DBM Reflex (Laval, Qubec) was founded in 1972 to produce reflex pin mold inserts for optical applications, and is now innovating in multi-shot injection molding of LED lenses.
One new example is the first application of a single coliminator molded LED lens for low-beam and high-beam headlamps. The new lenses are debuting in the new Ford F-150 pickup trucks. Mold tolerances on the optical surface are ±0.010mm. Tolerances on the molded part profiles are ± 0.040mm. Diamond cutting is used for the super precise finishes.
In a patent-pending process developed by DBM Reflex, the thick parts (up to 45 mmm) are molded with three shots in three stages in a 2,200 ton Engel with 4K capability. The first shot, which does not require precision tolerances, is for the center of the lens. The second and third shots (bottom and top) are super precise for the optical surfaces. The three-shot approach reduces cooling time, and speeds the manufacturing process.
The plastic used is PC- LED2245, which is a Makrolon polycarbonate from Bayer MaterialScience. PC replaces glass for the application. Multi-shot molding replaces casting and polishing of glass. Weight for the part is reduced from 0.31kg to 0.155 kg. Manufacturing cycle time is cut from 34 minutes to less than five minutes. Molding also introduces the potential for more design flexibility.
Optical efficiency is improved from 58 percent to 62 percent. Previously, Ford used multiple optical lenses to achieve the same level of light output. The LED light sources and lenses are designed to last for the life of a vehicle. Ford says that the new lens, which will be extended to more vehicles, provides a uniform light pattern with a color of light that is similar to a daylight color.
Cost savings are estimated at around $5 per vehicle.
DBM Reflex installed its first injection molding machines six years ago. Equipment at the company now includes single-color injection presses ranging from 90 tons to 300 tons and multi-shot injection presses ranging from 420 tons (2 color) to 2200 tons (4 color). One of its presses is a Krauss-Maffei CX 300-1000.
It was announced Oct. 30 that the part is a finalist in the Automotive Innovation Awards Competition held annually by the Automotive Division of the Society of Plastics Engineers (SPE).