{"id":2087,"date":"2021-07-22T00:52:00","date_gmt":"2021-07-22T00:52:00","guid":{"rendered":"https:\/\/sybridge.com\/?p=2087"},"modified":"2023-06-28T15:37:04","modified_gmt":"2023-06-28T15:37:04","slug":"know-your-materials-delrin-polyoxymethylene","status":"publish","type":"post","link":"https:\/\/sybridge.com\/know-your-materials-delrin-polyoxymethylene\/","title":{"rendered":"Know Your Materials: Delrin (Polyoxymethylene)"},"content":{"rendered":"\n

Previously published on fastradius.com on July 22, 2021<\/em><\/p>\n\n\n\n

Polyoxymethylene (POM), more commonly known as acetal or its branded name Delrin\u00ae, is an engineering plastic offering low friction, high stiffness, and excellent dimensional stability. Polyoxymethylene is a category of thermoplastics and includes many different formulations of the material, all of which vary slightly. As such, it\u2019s important to learn as much as you can about each type before choosing one for your next project.<\/p>\n\n\n\n

Delrin\u00ae is a semi-crystalline engineering-grade thermoplastic widely used to create highly precise parts. In general, Delrin\u00ae provides impressive dimensional stability and sliding properties. It\u2019s known for its high strength, wide operating temperature range (-40\u00b0C to 120\u00b0C), and excellent mechanical properties. Here\u2019s everything you need to know about this material, from how it\u2019s made to its best-fit applications.<\/p>\n\n\n\n

Inside the Polyoxymethylene Production Process<\/h2>\n\n\n\n

Acetal was first discovered by German chemist Hermann Staudinger in 1920 before it was commercially synthesized by research chemists at DuPont, the original manufacturers of  Delrin\u00ae plastic, in 1956. Like all other plastics, acetal is created by distilling hydrocarbon fuels down into lighter groups called \u201cfractions,\u201d which can then be combined with other catalysts via polymerization or polycondensation to produce a finished plastic.<\/p>\n\n\n\n

To make an acetal homopolymer like Delrin\u00ae, anhydrous formaldehyde must be generated by causing a reaction between aqueous formaldehyde and alcohol to form a hemiformal. The hemiformal is then heated to release the formaldehyde, and the formaldehyde is polymerized by anionic catalysis. The resulting polymer is stabilized when it reacts with acetic anhydride, which creates polyoxymethylene homopolymer.<\/p>\n\n\n\n

Acetal comes in many different commercial varieties and formulations, each with its own advantages and disadvantages. For example, Delrin\u00ae 500 is medium-viscosity, all-purpose polyoxymethylene that has a good balance of flow and physical properties. It can be used to produce parts via CNC machining and injection molding and is frequently used to manufacture mechanical parts, fuel systems, and fasteners. Delrin\u00ae 1700P, on the other hand, is a very low- viscosity, fast-molding resin that is best suited for parts with complex shapes, thin walls, long flow paths, or multi-cavity tools. It also offers the best molding thermal stability for deposit-free molding in demanding conditions.<\/p>\n\n\n\n

Since there are dozens of different formulations of acetal, it\u2019s important to do your research and make sure your prospective plastic offers all of the properties you need for your application.<\/p>\n\n\n\n

Delrin\u00ae Plastic Properties and Mechanical Specifications<\/h2>\n\n\n
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Delrin\u00ae can also be found in all-purpose industrial equipment like bearings, gears, pumps, and meters.<\/em><\/figcaption><\/figure>\n<\/div>\n\n\n

Acetal\u2019s excellent mechanical properties make it extremely versatile, offering a unique blend of properties that you won\u2019t find in most metals or other plastics. Delrin\u00ae plastic is strong, rigid, and resistant to impact, creep, abrasion, friction, and fatigue. It\u2019s also well known for its excellent dimensional stability during high-precision machining. Acetal can also stand up to moisture, gasoline, solvents, and a wide range of other neutral chemicals at room temperature. From a design standpoint, parts made with extruded POM naturally have a glossy surface finish.<\/p>\n\n\n\n

Since acetal is compatible with CNC machining, injection molding, extrusion, compression molding, rotational casting, and more, product teams are free to choose the manufacturing process that works best for their budget and their needs. However, it\u2019s worth noting that Delrin\u00ae plastic is typically very challenging to bond.<\/p>\n\n\n\n

Acetal material properties vary by formulation, but the mechanical properties<\/a> for Delrin\u00ae 100 NC010, one of the most popular formulations, include:<\/p>\n\n\n\n