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Wednesday, 1 October 2025

Say Goodbye to PTFE? Discover the UHMW-PE Advantage in Plastics

Hello and welcome to a new post in which we are looking for a smarter way to reduce friction and wear in engineering plastics—without relying on PTFE.

Replacement of PTFE with UHMW-PE - How much should I add?

Ultra-High-Molecular-Wheigt-Polyethelyne (UHMW-PE) stands out as a highly effective alternative to PTFE and molybdenum disulfide, especially when high temperatures are not a concern for your final application. Discover how this innovative approach can boost performance and open new possibilities for your polymer selection and engineering plastics projects.

Table 1 shows how adding just 5 wt% of UHMW-PE to materials like PA 6 can dramatically lower the kinetic friction coefficient from 0.6 to 0.23. Similar improvements are possible with PBT (from 0.51 to 0.2) and PPS (from 0.38 to 0.14)!

Check out this post too 👉Polymer Material Selection: What are PTFE free alternatives for friction and wear compounds?

Thanks for reading & #findoutaboutplastics

Greetings,

Herwig Juster

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Literature:

[1] https://plasticker.de/news/shownews.php?nr=45528&nlid=64581.d.h.2024-10-30

[2] https://www.findoutaboutplastics.com/2022/07/polymer-material-selection-what-are.html

Wednesday, 17 September 2025

Designers & Engineers: Tired of Warped Polyamide Parts? Meet PolyArylAmide (PA MXD6)!

Hallo and welcome to a new blog post on one of my favorite high performance Polyamides: PA-MXD6 (also known as Nylon MXD6, or simple PARA).

When designing with glass fiber-reinforced polymers, warpage is a common challenge—especially as fiber content increases. But what if you could achieve both high strength and dimensional stability?

Warpage Comparison: PA 6.6-GF30 vs PA MXD6-GF50

Figure 1 compares the warpage behaviour of a plate moulded in PA 6.6-GF30 and PA-MXD6-GF50. The graps shows that:

🔹 PA-MXD6-GF50 (50 wt% glass fiber) shows dramatically lower warpage and anisotropy than standard PA 6.6 GF30 (30 wt% GF)—even with a 20 wt% higher glass content!

🔹 Lower anisotropy means your parts stay true to design, reducing costly rejects and post-processing.

🔹PARA’s unique structure minimizes the difference between parallel and transverse shrinkage, delivering precision and reliability for your most demanding applications.

Figure 1: Warpage comparison of PA 6.6-GF30 vs PA MXD6-GF30 and PA MXD6-GF50 [3].

Why compromise? Choose PARA for your next polymer selection project to achieve:

Tighter tolerances
Superior aesthetics
Consistent, high-quality parts

Wednesday, 10 September 2025

Mastering Injection Molding Tools for High Performance PolyArylAmide (PARA; PA MXD6): 6 Key Steps to Success

Hello and welcome to a new blog post. Today we dive into the optimal tool making for Polyarylamide parts.

Designing and producing injection molding tools for Polyarylamide (PARA; PA-MXD6) is both an art and a science. This high-performance polymer offers outstanding mechanical properties and surface aesthetics—but only if your tooling is up to the challenge!

Here’s a deep dive into the six essential steps for success (Figure 1):

Figure 1: Overview of the six steps of tool making for molding Polyarylamide (PARA; MXD6).

1️⃣ Part Design: Build on Solid Foundations

Use generous radii (≥0.6 mm) to reduce stress and ease ejection.
Apply draft angles: at least 1° for polished, up to 3° for textured surfaces.
Optimize gate placement and size—locate at the thickest section, with land lengths of 0.8–1.6 mm.
Take advantage of PARA’s low shrinkage (0.20–0.25%) for tight tolerances and minimal sink marks.
Simulate your design (Moldflow®, Flow-3D®) to predict flow, weld lines, and optimize geometry.

