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.
Is HDPE Sheet and Acetal Homopolymer Sheet the same?
Here is another popular question asked by our clients. Is HDPE the same as Acetal Copolymer / Delrin Acetal Homopolymer? No, they are two totally different materials. Although the natural color of both is a milky white to opaque white, and they do look a bit similar, they are not. (HDPE is milky white to almost translucent depending on thickness, and the Acetal materials are a more opaque white to slightly milky – once again depending on thickness . See picture below of .500″ thick samples of HDPE and Acetal sheets)
HDPE and Acetal – Some Differences
The HDPE sheet and rod is a softer material, and is commonly known for its FDA certification and used in numerous food applications, such as: one gallon milk jugs, cutting boards, colored water glasses/cups, and many, many more. While it can be machined, because it is a bit softer and lighter, the tolerances it can be machined to are not very tight. It is not bondable, so it makes a great non-stick surface for sticky foods and adhesives.
The Acetal Copolymer and the premium Delrin® Acetal Homopolymer also have FDA certification, and are used heavily in the food processing industry. This material is a more mechanical material and is used in bearing and wear applications, cams, feeder screws, etc. This material is can be machined to tight tolerances, and will wear for long periods without lubrication. Due to its exceptional wear properties, it is not bondable, thus requiring mechanical fastening or threads to assemble. It has a very low water absorption, and you will find it in your toilet tank as the white moving parts in the filler mechanism. It is an extremely popular material for machinists, as it works much like soft brass.
While HDPE Sheet and Acetal Sheet look similar, they perform quite a bit differently.
While both materials are FDA approved, are machinable and can be used to make rigid wear resistant parts, they are two different resins and have drastically different physical properties. Another major difference is in the weight of these items, HDPE sheet and rod material weighs about 35% less than the Acetal sheet and rod material. Please check the data sheets for more information to assist in proper material selection.Acetal Data Sheet and HDPE Sheet Data
Acetal is commonly known as: Delrin Homopolymer Acetal, Tecaform AH,Ensital, Unital, Pomalux, Ultraform and many more.
HDPE is also known as: Ultraethylux,Densetec, Polystone G, Fortiflex, Versadur, Hostalen, and many more.
Contact us for more details on the HDPE and Acetal families of plastic materials, e-mail us or call 866-832-9315 Topic: HDPE sheet and Delrin Sheet (Acetal Sheet)
Acetal Copolymer and ABS (Acrylonitrile-Butadiene-Stryene) have some similar properties but are really very different materials. They similarities are: high impact strength, ease of machining with standard cutting tools and good mechanical properties. They are also both FDA compliant and are both good substitutes for brass. They also have great water absorption resistance and good electrical properties. Both materials are good for some of the same applications but certainly not all. Listed below are some of the major differences.
ABS Sheet and Rod Information
ABS comes as Natural (straw) and Black color in Plate, Slab, Sheets and Rods, and thin sheet (.040″ – .250″) it is available as White or Black with a textured surface one side. It can be cut from 48″ X 96″ sheets into strip, panels or pieces.
ABS is formable. ABS is a great thermo-formable material while Acetal is not. Acetal is used more for machined parts such as gears and screws. ABS is great for molding and shaping parts from vacuum to heat forming. Excellent for model building and prototype projects.
ABS is easily bondable (similar to PVC). ABS can be bonded or welded to itself. Because Acetal is self lubricating, it is not possible for anything to stick to it unless etching is done – therefor it is not bondable.
ABS is a great material for painting and silk screening. While Acetal can not be painted or silk screened unless it has undergone Corona Treating (a flame surface treatment), but if treated will nice paint or screened surface.
ABS has better chemical resistance than Acetals. Both are attacked by acids like sulfuric, but ABS has a wider range of resistance to chemicals like aqueous acids, alkaline and alcohol. Acetal will degrade when exposed to such chemicals as chlorine and alkaline.
Specialty grades of ABS are available, including: Glass Filled, Static Dissipating, and Fire Retardant Grades (like Royalite – R59)
ABS Typical Properties Table
General Property
ASTM Test
Value
Specific Gravity
D7921
1.08 – 1.25
Tensile Strength
Yield D638
4,100
Izod Impact – Notched
D256
7.7
Hardness – Rockwell
D785
R105
Deflection Temp @ 264psi
D648
177
Co. Thermal Expansion
D696
5.3X10-54.6 -5.5X10-5
Acetal Copolymer and Homopolymer Sheet and Rod Information
ABS Resin Structure
Acetal is the better machining plastic, considered the best machining plastic material. Because of its durability and wear resistance, Acetal is an excellent choice for producing a wide variety of parts that require high wear resistance over a wide period of time. When machining to tight and specific tolerances, Acetal is ideal.
Acetal has low co-efficient of friction. Due to its self lubricating properties, it is a great material for sliding and wear applications. This material provides years of maintenance free bushings and bearings.
Acetal sheet is produced from .062″ – over 6″ thick and sheet sizes of up to 48″ X 120″ as standard. The standard color for Acetal and Delrin is Natural (a deep milky white) and Black. Some colors are available as Medical Grade, and can be obtained in limited sizes. These sheet are available cut to: slabs, blocks, plates, slabs and blocks.
Acetal (Polyoxymethylene) can be both a homopolymer and a copolymer. The homopolymer acetal has a repeating chain of one atom while the Acetal copolymer has two atoms forming a repeating chain. Dupont™ Delrin® is a popular acetal homopolymer brand name and the most commonly used acetal homopolymer.
Acetal – Delrin Properties Table
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
ABS and Acetal – Similar, but very different materials
Both of these materials possess excellent qualities and have a wide range of different uses. Acetal is great for machining, while ABS is great for forming and bonding. They both can be used for machined parts and are great choices for food contact and electrical applications. These two materials are both strong and durable plastics, but one might be better than the other for a specific job. When picking the right plastic, it is important to compare plastics and their specific properties to make sure the material won’t fail and that your job will be successful.
Contact us for additional information, call us at 866-832-9315 or contact us here. Consider Industrial Plastic Supply for all your plastic needs, we want to be your go-to plastic supplier.
**Note: Delrin® is a registered Trademark of Dupont
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