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Wire sheet puts strength behind reinforced plastic parts
material are reported. The material was made b y casting plasticized e p o x y polymer around circular inclusions of the same hard cold-setting epoxy resin and was investigated by the technique of photoelasticity. F o r an array of inclusions in triangular pattern the stress distribution was found to vary with the elastic moduli of b o t h phases while for the isolated inclusion there was only a slight degree of dependence. (70/4/150)
Spray-up scheme for low cost emergency housing Winfield, G. Reinforced Plastics, 1Ioi 14, No 12, p 350 (August 1970) A system for low cost emergency shelters of flame retardant, weatherproof, glass fibre reinforced polyester is described as being of great use since in emergencies the otherwise restrictive clauses in building codes with regard to the use of plastics may be by-passed. Although there may be both psychological and sociological barriers to the acceptance of these buildings their versatility, low cost and durability should help to overcome them. (70/4/151)
Toughening thermosets with liquid butadiene/acrylonitrile polymers Rowe, E. H., Siebert, A. R. and Drake, R. S. Modern Plastics, Vol 47, No 8, pp 110 - 117 (August 1970) Fracture energy of e p o x y resin systems is increased by incorporation of liquid carboxyl-terminated butadiene/acrylonitrile copolymers. The molecular weight of the liquid polymer and the average size of the precipitated particles are of less importance than the acrylonitrile content. The optimum acrylonitrile content is in the range 12 - 18%. Five parts per hundred of the commercially available Hycar CTBN increases the fracture energy of DGEBA-type e p o x y resins by a factor of about 15. This information is of great importance in considering the toughness of CFRP. (70[4/152)
Understanding material
CFRP
as
a
design
Pearce, D. G. Fibre Science and Technology, Vol 3, No 2, p 1 2 9 (October 19 70) The interactions of resins and fibres and the effects on the properties of composites are examined from the point of view of the designer and a brief review of carbon fibre properties is followed by a survey of composite properties and the effects of fibre variables on them. The importance of
388
COMPOSITESDecember 1970
the anisotropy of such materials in the design of components is noted and there are short sections on fatigue, impact, friction and electrical and thermal properties of composites. It is pointed out that although a composite with ½% elastic strain followed by failure may seem alarming to the designer the elastic strain ie UTS/ Young's modulus for metals is actually less than this value. (70/4/153)
What processing does to reinforced thermoset molding compounds Hoffman, K. R. and Vellturo, J. W. Plastics Technology, 1Iol 16, No 8, p 50 (August 1970) The results of a study of moulding techniques on glass and mineral filled thermosetting resins are described and it is noted that the screw moulding process imparts a very favourable fibre directionality. It appears that fibres of about ~ in in length give the optimum mechanical properties and this thought to be due to their ability to flow and yet maintain integrity and to reorientate themselves under the applied stresses. (70/4/154)
Structures Cellophane webs: key to reinforced panel production Plastics Technology, Vol 16, No 9, p 73 A series of annotated photographs is used to explain how cellophane with its good release properties, dimensional stability and freedom from defects is used to contain polyester/ glass fibre compositions. The use of cellophane on both the continuous and press moulding lines of the Reichold Chemical plant is described. (70/5/18)
Laminates and bondings: manufacture, properties, uses Bergs, H. Textil Praxis International No 2, pp 31 - 33 (1970)
resin from which it is suggested that unique composites may be made are discussed. It is suggested that liquid urethanes are excellent media for introducing polycarbonates, nylon, ABS, acrylics and poly(vinyl fluoride) which may be then welded to woven glass fibres to give many new thermoplastics. Resin properties and properties of resin/glass laminates are tabulated and the article concludes with a short question and answer section on urethane laminates. (70/5120)
Vapour permeability of various composite layers in wall construction Zhukov, A. V., Kazkuk, K. V. and Spektor, B. V. Glass and Ceramics, Vol 26, Nos i - 2 pp 103 - 105 (January/ February 1969} The equilibrium moisture content and distribution, its relation to permeability, and the effect of vitrification on the permeability of various layer composite tiles were investigated. Single, double and triple layer tiles of ceramic, mortar and light weight concrete were used. The moisture content was found to be greatest for double or triple layer specimens having a facing of minimum permeability (glazed). Thus, although their vapour permeability is low, such layer tiles are less efficient heat insulators, and the former property should not therefore be used as the only criterion for evaluating their suitability for wail construction. (70/5/21)
Wire sheet puts strength behind reinforced plastic parts Jaray, F. F. The Engineer, p 53 (24 September 1970) The manufacturing techniques, applications and properties of laminate which employs hard drawn steel wire as the reinforcing medium are briefly reviewed. It is said that practical difficulties of the incorporation of such wires into a plastic matrix have been largely overcome by the use of a wire sheet of 0.01 in patented wires on a suitable sub-base and that strength for strength laminates are more economical than glass fibre laminates.
