Würzburg, Germany — Tilman Maucher, who is responsible for development of lighting modules and lenses at Hella GmbH & Co. KGaA in Lippstadt, Germany, talked about injected molded LSR optics for innovative headlamp systems at the March SKZ Silicone Elastomers Conference in Würzburg.
He focused on the LSR integrated lens and light-guide primary optics system part on the Daimler E-Class car's "Multibeam" HD LED matrix headlamps.
These matrix optics parts are molded by Optoflux GmbH in Nuremberg, Germany, a 2014 spinoff of the technical optics business of Eschenbach Optik GmbH, which had been molding plastic optical parts since 1998.
The mold inserts were polished to Ra 0.05µm surface roughness by Hochdorf, Germany-based Leonhardt Gravuren e.K. Dow Silicones has announced use of its Shore A 72 hardness MS-1002 Moldable Silicone for the parts, which involve 84 light-guides in three rows.
The same 84-LED (84 pixels) headlamps are used on the Porsche Panamera.
Another version, molded by injection molding machinery producer Engel Austria GmbH in the mentioned Dow Silicones LSR material at three 2018-19 plastics industry trade fairs, has 24 light-guide fingers in two rows.
Engel demonstrations, first at NPE2018 on an e-Victory 310/120 U.S. injection molding machine, used a two-cavity mold from Fischlham, Austria-based ACH Solution Hefner Moulds GmbH, which also supplied the mixing and dosing system, as well as its latest pneumatically activated ServoShot cold-runner valve-gate system with electrically set pins adjusting flow for balanced mold cavity filling. ACH refers to inkjet printing of QR codes on the parts molded by Engel at the March Koplas fair.
Esslingen, Germany-based molder and mold maker Wilhelm Weber GmbH & Co. KG revealed in December 2018 that it molds LSR lenses with integrated light-guide "fingers," namely for Hella headlamps on the Audi A8 car. These involve a LED matrix optic version with 32 light guides in two rows.
Weber molds the 48-gram shot weight Shore A72 hardness LSR Audi A8 lenses in a two-cavity, two parting line mold on an all-electric drive Arburg Allrounder 520A injection molding machine, using forced demolding and part removal by gripper.
Part quality is checked optically with a camera system and a data matrix code is applied to the moldings by laser for mold cavity and molding date and time tracing. A Fanuc six-axis articulated arm robot removes sprues and flash after post-curing the parts at 150° C.
Asked about the different parts, Maucher of Hella said in Würzburg, "Everything you say is correct. There are indeed, as you say, some two-row lenses, too, on some other cars now, in addition to the first most complex and technically challenging three-row one, some on headlamps of our competitors."
He added, however, that from a technical point of view, he prefers talking about the more complex and challenging three-row, 84-finger lens and light guide part.
One of Hella's competitors is the Osram Continental GmbH joint venture in Munich formed in July 2018, which produces several single-row 6-24 pixel Smartrix headlamp modules with LSR matrix lenses, developed with Plymouth, Mich.-headquartered Varroc Lighting Systems Inc.
These include units for the Jaguar e-Pace (20 pixels), as well as for Range Rover and Range Rover Sport cars (both 71 pixels, for low and high beams). Osram Continental is now developing multi-row lens systems with up to 100 pixels, due to go into production in 2020.
Maucher said present LSR shortages would not prevent more LSR matrix headlamp lenses being used in the next four to five years, as "Hella is also talking with other LSR material producers." He showed how high density LED headlamps accounted for 9 percent of all headlamp types in Europe in 2017-2018 and should reach 21 percent by 2020-22, followed then by NAFTA (7 percent) and China (3 percent).