Processability of Different Polymer Fractions Recovered from Mixed Wastes and Determination of Material Properties for Recycling

Selina Möllnitz; Michael Feuchter; Ivica Duretek; Gerald Schmidt; Roland Pomberger; Renato Sarc

doi:10.3390/polym13030457

Processability of Different Polymer Fractions Recovered from Mixed Wastes and Determination of Material Properties for Recycling

Polymers ◽

10.3390/polym13030457 ◽

2021 ◽

Vol 13 (3) ◽

pp. 457

Author(s):

Selina Möllnitz ◽

Michael Feuchter ◽

Ivica Duretek ◽

Gerald Schmidt ◽

Roland Pomberger ◽

...

Keyword(s):

Material Properties ◽

Polymer Processing ◽

Thermal Recovery ◽

Mechanical Recycling ◽

Compression Moulding ◽

Moulding Process ◽

Processing Depth ◽

Washing Process ◽

Mixed Wastes ◽

Mixed Waste

To achieve future recycling targets and CO2 and waste reduction, the transfer of plastic contained in mixed waste from thermal recovery to mechanical recycling is a promising option. This requires extensive knowledge of the necessary processing depth of mixed wastes to enrich plastics and their processability in polymer processing machines. Also, the selection of a suitable processing method and product application area requires appropriate material behaviour. This paper investigates these aspects for a commercial processed, mixed waste, and two different mixed polyolefin fractions. The wastes are processed at different depths (e.g., washed/not washed, sorted into polyethylene, polypropylene, polyethylene terephthalate, polystyrene/unsorted) and then either homogenised in the extruder in advance or processed heterogeneously in the compression moulding process into plates. The produced recyclates in plate form are then subjected to mechanical, thermal, and rheological characterisation. Most investigated materials could be processed with simple compression moulding. The results show that an upstream washing process improves the achievable material properties, but homogenisation does not necessarily lead to an improvement. It was also found that a higher treatment depth (recovery of plastic types) is not necessary. The investigations show that plastic waste recovery with simple treatment from mixed, contaminated wastes into at least downcycling products is possible.

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Effect of MWCNT on Mechanical Properties of γ-Irradiated UHMWPE during Shelf Ageing Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.410.160 ◽

2011 ◽

Vol 410 ◽

pp. 160-163 ◽

Cited By ~ 3

Author(s):

P.S. Sreekanth ◽

N.Naresh Kumar ◽

S. Kanagaraj

Keyword(s):

Mechanical Properties ◽

Material Properties ◽

Milling Process ◽

Stress And Strain ◽

Compression Moulding ◽

Moulding Process ◽

Mwcnt Concentration ◽

Irradiation Dosage ◽

Ageing Period ◽

Gamma Irradiated

Crosslinking of UHMWPE by gamma irradiation has been the prime choice to improve the wear resistance of the polymer. However, it is always associated with few setbacks like degradation of material properties during the shelf ageing period. In the present work, nanocomposites were prepared using ball milling process and then compression moulding process where UHMWPE was reinforced by MWCNTs with 0.20 and 0.40 wt. %. The samples were gamma irradiated using60Co at 25 and 50 kGy sterilizing doses in air without any post irradiative treatments and then shelf aged for 240 days. The mechanical properties of the composites were studied using small punch technique according to ASTM F2183 standards. Both toughness and hardness of the composites were found to be improved with an increase of irradiation dosage and MWCNT concentration. It is observed that the percentage reduction in Young’s modulus, yield stress and % strain at fracture of 0.4% composite at 50 kGy dose are 6.4%, 8.8% and 12.7%, respectively compared to that of virgin UHMWPE irradiated at same dosage. It is concluded that presence of MWCNTs in UHMWPE prevents the degradation of material properties during the shelf ageing period after irradiation.

