- Fast Mixing
- Excellent Processability
- Tailored for Continuous Vulcanization Process
- Reduced Inventory
- Reduced Profile Production Cost
Fast Mixing
High molecular weight grades are often difficult to mix. This is not the case with Vistalon bimodal grades, which are easily dispersed due to their tailored molecular weight distribution (MWD). Tailored MWD offers fast incorporation of carbon black as shown in this figure, by the higher power peak and shorter Black Incorporation Time (BIT) compared to a typical narrow or broad MWD EPDM grade. Its dispersion rate after BIT is also higher. Vistalon bimodal grades help reduce the variables in processing, aiding statistical process control and quality assurance.
|
Excellent Processability
The low compound viscosity of Vistalon bimodal grades compared to conventional EPDM significantly eases the processing of compounds, resulting in the ability to form complex profile shapes and thin lips and to meet precise tolerances, a must in modern car design. Due to easier processability, profiles have excellent consistency and show class-A surface aspects. Also Vistalon bimodal grades allow faster extrusion when used in a high elastic and polymer-rich compound. This results in improved productivity and significant cost saving to the finished component over conventional EPDM.
|
Tailored for Continuous Vulcanization Process
Vistalon bimodal grades provide faster extrusion rates by decreasing the dynamic viscosity at high shear. The result is higher output through the die as shown in the figure below. Bimodal grades show high collapse resistance and very high green strength due to their unique molecular structure. Their improved green strength compared to conventional EPDM results in:
|
|
Reduced Inventory
Vistalon bimodal grades eliminate the need to blend different EPDM grades.
This allows:
- Material inventory savings
- Superior mixing consistency
- Reduced risk of batch preparation errors
A blend is always a source of higher standard deviation in compound viscosity. Use of a single EPDM grade results in less variation in mixing leading to more consistency in extrusion profile geometry.
|
Reduced Profile Production Cost
Experience to date has demonstrated that using Vistalon bimodal grades for dense and soft body seal extrusion can provide significant cost savings due to:
- Faster mixing cycles
- Faster extrusion
- Lower scrap generation
- Reduced material inventory
The figure below illustrates cost savings of about 10% based on an ExxonMobil Chemical computer model in the following areas:
- 5% in mixing phase
- 2% in extrusion phase
- 3% in scrap reduction
|
