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Automotive Lamp Mold Design and Manufacturing Solutions

For cars, lamps are an indispensable feature. No matter whether it is a traditional or technologically-stylish model, the most important parts of the lamp are headlight body, reflector, decorative frame and lamp lens. As the automotive exterior parts in highest demand, the design and manufacturing requirements for lamps are also very high.


The first challenge comes from the headlight body.

Being an internal functional part, the appearance requirements are not very high. However, there are lots of holes and clips used for assembly, which means there may be risks in the design and manufacturing of lamp body molds:


Too many lifters, slides, and inserts in the mold, which could cause mismatch and flash easily;

Difficulties regarding mold cooling and conduct complex cooling system;

Increase in individual electrodes and proceed amounts of EDM.



Secondly, for the reflector, we need to manage the mold design depending upon its unique specification.

Reflectors are the exterior parts of the headlight lighting system which have a reflection function, preventing direct light. The surface is highly electroplated and has a large area pattern for surface decoration. The reflector needs to work in a high temperature environment and must be attractive while achieving the purpose of reflecting and condensing light. Therefore, automobile manufacturers often choose a prefabricated monolithic molding compound (BMC) thermosetting plastic with heat resistance, flame retardancy and strong creep resistance for part molding.


In order to achieve the manufacturing requirements of reflectors with strict light distribution and directly aluminum-plated, Immetech recommends paying attention on the following points during the mold design:


Avoid clearance at PL surface of the mold, to reduce the risk of flashes;

Mold flow analysis for good design of gate position and the welding line;

The layout of the heater of the cavity and core must be reasonable to prevent deformation;

Add ejector bush to prevent the ejectors burning out by high temperature;

The surface texture contour requires high accuracy;

Aim to keep the mold core as a whole, to avoid flashes inside of part.



Thirdly, for the decorative frame, attention should be paid at the mold design stage to accomplish high surface requirements.

This is a decorative function part of the headlight lighting system that is located inside, assembled with the lens, and can be seen from the outside of the headlight through the lens. Generally, the manufacturing materials of the decorative frame of a car lamp are PC / PBT + GF / PBT + PET / PA + GF, and the part requires surface plating.


For this purpose, Immetech’s experience is to select high-quality mold steel while paying attention to the points below:


The position of the gate and the welding line must be accurately designed by previous mold flow analysis;

The cavity must be designed to prevent part sticking;

The cooling system and the ejector system must be designed to prevent deformation;

Pay attention to the depth of the texture to prevent flow marks.



Finally, the lamp lens also requests high-quality mold design and mold manufacturing for product molding.

The lens is the outermost, transparent piece of a car headlight. Generally, the headlights of automobiles are white and transparent, and the rear combination lamp is transparent red or multicolor. The surface of the lamp lens is a Class A curved surface (that is, the gap between adjacent curved surfaces is between 0.001 and 0.005mm, the curvature changes below 0.005 °, and the shear rate changes below 0.16 degrees.). The outer surface has a super-hard coating, and the requirements for the inner and outer surface transparency are extremely high.


Key points for the mold:


The position of the gate and the welding line must be accurately designed by previous mold flow analysis;

Control the PL of all the mold structures such as lifters, slides, ejectors and so on;

The PL sealing surface design of two-color, three-color and multi-color mold is very important;

Pay attention to the depth of the texture to prevent flow marks;

The air vent design must be sufficiently reasonable and effective.

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In conclusion, based on the above product requirements and mold characteristics, Immetech has a complete solution from raw mold steel to mold delivery:


The material selections are all from professional automotive mold steel manufacturers such as SCHMOLZ+BICKENBACH in Germany, Datong in Japan and AssAB in Sweden;

High-precision imported equipment for machining:DMG (CNC) and FANUC(CNC), MITSUBISHI mirror and MAKINO(EDM, Sodick(WEDM)and EROWA processing system;


Selection of standard parts: Mold bases are from DME, HASCO, FUTABA or LKM, Hot runners are from Synventive, INCOE, MOLD MASTERS, YUDO, and Oil cylinders are from Parker, SMC, HEB, MERKLE or HPS;

Professional and scientific inspection methods are used at all stages, from mold design to mold approval: professional UG design software and Mold Flow verification software, steel verified by HT110 hardness tester, machining verified by Hexagon three-dimensional measurement system, Surface verified by JD520 surface roughness tester, mold fitting verified by SHUNXIN200T mold fitting machine and product molding feasibility verified by 1920Ton 3 colors of parallel+vertical injection machine.