2️⃣ Mold Definition: Specify for Performance

Select abrasion-resistant steel (≥54 HRc) like Stavax ESR or Orvar Supreme to withstand glass fiber wear.
Design for “steel safe” dimensions—easier to remove than add steel!
Ensure robust venting (max 0.01 mm) and cooling (10 mm channels, 15–20 mm spacing).
Use hot runners for efficiency and consistent quality.
Calculate clamping force: 1 ton/cm² of projected area.
Add cavity pressure sensors for processing optimization, especially with multi-cavity tools.

3️⃣ Detailed Drawings & Production: Precision Matters

Prepare comprehensive technical drawings with all tolerances and features.
Plan for heat treatment and machining—every detail counts for tool longevity and part quality.

4️⃣ Cutting Steel: Prepare for the Long Haul

Mill, heat treat, and quench your steel to achieve optimal hardness.
Allow for deformation during heat treatment (“steel safe” approach).
After treatment, remove any brittle, oxidized layers by sandblasting to prevent future tool issues.

5️⃣ Assembly & Testing: Fine-Tune for Perfection

Assemble and adjust all tool components, ensuring smooth operation.
“Blueprint” the tool at low clamping force to check split lines and prevent flash (PARA has good flow properties, similar to PPS).
Design for easy maintenance: include features like mold centering adjusters, ejector return pins, and replaceable components.

6️⃣ Polishing & Surface Treatments: Finish Strong

Polish all surfaces to ensure easy part ejection and premium aesthetics.
Apply specialized surface treatments to extend tool life—especially important with glass-filled PARA.

Pro Tip:
PARA’s high flow and low shrinkage enable thin, complex parts with exceptional surface quality. But to fully leverage these benefits, every step of your tooling process must be meticulously planned and executed.

Are you working with PARA or considering it for your next project? Let’s connect and share best practices for robust, reliable, and beautiful injection-molded parts!

Wednesday, 3 September 2025

Turning Product Requirements into Plastic & Plastic Part Specifications: The Key to Successful Material Selection!

Hello and welcome to a new blog post where we discuss an important material selection topic.

When developing a plastic part, clear and meaningful specifications are essential—they help control variations in function, appearance, and cost. By translating product requirements into detailed plastic specifications, you set the foundation for selecting the optimal material and ensuring consistent quality. Also, the specifications will help for sourcing plastic parts with the correct material.

What should a robust plastic specification and plastic part specification include?

✔️ Material brand, grade, and generic name (e.g., Ryton® R-4-200BL, PPS)

✔️ Surface finish

✔️ Desired parting line location

✔️ Flash limitations

✔️ Permissible gating and weld line areas

✔️ Void intolerance zones

✔️ Allowable warpage

✔️ Tolerances

✔️ Color

✔️ Decorating needs

✔️ Performance criteria

Example of turning a product requirement into a plastic specification:

If your product requirement is “the part must withstand high temperatures, needs to have low tolerance, and have a glossy black finish,” this translates into a plastic specification such as:

Material: Ryton® R-4-200BL (PPS) for heat resistance
Color: Black, high-gloss surface finish
Tolerance: ±0.05 mm
No voids allowed in load-bearing areas
Gating away from visible surfaces

Figure 1 demonstrates how plastic specifications act as a bridge between product requirements, material selection, and support for sourcing. First we turn product requirements into proper plastic specifications, which we can use for polymer selection. After identifying the plastic grade we can add it with commercial name to our specification list and use it for sourcing or to find alternativ materials, as well as sourcing the plastic parts themselfs.

Figure 1: Plastic specifications as bridge between product requirements, material selection, and support for sourcing.

Conclusions

Having proper specifications not only streamlines the material selection phase, but also greatly supports sourcing—especially when you need to identify or qualify alternative materials. Clear specifications ensure you can compare options confidently and maintain quality, even when supply chains change.

Getting these details right means your part will meet all functional, aesthetic, and economic goals. Start with clear specs—finish with a successful product!