New technology from Glycon takes real-time measurements of screw and barrel wear and provides data to guide processors as to when the time may be right to swap out these components.
Editorial Director, Plastics Technology
Despite their integral role in transforming pellets fed through the hopper into parts ejected from the mold, visibility into the performance, health and efficiency of screws is difficult to discern for many reasons, not the least of which being the fact they’re located inside a barrel.
Private equity firm Altair expects to close on acquisition during the first quarter of next year.
Very small screws have become more common with the growth of additive manufacturing. Designing such screws requires balancing their output requirements with their torque strength.
The more you know about what happens in a screw, the more you’ll be able to work with your supplier to optimize design.
Milacron has extended its exclusive partnership to offer Robert Barr Inc. designed screws on new Milacron injection molding machines or as aftermarket add-on to existing presses.
Most molders are still running with screw designs that haven’t changed much in 30 years. But they don’t need to.
Sixth new Nordson lab will open in Austintown, Ohio, at a newly built plant for Xaloy screws and barrels.
New design from Davis-Standard offers outputs comparable to barrier screws at lower melt temperatures.
Let’s take a deep dive into parallel and crossing types and see where each fit in.
Extruders are not like ovens. Tweaking barrel-temperature profiles will not influence melt temperature all that much. Here’s why.
You can avoid complicated melting equations when designing or evaluating a screw by using simpler methods that can save time and provide good results.
The cylindrical extruder developed by VTT could revolutionize processing of recyclable materials including plastics, textiles and food waste.
Processors can extend the life of equipment and improve productivity by coupling a preventive-maintenance program for their screws and barrels with routine use of chemical purging compounds..
Small-footprint machine reportedly uses up to 95% less energy/lb of material processed and can typically achieve dimensionally stable product within 20 min. of being turned on.
Variables such as shear rates, melting rate, residence time and conductive heating are all influenced in the scale-up.
Determining the cause of wear is the first step in eliminating it.
Here’s how to find out what’s happening to your screw and what to do about it.
A hand-held calculator and some basic equations can help determine whether your screw is up to snuff.
While there’s lots of data that influences screw design, processors usually don’t have access to it. So instead, try calculating drag flow to see if your screw is working properly.
In injection molding, the penalty for using a general-purpose screw in an application that has special requirements often takes the form of longer cycle times. Barrier designs can help.
A barrier screw without a metering section can reduce output and increase melt temperature.
Hard-surfacing failures without evidence of burrs indicate possible weld bond issues.
Being in tune with your film extrusion equipment will allow you to identify issues before they start impacting production.
Density affects the mass flow rate, and energy transfer is based on mass, not volume. As a result, polymer density enters into practically every calculation in a screw design.
If you are, you are inviting Murphy—as in trouble—to the party.