Today's KNOWLEDGE Share :Warpage & Shrinkage

-

Today's KNOWLEDGE Share

With glass fibers, shrinkage can be 10X lower in the flow direction than in the transverse direction.



This is the classical driving mechanism for warpage of GF filled compounds and most people will look at the ratio of perpendicular to parallel shrinkage as a sort of Warpage Index.


However, one can easily demonstrate that Warpage does NOT scale with this RATIO, but rather with the DIFFERENCE of perpendicular to parallel shrinkage.

This is crucial, because when you increase packing, you reduce both values (hence, their difference), but barely change the ratio.

And what we observe is that if you double the packing pressure, you roughly cut the warpage down by 50%, despite the anisotropy ratio remaining the same !

Packing is the single most effective way to reduce warpage in GF filled materials.


Credit: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