Rubén Paz Hernández

Universidad de Las Palmas de Gran Canaria | ULPGC · Department of Mechanic Engineering

The global consumption of thermoplastic materials of fossil origin continues to grow, generating high environmental impacts mainly due to the energy consumed during their production and processing. The use of natural materials, such as banana fiber (BF), present a sustainable alternative for the gradual replacement of these thermoplastic materials,...

This paper assesses the modifications in the properties of rotomolded polyethylene (PE) and polylactic acid (PLA) composites obtained with 5 and 10% giant reed fibers, mainly focusing on the alterations due to a bio-disintegration process. Thermal properties (melting temperature and crystallinity degree), morphology (via optical and scanning electr...

Atomic Diffusion Additive Manufacturing (ADAM) is an innovative Additive Manufacturing process that allows the manufacture of complex parts in metallic material, such as copper among others, which provides new opportunities in Rapid Tooling. This work presents the development of a copper electrode manufactured with ADAM technology for Electrical Di...

#SpecialIssue "Design and Application of Additive Manufacturing: Volume II", edited by Prof. Dr. Rubén Paz (Department of Mechanical Engineering, University of Las Palmas de Gran Canaria, Spain) is open to submissions! https://lnkd.in/g7va7QK8 Volume I has published 11 papers and viewed 8588 times. Keywords #additive manufacturing #innovative app...

Neurosurgery is one of the medical specialties in which the practical training of students is more limiting since it requires a high degree of preparation for the interventions to be satisfactory. That is why the manufacture of synthetic models through additive manufacturing (AM) arises to develop the skills that the neurosurgeon requires. The pres...

Porous structures are of great importance in tissue engineering. Most scaffolds are 3D printed, but there is no single methodology to model these printed parts and to apply finite element analysis to estimate their mechanical behaviour. In this work, voxel-based and geometry-based modelling methodologies are defined and compared in terms of computa...

This paper compares the mechanical properties of different natural fiber composites produced by rotational molding as a way of waste valorization from campaigns to control invasive plant species in Macaronesia. Rotomolded parts produced with polymeric matrices (polyethylene) and filled with up to 20% by weight of cellulosic fibers obtained from Aru...

The degradation rate of polycaprolactone (PCL) is a key issue when using this material in Tissue Engineering or eco-friendly packaging sectors. Although different PCL-based composite materials have been suggested in the literature and extensively tested in terms of processability by material extrusion additive manufacturing, little attention has be...

Bags used to protect and accelerate the ripening of bananas are a clear example of the environmental problem of packaging waste. Small pieces of these non-biodegradable bags are frequently disposed on the soil by accident (environmental conditions and poor handling during the harvest) and remain there for years. This work focuses on the development...

The first ISO/ASTM joint standards were published in 2013 thanks to the Partner Standards Development Organization (PSDO) agreement to develop only one set of additive manufacturing (AM) standards to be used all over the world. Since then, many experts in different fields of AM have carried out an intense work in the development of new standard doc...

A fire extinguisher is a portable element designed to fight emerging fires, with a useful life of around 20 years. After this period, they are withdrawn from the market. All their components (shell, hose, and so on) are usually separated and recycled, except the chemical powder used as extinguishing agent, which usually consists at monoammonium pho...

The banana plant is a species that bears fruit only once in its life cycle. After the harvesting, the pseudostem is left on the plantation without generating a relevant nutritional value for the soil. Despite the high content of antioxidants of this subproduct, currently it is occasionally used for cattle feeding. This work is focused on the valori...

Several natural materials and vegetable waste have relevant mechanical properties, mainly in its fiber format. Particularly, banana fiber (BF) provides a close behavior to the widely spread glass fibers, which places it in an advantageous position for use as a reinforcing material in plastic composites. This work characterizes the behavior of acryl...

The influence of manufacturing parameters of filament extrusion and extrusion-based Additive Manufacturing (AM), as well as different post processing techniques, on the electrical conductivity of 3D printed parts of graphene nanoplatelets (GNP)-reinforced acrylonitrile butadiene styrene (ABS) has been analyzed. The key role of the manufacturing par...

This paper summarises the results obtained from the characterization assays from century plant (Agave americana L.), determining the chemical composition of different parts of the plant. Fibres were obtained by means of a mechanical device, specifically designed and built for Agave americana leaves processing. Obtained fibres were subjected to ther...

The optimum scaffold for tissue engineering must guarantee the mechanical integrity in the damaged zone and ensure an appropriate stiffness to regulate the cellular function. For this to happen, scaffolds must be designed to match the stiffness of the native tissue. Moreover, the degradation rate in the case of bioresorbable materials must be also...

