What is the beautiful “in-mold decoration” used on the camera this time?

Hi, this is ubu369.
This time, I would like to introduce the beautiful exterior design that was manufactured without compromising quality.
We asked Shigeo Yoshida, President of Yoshida Technoworks Co., Ltd., the company that produces the exterior of THETA MIKU using their expert techniques, about “in-mold decoration” which is vital to achieving the external design.

Exterior parts of THETA MIKU are made from plastic molding. Among the various manufacturing methods, what type of technology does “in-mold decoration” use?

Mr. Yoshida: “When manufacturing normal exterior parts, plastic melted by applying heat is injected into a metal mold and then the part created from this process is painted and finished. With “in-mold decoration”, a single sheet of transfer film is sandwiched between two metal molds and then the plastic is poured into the molds to form a shape. The film has already been printed beforehand with the exterior color and the illustration of Hatsune Miku so that the color and illustration are transferred due to heat and pressure when the hot melted plastic is pushed into the mold on the injection molding machine. This is “in-mold decoration” technology.”

Mr. Yoshida: “A blue green body color and Hatsune Miku illustration are transferred onto the front side of the current Hatsune Miku model. However, when you look at the reverse side, you can see that the color of the plastic itself is transparent. Our company, which was founded in the 1940s, was the first in the world to develop this technology in the 1970s. Over the next 40 plus years, we have been accumulating in-mold decoration technology.”

It looks much more beautiful than simply finishing it with a paint coating afterwards. What do you think?

Mr. Yoshida: “Printed layers are repeatedly layered on a base film of thickness 38 micrometers. Gravure printing and silk-screen printing are available for the printing method, and the most suitable method is selected to match the exterior design and required quality. Depending on the product, we manufacture film with up to a dozen printed layers. We have unique expert knowledge of how to achieve the most beautiful and highest quality product by combining countless methods and materials.”

Mr. Yoshida: “As an example, factories throughout the world were contacted about working on the exterior of a very famous product. As a result, an order was placed with 2 companies, ourselves and an overseas molding company. At first glance, the exterior design appears to be nothing special. After our basic patent expired, various molding companies began to enter the in-molding decoration business. However, it is in fact very difficult to create the quality you are aiming for. Therefore, when mass production began, it was decided that most of the exterior for this product would be produced at Yoshida Technoworks.”

Mr. Yoshida: “The current Hatsune Miku model appears to have a simple blue green colored body. However, if an LED is turned on, you can see that the light from the LED passes through the body of the camera. We have devised the printed layers formed on the film in this way so that various effects can be produced. The transparent plastic body has films inserted on both the front side and the reverse side, and these films achieve a 3D design representation. This technology is referred to as “double-sided in-mold decoration” and has been used here for the first time in the world.”

Packed with expert knowledge, the films and injection molding machine for the Hatsune Miku model

The very delicate illustration from KEI and the fine lettering for the 10th anniversary logo have been precisely reproduced for the Hatsune Miku model. A matte feel for the surface was achieved, which feels high-grade while having a vivid blue green color.
* The matte feel is a finish with a gentle and smooth soft feel to the touch without a glossy finish

Mr. Yoshida: “In order to achieve the beautiful coloring and precisely reproduce the illustration and fine lettering on the curved surface it is necessary to meet a great many conditions. Optimal molding conditions have a narrow range. We repeat trial manufacture changing factors such as the metal mold temperature, plastic temperature, injection speed, and metal mold pressure while setting the optimal conditions using our expert knowledge accumulated over the years. In fact, the beautiful vivid coloring and matte feel are contradictory. They have a relationship that is such that the colors become less pronounced when seeking to create a matte feel. For this project, we ran trial manufacture many times for the film and devised a method to increase the matte feel just to the point that clearly brought out the blue green color while also reproducing the illustration precisely using the silk-screen printing method.”

Each finished exterior part is inspected carefully.

In addition to the non-compromising design concept, the camera is filled to the brim with technology!

Mr. Yoshida: “This is what we love so much about this project lol. With the basic stance of “welcoming problems”, we simply want to achieve a situation in which people throughout the world believe that something cannot be done unless it is done by Yoshida Technoworks! We always say that we will never give up until successful, as long as we don’t give up, we will not fail.”

You know, the Chairman of Ricoh also likes this saying! lol Thank you today for allowing us to hear about your passion for the technology, something we do not normally get to hear about.