2021

ArticlesFeaturedSilicone & Medical

Low density liquid silicone enhances recycling

Dow announced the general availability of its first low density LSR for injection molding as part of its Silastic line, and the LSR is initially available to brand owners and formulators in Europe and North America. The material’s properties make it a favorable option, particularly for food dosing valves, closures, dispensers, seals, gaskets and other food contact applications

Read More
ArticlesExtrusionFeatured

Medical tubing process and die optimization, part 1: Troubleshooting and fine tuning

An extrusion die is a purpose built tool designed by cutting shapes in plates to reflect an intended extruded rubber product. In advance of an extrusion project, a process engineer designs the die according to specifications of the project and those of the customer, and installs it on an extruder. Often, an extrusion die is made from hard metal, like steel, polished and with sharp edges. Once all plates of the mold or die are created, rubber is forced through them under high pressure in a high temperature zone

Read More
ArticlesExtrusionFeatured

New developments in polymer science lead to ultra low density closed cell EPDM sponge extrusion

It has long been established that unvulcanized solid elastomer compounds can be expanded to sponge forms by the incorporation into the formulation of thermally activated gas releasing chemicals known as blowing agents. During controlled heating of the compound, there is molecular dissociation of these blowing agents, and this is often designed to occur in conjunction with the onset of vulcanization of the compound, enabling the production of a range of sponge structures.

Read More
ArticlesExtrusionFeatured

Development of an enabling EPDM polymer to improve performance and processability of EPDM compounds

Royalene EPDM, a terpolymer of ethylene, propylene and a
non-conjugated diene, is one of the most versatile specialty
elastomers in commercial use today. The main attributes of
EPDM are its outstanding resistance to oxidation, ozone and
the effects of weathering. It is also highly extendable, allowing
high levels of fillers and plasticizers to be added, while still
maintaining good physical properties

Read More
ArticlesFeatured

Ultra high Mooney branched EPDM: Easy to process high filler loading compounds

many EPDM grades are still produced using conventional Ziegler-Natta catalysts, molecular catalysts for EPDM production have been adopted readily and have grown rapidly. Dow has introduced its Advanced Molecular Catalyst (AMC) technology as a new benchmark in the EPDM industry by enabling even higher process sustainability and catalyst efficiency

Read More
ArticlesFeatured

Diamine cured HNBR for improved long term compression set on thin sectioned articles

HNBR is rated for continuous use at temperatures from125°C to 150°C, depending on several compounding factors, with the choice of cure system being one of the most critical. While a sulfur cure can provide flex fatigue and high tensile properties, it does not have high temperature stability. Peroxide cured HNBR is the only suitable cure system for long term, 150°C temperature resistance. Peroxide cured HNBR also provides high modulus and low compression set, making it an ideal material for sealing applications. HNBR is the sealing material of choice in many automotive and oil well applications where high mechanical strength is needed, in addition to high temperature and chemical resistance

Read More
ArticlesFeatured

Damping materials based on liquid poly(butadienes): Structure-property relationships

Liquid poly(butadiene) resins can be defined as oligomers with a degree of polymerization (Dp) of 100 and molecular weights below the critical molecular weight. These materials have rheology defined as viscous flow at temperatures of less than 60°C. In this regime, properties such as glass transition temperature and viscosity are determined by both microstructure and macrostructure. In applications such as adhesives, thermoplastic modification or tire compounding, liquid poly(butadienes) are often used as high value additives, imparting specific performance enhancement

Read More
ArticlesFeatured

Recycled polypropylene modified with hydrogenated styrenic block copolymers for automotive applications

Polypropylene (PP) is one of the most widely used polyolefins owing to its low density, low cost, high softening temperature and easy processing. PP is used in the form of molded pieces, sheets, films and fibers in medical, cosmetic and electronic applications. In the automotive industry, it represents 9% of the market, and is used in dashboards, door panels, bumpers and grilles. PP based composites are increasingly becoming preferred materials in automotive applications, and in particular for both exterior and interior parts. In the automotive industry, PP based composites are generally used for the manufacture of bumpers.

Read More