Development story of Metallic Decorative films
“A business inquiry from the US”
In 1998, we received a requirement from a company in the United States saying that they wanted to make the housing for automotive rearview mirrors, a 3D shape, by using our metallic film. More specifically, they wanted to make decorative films without using chrome plating. At that time, Japan Wavelock Co., Ltd., (now Wavelock Advanced Technology) had decorative films for flat surfaces that were used for automotive door moldings/trims and bumper moldings/trims, and they wanted to reflect the metal-effect lustre on deep-draw (3D) parts.
In our product groups, we had a grade of product that could be bent, although it was designed for use with the flat strip decoration on the front window and rear window surrounds of cars. We believed that we might satisfy the requirement by modifying the product according to the customer’s processing method. Indeed we made a change to the resins to adapt to their new processing method, thus offering a prototype product to them. Their reply was that the product was good for the deep-draw performance, but it was a little whiter compared to the plating- it lost the metallic appearance, and the surface hardness was insufficient. In short, they were satisfied with the 3D performance, but those 2 problems remained.
“Overcoming the lack of a metallic look”
Although, as a flatfilm, the look was not inferior to the quality of plating, why did the film turn white when it was formed into 3D shapes?
To understand the problem and implement corrective actions, we first started by refurbishing some old equipment within the company which would enable us to reproduce this phenomenon where the film turned white. We established the conditions that would allow us to research a kind of metal layer that did not deteriorate even when it was deeply formed into a 3D shape. After repeated trial and error builds to of various thin-film metal materials and carrying out numerous experiments, we identified a certain type of metal could maintain the appearance of metal without turning white! This took a full six months of investigation.
“Trade-off between surface hardness and formability”
Using a general hard coat results in breakage when the film was formed into a 3D profile.
For days we searched for hard materials and formed them into 3D shapes. One day, the desired hardness and formability were confirmed on a certain material, and we applied the thin metal film onto this material. This solved the problem, but created a new one. The material cost was very high. The processing costs increased due to the effect of the thickness of the material and we could no longer meet the price range desired by the customer.
“The challenge of cost reduction”
Which materials can be formed a thin film and are stretchable for the thin metal film coating process?
We continued our material science investigations and carried out numerous trial-and-error experiments. Eventually, a thin film material that could be deep-drawn and had been used for beverage cans caught our eye. We adapted this to our process and succeeded in obtaining a significant reduction in the processing costs when coating the thin metal film. However, since we could not achieve the the desired surface hardness with this material, we decided to revert to a material featuring a trade-off of the hardness and formability that we had found earlier.
In such way, the ‘MTIA’ construction film (metallic decorative film enabling 3D molding) that features the multilayer structure for ensuring the best balance between the surface hardness and a formable metal layer was born.
“Getting the Approval from the Board”
We submitted our findings to the board, explaining that the new development was a multilayer structure, and the president rejected the sample, saying “If we have to have two different processes within the company, this may result in lower yield and impact our quality, therefore, there is no advantage to mass-production.”
However, we did not give up. We continued to submit the trial cost balance sheets and reports of repeated manufacturing of prototypes, and we explained the advantages, including the ability to achieve color variations. We repeated such actions over five months before we finally obtained the approval of the president. Since the beginning of our investigation, two years had passed when we reached this stage.
“Actual market situation”
Although we added the product for 3D molding to our product lineup, there was no notable sales revenue for the first three years. Many of the orders we received were spot orders for the touch-panel frames of refrigerators, aftermarket parts and accessories and similar small orders. The situation such that we manufactured the product only once in a month continued.
The project that drastically changed the situation was the opportunity to change the automotive wheel center cap to a decorative film part. The part, at that time, had a problem with corrosion because it was chrome plated. There was a customer who had been looking for a method to completely prevent this corrosion. As such, a production project presented itself. However, because this was our first project to make parts for a car manufacturing line, a significant amount of trial work and laboratory testing had to be undertaken.
It took another year from the initial inquiry to get to mass-production once we had satisfied the end customer’s requirements.
“Our departure point was the replacement of plating”
At present, we continue to work on the development of new products and continually improving the product quality of our existing product line. We also work with automotive designers to develop new and colored metallic designs featuring deep-look color effects that cannot be achieved by painting. We realize that we must continue to offer differentiated products that will add functionality and value, not simply offer products that are positioned as replacements of plating or painting.
