by sitemanager | Mar 12, 2013 | High Performance Plastics, Informational Post, Mentor Nuggets
Innovative Plastics Manufacturer
Produces Innovative Sheet and Rod Materials
Gehr Plastics has been a major global manufacturer in the plastic sheet and rod industry since 1932. During this period, Gehr has become a leader in a variety of product lines, and also become known for very large sizes in both sheet and rod. Currently Gehr can produce Acetal rod up to 20″ in diameter and sheets up to 8″ thick. Some of the many plastic materials the Gehr produces:
Winner of the 2008 Bioplastics Award

Radel Rod is produced in many medical grade colors
Being innovative also means looking forward. Gehr was selected as the Bioplastics manufacturer of the year in 2008, partly for the new line of plastic materials which have a bio base. These materials have a variety of bio based forms, including: a PLA base, Cellulose based, Polyamide and Wood – Plastic Composite (WPC). One such material is ECOGEHR PLA-L which is a blend of polylactic (polylactic acid), some lignine, fatty acid and wax. This biopolymer is new to our industry and can be used in temperatures ranging from -22 °F to +140 °F. This complete line of materials is one of the only available in the plastic industry to be comprised of many renewable raw materials. Gehr leads the way in this exceptional and innovative product line.
ClearGehr Polyamide Rod
This brand new product is a Clear Polyamide rod. The outside surface is as extruded, and can be polished. This enables the production of a relatively clear sight glass quality material with most of the high end properties of Polyamide – Nylon material. We have supplied this material for small machined parts where neither Polycarbonate nor Acrylic would work well. Because of the natural inherit chemical resistance of Polyamide, this high end ClearGehr rod can out perform all normal transparent plastics. Give us a call to see if this new innovative product will work in your difficult application.
FDA Approved Wear Grade Acetal
Have you been looking for an extended wear Acetal material (like the PTFE filled Acetals – Delrin AF), but need it to be FDA approved? Then perhaps you should consider WearGehr. This proprietary filled Acetal material has excellent wear resistance, and retains the FDA approval of the base Acetal, unlike the PTFE filled Acetal materials which are not FDA approved. It is made in a blue color for easy identification, also it remains very machinable. Contact us for more information on this excellent high tech material. Call us at 866-832-9315 or send us a note here.
by sitemanager | Feb 25, 2013 | Choosing A Plastic Material, Educational Post, Material Comparison, Mentor Nuggets
Are Acetal Copolymer and Homopolymer Acetal the same?
This is one of our most common questions, and it is a bit involved of an answer.
There are two main versions of Acetal Resin
Homopolymer Acetal and Copolymer Acetal
The most popular name for a Homopolymer Acetal is the Dupont Delrin, which is a premium Homopolymer Acetal.
The second Acetal is a Copolymer acetal, and there are many suppliers of this resin.
Acetal is the generic, and not all Acetal is Delrin® Hompolymer, nor is it Acetal Copolymer. A distinction is required to determine which is best for your application. There are several manufacturers that produce Acetal Copolymer resin, including: Celanese®, BASF®, Ticona®, SABIC® and many more.
Acetal Copolymer compared to Delrin® Homopolymer Acetal
Delrin® is a premium homopolymer Acetal produced by Dupont. Many of the physical properties of the homopolymer exceed that of the copolymer Acetal. Dupont™ Delrin® is a popular acetal homopolymer brand name and the most commonly used acetal homopolymer.
The generic term ‘Acetal’ covers both the homopolymer from Dupont and the copolymer grades of resin. Both materials meet the ASTM-D-4181, ASTM-D-6100 or ASTM-D-6778 specification (an old call out is L-P-392). Homopolymer Acetal is POM111, and Copolymer Acetal is POM211.
Both are very tough and machinable, and have some similar properties.
An additional difference is the inherit problem of center-line porosity in some of the homopolymer grades. This is caused by out gassing during manufacturing, and can be found at the center or on the surface of all homo-polymer extrusions. This porosity can cause some problems with machining or moisture permeation through the material. The copolymer resin has little to no porosity issue.
Some of the other differences are in the physical properties of the resin. Review the chart for some of the most popular properties people ask for when looking at Acetal Copolymer or Homopolymer Acetal.
See Homopolymer and Copolymer Acetal properties chart below.
| Properties |
Homopolymer Acetal |
Copolymer Acetal |
| Tensile Modulus of Elasticity |
450,000 |
400,000 |
| Flexural Modulus of Elasticity |
470,000 |
366,000 |
| Heat Deflection Temp @ 264 psi – degrees F |
257 |
220 |
| Melting Point – degrees F |
347 |
335 |
| Coef. of Linear Thermal Expansion |
6.8 x 10-5 |
5.4 x 10-5 |
| Water Absorption @ Saturation |
0.90 |
0.80 |
Material is available as both Acetal Copolymer or Acetal Homopolymer in Rod, Block, Sheet and Slabs.
Acetal is one of the most widely available plastics, especially on the West Coast (for some reason the East Coast seems to like the Nylon – Polyamide material more). Most commonly available in Natural (White) or Black, but can be produced in a wide range of colors with minimum orders. This enables material matching your product color or for easy identification of parts.
While these properties are similar, depending on your application, one material may be better suited than the other. Review our Delrin® Homopolymer and Acetal Copolymer page for additional information on the product availability and data sheets. We get calls for the premium Delrin® Homopolymer product, but some people may call it Delron, Delran, Delrun, Derlin and many other names, but it is still premium Delrin® Homopolymer Acetal to us.
Looking for other colors of Acetal Copolymer or Acetal Homopolymer Rod?
Contact us today for more information on Acetal Copolymer or premium Delrin® Homopolymer Acetal or any other plastic material.
Call us at 866-832-9315 or Email Us for more additional details
**Note: Delrin® is a registered Trademark of Dupont