Today's KNOWLEDGE Share:High packing pressure reduce warpage

-

Today's KNOWLEDGE Share

How could that be, since the packing pressure is not going to really change fiber orientation ?


The mechanism is a bit more subtle.


GF induced warpage is linked to the mismatch of "shrinkage" of the glass fiber vs. the shrinkage of the matrix. Such mismatch creates a much bigger shrinkage perpendicular to the fibers because in the parallel direction, the fibers can better "resist" the pull from the matrix.


So why would a higher packing pressure reduce warpage ?


Think about it. If you could increase the packing to the point where the matrix would hit nearly zero volumetric shrinkage (check the PvT curves, it is possible although usually unreasonable) then the matrix would not want to shrink anymore, and the conflict with the glass fibers (which also don't want to shrink much) is gone !

So...no warpage !


So, remember, the more you pack a GF filled part, the less it will warp (at least from the anisotropy effect, differential shrinkage is another story).


Of course there are limits to how much you can increase the packing without running into other issues...


Source:Vito leo

Comments

Post a Comment

Popular posts from this blog

ENVALIOR ANNOUNCES NEW PPS COMPOUNDING FACILITY IN EUROPE

-
Image
Envalior launches new PPS compounding facility in Uerdingen, Germany. New facility supports growing demand for Xytron™ in Europe and the Americas. To better serve growing customer demand in Europe and the Americas, Envalior – a global leader in sustainable and high-performance engineering materials – announces that it will invest in a PPS (Polyphenylene Sulfide) compounding facility in Europe. Envalior’s PPS material Xytron™ combines a strong set of properties, including excellent chemical and hydrolysis resistance at elevated temperatures, extremely stable heat aging performance up to 240°C, very good and stable electrical properties at elevated temperatures, low moisture absorption with high dimensional stability, and inherent flame retardance that meets UL94 V0.  Since 2016, when Xytron™ entered the market, the PPS material has built a strong track record across OEMs and tier customers. The new facility will provide local supply and additional services to customers in Europe whi...
Read more

Today's KNOWLEDGE Share : What Is Going Wrong in UK Plastics Recycling?

-
Image
Today's KNOWLEDGE Share What Is Going Wrong in UK Plastics Recycling? Biffa shut its Sunderland plant. Viridor walked away from Avonmouth and Rochester. Yes Recycling Fife collapsed within a year. All three were backed by major investments All three had buyers lined up for recyclate All three are now offline This is not bad luck It is bad structure Over the next four posts I will break down: 1. Why cheap virgin imports are undercutting UK recyclers 2. How weak policy enforcement is fuelling market failure 3. What volatile PRNs and cheap exports are doing to infrastructure 4. Why demand from brands is softer than their promises Let’s start with the first: **Cheap Virgin Resin = Broken Economics** Virgin PE, PP, and PET have been flooding the global market. New capacity in Asia and the US has driven prices down 30 to 40 percent. Meanwhile, recycled plastic costs more to produce in the UK than it can sell for. We are asking UK recyclers to compete with materials made in places with – ...
Read more

Today's KNOWLEDGE Share : Robotic 3D printing can compete with traditional boatbuilding

-
Image
Today's KNOWLEDGE Share “Robotic 3D printing can compete with traditional boatbuilding”, Simone Barbera and Mattia De Santis, Caracol V2 catamaran was printed in Italy at Caracol’s production center and headquarter in Barlassina, near Milan, with a Heron AM 400, Caracol’s robotic Large Format Additive Manufacturing (LFAM) platform. The lattest was specifically configured with a 7-axis robotic arm mounted on a rail, enabling the printing of parts up to 10 meters in length. How did the collaboration between V2 Group and Caracol come about? Simone Barbera : The collaboration between V2 Group and Caracol originated from a shared vision to revolutionize boat manufacturing through sustainable innovation. V2 Group, a Spanish-company specialized in nautical design and engineering, is seeking to develop electric vessels manufactured sustainably. On the other hand, Caracol, leader in robotic advanced manufacturing technology, had had years of experience working with Large Format Additive Ma...
Read more