25 September 2018
25 September 2018
Sumitomo Chemical reports that its polyethersulfone (PES) micro-powder additive SumikaExcel 5003P boosts fracture toughness and resistance to micro-cracking for fibre reinforced epoxy composites over a broad temperature range without negatively impacting dimensional stability, flame/smoke/toxicity (FST), creep resistance, modulus, impact, or yield strength.
The company says that functional additive is widely used by the aerospace industry for prepreg and resin transfer moulded carbon fibre reinforced epoxy, is gaining ground in automotive, and could also be used for high-performance sporting goods. The material is produced by Sumitomo Chemical, Tokyo, Japan, and sold in North America by Sumitomo Chemical Advanced Technologies, Phoenix, Arizona, US, which will exhibit for the first time at CAMX 2018, 16-18 October in Dallas.
PES is an amorphous engineering thermoplastic known for its high temperature capabilities, high strength and impact resistance, excellent creep resistance at elevated temperatures and loads, very good dimensional stability, low coefficient of linear thermal expansion (CLTE) over a broad temperature range, inherent flame retardance, low smoke, minimal outgasing, good chemical resistance, and resistance to hot water (to 180oC). It is offered pelletised for injection moulding, extrusion and film processes and in powder form for cast films, filtration membranes, and as an epoxy additive for composites, high-temperature paints and coatings, and adhesives.
PES grades are used in the aerospace, automotive, electrical/electronics, medical device and food handling industries. In its role as a functional additive for epoxy composites, specific grades with hydroxyl (-OH) end groups are used. The end groups react with glycidyl groups on the epoxy matrix to form a cross-linked, interpenetrating polymer network (IPN). Even though the additive is typically used at low let down ratios of 2-12 wt%, it adds greater flexibility to the IPN, which in turn boosts the toughness of the epoxy composite. SumikaExcel 5003P has a glass transition temperature (Tg) of 230oC, which is higher than that typical of aerospace-grade epoxy resins (120-200oC), and since it also has good stiffness and strength, it improves impact and crack resistance without compromising other thermo-mechanical properties. Especially important for aerospace applications, it does all this without affecting FST or the ability to mould and hold very tight tolerances. Although it is most commonly used with high-performance carbon fibre reinforced epoxy composites, it is said to be equally effective in glass or basalt reinforced epoxy composites.
Sumitomo Chemical maintains dedicated PES polymerisation facilities in Chiba and Ehime, Japan, and a dedicated micro-level powder grinding facility in Phoenix, Arizona, US. This eliminates the possibility of cross-contamination with other polymers – a critical and highly enforced requirement in the aerospace industry – and also simplifies the supply chain for processors and OEMs. Powders as fine as 30 mm and as large as 500 mm are produced at the Phoenix facility using rotary-classifier grinding mills, which are more efficient and accurate than conventional grinding units. Laser-diffraction characterisation equipment is used to measure particle size in both incoming feedstock and outgoing finished powder, and an inductively coupled plasma device checks every lot for metals before and after grinding operations to ensure that the product meets specification requirements. SumikaExcel 5003P is typically supplied in 15 kg bags and 600 kg supersacks, although custom packaging is available upon request.
Sumitomo Chemical Advanced Technologies will exhibit at CAMX 2018 in booth G86 and will have information about SumikaExcel micro-powder additive as well as its other families of high-performance engineering thermoplastics, including SumikaSuper liquid crystal polymer (LCP) and Sumiploy polymer alloys, on display.
Photo provided by Sumitomo Chemical Advanced Technologies
Chomarat is developing its Coatings & Films business at its French sites. The Group has just acquired an extruder and a graining line to increase its production capacities and develop new, more efficient solutions, particularly in the field of TPO (polyolefin thermoplastics).
Group Rhodes, through its Rhodes Interform business, has developed a revolutionary new process that enables large monocoque components, particularly those produced by super plastic forming (SPF) from very thin material, to more accurately retain their shape on cooling.
A 3D-permeability measurement bench that provides accurate data and fast processing of samples has been added to a stable of high-performing equipment at the AMRC Composite Centre thanks to the support of funding from the Aerospace Technology Institute (ATI).