Delrin® Homopolymer Acetal compared with Acetal Copolymer
Many of our clients assume that Delrin® rod and Acetal rod are the same thing. This is not true.
Yes, all Dupont Delrin® rod is Homopolymer Acetal rod, but not all Acetal rod is Delrin® rod.
Delrin® is the trade name for Homopolymer Acetal made by Dupont. Dupont™ Delrin ® is a popular acetal homopolymer brand name and the most commonly used acetal homopolymer.
This is the most recognized of all trade names for Acetal materials, but not the only available Acetal material. The Copolymer Acetal resin is produced by a wide variety of large plastic manufacturers, BASF is probably one of the largest and most well known. Some main resin names are: BASF Ultraform® H4320, Kepital® F10-02, Hostaform® M25 and many others.
While Delrin® Homopolymer Acetal is a wonderful material, in a larger cross sections Homopolymer can exhibit center line porosity, or ‘soft centers’. This can sometimes be seen with the naked eye, and is a darker white in a normally milky white natural colored material. This center line porosity can cause problems in some applications. This porosity can cause leakage of fluid if under pressure, or soft center’s of homopolymer rod and sheet.
This should not stop you from considering Delrin® Homopolymer Acetal though. Many other properties of the homopolymer resins are superior to the copolymer resins. These properties are:
Typical Value Unfilled Homo-Polymer
Typical Value Unfilled Co-Polymer
Tensile Strength Yield
9,600 – 11,000
9,000 – 10,200
Izod Impact – Notched
Hardness – Rockwell
Deflection Temp @ 264psi
Deflection Temp @ 66 psi
Water Absorption @ 24 hrs
Co. Thermal Expansion
Some key properties for homopolymer acetal are: higher tensile strength, increased Izod impact, higher deflection temperatures and it is slightly harder. The co-efficient of thermal expansion is a bit higher, and needs to be considered when designing a new part. Extruded Delrin® brand homopolymer resin material also comes in several resin variations, including: Delrin® 150 and Delrin® 507, contact us for details. Dupont™ Delrin® is a popular acetal homopolymer brand name and the most commonly used acetal homopolymer.
Many of our clients prefer the homopolymer rod and sheet for small machined parts. This is due to the increase in a few key properties, and of course brand recognition. Some of our major brand names for quality Copolymer Acetal (POM-C) sheet and Rod include: Tecaform AH®, Sustarin C®, ZL 900® and Pomalux®.
Both resins meet the standard ASTM-D-6778, and the cancelled specs, L-P-395 and ASTM-D-4181. Contact us for certification and specifications you may require.
The Acetal family of plastic resins are excellent for wear resistance, great mechanical strength, and superior machining properties. It is available in a huge range of sizes and shapes. Click here for more details on Acetal – Homopolymer Acetal Rod, and sometimes referred to as plastic dowel. We also have the capacity to supply colored Acetal Copolymer or Delrin® Homopolymer Acetal rod; click here from more details on the colored Acetal material.
Similar materials to Acetal Copolymer – Homopolymer Acetal are Nylon Rod, PET Rod and Noryl® Rod. Most materials are available as round rod, square rod, bar, strip, sheet and plate.
Since 1975 we have provided large diameter plastic rods and thick plastic sheets, plates, slabs and blocks. One of our long time ‘secret’ sources has been Gehr Plastics. Since 1932 the Gehr family has owned and operated the Gehr Plastics company. They are a worldwide leader in semi-finished plastic shapes in thermoplastics, primarily sheet and rod. The headquarters for Gehr Plastics is in Mannheim, in south western Germany. For almost 30 years, Gehr Plastics has had production facilities in the Philadelphia area, providing the USA with the same high quality plastic shapes.When we mention large diameter rod, we mean it! Gehr can produce plastic rod up to almost 20″ diameter in several grades of plastic. They also produce sheet plastics up to 8″ thick, and make the largest materials of most manufacturers of plastic sheets and rods.
