Four white papers from HEXPOL provide valuable technical information about HCR Silicone Injection Molding, Continuous Process Improvement (CPI), Understanding Performance Additives, and Compound Designs for Automated Elastomer Molding. Descriptions of these white papers and access to corresponding PDFs are included below.
Happenings at HEXPOL
Maximizing the benefits of High Consistency Rubber (HCR) silicone for injection molding and leveraging its versatility requires special considerations to manufacture quality parts.
Due to its inorganic polymer backbone, HCR silicone processing poses unique challenges when compared to organic polymer-based rubber compounds, but provides excellent bene ts. This white paper addresses those challenges and how to meet them. Press selection, mold design, and gate design considerations are, in most cases, similar for both HCR silicone and organic rubber. However, processing issues are, in some aspects, significantly different. Therefore, issues such as part shrink- age, air entrapment and hot tear when using HCR silicone are reviewed in detail. Substrate bonding strategies and trouble-shooting steps unique to HCR silicone are addressed as well.
The concept of continuous improvement has been around for decades. Countless enterprises – manufacturing, healthcare, education and financial services, to name a few – implement some or all of its components. This white paper addresses HEXPOL Compounding's Continuous Process Improvement (CPI) methods, and how they help improve an organization's processes, products, and services.
The HEXPOL CPI program is used by our Field Technical Services Group to collaborate with customers and analyze their processes. HEXPOL's CPI model includes these eight components:
- Application Definition
- Knowledge & Resources
- Formulation & Testing
- Trial Batch
- Technical Visit Reports
- Chemistry Modi cation
- Set Process Limits
- Continuous Tech Support
This white paper addresses when and how to use performance additives. When properly selected, performance additives bring value and clear benefits to the application. They address manufacturing and process concerns to help maintain quality and consistency during compounding.
The number of available additive options can be overwhelming to compounders and plant chemists. Therefore, a systematic approach to performance additive selection should be used to define objectives clearly, such as: better throughput, precise control of critical ingredients, lower costs with shortened mixing cycles, timely and complete dispersion, worker safety, and color control, to name a few.
Reasons for using performance additives, proper selection of additives to meet application objectives, different performance additive types, and manufacturing and cost benefits are addressed in this white paper.
Elastomer compound design for injection molding is a complex balance of end-use properties, product specifications, chemistry, and processing characteristics. Careful consideration must be given to all variables. This white paper addresses many of those variables, such as the line callout – which includes service requirements for fluid compatibility, temperature, cost considerations, and the physical form of the compound. Other topics covered and their effect on successful compound design for injection molding includes:
- Polymer Type Selection
- Compound Cure System
- Compound Viscosity
- Cost Parameters
- Hot Tear Issues
- Mold Release
- Mold Fouling
- Cycle Time
The compounder, whether in-house or a custom compounder, should be consulted as early as possible during the process design. A joint effort, including the developer of the tooling, process engineers, and compound chemists is ideal.