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About Harvest Suppliers Products Applications Processing News Contacts |
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Like all TPE's they combine the process properties of thermoplastics with the performance properties of vulcanised rubber. The versatility of Dryflex and Elastron SBS and SEBS compounds stems from its unique molecular structure as a block co-polymer. The key characteristic is the tri-block structure, where the structure of the mid block determines the difference between the various styrene-based grades: Thus: SBS - Poly [styrene-(block)- butadiene-(block)-styrene] and: SEBS- Poly [styrene-(block)-ethene-co-butane-(block)-styrene] or more usually, Poly[styrene-(block)-ethylene-butadiene-(block)-styrene]
In both cases the two end blocks consist of polystyrene domains and are hard at room temperature but flow under heat, as they soften. These domains act as the physical cross-links with the mid block to form a highly elastic continuous rubber network. At room temperature this mid block is soft and elastic. The range of hardness can be 5A to 50D Dryflex and Elastron SBS and SEBS compounds consists of a mixture of various polymers and a multitude of additives blended in a highly complex compounding process. The result of this technology is a family of TPE compounds with an enormous range of property combinations suited to a spectrum of applications. The Dryflex S series of compounds contains more than 250 grades specially formulated in 5 Shore steps with or without fillers, to meet the most precise requirements. The Elastron D and Elastron G series of compounds comprise almost 1000 different grades fine tuned for specific applications The higher hardness Dryflex grades have higher tensile strength, and even the lower softness grades have low compression set. Operating temperatures for Dryflex are between -50 degrees C and +150 Degrees C. Dryflex and Elastron are naturally opaque white, but are also available in translucent and transparent grades. A wide variety of fillers are possible All methods of thermoplastic process are suitable for Dryflex and Elastron and their special characteristics make them especially suitable for over-moulding or co-extrusion with many other polymers.
Dryflex 1234567 The first figure shows the basic material type:  2-EPM
or EPDM 3-Modified SBS 4-SBS 5-SEBS unfilled 6-SEBS
filled 7-SEBSand SBS blends 8&9-customer specificeach of these is referred to as the "400series" or "600series" The second figure shows the Shore hardness scale or other characteristics: 0-ShoreA 2-ShoreD 4-Increased
flexibility in Shore A 5-Increased
temperature stability in Shore A 6-semi-filled
SEBS in Shore AThe third figure shows the colour/additive: 0-natural or translucent 1-grey 2-black 3-antislip
agent 4-blue5-white6-brown7-green8-red9-yellowThe 4th and 5th figure denote the actual hardness numerically The 6th figure is a serial number The 7th figure denotes a product family S- standard grade -
NB some older grades do not carry this "S"designationAdhesion/over-moulding
gradesExample Dryflex 660650S is a semi-filled SEBS grade Shore A 65 Natural and Dryflex 602550S is a filled SEBS grade Shore A 55 Black
Contact Harvest Polymers direct for further information on the Dryflex and Elastron Range
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