Effect of the filler amount on the optical absorption properties and the surface features of polymeric joints based on biomedical UHMWPE welded by a Nd:YAG laser

Visco, Annamaria; Torrisi, L.; Galtieri, G.; Scolaro, Cristina

doi:10.1177/0892705716662515

Cited by 15 publications

(7 citation statements)

References 27 publications

(30 reference statements)

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“…Nonetheless, the incident energy is not to be mistaken with the absorbed energy. The processing of UHMWPE through SLS is hindered by the fact that the absorption coefficient is very low, about 0.01 cm

at a wavelength of 1064 nm [ 126 ]. As a result, the excessive heat gives rise to a decrease in resolution, increases warpage, and leads to oxidative degradation processes [ 38 ].…”

Section: Approaches Used For the Additive Manufacturing Of Polyolefinsmentioning

confidence: 99%

Additive Manufacturing of Polyolefins

2022

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Polyolefins are semi-crystalline thermoplastic polymers known for their good mechanical properties, low production cost, and chemical resistance. They are amongst the most commonly used plastics, and many polyolefin grades are regarded as engineering polymers. The two main additive manufacturing techniques that can be used to fabricate 3D-printed parts are fused filament fabrication and selective laser sintering. Polyolefins, like polypropylene and polyethylene, can, in principle, be processed with both these techniques. However, the semi-crystalline nature of polyolefins adds complexity to the use of additive manufacturing methods compared to amorphous polymers. First, the crystallization process results in severe shrinkage upon cooling, while the processing temperature and cooling rate affect the mechanical properties and mesoscopic structure of the fabricated parts. In addition, for ultra-high-molecular weight polyolefins, limited chain diffusion is a major obstacle to achieving proper adhesion between adjunct layers. Finally, polyolefins are typically apolar polymers, which reduces the adhesion of the 3D-printed part to the substrate. Notwithstanding these difficulties, it is clear that the successful processing of polyolefins via additive manufacturing techniques would enable the fabrication of high-end engineering products with enormous design flexibility. In addition, additive manufacturing could be utilized for the increased recycling of plastics. This manuscript reviews the work that has been conducted in developing experimental protocols for the additive manufacturing of polyolefins, presenting a comparison between the different approaches with a focus on the use of polyethylene and polypropylene grades. This review is concluded with an outlook for future research to overcome the current challenges that impede the addition of polyolefins to the standard palette of materials processed through additive manufacturing.

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at a wavelength of 1064 nm [ 126 ]. As a result, the excessive heat gives rise to a decrease in resolution, increases warpage, and leads to oxidative degradation processes [ 38 ].…”

Section: Approaches Used For the Additive Manufacturing Of Polyolefinsmentioning

confidence: 99%

Additive Manufacturing of Polyolefins

2022

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“…The feasibility of laser welding process for the polymer nanocomposites was also investigated in. [ References 31–33 ]…”

Section: Introductionmentioning

confidence: 99%

Investigating the mechanical properties and microstructure of the weld joint obtained by laser welding of PA12/CNT nanocomposites

Samadi

Afshari

Nasehi

et al. 2023

Polymer Engineering & Sci

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In this article, the 3D printed polyamide12/carbon nanotube (PA12/CNT) nanocomposites were joined using laser welding. The factorial design method was applied to study the effect of laser power, welding velocity, and CNT content on the tensile and impact strengths of welded samples. The differential scanning calorimetry and thermogravimetric analysis were also used to measure the thermal stability and weight loss temperature of the nanocomposite. The results indicated that the increase of CNTs enhanced the thermal stability of the nanocomposite and so increased its melting point and crystallinity percentage. The impact and tensile strengths of the weld enhanced when laser power elevated from 40 to 50 W, but elevation of laser power up to 60 W decreased the impact and tensile strengths due to thermal degradation of the nanocomposite. A rise in welding velocity from 10 to 20 mm/s enhanced the tensile strength, while the impact strength initially enhanced and then decreased. The highest tensile strength obtained at 2 wt% CNT, whereas the addition of CNTs up to 4 wt% led to their agglomeration, which resulted in the reduction of impact and tensile strengths. Finally, the optimal conditions for concurrent increase of impact and tensile strengths include the laser power of 51 W, welding velocity of 12.5 mm/s, and CNT content of 2.3 wt%.

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“…Among all the polymers, polyethylene has been widely studied from several points of view due to its high flexibility, strength, easy of processing, transparency, lightweight, and versatility for the various industrial sectors of application, from simple objects of everyday life to prostheses used in the biomedical field, pure and combined in nanocomposites 1–4 …”

Section: Introductionmentioning

confidence: 99%

Diffusion of nitrogen gas through polyethylene based films

Visco

Scolaro

Torrisi³

et al. 2021

Polymer Crystallization

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Polyethylene-based films can be used as sealant materials at room temperature in packaging applications. They can be also melted and sealed with glass, acting as sealant material in solar cells. The polyethylene-based polymers investigated in this paper are a linear low-density polyethylene modified with maleic anhydride (or PE-MAH), and an ethylene acrylic acid copolymer (or EMAA). Measurements of nitrogen gas diffusion coefficient (D) have been performed at three different temperatures ranging between 23 C and 32 C. The experimental apparatus used to measure the diffusion coefficients is original compared with other commonly used. The obtained D results have been correlated with the polymeric structure and morphology by means of differential scanning calorimetry (DSC), thermogravimetric-analyses (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM) experimental analyses. Furthermore, D-coefficients are compared with the literature data of other polyethylenes with different structural organization (HDPE, LLDPE, and LDPE). The thermal activation energy is evaluated for the two polymers. Arrhenius plot has been used to calculate the activation energies of both polymers and to predict the D-coefficient at other temperatures, close to these analyzed.

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Effect of the filler amount on the optical absorption properties and the surface features of polymeric joints based on biomedical UHMWPE welded by a Nd:YAG laser

Cited by 15 publications

References 27 publications

Additive Manufacturing of Polyolefins

Additive Manufacturing of Polyolefins

Investigating the mechanical properties and microstructure of the weld joint obtained by laser welding of PA12/CNT nanocomposites

Diffusion of nitrogen gas through polyethylene based films

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