Jan-Anders Edvin Maansson

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transverse direction is investigated with application to the Glass Mat reinforced Thermoplastics (GMT) lamination process in a double belt press.Amodel proposed in Part I to simulate the kinetics of impregnation and the evolution of the fiber volume fraction profile as the resin front progresses across the fiber mat, as well as after macro-impregnation is complete, is further developed to include micro-impregnation effects. The predictions are compared with experimental results obtained using model systems

Experimental squeeze flow results show that the behaviour of concentrated short fibre suspensions and concentrated long fibre suspensions impregnated with polymer melts are qualitatively different. Short fibre suspensions have a low yield stress, have an overall squeeze pressure independent of the fibre length, but gap dependent. In contrast, long fibre suspensions have a higher yield stress and their squeeze pressure is proportional to the square of the fibre length, but is gap independent. In both types o

Dendritic hyperbranched polymers have been shown to be able to double the interlaminar fracture resistance of epoxy-based composites and to reduce the internal stress level by as much as 80% with only 10 phr of modifier. These property improvements were obtained without affecting the viscosity, and thus the processability, nor the glass transition temperature of the epoxy resin. In the investigation, both fully soluble and phase-separating epoxy-functionalised hyperbranched polymers were used, the latter sh

The influence of the mould material on the build-up of internal stresses during autoclave cure of a unidirectional carbon fibre composite material was investigated using embedded optical fibre Bragg gratings. Four flat moulds (i.e. aluminium, steel, carbon ...

The low frequency mechanical and dielectric behavior of three different elastomers has been investigated by dynamic mechanical analysis and dielectric spectroscopy, with the aim of accounting for the frequency dependence of the characteristics of the corre ...

Flexible displays form complex structures joining together multiple layers of very various materials: metal or plastic flexible substrate, barrier and encapsulation layers, thin-films of transistor and optoelectronic devices. Residual stresses are inherent ...

The aim of the present research has been to quantify the influence of different materials on the global dynamic response of a ski. The properties of the individual constituent materials were characterized as a function of temperature and frequency using dy ...

The present work analyses silicon oxide coated polyester films, with attention paid to the effect of substrate process additives on the coating defect population, and on the coated film mechanical properties. The defect population is characterized by means of reactive ion etching, and the mechanical properties are determined from the analysis of uniaxial fragmentation tests. The coating crack onset strain is decreased by the presence of substrate additives, due to a broadening of the Weibull defect distribu

The non-isothermal flow rheology of a glass mat reinforced polypropylene composite for compression flow moulding has been investigated experimentally and numerically. The influence of the processing conditions on the macroscopic flow of the material was studied experimentally, while a numerical model relating this macroscopic flow to the local deformation of the matrix at fibre interaction points was developed. By following the local evolution of the shear rate, temperature and viscosity of the matrix polym

This paper describes the production of "green" microfibrillated cellulose-reinforced polylactide cellular biocomposites using a wet mixing technique combined with super-critical carbon dioxide foaming. The effect of composition on the morphology, density a ...

A design tool able to predict the residual stress state and dimensional stability of large complex shaped composite parts has been developed. It is based on a finite element model, using a three-dimensional anisotropic thermo-viscoelastic formulation. Asym ...

Bone is a natural composite construct, with a gradient structure going from a loose interconnected cellular core to an outer dense wall, thus minimizing bone weight while keeping a high mechanical resistance. Due to this unique and complex structure, bone ...

A process has been developed where multiple yarns of commingled glass and polypropylene are heated and placed to a desired geometry. The placed unidirectional (UD) tow is then encapsulated by over-moulding with glass mat thermoplastics (GMTs). The effects of both force (20 80 N), with an equivalent pressure range of 8 46 bar, and the displacement rate (20 100 mm/s) during tow placement on void content and flexural modulus were investigated for nine placement conditions. Placement rate affected the tow quali

Diffusion of CO2 in polylactide was modelled by assuming the diffusion coefficient to depend on CO2 concentration, c, according to D[c]=D[0]exp[Ac], where D[0] and A are empirical constants, with the aim of optimizing impregnation of nominally amorphous an ...

The development of the interfacial bond strength as a function of bonding conditions has been investigated in two representative semicrystalline thermoplastics, isotactic polypropylene and polyamide 12. If one side of the interface is well above the melting point immediately before contact, more rapid effective bonding is obtained for a given estimated interface temperature than under isothermal conditions. This is discussed in terms of a simple two-parameter model for the critical strain energy release rat

Although addition of montmorillonite (MMT) clay to isotactic polypropylene (iPP) results in large increases in the melt viscosity at low shear rates, satisfactory impregnation of glass mats is obtained with iPP/MMT under conditions typical of industrial pr ...

Shear thickening fluids (STF) demonstrate the ability to simultaneously stiffen and increase their damping capacity above a critical shear strain, which depends on the particle concentration and aspect ratio in the STF. The present work considers two types ...

The evolution of morphology of reactive thermoplastic/unsaturated polyester blends at the surface of glass fibers is investigated during curing. The study focuses on two different types of thermoplastics, incompatible and compatible respectively with the p ...

The dynamic shear-thickening behavior of concentrated colloidal suspensions of fumed silica in polypropylene glycol has been investigated. Dynamic frequency sweeps showed that, for any given solids concentration, the complex viscosity at different imposed ...

The increase of the elongational viscosity of recycled poly(ethylene terephthalate) (PET) is investigated with the aim of producing closed-cell foams by means of a cost-effective reactive extrusion technique. A recycled PET grade containing controlled contamination levels of polyvinyl chloride (PVC) and poylethylene (PE) is selected, and compared with virgin bottle-grade PET as a reference. Reactive processing with a tetrafunctional epoxy additive induces randomly branched molecules with a lower degree of b

Jan-Anders Edvin Maansson

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Impregnation of compressible fiber mats with a thermoplastic resin, Part II: Experiments

Squeeze flow of concentrated long fibre suspensions: experiments and model

A Review of Dendritic Hyperbranched Polymer as Modifiers in Epoxy Composites

Influence of the mould thermal expansion on composite stress build-up during curing

Frequency dependent dielectric and mechanical behaviour of elastomers for actuator applications

Thermo-hygro-mechanical behaviour of ultrathin multilayer composite materials for flexible display applications

Dynamic Properties of Materials for Alpine Skis

Durability of hybrid PECVD-based coatings on semicrystalline polymers

Non-isothermal process rheology of thermoplastic composites for compression flow moulding

Cellular biocomposites from polylactide and microfibrillated cellulose

Thermoviscoelastic anisotropic analysis of process induced residual stresses and dimensional stability in real polymer matrix composite components

Bioresorbable composites prepared by supercritical fluid foaming

Robotic tow placement for local reinforcement of glass mat thermoplastics (GMTs)

Liquid CO2 processing of solid polylactide foam precursors

Non-Isothermal Fusion Bonding in Semicrystalline Thermoplastics

Hybrid glass mat reinforced polypropylene-montmorillonite nanocomposites

Structural damping of model sandwich structures using tailored shear thickening fluid compositions

Wettability of Glass Fibers in Reactive Thermoplastic/Polyester Blends: Comparison between Compatible and Incompatible Thermoplastics

Pre- and Post-Transition Behavior of Shear Thickening Fluids in oscillating Shear

Recycling of poly(ethylene terephthalate) into closed-cell foams