Japanese automobiles are becoming more and more high-performance and fuel-efficient. They're also increasingly earth-friendly, and the average driving experience is becoming ever more comfortable. Our resins are used in the production lines of world-famous Japanese cars.
An Essential Part of Automobile Component Manufacturing
Resin is now an indispensable material in automobile manufacturing. It is not only used in the components themselves, but also in the manufacturing process for suspension system components and exhaust system parts, for example. That process is known as casting. A molten alloy (such as aluminum or iron) is poured into a mold and solidified into a cast-metal component. Many automobile parts are manufactured in this way since a complex shape can be produced using only one mold. Various casting methods exist, and ASAHI YUKIZAI manufactures shell mold resin, a material used in the sand casting method (especially in the sand core molding method). Casting using a sand mold is a method that utilizes sand hardened by a binder and formed into a strong mold. Shell mold resin is a type of binder that acts as an adhesive, gluing sand particles together for hardening. We also manufacture resin-coated sand, in which sand is precoated with resin, and carry out research and development on binders and resin-coated sand in response to our customers' needs. As a result, we can now offer more than 200 types of resin-coated sand.
Resin-Coated Sand Used as a Material for Molds
Resin-coated sand (also known as RCS) is sand that has been coated with shell mold resin. When RCS is poured into a metal mold heated to approximately 250℃, the resin that comes into contact with the metal mold softens, melts and then hardens. A hard layer a few millimeters thick generally takes between 10 and 20 seconds to form. Once the required thickness is obtained, the metal mold is inverted and the surplus RCS removed. A mold core and outer mold*1 are manufactured in this way. This is known as a shell*2 mold.
The entire casting process is as shown below. We provide the shell mold resin and RCS used in Stage 1. We also recycle the sand retrieved in Stage 6.
*1 The core and outer mold (main mold) are joined together and molten metal poured into the cavity to produce a cast-metal object. The core remains inside the cast-metal product, so the core sand is later removed to create a central cavity. (This process is used, for example, to create engine parts that carry coolant.)
*2 The name is derived from the seashell shape.
A Huge Contribution to Boosting Car Performance
Japanese cars are amongst the best in the world when it comes to performance. We have provided tremendous background support in the progress of the automotive industry. Thanks to the different types of RCS we have developed, complex molded shapes can now be mass-produced, an advance that has contributed greatly to boosting automotive performance. For example, when organic binders such as RCS are used for molds, thermal decomposition during casting causes tar and gas to be generated. In recent years, production of aluminum parts is increasing. Molds have to be cooled down further when casting aluminum, which tended to lead to more tar adherence, and an increase in gas defects and misruns. We therefore developed an improved tar-reducing RCS specifically for aluminum that is suitable for casting at low temperatures. We succeeded in both dramatically reducing the amount of tar adherence to the metal mold and obtaining superb collapsibility. Productivity has skyrocketed thanks to these new materials, which have helped make automotive parts increasingly lightweight. Our phenolic resin and RCS are making a major contribution to boosting the performance of modern automobiles and decreasing their weight.
Recycling for Over 40 years
ASAHI YUKIZAI has engaged in recycling for more than 40 years. Sand used in casting is retrieved, fluidized, and reused as reclaimed sand, a component in RCS. This helps to reduce waste and save resources. We have also developed a low-formaldehyde resin that reduces emissions of formaldehyde, which is designated as a hazardous pollutant in the revised Air Pollution Control Law. We succeeded in reducing the production of formaldehyde by 50% in comparison with conventional novolac resins. We have also developed a preheater that makes it possible to reduce the offensive odors generated by lower metal mold temperatures, and HexaPass®, a product that reduces casting process odors. These new materials are helping to improve the environment both within factories and in their vicinities by effectively reducing offensive odors during manufacturing. We will continue to engage positively in the development of environmentally friendly products and equipment.