A condensed account is given of the present technical position in the manufacture and use of bonded and laminated fabrics. Various machines and processes are described, including a novel method of bonding fabrics by use of a polythene foil net which is heated at 175°C for 15 s between the layers, giving bonding at an array of points only. (70/5/19)
General
Urethane laminates Delmonte, J. Reinforced Plastics, Vol 14, No 13, p 382 (September 1970)
Carbon fibre man weighs up Europe's big market Mortimer, J. The Engineer, Vol 231, No 5972, p 22 (9July 1970)
The properties of Uralane 5716 A/B a room temperature curing urethane
The scope for the application and production of carbon fibres and of
(7015/22)
Spray-up scheme for low cost emergency housing Winfield, G. Reinforced Plastics, 1Ioi 14, No 12, p 350 (August 1970) A system for low cost emergency shelters of flame retardant, weatherproof, glass fibre reinforced polyester is described as being of great use since in emergencies the otherwise restrictive clauses in building codes with regard to the use of plastics may be by-passed. Although there may be both psychological and sociological barriers to the acceptance of these buildings their versatility, low cost and durability should help to overcome them. (70/4/151)
Toughening thermosets with liquid butadiene/acrylonitrile polymers Rowe, E. H., Siebert, A. R. and Drake, R. S. Modern Plastics, Vol 47, No 8, pp 110 - 117 (August 1970) Fracture energy of e p o x y resin systems is increased by incorporation of liquid carboxyl-terminated butadiene/acrylonitrile copolymers. The molecular weight of the liquid polymer and the average size of the precipitated particles are of less importance than the acrylonitrile content. The optimum acrylonitrile content is in the range 12 - 18%. Five parts per hundred of the commercially available Hycar CTBN increases the fracture energy of DGEBA-type e p o x y resins by a factor of about 15. This information is of great importance in considering the toughness of CFRP. (70[4/152)
Understanding material
CFRP
as
a
design
Pearce, D. G. Fibre Science and Technology, Vol 3, No 2, p 1 2 9 (October 19 70) The interactions of resins and fibres and the effects on the properties of composites are examined from the point of view of the designer and a brief review of carbon fibre properties is followed by a survey of composite properties and the effects of fibre variables on them. The importance of
388
COMPOSITESDecember 1970
the anisotropy of such materials in the design of components is noted and there are short sections on fatigue, impact, friction and electrical and thermal properties of composites. It is pointed out that although a composite with ½% elastic strain followed by failure may seem alarming to the designer the elastic strain ie UTS/ Young's modulus for metals is actually less than this value. (70/4/153)
What processing does to reinforced thermoset molding compounds Hoffman, K. R. and Vellturo, J. W. Plastics Technology, 1Iol 16, No 8, p 50 (August 1970) The results of a study of moulding techniques on glass and mineral filled thermosetting resins are described and it is noted that the screw moulding process imparts a very favourable fibre directionality. It appears that fibres of about ~ in in length give the optimum mechanical properties and this thought to be due to their ability to flow and yet maintain integrity and to reorientate themselves under the applied stresses. (70/4/154)
Structures Cellophane webs: key to reinforced panel production Plastics Technology, Vol 16, No 9, p 73 A series of annotated photographs is used to explain how cellophane with its good release properties, dimensional stability and freedom from defects is used to contain polyester/ glass fibre compositions. The use of cellophane on both the continuous and press moulding lines of the Reichold Chemical plant is described. (70/5/18)
Laminates and bondings: manufacture, properties, uses Bergs, H. Textil Praxis International No 2, pp 31 - 33 (1970)
resin from which it is suggested that unique composites may be made are discussed. It is suggested that liquid urethanes are excellent media for introducing polycarbonates, nylon, ABS, acrylics and poly(vinyl fluoride) which may be then welded to woven glass fibres to give many new thermoplastics. Resin properties and properties of resin/glass laminates are tabulated and the article concludes with a short question and answer section on urethane laminates. (70/5120)
Vapour permeability of various composite layers in wall construction Zhukov, A. V., Kazkuk, K. V. and Spektor, B. V. Glass and Ceramics, Vol 26, Nos i - 2 pp 103 - 105 (January/ February 1969} The equilibrium moisture content and distribution, its relation to permeability, and the effect of vitrification on the permeability of various layer composite tiles were investigated. Single, double and triple layer tiles of ceramic, mortar and light weight concrete were used. The moisture content was found to be greatest for double or triple layer specimens having a facing of minimum permeability (glazed). Thus, although their vapour permeability is low, such layer tiles are less efficient heat insulators, and the former property should not therefore be used as the only criterion for evaluating their suitability for wail construction. (70/5/21)
Wire sheet puts strength behind reinforced plastic parts Jaray, F. F. The Engineer, p 53 (24 September 1970) The manufacturing techniques, applications and properties of laminate which employs hard drawn steel wire as the reinforcing medium are briefly reviewed. It is said that practical difficulties of the incorporation of such wires into a plastic matrix have been largely overcome by the use of a wire sheet of 0.01 in patented wires on a suitable sub-base and that strength for strength laminates are more economical than glass fibre laminates.
A condensed account is given of the present technical position in the manufacture and use of bonded and laminated fabrics. Various machines and processes are described, including a novel method of bonding fabrics by use of a polythene foil net which is heated at 175°C for 15 s between the layers, giving bonding at an array of points only. (70/5/19)
General
Urethane laminates Delmonte, J. Reinforced Plastics, Vol 14, No 13, p 382 (September 1970)
Carbon fibre man weighs up Europe's big market Mortimer, J. The Engineer, Vol 231, No 5972, p 22 (9July 1970)
The properties of Uralane 5716 A/B a room temperature curing urethane
The scope for the application and production of carbon fibres and of
(7015/22)