What Is Flushing/Purging Compound
Flushing compound is a plastic resin compound specifically designed for cleaning primary plastic machinery, including injection molding machines, blow molding machines, and extruders.
- It serves to clean and purge the extrusion machinery and equipment, ensuring that any residual color or material from previous runs is removed.
- By using flushing compound, manufacturers can transition smoothly from one color or material to another without contamination.
It serves several purposes
- Color Change: When transitioning between different colors, a purge masterbatch helps remove residual colorants from the equipment.
- Resin Change: During resin changes, it ensures that remnants of the previous resin are effectively cleaned out.
- Contaminant Removal: It eliminates black specks or other contaminants that may accumulate during production.
Properties
- Smooth Color Transitions: When changing colors or materials, flushing compound ensures a clean start for the new batch.
- Optimized Production: It minimizes downtime during color or material changes, improving overall efficiency.
- Compatibility: Flushing compounds are compatible with various polymers and masterbatches.
Benefits
Flushing compounds are specialized masterbatches designed to expedite the transition from one color, product, or resin to another in plastic processing equipment. They achieve this through a combination of mechanical and chemical action. Here’s how they benefit processors
Efficient Changeover
When switching colors or resins, purging concentrates help clean out residual material from the machinery. They ensure a smoother transition by removing remnants of the previous material.
Cost Savings
By reducing the amount of resin consumed during changeovers, purging compounds save money for processors. Less wasted material means improved efficiency and reduced downtime.
Application Flexibility:
Purging concentrates perform well in various applications, including extrusion, injection molding, and blow molding. They supercharge your own processing resins for superior cleaning.
Color and Resin Changes
- When transitioning between different colors or resins, the machinery components (such as the barrel, screw, nozzle, and mold) must be free of any residue or contaminants.
- For instance, if a molder switches from producing black parts to white parts, the black plastic resin must be thoroughly removed before white parts can be manufactured.
- Similarly, when changing tooling or material, any remnants and contamination (like black specks) must be purged out for satisfactory part production.
Advantages of Flushing Compound
- Without a thorough purge during color or material changes, defects like black specks or streaking can lead to rejected parts and costly machine downtime.
- Purging compounds help prevent these issues, resulting in cost savings for manufacturers.
- An ideal commercial purging compound (CPC) consists of resin pellets blended with proprietary materials, optimized for various manufacturing processes and temperatures.
Applications
Commercial flushing compounds are available for a wide range of materials, including commodity plastics like acrylic, polypropylene, polyethylene, polystyrene, and polyvinyl chloride. Engineering resins such as ABS, polycarbonate, PET, PBT, nylon, TPO, and TPE. They effectively clean nozzles, screws, barrels, extrusion dies, and even hot runner systems. Regular use of quality purging compounds can eliminate the need for manual screw cleaning and improve startup after machine shutdown.
Color and Material Changes:
- Flushing compounds are commonly used to facilitate smooth transitions between different colors or materials.
- When switching from one resin type to another, these compounds ensure that any residual material from the previous production run is effectively removed.
- This process prevents contamination and ensures consistent product quality.
Extrusion Processes
- Flushing compounds find applications in various extrusion processes, including:,
- Tubing, Sheet, Film, Pipe, Profile, Compounding , Extrusion blow molding
Hot Runner Molds and Injection Molding
- Flushing compounds are essential for maintaining the cleanliness of hot runner molds and injection molding machines.
- They prevent issues like black spots, silver streaking, and material contamination.
Contaminant Removal and Shutdown Sealings
- By reducing the amount of resin consumed during changeovers, purging compounds save money for processors.
- Less wasted material means improved efficiency and reduced downtime.