4a, a specialist in thin foams and micro sandwich materials for acoustic and lightweighting applications, produces hard foam sheets under the MILLIFOAM brand down to a thickness of 0.2 mm and combines them with metal skins to form ultra-thin CIMERA sandwich materials. 4a materials are designed to increase stiffness with no added weight, or to maintain stiffness whilst reducing weight and saving material across a range of markets from micro speakers in consumer electronics to ultra-light sports equipment.
NTPT and 4a began to work together earlier this year when 4a sought to increase the stiffness of the aluminium sandwich skins in materials for high-performance micro speakers typically used in mobile devices such as laptops, mobile phones and tablet computers. One of the main challenges for prepreg materials in these thin sandwich materials is maintaining uniformity of the carbon fibre layers, and this becomes an even more critical property as ply weights decrease. NTPT’s fibre spreading capability facilitates highly uniform UD prepreg tapes with areal weights as low as 15 gsm. The company reports that it was this thickness control, combined with its expertise with ultra-high modulus fibres (>300 GPa), that led to the development of a new CIMERA micro sandwich using a 20 gsm (0.02 mm thickness) prepreg and a total thickness lower than 0.2 mm.
The two companies can offer customers flat panel carbon fibre CIMERA micro sandwich laminates (direct from 4a) or a materials package of NTPT thin ply prepregs and MILLIFOAM cores for companies wanting to mould their own ultra-thin 3D sandwich components. TPT preforms, stacks of unidirectional prepreg plies laid down by machine at precise angles defined by NTPT engineers and the customers’ technical team, can also be used with 4a’s cores to improve accuracy and reduce mould draping time for lightweight sandwich parts.
“We were delighted when 4a manufacturing first approached us for help developing ultra-thin carbon fibre skins for their CIMERA sandwich materials,” comments James Austin, CEO at North Thin Ply Technology. “It’s a natural partnership to bring together the world leaders in thin ply prepreg and thin core technologies.”
Companies: North Thin Ply Technology