Millathane E40 is a sulfur or peroxide curable polyether polyurethane rubber for the production of rollers, belts seals, gaskets, and other molded parts which require excellent abrasion resistance, low temperature performance, hydrolytic stability and high mechanical strength.
Millathane E40 is processed by techniques that are common to the rubber industry. Compounds can be mixed on an open mill or in an internal mixer. Millathane E40 has been designed not to crystallize at ambient temperatures, which allows mixing “right out of the box”. Due to the toughness of E40, a two-pass mix using an internal mixer is recommended. Very often a masterbatch can be mixed and followed by addition of curatives on a two-roll mill. Molded articles can be produced through compression, transfer or injection molding. Injection molding Millathane E40 provides very short cycle times, excellent flow and de-molding. Millathane E40 can be cured in steam autoclaves (protected from direct contact with the steam) and is suitable for large roller, hose or belting applications. Calendered sheets can be press-cured or rotational-cured.
Compound design of Millathane E40 follows the typical pattern of formulating for oil resistant polymers. Reinforcing fillers like carbon black or fumed silica increase the mechanical strength. Sulfur cure is accomplished with the use of MBTS, MBT zinc stearate and Thanecure® ZM. A variety of dialkyl peroxides like dicumyl peroxide, t-butyl cumyl peroxide, 2, 5-dimethyl-2,5-di (t-butylperoxy) hexane etc. can be used as vulcanization chemicals. The use of co-agents like triallylcyanurate (TAC) results in a very high crosslinking density and improves the compression set. Adding various plasticizers and softeners, especially coumarone indene resins and TP-95 (DBEEA: Dibutoxyethoxyethyl adipate), improve processibility.
TYPICAL POLYMER PROPERTIES
|Chemical type||Polyether polyurethane|
|Color||Pale amber to dark|
|Physical form||Solid bale or milled sheets|
|Solid bale*:||38 lb (17.2 kg) carton|
|Premilled sheets*||50 lb. (22.7 kg) carton|
|*Bale wrap||Strippable film (not meant to be incorporated into the compound)|
35 – 55
|Storage stability||3 years when stored under dry and cool conditions|
TYPICAL COMPOUND PROPERTIES
|Hardness range||45 to 90 A|
|Tensile strength||Up to 4500+ psi, (31+ MPa)|
|Tear strength||Up to 490 lb/in (86 kN/m)|
|Heat aging||Fair/Good (100ºC)|
|Hydrolysis resistance||Very Good|
|Oil & fuel resistance||Good/Very Good|
|Low temperature||-48º C brittle point|
|Resilience||Up to 55%|
Vulcanizates based on Millathane E40 offer a very good abrasion resistance, excellent low temperature properties, excellent hydrolytic stability, high mechanical strength and outstanding dynamic properties. Millathane E40 maintains its properties nearly unchanged over a wide range of temperatures and makes it a perfect choice for rollers seals, gaskets, CV-boots, dust covers, mounts and bearings for the automotive industry and for many other hydraulic or pneumatic applications. It is particularly suited for production of injection molded rollers for office machines due to its ability to bond to metal shafts.
Compounds based on Millathane E40 can be vulcanized at temperatures between 140 - 165ºC, depending on the cure system and the thickness of the part.
(See the Millathane Formulary for other compound examples)
|Press Cure 7'/160ºC|
|100% Modulus, psi (MPa)||455 (3.1)|
|300% Modulus, psi (MPa)||1670 (11.5)|
|Tensile Strength, psi (MPa)||3680 (25).4|
|Tear Die C, lb/in (kN/m)||237 (41.5)|
|Tear Die B, lb/in (kN/m)||392 (68.6)|
|DIN Abrasion, mm³ loss||66|
|Compression set, 22 hr/70ºC, %||37|