Acetal Copolymer vs Dupont Delrin® Homopolymer: Properties and Benefits of Each
Industrial Plastic Supply, Inc. has been supplying a vast inventory of plastics to a wide customer base since 1975. Today, we put the spotlight on two products that are incredibly similar, but have key differences that result in each performing optimally in certain applications: the Acetal Copolymer and the Delrin® Homopolymer.
Both of these acetal materials are incredibly similar, with similar beneficial properties. They are both compliant with FDA, ITAR, and RoHS standards. Both are very stiff plastics with excellent dimensional stability in average environments. They are self-lubricating, easy to cut with standard tools, and abrasion and wear resistant. The major differences between them however are a result of their differing structures.
What Is Polyoxymethylene
Polyoxymethylene (also known as POM for short) is an important and commonly used engineering plastic material. There are two distinct types of POM; the first is Homopolymer Acetal and is commonly called Dupont Delrin®. The other is Copolymer Acetal and is referred to by the trade names Celcon®, Sustarin® C, Tecaform®, Ultraform®, Kepital® and many others. Both versions of POM are very popular thermoplastic materials. They both are commonly used for parts that need to be stiff, dimensionally stable and have low surface friction.
Delrin® Homopolymer
The homopolymer possesses much more regularity in its structure, with a repeated, crystalline pattern throughout the plastic. As a result of its strong, crystalline makeup, the Delrin® Homopolymer has superior physical properties, such as better fatigue and creep resistance, and bearing properties. Also, it has better short-term heat resistance compared to the acetal copolymer, with a much higher melting point.
However, this homopolymer does experience minor and inherent center-line porosity. This is basically a band area of tiny porous holes along the center of a rod or sheet. Depending on the severity of the porosity, these holes could weaken a finished part or cause other problems with its performance.
Acetal Copolymer
We’ve found that our customers tend to gravitate towards the acetal copolymer when they require a wider processing window, lower costs, and better long-term resistance to heat and alkaline environments. The acetal copolymer is not as crystalline in its structure, which causes it to not only have a generally lower melting point, but when incorporated with other materials, also increases the tolerance for high melting temperatures.
The less crystalline structure of the copolymer means that this plastic isn’t quite as strong. However, its mixed molecular structure has several benefits. The acetal copolymer has improved resistance to oxidation, improved chemical resistance, and much better long-term resistance to heat. That difference in chemical resistance is much more pronounced with exposure to hot water, especially chlorinated water. The acetal copolymer survives much longer than the homopolymer in these conditions.
Final Thoughts
Both the Acetal Copolymer and the Delrin® Homopolymer have their benefits. Depending on your application and requirements, you can choose the best acetal based plastic for your needs. In need of a supplier of plastics and plastic materials? Check out the rest of Industrial Plastic Supply today!
High Standards And Procurement From Reliable U.S. Manufacturers
Industrial Plastic Supply Inc. is ISO-9001:2015 certified. This benefits our customers since this certification communicates that we take quality and consistency seriously. We distinguish ourselves by providing Acetal Copolymer rods and sheets of exceptional quality over and over again so customers don’t have to wonder what they are getting when they do business with us.
American sourcing is another point of pride. In a time of global trade, a distributor may choose to do business with suppliers outside the U.S.. However, we believe that American quality and standards are top of the line. As such, our Acetal Copolymer is sourced from U.S. manufacturers. Our business partners – customers and vendors alike – can take pride knowing that their investments and dealings with Industrial Plastic Supply benefits U.S. customers, employees, and communities.
U.S. Sourcing Advantage
The benefit to customers in sourcing plastic from U.S. producers is more than patriotic or sentimental. Fact is, supply chains are more delicate than many of us imagine. Whether due to natural disasters, materials shortages, or politics, supply chains can fray and even snap. When that happens, price predictability and long-term supply/shipping agreements are thrown into disarray. Customers don’t want to hear excuses and “maybes” after they have signed contracts, paid money, and anticipate Acetal Copolymer products.
We pride ourselves on stocking and providing quality North American made Acetal Copolymer produced under the trade names: Tecaform® AH, Sustarin® C and ZL® 900. Each of these quality brand names are widely known for exceptional quality, consistency and durability.
Why Acetal Copolymer Is A Good Investment
Acetal Copolymer Performance Plastic
Acetal Copolymer is FDA compliant, opening up its use for food processing and packaging. The material is also stiff, resilient, and abrasion-resistant to a very high degree. Industrial Plastic Supply provides Acetal Copolymer materials in natural (white), black, and blue. Its stiffness and ability to hold shape under harsh conditions means that Acetal Copolymer sheets and rods can be shaped with standard cutting tools. This quality Copolymer Acetal material is FDA and NSF approved.