At Gehr Plastics, Quality Engineering Plastic Comes First
Our first purchases with Gehr Plastics was in the PVC rod family. Once again, they make huge cross sections in many materials, including the PVC rod. Many manufacturers struggle with large sections of PVC rod because keeping it void free throughout the large diameter is very difficult. Not for Gehr Plastics, they specialize in engineering plastic materials. We have chosen this high quality manufacture for their exceptional product quality. We know the demands of our client base, and only choose the best factories to supply our products. Gehr is definitely one of the premier plastics producers in the world. While the quality of the PVC rod is excellent, the rest of the Gehr Plastics product line is also some of the best plastic semi-finished shapes available in the market place. Here is a list of some of the many materials that Gehr Plastic produces:
And a new and exciting product – Clear Nylon Rod (Contact us for more information)
Many of the above items are also available in sheets, plates, slabs or blocks.
Gehr Plastics – one of our engineering plastic partners
We have been proud to offer the complete line of plastic rod, sheet, slab, plate and block from Gehr Plastics, and consider them a highly valued partner in supplying these engineering plastic materials to you, our valued client. For more information on the size range, availability and pricing on these and other plastic materials,click hereor call us at 866-832-9315
What is the difference between Noryl and PPO (or Modified PPO)?
Noryl® is a trade name for Sabic Plastics (formerly GE Plastics) for their Modified PPO (Modified PolyPhenyleneOxide). Sabic is the world leader in engineering and mechanical plastic resins.
This resin is a remarkably versatile material. PPO exhibits unusually low moisture absorption and great machinability. Noryl® is an excellent choice for water filtration and fluid handling parts. Noryl has excellent impact resistance, long term dimensional stability and is light weight. Noryl® has exceptional electrical properties (properties boosted by lack of water absorption). It can be thermoformed and machined to tight tolerances. It carries a UL flammability rating between UL 94-HB to UL 94 V-1. The primary specification covering PPO (Noryl®) is ASTM-D-4349.
Sabic Noryl is available in two standard unfilled varieties, EN-185 and EN-265. The number indicates the heat deflection temperature of the material. This material is easy to machine, holds tolerances well, and is great for water immersion applications. A complete data sheet is found here.
We stock this material in both sheet and rod. The standard natural color for Noryl is opaque Black and is stocked as the EN-265 grade of resin. Noryl® is also available as a glass filled material which enhances both the mechanical and thermal properties of the resin. Chemical attack from water, most salt solutions, acids and bases is also minimal with Noryl®.
Some of our most popular questions are “Is this material UV stable”, or “How long will this last in direct sunlight”, or something similar. These are great questions. Just look at the ‘cheap’ backyard furniture you bought last year, yep, it is faded and cracking. Why is that?
The quick answer is the material had either no UV (Ultra Violet Light) stabilizer or very little. Most plastic materials are not UV stable to start with, other than Acrylic which is invisible to UV. All other materials need a little something to give it the protection it may need from the sun. Many plastic materials, if given the proper additives, can be used in direct sunlight for 10 – 15 years giving excellent performance.
The first factor in picking such a material is the intended use. Not all materials are good candidates for all applications.While some materials will perform very well, others under the same conditions will fail. Please contact us for details on a material to meet your needs. HDPE sheet is one of the best materials for long term outdoor use, if given the proper additives. Next time you drive by a children’s playground in your local city, look at the brightly colored panels used to make the play equipment. This is a HDPE sheet with heavy UV additives, and this makes an excellent application. Available in a rainbow of colors and able to be fabricated easily, this material is excellent for many outdoor applications. If your application is more mechanical, other materials that might be used would be: Polycarbonate, UHMW, ABS (especially with Korad cover), Acetal, Noryl and many more. Our standard Covestro Makrolon Polycarbonate is a UV stable material in sheet, and is frequently used in replacement glazing applications. The remaining materials on the list are available in Black (a carbon black pigment) which extends outdoor usage. While still not recommended for direct sunlight, they can be used with a good possibility of success – depending on design. Plastics can become brittle or lose properties over time if material does not have UV stabilization, with the proper material and the proper additives, you can get years of trouble free service.