How much do you know about some of the key materials that handle earphone cavities?

The appearance of earphones directly affects the desires of everyone who buys them. Good-looking headphones not only have a visual sensation, but the choice of material also makes a big difference in appearance.

In retrospect, the first earphone must be made of metal. But earplugs weren’t just consumer products, they were just lab products. Therefore, the design does not need to consider appearance.

Early earphones were mostly made of plastic like ABS. Later, the surface treatment technology of the earplug cavity gradually increased, and chrome plating and matte spray coating were used, and the appearance gradually became eye-catching. In the past, plastic has been the core material in the manufacture of earplug housing cavities, mainly because it is cheap to mold and suitable for mass production. In addition, the ease of processing plastic allows designers to implement a variety of specially shaped cavity designs.

However, plastic is always a fragile and wearable material. In another situation, plastics are always apt to give the impression of low prices, and products cannot be sold at high prices, resulting in a gradual increase in metal hollow earplugs.

Machining a metal headset cavity is much more complicated than creating a plastic headset cavity. Most metal earphones require the use of CNC technology to cut and cut the entire piece of metal into a hollow shape. The use of a milling machine is very time consuming and can be processed in small quantities a day. After cutting from the CNC, polishing, polishing, painting, or electroplating may be required. Any problems that occur at each step here will affect yield and therefore cost. As a result, good-looking metal earphones are often not cheap.

However, while the metal earphone cavity looks high quality, be careful. In particular, the surface after metal plating is also easily scratched.

And between metal CNC and plastic, there is a new and popular material, photosensitive resin. It is a liquid material that can undergo rapid physical and chemical changes in a short period of time after being exposed to UV light to crosslink and cure oligomers. It was first developed and applied by Bayer in Germany in 1968.

This material has been used in the earphone field for some time, and in fact we often come into contact with it in our lives. For example, the filler we use to fill our teeth, and the “phototherapy nail polish” that women often call, the raw material used is actually a kind of photosensitive resin.

In the field of earphones, the oldest materials were also used in medical hearing aids. Later, American sound mixer Jerry Harvey used this material for use in 1995 and developed a customized listening ear (customs clearance in-ear monitor) for band musicians. This was also the starting point for the wave of custom headphones.

The custom earphones referred to here use photosensitive resin to collect the ear prints of the contours of the individual ears and, depending on their shape, to create a shell that has the same shape as the cavity of the earphone, in which the sounding unit. Is created by placing. After the cavity and panel are joined, a layer of glossy lacquer is completed after polishing. This layer of bright lacquer is harder and more wear resistant, which makes the shell look brighter and protects it. The shape is customizable, so the photosensitive resin itself can blend different colors. Custom headphones have always been considered the most personalized headset product, as you can also create a “multicolor black” look.

Conventionally, in order to use photosensitive resin as a cavity, it was necessary to manufacture a mold in advance. For custom headsets, you have to create a shell for each mold individually, which is very time consuming. Next, some manufacturers have developed “male model” products. Its shape can fit most consumers as closely as possible. Reusable molds significantly reduce mold production time and cost, and also allow many people to experience closer to traditional custom headphones at a relatively low price. In addition, the resin material is a very gentle material that does not irritate the skin like metal when worn. Abrasion and stain resistance properties, combined with a variety of color customization services, make many young people like this personalized headset.

Today, applications of 3D printing technology produce the above headphones that require CNC cutting and resin injection molding to form cavities. In addition to metal printing, photosensitive materials are also very commonly used in 3D printing. As a result, many earphone brands are beginning to use 3D printing technology to create cavities, and products using related technologies are expected to be available in the future.