Delrin® Product Reference Guide

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Delrin® | Product Reference Guide

Discover How to Select the
Ideal Grade of Delrin® for Your
Engineering Components
Delrin® provides reliability and high performance for your most
challenging applications

Delrin® | Product Reference Guide

Table of Contents
1. Delrin® acetal........................................................................................... 3
2. Applications............................................................................................ 4
3. Product chemistry.................................................................................. 7
4. Product line............................................................................................. 9
Table 4.1. Delrin® flow families......................................................... 9
Table 4.2. Compositions of Delrin® acetal resins.......................... 10
Table 4.3. Delrin® technology nomenclature descriptions............ 11
Table 4.4. Datasheet properties of selected Delrin® grades......... 12

Delrin® | Product Reference Guide

1. Delrin® acetal
Delrin®, the world’s first acetal resin, is a highly versatile engineering plastic with metal-like properties.
It offers an excellent balance of desirable properties that bridge the gap between metals and ordinary
plastics. In fact, Delrin is the stiffest, strongest and toughest engineering polymer available without glass
or other reinforcement, enabling efficient design of thinner, lighter and longer-lasting parts in a broad range
of demanding applications. Since its introduction in 1960, Delrin has been widely used around the world in
many applications, such as automotive, appliance, construction, hardware, electronic and consumer goods
industries. Delrin has gained widespread recognition for its reliability and performance in thousands of
engineering components.

Mechanical performance
Due to its very high crystallinity of up to 60%, Delrin is very resistant to creep, offers high mechanical
strength and stiffness without reinforcement, and also offers exceptional fatigue and impact resistance.
This makes Delrin an ideal choice for gears and snap fits and many other engineering components.

Tribology performance
Low friction properties combined with low wear and low noise properties make Delrin well-suited for sliding
applications.

Wide in use temperature range
Delrin retains its outstanding toughness, fatigue and impact resistance from temperatures below -50°C up to
90°C; intermittent to 120°C. This makes Delrin an excellent material for automotive interior applications.

Dimensional stability
Delrin is widely used for precision parts because of low moisture pick-up and very good dimensional
stability.

Low emission
Many Delrin grades meet the requirements for healthcare, food and cosmetics industries for emissions.
Special modified grades are also available for meeting the strictest air quality standards of automotive
cabins (2 ppm formaldehyde per VDA275).

Sustainable
Delrin® Renewable Attributed base polymer is produced using 100% bio-feedstock from waste according to
ISCC (International Sustainability and Carbon Certification) mass balance certification. It is manufactured
with 100% certified renewable electricity and has the potential to be 100% recycled.
Delrin® Renewable Attributed has up to 75% lower global warming potential and up to 57% lower use of
fossil resources compared to fossil-based POM while maintaining mechanical properties.

Figure 1.1. Delrin® makes mechanical gears lighter, quieter and longer-lasting

Delrin® | Product Reference Guide

2. Applications
Delrin® offers a unique combination of properties and processing capabilities which help contribute to
innovation for new applications. Customers look to Delrin to develop parts and products that help cut costs,
improve performance, reduce weight and create new business opportunities.
The gear assembly in Figure 2.1 demonstrates the importance of the many characteristics of Delrin in the
functionality of an application. The fine teeth require high strength, stiffness and creep resistance when an
assembly is meant to be under long-term loads. The cyclic nature of gear assemblies require resistance to
fatigue. The left-most gear in the assembly in Figure 2.1 indicates a back-and-forth functionality, signifying
potential sudden stops, requiring superior toughness and impact resistance in the material. Precision
assemblies require the dimensional stability of Delrin, through its low moisture pick-up. Even though plastic-on-plastic assemblies are generally not recommended due to adhesive wear, the AL (advanced lubricant)
technology in Delrin® 100AL and 500AL allows the flexibility to do so.

Figure 2.1. Delrin® acetal homopolymers (Polyoxymethylene POM)
successfully replaces metals—even in fine critical gears—with superior quality
Delrin provides outstanding performance in a wide variety of applications in automotive, healthcare and
various other industrial and consumer products. Examples include:
• Auto parts and systems (Figure 2.2): Push buttons, pillar loops, actuator gears, door systems and
various parts with excellent spring-back behavior like clips
• Medical products (Figure 2.3): Components in injection devices, inhalers, applicators for wearables and
laboratory and hospital equipment
• Consumer products (Figure 2.4): Springs, ski bindings, fasteners, bearings, e-bike gears, lighter bodies,
keyboard parts and remote vacuum cleaners
• Industrial products (Figure 2.5): Valves, clips, fasteners, bearings, irrigation, conveyor belts and stock
shapes

Delrin® | Product Reference Guide

Figure 2.2. Autoliv safety belt retractor bearing plate made with Delrin® 300TE

Figure 2.3. Delrin® provides excellent impact toughness, creep resistance and sliding performance for
drug delivery devices

Delrin® | Product Reference Guide

Figure 2.4. Ski bindings and clips made with Delrin® offer strength, stiffness and dimensional
stability in harsh conditions

Photo: Courtesy of Regina Catene Calibrate

Figure 2.5. The enhanced tribology of Delrin® modified grades results in low wear, low
friction and low noise

