Acetal provides high strength and stiffness coupled with enhanced dimensional stability and ease of machining. As a semi-crystalline material, acetal is also characterized by a low coefficient of friction and good wear properties -- especially in wet environments.
Because acetal absorbs minimal amounts of moisture, its physical properties remain constant in a variety of environments. Low moisture absorption results in excellent dimensional stability for close-tolerance machined parts. In high moisture or submerged applications, acetal bearings outperform nylon 4 to 1. Acetal is ideally suited for close tolerance mechanical parts and electrical insulators which require strength and stiffness. It also offers resistance to a wide range of chemicals including many solvents.
Mitsubishi Chemical Advanced Materials offers both homopolymer and copolymer grades of acetal including enhanced bearing grade materials. Acetron® GP acetal is porosity-free and offered as our standard general purpose grade. For slightly higher mechanical properties, we offer a broad size range of the homopolymer acetal (Delrin®) products. For improved frictional properties PTFE-enhanced Delrin AF products are available.
Acetron® GP is Mitsubishi Chemical Advanced Materials's general purpose copolymer acetal and is the only porosity-free acetal product available today. Investments in process technology by Mitsubishi Chemical Advanced Materials now provide the performance and machinability of acetal without center core porosity. Our in-line photometric quality procedure assures every plate and rod is porosity-free as measured by Mitsubishi Chemical Advanced Materials's dye penetrant test making it the preferred acetal for food contact and medical applications. Acetron® GP natural is FDA, USDA, NSF, Canada AG and 3A-Dairy compliant.
Porosity-free Acetron® GP acetal is intricately fabricated into this electrical test part with dozens of tight tolerance machined holes required at its centerline. (Prior material: Standard Acetal)
Acetron® GP maintains tight tolerances despite environmental and clean in place chemical exposure on dairy equipment. (Prior materials: Bronze, Stainless Steel)
Guide rollers machined from Acetron® GP rod operate smoothly and reliably in lift gate systems used to load cargo onto truck beds. (Prior materials: Cast Iron, Cast Aluminum)
Acetron® AF Blend is a unique thermoplastic material for use in moving parts in which low friction and long wear life are important. It is a combination of PTFE fibers uniformly dispersed in Delrin acetal resin. This combination offers better wear characteristics than unfilled Delrin.
Acetron® Blend POM-H, supplied as a 2:1 blend of PTFE filled POM-H and virgin POM-H resins, has excellent sliding/friction properties. Bearings made of Acetron® AF Blend can operate at higher speeds while exhibiting reduced wear. These bearings are also essentially free of slip-stick behavior because the static and dynamic coefficient of friction are closer than with most plastics.
Acetron® AF Blend retains 90% of the strength that is inherent in unmodified Delrin acetal. Some properties are changed due to the addition of the softer PTFE fiber. The natural color of Acetron® AF Blend is dark brown.
Consider Ertalyte® TX. This variation contains a solid lubricant which gives it a lower coefficient of friction. Ertalyte® TX will last nearly two times as long as the Acetron® AF Blend. For more information, continue here, and choose the Ertalyte® TX tab.
Acetron LSG (POM-C) stock shapes are produced from selected batches of polyacetal copolymer resin. This engineering plastic combines good mechanical strength, stiffness, impact strength, chemical resistance, dimensional stability and friction and wear properties with an excellent machinability. The compositions of the resins used for the production of the Acetron LSG stock shapes comply with the regulations that apply in the Member States of the European Union (Directive 2002/72/EC, as amended) and in the United States of America (FDA) for plastic materials and articles intended to come into contact with foodstuffs. Acetron LSG stock shapes have also been successfully type tested for their compliance with ISO 10993-1 guideline requirements for Biocompatibility Testing of Materials, and they come with full traceability from resin to stock shape. These features, added to the availability of different colors (natural / black / yellow / red / blue / green / brown) which allow for easy differentiation between similar parts (e.g. different sizes of trial implants), make Acetron LSG stock shapes very suitable for applications in the medical, pharmaceutical and biotechnology markets.
This copolymer acetal grade, containing a metal detectable additive, has been specifically tailored for use in the food processing and packaging industries where it can easily be traced by the conventional metal detection systems installed to detect contamination of the foodstuffs (results may vary depending on the sensitivity of the metal detection system used). Acetron MD presents good mechanical strength, stiffness and impact strength, and it also features a food contact compliant composition.
Acetron POM-H Delrin is a homopolymer acetal, manufactured and stocked in rod and plate. It offers slightly higher mechanical properties than Acetron® GP Acetal, but may contain a low-density center, especially in larger cross-sections. Copolymer acetal also offers better chemical resistance than homopolymer acetal. Delrin is ideal for small diameter, thin-walled bushings that benefit from the additional strength and rigidity of homopolymer acetal.
Delrin* acetal delivers outstanding fatigue and impact resistance in this continuously loaded structural keel for a prosthetic device. (Prior materials: Nylon, Elastomer)
Unblended Delrin AF, offers a slightly higher limiting PV and lower coefficient of friction due to additional PTFE content. This added PTFE typically decreases the wear capability and impact strength. Delrin AF 100 is available on a custom basis.
|Acetal||Wear Factor "k" (1)||Comparative Wear Rate to Acetron NS||Coefficient of Friction Static (2)||Coefficient of Friction Dynamic (3)||Limiting PV (4)|
|Delrin AF Blend||57||1.2||.18-.19||.19-.20||8.300|
|Delrin 500CL (a)||176||3.7||.22-.24||.23-.25||3,500|
In general, acetals do not perform as well in abrasive wear applications as nylons. Compensation for moisture related growth generally allows Nylatron® nylons to be used for wet, abrasive applications. If your application requires dimensional consistency in an abrasive, high humidity or submerged environment, Ertalyte® PET-P will often offer improved performance.