There are several special grades of Acetal that are formulated for tough food processing applications. Acetal Copolymer is available in a food grade blue for optical detection during food processing. This eliminates broken parts from getting into finished food products. There are also ultra detectable grades that are visual, x-ray and metal detectable for high end food processing applications. Contact us for more information on these special materials.
Automotive, Aerospace, and Medical Use
This plastic has exceptional ability to hold shape under stress, making it an excellent product in automotive and aerospace hardware. Gears, rollers, fuel lines, pumps and medical equipment all make use of Acetal Copolymer. However, care must be taken that the Acetal Copolymer is not exposed to temperatures above roughly 230 Fahrenheit (110 Celsius).
Safety Considerations
There are several factors to keep in mind when handling Acetal Copolymer:
Upon intense heating, Acetal Copolymer releases formaldehyde and carbon monoxide.
If machining or grinding, small Acetal Copolymer dust particles pose an inhalation and explosion hazard.
Prolonged exposure to UV light degrades Acetal Copolymer exposed surfaces and may change physical resilience.
Therefore, proper procedures must be taken when handling and machining this material. This is something Industrial Plastic Supply Inc. takes very seriously, not just for compliance reasons but also for the health and well being of our employees, customers, and ultimately the end-users.
Contact Industrial Plastic Supply for Acetal Copolymer
Industrial Plastic Supply Inc. is proud to be a distributor of Acetal Copolymer and other polymers. Contact us today for a quote and details about products, delivery, prices, and more. Call us @ 866-832-9315
The history of metals is thought to have begun with the use of copper about 11,000 years ago. Gold, silver, iron, lead, and even some brass began to be used before the first known appearance of bronze in the 5th millennium BCE
Artifacts made of smelted iron have been found dating from about 3000 BC in Egypt and Mesopotamia. In those times, iron was a ceremonial metal; it was far too expensive to be used in everyday life. Metals are commonly very stiff, tough and strong. However, they are also generally quite heavy. Also, the cost to heat metal to production temperatures is extremely high, over 5 times that of Performance Plastic materials. When metals corrode they get smaller, and many can decompose to yield rust.
In comparison, plastics only were first made in the early 1900’s. The world’s first known fully synthetic plastic was bakelite (now days considered Phenolic), and was invented in New York in 1907 by Leo Baekeland who coined the term ‘plastics’. Since this date, thousands of chemists and material scientists have synthesized dozens of plastic base materials. Plastic materials are currently available in over 80 types, and each of these are molded or processed at slightly different temperatures. The wide range of performance plastic materials will allow you to choose the perfect material for your next application.
Some of The Advantages of New Performance Plastic Materials
New Higher Temperature Performance Plastic Materials
New Performance Plastic materials like Victrex 450g PEEK and Sabic Ultem 1000 have much higher use temperatures over previous performance plastic materials. The Ultem 1000 unfilled has a continual use temperature above 400 degrees F, while the newer Victrex 450g PEEK materials work well at 480 degrees F on a continuous basis. In addition to the higher temperatures, they are still food grade materials.
Most plastic materials can typically be molded in a temperature range of 400 to 600 degree F. While steel starts to melt at 2,500 degrees F. This is five times the temperature, meaning it takes 5 times the energy to convert steel instead of plastic. Lower temperatures equates to lower costs of production.
New Lower Weight Materials
The average plastic weighs just 20% of the average metal product. Many plastics have exceptional weight to strength ratios, meaning that for the weight of the product they are very strong. This low weight means much less raw materials and less impact on the environment if using plastics over metals. This results in lower cost to manufacture parts from plastics over metal.
For instance, new UV grades of HDPE or High Density Polyethylene are very light, with a density of just .96, so light it floats in water. And yet, this new UV grade of HDPE is a workhorse in the plastic market, and is used to replace wood and metals in outdoor furniture.
New Detectable Materials For Food Contact Approved
Most Performance Plastic materials were engineered to be food contact compliant, and in most cases FDA approved for food contact. With the increase in food recalls, finding the proper materials to ensure that our foods are safe is imperative. Materials like Acetal Copolymer, Acetal Homopolymer, Nylon, Ultem 1000 and Victrex 450g PEEK are all FDA approved for direct food contact.
Which Performance Plastic Will Work The Best
Here are some new performance plastic material grades that include additives to make these materials detectable during food processing. These newly released detectable products include Tecaform AH UD (copolymer acetal base), Tecapeek UD Blue (PEEK based) and Hydex 4101 UD Blue PBT – Polyester base). Each of these new performance plastic materials comes in Blue color to be detected by color sensors during food processing. The “UD” portion allows these materials to be detected by X-Ray and Metal Detection scanners in food processing production lines. Using these new detectable performance plastic materials in food processing plants can help to eliminate food contamination issues and massive food recalls.
Recent Rising Costs Of Transportation
Changes in transportation rules and regulations since 2018 have made shipping raw materials significantly more expensive. Weight, size restrictions and surcharges for longer packages have more than doubled in the last year.