Delrin® | Product Reference Guide

3. Product chemistry
Acetal is a simple molecule. The repeating unit is formaldehyde. It may be called acetal, polyacetal or
polyformaldehyde, but the most common name is POM (polyoxymethylene). Though first discovered in the
1920s by DuPont, thermally stable versions of both homopolymer and copolymer acetal were not invented
until the late 1950s. Homopolymer uses only formaldehyde to form the polymer chain and a second molecule to endcap the chain to stabilize it and control the molecular weight. Copolymer uses roughly 1% of
a second monomer to stabilize the chain and form the endcaps. Even though it is more difficult to manufacture, DuPont chose to commercialize only the homopolymer under the Delrin® brand name for its higher
mechanical performance relative to the copolymer version.
The copolymer process chemistry results in 92–99 wt% of linear polymer chains with a randomly inserted
comonomer and 1–8% of low molecular weight cyclic oligomers. The comonomer hinders the natural tendency of the polymer to crystallize by disrupting the alignment (Figure 3.1) while the oligomers are absent
from crystallization altogether. Copolymer typically exhibits 45–50% crystallinity.
The uniform backbone of Delrin acetal homopolymer allows it to participate in large scale crystallization
aided by dipole-dipole interactions, tightly packing the polymer chains together, leading to roughly 55–60%
crystallinity. The larger crystalline blocks of Delrin homopolymer lead to more interconnections (entanglements) between blocks. The tight network of crystalline blocks and entanglements is what gives rise to the
short-term and long-term mechanical property dominance of Delrin homopolymer over acetal copolymer.

Acetal copolymer

Delrin® homopolymer

Figure 3.1. Crystalline structures of acetal copolymer versus acetal homopolymer

Figure 3.2 shows the difference in mechanical properties between Delrin® 500P NC010, the general
purpose Delrin offering, versus those of the typical general purpose acetal copolymer (MVR = 8–9). Not
only does the higher level of crystallinity increase the strength and toughness of the resin, but it does so
with lower molecular weight polymer, resulting in a significant improvement in melt flow rate (MFR) and
moldability. The differences between Delrin homopolymer and acetal copolymer are described in detail in
the white paper, Delrin® Acetal Homopolymer – How to Maximize the Property Advantages of Delrin® Acetal
Homopolymer over Acetal Copolymer.

Delrin® | Product Reference Guide

Figure 3.2. Mechanical properties of acetal copolymer versus Delrin® homopolymer

Figure 3.3. Low-wear, low-friction window regulator components made with Delrin®
deliver long life and quiet operation

Figure 3.4. Select grades of Food Contact Compliant Delrin® combine safety with
superior strength and wear resistance

Delrin® | Product Reference Guide

4. Product line
Delrin® acetal homopolymer is available in four general families, based on molecular weight/flow rate. As
shown in Table 4.1, the 100 family offers higher molecular weight, which leads to exceptional toughness,
impact resistance and elongation at break. At the opposite end, the 900 family exhibits much higher flow
rates, which is ideal for long parts with thin walls. The shorter polymer chains result in a higher crystallinity
with fewer entanglements, leading to relatively moderate toughness.
A designer may desire to use the 100 family to get the best combination of strength and toughness, while a
molder may prefer to use a lower molecular weight resin to ensure best part filling and appearance.

Preferred by
designers

Flow family

Melt mass-flow
rate (g/10 min)

Melt volumeflow rate
(cm3/10 min)

2.4

Preferred by
molders

Table 4.1. Delrin® flow families

The spider chart in Figure 4.1 shows in more detail the differences between the flow families. The 100 family
has slightly lower stiffness (tensile modulus), but greater toughness characteristics (charpy notched, yield
strain and nominal strain at break).

Figure 4.1. Mechanical properties of Delrin flow families—higher molecular weight results in higher toughness

Delrin® | Product Reference Guide
Table 4.2 below illustrates, in greater detail, the general characteristics of the Delrin flow families as well as
the types of compounded formulations available in each family. Table 4.3 lists the nomenclature used to
indicate the various technologies available in the Delrin product line and their targeted uses. Table 4.4 lists
a small selection of grades from the Delrin product line to illustrate the range of properties possible. The full
set of properties of all grades in the Delrin portfolio can be found in the Delrin Product Data Sheet System
(https://delrin.materialdatacenter.com).
Flow
family

General characteristics

Modified grades available for
extended performance

• High viscosity acetal homopolymer for use in easy-tofill molds (thick walls)
• Injection moldable and exhibits sufficient melt strength
for extrusion
• Best combination of strength and toughness without
modification

• Enhanced productivity
• Low emission
• Extrusion
• Toughened
• UV-stabilized
• Low wear/low friction
• Renewable Attributed

• Medium-high viscosity acetal homopolymer with
an outstanding balance of ease of processing and
mechanical performance

• Enhanced productivity
• Low emission
• Toughened
• UV-stabilized
• Antistatic
• Renewable Attributed

• General purpose medium viscosity acetal
homopolymer with an optimum combination of
flow and mechanical properties

• Enhanced productivity
• Low emission
• Toughened
• UV-stabilized
• Low wear/low friction
• Glass filled/reinforced
• Renewable Attributed

• Low viscosity acetal homopolymer for multi-cavity and
thin wall molding
• Easy filling resin with slightly lower toughness than the
500 family

• Enhanced productivity

Table 4.2. Compositions of Delrin® acetal resins

Delrin® | Product Reference Guide