Session 11: Corrosion & Wear Deposit Coatings
Plastic molding requires high equipment operation efficiency and low defect rates to reduce production unit costs. When the chromium oxide film we developed is applied to mold dies in conjunction with another enhancement, remarkable improvements can be achieved to prevent wear, corrosion, contaminant adhesion and mold release failures. As a result, this can improve the mold die life and production cycle time, and reduce product defects and maintenance time.
Corrosion or Wear Deposits/Coatings
Technologies for Improved Performance or Increased Efficiency
Plastic molding is an indispensable method for the mass production of industrial products. Plastic-molded products are extensively used in daily life, such as for plastic water bottles and a variety of cases and containers. They are also widely utilized in automobiles, airplanes, machining tools, and electronics.
In recent years, in light of climate change, many countries have been promoting the weight reduction of automobiles, and some automobile parts materials have been replaced by lighter metals and plastics. For parts requiring strength and heat resistance, including engine parts such as water pumps and intake manifolds, engineering plastics such as POM, PA and PBT and super-engineering plastics like PPS and PEEK are used instead of standard plastics.
In addition to cutting to make parts, there are other mass production methods such as stamping and plastic molding using dies. Dies and molds are generally made of high-strength steel called die/mold steel. When processing metal materials like iron and aluminum, the surface of the die/mold is coated with a very hard film to prevent wear.
On the other hand, the surface of molds/dies for plastic molding rarely wears, except when a hard filler such as glass is added to the plastic material. Still, there are other problems that can occur besides wear, such as corrosion, gas (deposit) adhesion, and mold release failures. Such problems can result in a decrease in productivity and degradation of product quality.
We will report on the characteristics of chromium oxide films deposited by physical vapor deposition (PVD) in a vacuum chamber, where the raw material metal is ionized and deposited on an object such as a die. We will also present some case studies where such chromium oxide films resolved the issues described above.