The trauma of central nervous system (CNS) can lead to glial scar, and it can limit the regeneration of neurons at the injured area, which is considered to be a major factor affecting the functional recovery of patients with CNS injury. At present, the study of the glial scar model in vitro is still limited to two-dimensional culture, and the state...

The use of natural fibres allows reducing environmental impact, due to their natural renewable origin and the lower energy needed for their production and processing. This work presents the mechanical characterization of a newly developed technical textile, with banana fibre treated by enzymes, comparing experimental results with numerical simulati...

Interest in lightweight geometries and cellular structures has increased due to the freeform capabilities of additive manufacturing technologies. In this paper, six different cellular structures were designed and parameterised with three design variables to carry out the lightweight optimisation of an initial solid sample. According to the limitati...

Although AM technologies have high potential in terms of productivity and competitiveness for companies, their diffusion is still relatively limited among manufacturers and end users. In the context of two European Projects (KTRM and SASAM), this chapter presents an approach of how to transfer knowledge to people working in the manufacturing indust...

The purpose of this chapter is to describe experience in the development, use, and evaluation of interactive didactic material oriented towards the ISO GPS system that has been introduced into recent academic courses of subjects of various engineering degrees at the University of Las Palmas de Gran Canaria. The Educational Innovation Group Ingenier...

Hybrid Manufacturing combines the advantages of Additive Manufacturing (AM) and Subtractive Manufacturing on a single machine. Although previous research has provided a good background of the manufacturing parameters, the analysis is often carried out separately and there is a lack of combined knowledge. The purpose of this research is to examine t...

This work presents several interactive learning materials developed by the Group of Educational Innovation Manufacturing Engineering of the University of Las Palmas de Gran Canaria. This work presents the methodology followed, the main results achieved, the first classroom experiences, their evolution, new materials that are being developed, and th...

Banana fibers have been extracted by mechanical means from banana tree pseudostems, as a strategy to reevaluate banana crops residues. Extracted long fibers are cut to 45 mm length and then immersed into an enzymatic bath for their refining. Conditions of enzymatic treatment have been optimized to produce a textile grade of banana fibers, which hav...

4D printing is a technology that combines the capabilities of 3D printing with materials that can transform its geometry after being produced (e.g. Shape Memory Polymers). These advanced materials allow shape change by applying different stimulus such as heating. A 4D printed part will usually have 2 different shapes: a programmed shape (before the...

Purpose The purpose of this paper is to extend existing knowledge of 4D printing, in line with Khoo et al. (2015) who defined the production of 4D printing using a single material, and 4D printing of multiple materials. It is proposed that 4D printing can be achieved through the use of functionally graded materials (FGMs) that involve gradational...

The fourth dimension in 4D printing refers to the ability of materials to alter its form after they are produced, thereby providing additional functional capabilities and performance-driven applications. Stimuli materials provide this capability through the use of shape memory polymers. For this research, the property of programming the determined...

Digital light processing (DLP) is an accurate additive manufacturing (AM) technology suitable for producing micro-parts by photopolymerization. As most AM technologies, anisotropy of parts made by DLP is a key issue to deal with, taking into account that several operational factors modify this characteristic. Design for this technology and photopol...

The application of cellular structures in additive manufactured parts combined with lightweight optimisation has an enormous potential, reducing weight, production time and cost. This paper presents a new method based on design of experiments, metamodels and genetic algorithms (combined with Computer Aided Design and Finite Element Method tools) to...

Natural fibers have been used as an alternative to synthetic ones for their greener character; banana fibers have the advantage of coming from an agricultural residue. Fibers have been extracted by mechanical means from banana tree pseudostems, as a strategy to valorize banana crops residues. To increase the mechanical properties of the composite,...

This paper focuses on the development of a more energy-efficient mould for rotational moulding of plastic parts where the tool is made by electroforming of two materials (Ni–Cu), starting from a model of additive manufacturing. Studies on the poor adhesion between nickel and copper layer have not been previously carried out. The paper presents the...

The continuous evolution of materials and technologies of additive manufacturing has led to a competitive production process even for functional parts. The capabilities of these technologies for manufacturing complex geometries allow the definition of new designs that cannot be obtained with any other manufacturing processes. An application where t...

Additive manufacturing (AM) has become in a competitive method for short series production and high flexibility applications even for functional parts. Few constraints in the manufacturing process involve a great design freedom, allowing minimization of weight by using internal cellular and lattice structures, while minimal mechanical requirements...

Purpose – The purpose of this paper is to report on the use of a combination of selective laser sintering (SLS) and vacuum casting to create plastic composites made by additive manufacturing. Design/methodology/approach – The research has been carried out by approaching a new concept of the final part consistent in a plastic component, where the m...