacteristic because the speaker grilles are subjected toimpact stress once mounted in the passenger or cargo area.Colorability and processability are important when comparingthe costs of the plastics considered for speaker grilles.Pre-colored Celcon ® acetal reduces the cost of speaker grillesas much as 25% over painted metal and other plastics byeliminating painting. (Pictured: General Motors, Ford andVolkswagon speaker grilles made from Celcon acetal.)Pre-colored plastics which adhere to a critical color match,standard for other interior parts, allow auto makers to reducethe cost of manufacturing speaker grilles by eliminatingpainting. A plastic which allows for short cycle times canreduce molding costs. A high flow plastic makes possiblecomplex designs that many people think can only beachieved by metal.ResultsMany auto makers have specified Celcon ® acetal copolymeras their speaker grille material including: Ford for theMondeo, Contour, and Mystique; GM for the Lumina;and Volkswagon for the Golf and Jetta.Ultraviolet light resistance - Celcon resins resist fadingand deterioration of mechanical properties when exposed tosunlight. Celcon acetal has been used for over 10 years inunpainted automotive interior and exterior parts (see thecolor stability table). Pre-colored Celcon UV90Z andUV270Z have by far the best UV resistance of the plasticsconsidered and of any acetal.Heat distortion temperature - Celcon resins are moreresistant to distortion under load in high temperatureenvironments than the other plastics considered. With anHDT of 316°F at 66 psi loading, Celcon UV resistant gradeshave a higher heat distortion temperature than ABS (245°Fannealed), PC (280°F), PP (250°F), and PPO (279°F).

Impact strength - Celcon acetal copolymer provides theneeded strength to withstand typical impact loadings whilemounted in the passenger or cargo area, even at -30°C (-20°F)as required by car companies.Colorability - Pre-colored Celcon UV resistant resins arecritically color matched in over 220 automotive colors, alllead and cadmium free. Celcon acetal resists color fading andmechanical property degradation better than the other plasticsconsidered. ABS, PC, and PPO require painting to produce thedesired color and/or UV light stability and this paint can bescratched off the speaker grilles, revealing a different basecolor. The molded-in color of Celcon acetal provides a qualityadvantage because the color cannot be scratched off. In onedesign, eliminating painting saved 50 cents per part.Processability - Celcon acetal copolymer provides thefollowing benefits in processing:■ The high flow of Celcon acetal allows it to fill moredetailed molds than ABS, PP, PC, and PPO and results inhigh weld line strength. An appreciable cycle time reductionshould be attainable with Celcon acetal vs. ABS, PC and PPOdue to the high flow and fast crystallization rate of Celcon.■ An assembly step can be eliminated by insert molding thescrim cloth rather than attaching it after painting as requiredfor metal, ABS, PC, and PPO speaker grilles.■ The level of gloss can be controlled for Celcon acetal.When proper molding temperatures and pressures are used,Celcon acetal will closely match the finish on the mold: amatte finish mold will result in matte finish parts, a highgloss mold leads to high gloss parts.If you are interested in obtaining a sample or would like toknow more about our UV light resistant acetal grades, pleasecall 1-800-833-4882 and mention “Application Sheet 94-04.”Cost Comparison – The following cost comparison for a typical speaker grille shows that pre-colored Celcon acetal copolymer provides abetter value than the painted polycarbonate part even at a higher raw material price.Item Celcon ® UV90Z Pre-colored Part Polycarbonate Painted PartPart weight (lbs./part) 0.17 0.14Raw material price ($/Ib.) 2.61 2.00Raw material cost ($/part) 0.44 0.28Painting cost ($/part) 0.00 0.50Finished part cost ($/part)* 0.44 0.78*This comparison, based on truckload raw material list prices, excludes molding costs which were not available. However, because of its lower processingtemperatures, Celcon acetal has a lower energy cost associated with molding than PC and a faster cycle time.Color Stability Test (Xenon Arc) – This comparison shows that Celcon UV90Z retains its color better than PP; and with exposure over 4times more intense, holds each color better than the typical UV resistant grade of ABSCelcon ® UV90Z Typical UV Grade Typical UV GradeAcetal Copolymer ABS PolypropyleneExposure Energy, kj/m 2 : 1240.8 263.2 1240.8Approx. Exposure Time, Hrs.: 800 168 800Color Delta E* Color Shift Delta E* Color Shift Delta E* Color ShiftBlack 0.2 0.5 Not testedLight Beige 0.2 1.4 Not testedLight Tan 0.2 2.3 0.8Medium Tan 0.6 2.5 Not testedBrown 0.2 1.4 Not testedMedium Gray 0.3 Not tested 1.3Dark Blue 0.5 1.7 1.9Flame Red 0.9 1.1 Not testedMaroon 1.2 2.2 3.3*Delta E (measured in CIELab units as per SAE J1885 Accelerated Indoor Weathering Test) is the color difference between the unexposed sample and theexposed sample. The lower the value, the better the color retention.Ticona90 Morris AvenueSummit, New Jersey 07901-3914(908) 598-4000© 2000 TiconaPrinted in U.S.A. AP94-04/4M/1200