Dispersion/Redispersible polymer powder produced by spray-drying special water-based emulsion, mostly based on vinyl acetate and ethylene. It dissolves in water easily and quickly forms emulsion. Dispersion polymer powder gives the mortar higher flexural strength, excellent waterproofing property, improved workability, increased impact and abrasion resistance, durability, weather-ability, better deformability, increased adhesion to a variety substrates, improved wetting of the substrate, higher flexibility, increased impact and abrasion resistance, higher durability and freeze thaw resistance. It is suitable for tile adhesive/tile grouts, skim coat/ wall putty, adhesive and base mortar for EIFS (external insulation finish system), joint filler, decoration mortar, fundamental dry mix mortar, waterproofing membrane/ mortar, flexible waterproofing putty, floor screed and self-leveling compound etc.
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Vermicular graphite cast iron: Quaker's new technology reduces tool wear by nearly 30%
**Part 1: Research and Overcome the Machining Challenges of Compacted Graphite Iron (CGI)**
The use of compacted graphite iron (CGI) is on the rise, especially in the production of cylinder heads for truck and automotive diesel engines. Engineers are leveraging CGI’s unique properties to enhance fuel efficiency, performance, and durability. Compared to traditional gray cast iron or high ferromolybdenum iron, CGI offers a better strength-to-weight ratio, improved wear resistance, superior thermal conductivity, and enhanced shock absorption—making it ideal for modern engine applications.
However, despite its advantages, CGI presents significant challenges during machining. Manufacturers have discovered that CGI is more difficult to cut than conventional cast iron. When using metalworking fluids designed for gray cast iron, tool wear can increase by up to 90%, leading to higher costs and increased machine downtime. Additionally, lower cutting speeds and feed rates often result in longer machining times, which further impacts productivity.
So why is CGI so hard to process? Under similar machining conditions, tool wear on CGI is about 30 times greater than that on standard gray cast iron. This difference becomes most noticeable when machining at moderate to high speeds (250–700 m/min), which are commonly used in operations like boring engine cylinders.
To address this issue, we need to understand the root causes of CGI’s poor machinability. One key factor lies in the differences between gray cast iron and CGI. The graphite structure in gray cast iron is flake-like, which helps reduce friction and improves cutting performance. In contrast, CGI has a worm-like or coral-like graphite structure, which increases its strength but makes it harder to machine.
Another critical difference is the presence of manganese sulfide (MnS). In gray cast iron, MnS acts as a natural lubricant during machining, especially at certain cutting speeds. However, CGI typically lacks MnS, resulting in less lubricity and more tool wear. As shown in the micrograph below, MnS is clearly visible in gray cast iron, but not in CGI.
[Image: Manganese sulfide in gray cast iron]
To overcome these challenges, new metalworking fluid technologies have been developed. These fluids are specifically designed to improve tool life and surface finish when machining CGI. They perform well in high-speed continuous operations such as boring, which are common in engine manufacturing. While these advancements have significantly reduced the performance gap between gray cast iron and CGI, there is still room for improvement in terms of cost efficiency and machining performance.
If you're planning to machine CGI, it's advisable to consult with your metalworking fluid and tooling suppliers. They can recommend the best solutions tailored to your specific application and help you optimize both tool life and machining efficiency.