Search results for "moulding"

DEGRADATION OF MATER-BI /WOOD FLOUR BIOCOMPOSITES IN ACTIVE SEWAGE SLUDGE

2009

The mechanical properties of Mater-Bi® are, in general, not adequate for certain applications and the addition of a filler is therefore necessary. Among the different fillers, natural fibres are particularly interesting because they potentially allow improving the performance of the material without compromising its biodegradability. In order to improve the basic mechanical properties of a Mater-Bi grade and to obtain a new, fully biodegradable material, wood flour based composites were prepared by different processing methods. To simulate actual and not laboratory bacterial attack on the prepared materials, in this work we studied the biodegradation of the composites in a real active sewag…

Recycling of compatibilized and uncompatibilized nylon/polypropylene blends

2001

The recycling of compatibilized and uncompatibilized nylon6/polypropylene blends has been carried out by repetitive extrusions. The change of the properties of the blends is a function not only of the number of reprocessing steps but also of the type of compatibilizer. The worsening of the mechanical properties is small and, indeed, some improvement can be observed after one or two extrusion steps for some blends. It is hypothesised that the decrease of the molecular weight, the typical effect occurring during this thermomechanical treatment, is counterbalanced and overcome by the possible formation of new copolymers that act as bridges between the two phases. This behaviour is displayed by…

Degradation od Mater-Bi/wood flour biocomposites in active sewage sludge

2009

Opuntia Ficus Indica based green composites for NPK fertilizer controlled release produced by compression molding and fused deposition modeling

2022

Excessive fertilization causes ecological problems due to leaching issues. To solve this problem and promote agriculture sustainability an innovative green composite for controlled release fertilizers was produced by adding NPK fertilizer flour to a biodegradable polymer with or without Opuntia Ficus Indica (OFI) particles. Six for- mulations were produced and employed for the fabrication of devices both for compression molding and fused deposition modeling (FDM). Both fillers displayed a good dispersion in the composites, excellent adhesion with the polymeric matrix and effectively acted as reinforcement. The decrease of NPK release rate (up to 30 days) was achieved using whole composites …

Green composites for fertilizer controlled release produced by compression molding and FDM

2023

Excessive fertilization causes ecological problems due to leaching issues. To solve this problem and promote agriculture sustainability an innovative green composite for controlled release fertilizers was produced by adding NPK fertilizer flour to a biodegradable polymer with or without Opuntia Ficus Indica (OFI) particles. Six formulations were produced and employed for the fabrication of devices both for compression molding (CM) and fused deposition modeling (FDM). Both fillers displayed a good dispersion in the composites, excellent adhesion with the polymeric matrix and effectively acted as reinforcement. The decrease of NPK release rate (up to 30 days) was achieved using whole composit…

The concept and the application of no-flow temperature (NFT) in simulation of injection moulding

2009

Thermal expansion of Glass fibre reinforced (GRF) thermoplastics: influence of the nature of the polymer matrix and of the fibre content

2009

Cuerpos moldeables y vidas modulables: La invención del estado holísticamente saludable como bienestar (integral)

2020

The article argues ?from the Deleuzian concepts of society of control, moulding and modulation and the Rosean theory on the economization and medicalization of life? that the expansion of the concept of health in terms of integral and subjective well-being is the effect of a socio-historical shift in the way we relate to this signifier, and therefore to our bodies and ourselves. We use this interpretative network to analyze the effects that the biopsychosocial health paradigm has had in the context of aesthetic surgery and fitness practice. As a result, we see that the expansion of the concept of health has extended the domain of medicine into the spheres of personal care and physical appea…

Correlation between processability and properties of a high density polyethylene by a rheological approach

2002

The thermal-oxidative and thermal-mechanical stability of high density polyethylene (chromium based catalyst technology) was examined at many different temperatures using a rheological approach. The changes in molecular structure, which take place during processing, have been studied using a Clextral co-rotating twin-screw extruder in comparison with dynamic measurements performed with a rotational rheometer under definite conditions of temperature, strain and frequency and in presence of air. In order to evaluate the degradation response, an investigation of elastic modulus G' as a function of frequency ω on the residual sample after ageing has been carried out. The molecular weight increa…

The use of master curves to describe the simultaneous effect of cooling rate and pressure on polymer crystallization

2003

In a previous work a master-curve approach was applied to experimental density data to explain isotactic polypropylene (iPP) behaviour under pressure and high cooling rates. Suitable samples were prepared by solidification from the melt under various cooling rate and pressure conditions with the help of a special apparatus based on a modified injection moulding machine. The approach here reported is more general than the case study previously shown, and is suitable to be applied to several materials and for different measures related to crystalline content. The proposed simple model is able to predict successfully the final polymer properties (density, micro-hardness, crystallinity) by supe…