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)
Delrin 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.
Delrin AF Blend, supplied as a 2:1 blend of Delrin AF100 and Delrin 150 resins, has excellent sliding/friction properties. Bearings made of Delrin 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.
Delrin 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 Delrin AF Blend is dark brown.
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 isa homopolymer acetal, that is 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.
Acetron POM-H Delrin* delivers outstanding fatigue and impact resistance in this continuously loaded structural keel for a prosthetic device. (Prior materials: Nylon, Elastomer)
Ertacetal® C ELS is Mitsubishi Chemical Advanced Materials's copolymer conductive acetal grade. This grade is specifically developed for the use in applications where the characteristics of POM C are required, but with the added benefit of good electrical conductivity, such as in electrical applications and explosion sensitive areas; for ATEX cases, the conductivity shall be <109 Ohm (surface resistivity measurement).
Mitsubishi Chemical Advanced Materials has developed this specific laser-writable Ertacetal® product since the standard POM-C natural grade does not show markings with common laser technologies (e.g. IR-YAG, UV-YAG).
Instead, the surface of standard POM-C just experiences burning but no visible dark marking.
The new product shows identical physical properties and machinability as Mitsubishi Chemical Advanced Materials’s standard Ertacetal® C natural [POM-C] product and is available in a bright-white, less transparent colour.
Ertacetal® C LQ POM-C is processed by extrusion technology.
It is available in the form of plates in dimension of 10 – 60 x 610 x 3000 mm.
Stock items are available in the form of sheets in 20 and 25 mm thickness.
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.