Manufacturing Technology

Metal Particle Tape Process

The MP Tape process can be split into 5 main processes which are :
  • Mixing
  • Coating
  • Calendering
  • Slitting
  • Winding

The structure of MP tape

Magnetic Layer

This layer record each kind of signals such as video and audio signal. It is made up of magnetic powder, binder and etc.

Base film

It is the base of tapes. A base film is made by material which is robust and strong so that it can resist water and harmful ultraviolet rays.

Back coat

Back coating is to prevent static during tape running in the machine. It also protect tapes from collection of dust.


The mixing process produce magnetic paint.

In this process, the magnetic tapes agents (Magnetic Powders, Binders, Abrasives, Lubricants, and Solvents) are mixed together in a special Mixing storage container.

Next, the Milling process will avoid all agglomeration of particles in order to obtain an evenly mixed paint.

Chemical reaction is observed at all times to ensure Sony's manufacturing quality. When ready, the magnetic paint is filtered for the Coating process.


In the Coating Process, the magnetic paint is coated onto the base film using a Coating Head.

At this stage, while paint is still wet and strong magnetic fields are applied to optimize the particles orientation in order to improve magnetic properties of the tape (Sony's quality control). Once oriented, the solvents are evaporated through a drying oven in order to bind the magnetic layer onto the base film.

The coating thickness is controlled in real time in order maintain quality and stability. After this, the wound Jumbo Roll is ready to receive the final surface treatment: Calendering.

Two types of coating process is available, the gravure coating (like newspaper printing), and die coating (like a fountain pen).

Calendering process

This importance of this step aims at improving the tape surface roughness and so that the signal-to-noise (SN) ratio can be enhanced. The magnetic tape is rolled between high temperature and pressure rollers in order to achieve a perfect tape surface smoothness similar to a mirror.  

The 2 ways of Coating Process


After jumbo roll is produced, the tape is cut to the required width by a process called Slitting . The slitter machines use multiple rotary knives to slit the roll which are then wound onto hubs known as " Pancakes " .

  • After slitting, the pancakes are then conveyed to the Winding Process , where the tape is loaded into empty cassette shells.
  • At the end of the Winding line, all cassettes are checked by a "Part Checker" which guarantees that 100% Sony quality. A serial number is printed on the cassette shells to give us a complete traceability of our products manufacturing process.
  • Finally, the cassettes are sent to packaging and distribution section.