MATERIALS KNOW HOW

Tracing the History of Polymeric Materials, Part 3

In this series we delve into a discerning look back into the history of our industry and how we all got here.   

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In this Tech Day session, experts Walter Smith of Nordson and Steve DeAngelis of Davis-Standard will speak about new developments in high-speed sheet extrusion and next-generation tooling.

Tracing the History of Polymeric Materials: Part 1

In this series we’ll delve into a discerning look back into the history of our industry and how we all got here.  

Materials: Annealing Tips for Polyamide-imide, Part 7 of 7

PAI is a material capable of achieving levels of performance that even semi-crystalline engineering polymers like PEEK, PPS, and PPA cannot. But you have to be willing to work for that performance, and the annealing process is an essential part of this. 

Materials Part 6 of 7: Annealing Tips for Thermoplastic Polyurethanes

TPUs form physical, rather than chemical, crosslinks that can be broken by reheating. Formation of these crosslinks can be sped up by annealing, which improves a variety of properties.
#bestpractices #tpe

Materials Part 5: Annealing Tips for Crosslinked Polymers

As with semi-crystalline thermoplastics, annealing can be used in thermosetting polymers to obtain a level of crosslinking that may not be possible within the molding cycle.
#bestpractices

Materials: Annealing Tips for Semi-Crystalline Polymers: Part 4

You can forgo the elevated mold temperatures normally recommended for high-performance semi-crystalline materials. But it’s risky and likely to yield parts that under-perform expectations … assuming that they emerge from the annealing process looking anything like the drawing.
#pet #bestpractices

Part 3 Materials: Annealing Tips for Semicrystalline Polymers

For these polymers, annealing is done to establish a level of crystallinity that cannot be practically obtained within the parameters of a normal molding cycle. Here’s some guidance on setting annealing time and temperature.
#bestpractices

Materials: Annealing Tips for Amorphous Polymers, Part 2

In amorphous polymers, annealing is performed to draw down the internal stresses to a level not achievable within the conditions of a normal molding process. But a few parameters are important to achieving the desired results.  

Materials Part 1: What Annealing Can Do for Your Process

Relatively rapid cooling rates in processing introduce internal stress. If functional problems in use result, annealing may draw down the stress to levels that may not be achievable during processing.

Is It Glass Filled or Glass Reinforced?

Here is how to tell the difference.

Polyethylene Fundamentals: Part 6 of 6

Don’t assume you know everything there is to know about PE because it’s been around so long. Here is yet another example of how the performance of PE is influenced by molecular weight and density.
#polyolefins #bestpractices

PBT and PET Polyester: The Difference Crystallinity Makes

To properly understand the differences in performance between PET and PBT we need to compare apples to apples—the semi-crystalline forms of each polymer.

Part 5 of 6: Fundamentals of Polyethylene

How the development of new catalysts—notably metallocenes—paved the way for the development of material grades never before possible.
#polyolefins #bestpractices

Part 4 of 6: Polyethylene Fundamentals

Injection molders of small fuel tanks learned the hard way that a very small difference in density—0.6%—could make a large difference in PE stress-crack resistance.

Part 3 of 6: Fundamentals of Polyethylene

PE parts can fail when an inappropriate density is selected. Let’s look at some examples and examine what happened and why.

Part 2 of 6: The Fundamentals of Polyethylene

PE properties can be adjusted either by changing the molecular weight or by altering the density. While this increases the possible combinations of properties, it also requires that the specification for the material be precise.

Part 1 of 6: The Fundamentals of Polyethylene

You would think we’d know all there is to know about a material that was commercialized 80 years ago. Not so for PE. Let’s start by brushing up on the basics.
#polyolefins

PART 2: The Importance of Mold Temperature When Processing Polycarbonate

Don’t be afraid to increase mold temperature to improve part quality when making PC parts. Take a look at a few examples here.

Part 1: The Importance of Mold Temperature When Processing Polycarbonate

An often overlooked factor in optimizing the ductility of PC is the rate at which the polymer is cooled in the mold.

Part 5: Heat Deflection Temperature vs. Dynamic Mechanical Analysis

In the final part of this five-installment series, we bring DMA to a practical level using the results for glass-filled nylon.

Part 4: Heat Deflection Temperature vs. Dynamic Mechanical Analysis

The presentation of DMA data can sometimes frustrate users and discourage its adoption. Those unfamiliar with DMA should insist on receiving data relevant to the manner in which the part they are developing will be used.

Heat Deflection Temperature vs. Dynamic Mechanical Analysis (Part 3)

DMA provides a rich and detailed picture of polymer performance, and it can be challenging to understand all the things that we can and should know about our materials. But the fact that it may be hard does not mean that it should not be attempted.