This has made one of the most expensive components of materials reaching the marketplace is transportation costs, and over the last several years the costs of moving materials across the country has skyrocketed. Metals are heavy, and this weight makes many items very expensive to transport.
Each step in the production of a finished good generally involves shipping to the next step. Raw material converted into base material, then base material converted into usable shape. Later this shape is turned into a component or part. Each time there is a conversion, there normally is shipping to the next processor. Metal weight can limit the amount of metal that can be moved at one time, where plastics can ship up to five times more product per truckload.
With performance plastics, often the conversion in small factories that can be located near final assembly of components limits the amount of shipping of plastic parts. Also, due to the light weight of plastics, trucks can hold up to five times the amount of plastic over metals for shipping. Many plastic parts are made very close to where they will be consumed, cutting logistics fees. This five times the weight also translates to five times higher cost to ship metals. This reduction of transportation costs moves more profit to the bottom line.
New Performance Plastic Materials Eliminate Need For Lubrication
Often, on large metal parts or assemblies, grease ports are added to make lubricating the metal parts easy. Metal on metal parts will wear out very quickly, and therefore require regular service and lubrication.
Newly released performance plastic materials have made lubrication obsolete. One such material is a new compounded Nylon material, called Nylatech PVM has FDA approved oil additives. This new Cast Nylon material runs well for extended periods without external lubrication. This material runs quieter and smoother than previously used metal parts due to a much lower coefficient of friction, and requires no regular maintenance.
Another new grade of Performance Plastic material that is rated as ‘self-lubricating’, and have excellent wear resistance is Lub-X UHMW, which now makes curves in bottling plants move smoother, quieter and require no lubrication. These long wearing and high strength materials outperform most other substrate for low cost, high performance, low weight and self lubrication.
Each of these plastic advantages yield cost savings and long product life. Along with these new areas of advantage, Performance Plastics are 100% recyclable, and can be reprocessed into high strength parts again and again. The plastic recycling industry is still in its infancy, and as it becomes more adept at recycling and reusing valuable plastic materials, our planet and our pocket books will benefit.
Gehr Plastics Announces Huge 24″ Diameter Acetal Rod
Gehr Plastics is an industry leader in large high performance plastic materials. They announced at this years IAPD Conference in San Diego, the new production of 24″ diameter (600mm) Natural Copolymer Acetal Rod.
Being an industry leader is more than making the largest material, it is also about making the best quality material. Gehr Plastics is ISO 9001 and ISO 14001 approved and certified, guaranteeing a consistently high quality product. The product line that Gehr Plastics produces is also quite large. The materials include: ABS, Acetal (POM-C and POM-H), HDPE, Kynar, Noryl, Nylon, PEEK, PEI, Polypropylene, Polysulfone, PPO, PVC (Type 1, Type 2 and CPVC), PVDF and Ultem materials. All of these materials are available in a wide range of sizes, and yes, some of the largest.
Gehr Plastics Long History
Gehr Plastics has been leading the industry in innovation since 1932, and is now in the third generation of family owned and operation. From the wide range of materials to the extremes in size range, this is cutting edge performance from a family run company. They also released a web-app for picking plastic materials, Gehr Plastic Selection Tool, and it is also available for mobile devices. This comparison tool compares not only plastics, but metals as well, for a great look at the best physical properties for an application.
While quality and size are keystones to excellence, Gehr Plastics is also interested in materials that the rest of the industry has not
Large Cast Nylon Type 6 Rod
considered. Over the last several years, Gehr has produced some PLA materials (made from plants) and even a Clear Nylon Rod for higher temperature sight-glass applications. These are just a few of the cutting edge areas that Gehr Plastics is leading in this industry.
Industrial Plastics is Master Distributor
Gehr Plastics materials are sold through a tight network of Master Distributors throughout the United States. Industrial Plastic Supply, Inc. of Anaheim, CA is proud to be one of the top selected suppliers of these innovative materials. Contact us for any of these high quality and wide size range materials, call us @ 866-832-9315 or send us a note here.
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:
General Property
ASTM Test
Typical Value Unfilled Homo-Polymer
Typical Value Unfilled Co-Polymer
Specific Gravity
D792
1.42
1.40
Tensile Strength Yield
D638
9,600 – 11,000
9,000 – 10,200
Tensile Modulus
D638
450,000
400,000
Izod Impact – Notched
D256
1.2
1.0
Hardness – Rockwell
D785
M94
M90
Deflection Temp @ 264psi
D648
257
220
Deflection Temp @ 66 psi
D648
347
335
Water Absorption @ 24 hrs
%
0.24
0.25
Co. Thermal Expansion
D696
6.83X10-5
5.4X10-5
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.
Please contact us for more details on these and other plastic materials. For a comparison chart of plastic materials click here: Plastic Materials Selection Guide
**Note: Delrin® is a registered Trademark of Dupont