In recent years, because various types of sensors are featured with industrial products (like cars and home electric appliances) the voices of our customers have told us that they want decorative materials that do not block the electromagnetic waves of a specific wavelength. We are aggressively and successfully tackling the development of such products.
Aiming to “delight our customers with the world’s best quality and lineup.
“Our experience with travel suitcases”
~Acquiring color variation expression~.
In 2000, the domestic market had been appreciating our ability to express high-quality aluminum attache cases in lightweight plastic through the use of metallic decorative film, and in 2007, a domestic customer approached us about a metallic design with a metallic feel as a surface material for travel suitcases. However, if a film could be used, the weight restriction could be cleared and the metallic design could be used to differentiate the product from others. However, at the time of planning, it had already been decided that the same shape would be available in six colors, and the project began with a trial-and-error approach to metallic and color expression. In addition to designing the processing method and coloring materials, it was necessary to clear all product inspection items, including impact resistance as a bag. After about a year of development, a production system for the entire color lineup was established. At the same time, the company was able to acquire metallic color control technology, a powerful weapon for later development into automotive components.
“Growth through Light Transmission Components”
～Strengthening Quality Control~.
As the transition from gasoline-powered to electric vehicles (EVs) began in earnest, the number of plans for vehicle parts equipped with LED backlighting increased. These parts have a transparent resin on the back and LEDs are lit from the back to express a metallic design during the day and a luminous design at night. Although small parts have been available with a colorless and transparent backside, around 2016, even emblems on vehicle exteriors, which symbolize automobile manufacturers, began to be conceived with the concept of light transmittance performance. These parts are items that can be called the face of an automobile, and they required particularly strict surface quality control. Even the smallest of metal layer chips were pointed out, and after a concerted effort by all factory personnel to investigate the cause, it was discovered that a slight abrasion existed when the specific guide rolls came into contact. After verifying and taking measures to optimize the roll surface for substrate conveyance, the fine metal layer missing, which had been pointed out, was dramatically improved. This effect was laterally extended to other related equipment to further solidify the effectiveness of the countermeasures.
“Responding to Changing Demand for Light Transmission”
～Control of light transmittance color~.
At a time when light-transmitting materials were becoming widely recognized, we received a request from a customer for tuning of light-transmitting light color. The customer wanted to solve the problem of hue shift from the color of the light source itself when an LED light source emits light through a metallic layer. In response, it became necessary to develop a method to control the transmitted color.
After determining all the transmitted colors of each base material, we succeeded in controlling the transmitted colors by placing color components on the back of the film in the opposite direction of the shift in accordance with the shifted hue. Since the improvement was made on the backside of the metal layer, it was possible to control the transmittance color without changing the metal design when the LED lights are off, thus meeting the demand.
“Efforts in Europe and New Challenges”
~Expression of millimeter wave transmission performance~.
In 2019, our subsidiary in Europe began to receive inquiries about electromagnetic wave transmission performance in the frequency band called millimeter wave. They said, “We want to place a radar sensor that detects the distance between vehicles behind a front emblem component. Conventional plating would block millimeter waves, so can’t we use a film? This was the question. Although it was possible to express millimeter-wave transmission performance of metallic decorative film depending on the state of the metallic layer, there was still a problem in implementing metallic layer management, assuming the post-processing of thermal processing of the film. Therefore, we conducted detailed verification of the state of metal atoms and transmission performance by layer thickness to understand the metal layer state that can stably reproduce millimeter-wave transmission performance and reflect this in the manufacturing process. Furthermore, we have established a method for verifying performance in film form, making it possible to provide metallic tone films that express millimeter-wave transmittance performance.
As of 2023, with the world undergoing rapid change, the environment surrounding the automotive industry is also undergoing dizzying changes: the rise of CASE (connected, automated, sharing, and electrification), MaaS (provision of mobility services) business models, the shift from ICE (internal combustion engine) to EV and fuel cell vehicles ( FCVs), and growing environmental, social, and corporate governance (ESG) awareness, primarily focused on reducing greenhouse gas (GHG) emissions. With these trends, people around the world are searching for the best way forward. We will move forward with greater speed, flexibility, and a sense of unity as a team than ever before.