Delrin is one of the most versatile and widely used engineering thermoplastics today. As an exceptionally strong and durable material that offers high dimensional stability along with low moisture absorption properties, it’s the material of choice for manufacturers across industries like automotive, healthcare, and electronics.
But can Delrin be injection molded to create the sturdy plastic parts and precision components that its stellar reputation promises? As a professional plastic injection molding manufacturer, I will help you to find it out!
Delrin’s Suitability for Injection Molding
Can Delrin be injection molded? The short answer is yes. Delrin’s unique properties make it highly suitable for the injection molding process. Let’s look at why this material that’s sometimes called “plastic steel” is an injection molding all-star.
Delrin has a relatively low melt viscosity. The ease with which molten Delrin flows into complex injection molds enables smooth mold filling and easy part release. This important characteristic also facilitates short molding cycles.
It provides exceptional heat resistance. The recommended mold temperature range for Delrin is 176°F to 230°F (80°C to 110°C). However, this versatile material withstands much higher service temperatures, especially considering its thermoplastic composition.
Dimensional stability is excellent. Despite its tendency to shrink by almost 3% during cooling, Delrin offers consistent dimensional stability across a wide range of temperatures once molded parts have cooled down.
The material composition is uniform. Delrin’s highly ordered crystalline structure ensures molded parts don’t suffer inconsistencies between surface and core. The semi-crystalline composition is consistent throughout the entire molded part.
Clearly, Delrin checks all the right boxes for suitability in an injection molding application. Next, let’s look at some of the things you need to keep in mind when injection molding parts made of Delrin.
Design Considerations for Injection Molded Delrin Parts
Any experienced mold designer will tell you that designing a mold for precision injection molded components requires an intimate understanding of the plastic material’s unique injection molding characteristics.
Maintain nominal wall thicknesses between 0.04 and 0.16 inches (1 and 4 mm) for optimal results. Adhering to these general Delrin injection molding design guidelines will help avoid unwelcome surprises:
- Sink marks can occur when there are drastic variations in wall thickness
- Excessive wall thicknesses can result in residual internal stresses
- Thinwall sections may be prone to distortion or warpage
All mold components should use stainless steel because Delrin’s melt releases aggressive vapors that readily corrode lesser alloys. Any non-stainless mold materials will erode quickly with repeated exposure.
And unless you want those corrosive vapors depositing as soot on your nice clean molded parts, stainless steel venting is also essential.
Lastly, allow for shrinkage and avoid geometry that increases residual stress when designing precision Delrin injection molded components. Ribs, bosses, and holes can all contribute to residual stress buildup as the material cools inside the mold.
Optimizing the Injection Molding Process for Delrin
Delrin may be an accommodating material when it comes to injection moldability, but don’t let that fool you. It still requires tight process control to achieve consistent results batch after batch.
Maintain injection velocities between 1 and 4 inches/second depending on part thickness. Faster speeds minimize pre-hardening but may lead to jetting and subsequent loss of strength.
Carefully control mold temperatures. As previously mentioned, molds for Delrin injection molding are typically heated to temperatures ranging from 320°F down to 230°F (160°C to 110°C) with a general guideline to start testing around 250°F (120°C).
Implement adequate venting to rapidly evacuate aggressive vapors and avoid deposit contamination on finished molded components. This usually takes the form of shallow vents etched into the mold surface at 0.5mm depth.
As long as you proactively address processing factors that are specific to Delrin’s unique characteristics, you can absolutely utilize injection molding to manufacture exceptionally durable parts that leverage the material’s inherent strength and dimensional stability.
Why Injection Molded Delrin Parts Are a Smart Choice
Delrin parts produced by precision injection molding accurately replicate even the most complex product designs with exceptional repeatability and precision tolerances.
Beyond its stellar injection molding process compatibility and versatility, Delrin offers intrinsic benefits like tensile strength, fatigue and creep resistance, and abrasion resistance, which can directly enhance product quality and market differentiation.
Its unique self-lubricating characteristic imparts excellent wear resistance without external lubricants. This facilitates maintenance-free operation and reduced friction in movement even after extended product use.
An added bonus when injection molding parts using Delrin is the option to choose medical grades conforming to USP VI standards, or even incorporate color for increased aesthetic appeal.
Final Thoughts
So in summary, yes, Delrin is definitely injection moldable. And its exceptional strength properties combined with high dimensional stability, make it a go-to choice for molding high-precision components capable of delivering reliable long-term performance in the harshest operating environments.
What sets Delrin apart is how it enables molders to produce intricate, high-tolerance plastic parts combining complex geometries with exceptional structural integrity. When you need parts that can replicate sophisticated product designs using a robust engineering thermoplastic, very few options can compete with injection molded Delrin.
So if you’re looking to enhance your product with resilient and durable yet precision-molded plastic components, Delrin may just be the perfect solution for your specific injection molding needs.