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Effect of Cobalt Stearate and Vegetable Oil on Uv and Biodegradation of Linear Low-Density Poly(Ethylene)-Poly(Vinyl Alcohol) Blends

Polymers from Renewable Resources ◽

10.1177/204124791100200401 ◽

2011 ◽

Vol 2 (4) ◽

pp. 131-148 ◽

Cited By ~ 1

Author(s):

Francis Vidya ◽

Subin S. Raghul ◽

Sarita G Bhat ◽

Eby Thomas Thachil

Keyword(s):

Vegetable Oil ◽

Vinyl Alcohol ◽

Water Soluble ◽

Poly Vinyl Alcohol ◽

Low Density ◽

Compression Moulding ◽

Melt Mixing ◽

Degradation Behaviour ◽

Moulding Process ◽

Poly Ethylene

The main objective of this study was to enhance the rate of UV and biodegradation of polyethylene by incorporating biodegradable materials and prooxidants. Prooxidants such as transition metal complexes are capable of initiating photooxidation and polymer chain cleavage, rendering the product more susceptible to biodegradation. In this work, the effect of (1) a metallic photoinitiator, cobalt stearate, and (2) different combinations of cobalt stearate and vegetable oil on the photooxidative degradation of linear low-density poly(ethylene)-poly(vinyl alcohol) (LLDPE/PVA) blend films has been investigated. For this, film-grade LLDPE was blended with different proportions of PVA. PVA is widely used in the industrial field, and recently it has attracted increasing attention as a water-soluble biodegradable polymer. Cobalt stearate and vegetable oil were added to the blends as prooxidants. The blends were prepared by melt mixing in a Thermo HAAKE Polylab system. Thin films containing these additives were prepared by a subsequent compression moulding process. The effect of UV exposure on LLDPE/PVA films in the presence as well as absence of these additives was investigated. Tensile properties, FTIR spectra, and scanning electron microscopy (SEM) were employed to investigate the degradation behaviour. It was found

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Mechanical Properties of Compression Moulded Aggregate-Reinforced Thermoplastic Composite Scrap

Journal of Composites Science ◽

10.3390/jcs5110299 ◽

2021 ◽

Vol 5 (11) ◽

pp. 299

Author(s):

Julien Moothoo ◽

Mahadev Bar ◽

Pierre Ouagne

Keyword(s):

Mechanical Properties ◽

Tensile Properties ◽

Test Method ◽

Thermoplastic Composite ◽

Recycled Aggregate ◽

Thermoplastic Composites ◽

Mechanical Recycling ◽

Compression Moulding ◽

Grain Sizes ◽

Recycled Composites

Recycling of thermoplastic composites has drawn a considerable attention in the recent years. However, the main issue with recycled composites is their inferior mechanical properties compared to the virgin ones. In this present study, an alternative route to the traditional mechanical recycling technique of thermoplastic composites has been investigated with the view to increase mechanical properties of the recycled parts. In this regard, the glass/polypropylene laminate offcuts are cut in different grain sizes and processed in bulk form, using compression moulding. Further, the effect of different grain sizes (i.e., different lengths, widths and thicknesses) and other process-related parameters (such as mould coverage) on the tensile properties of recycled aggregate-reinforced composites have been investigated. The tensile properties of all composite samples are tested according to ISO 527-4 test method and the significance of test results is evaluated according to Student’s t-test and Fisher’s F-test respectively. It is observed that the tensile moduli of the recycled panels are close to the equivalent quasi-isotropic continuous fibre-reinforced reference laminate while there is a noteworthy difference in the strengths of the recycled composites. At this stage, the manufactured recycled composites show potential for stiffness-driven application.

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Mechanical Characteristics of Aluminium Powder Filled Glass Epoxy Composites

International Journal of Engineering and Technologies ◽

10.18052/www.scipress.com/ijet.12.1 ◽

2017 ◽

Vol 12 ◽

pp. 1-14 ◽

Cited By ~ 1

Author(s):

Pujan Sarkar ◽

Nipu Modak ◽

Prasanta Sahoo

Keyword(s):

Mechanical Characteristics ◽

Tensile Modulus ◽

Epoxy Composites ◽

Aluminium Content ◽

Compression Moulding ◽

Moulding Process ◽

Aluminium Powder ◽

Void Fractions ◽

Aluminium Addition ◽

Powder Addition

Mechanical characteristics of glass epoxy and aluminium powder filled glass epoxy composites are experimentally investigated using INSTRON 8801 testing device as per ASTM standards. With a fixed wt% of fiber reinforcement, glass epoxy and 5-15 wt% aluminium powder filled glass epoxy composites are fabricated in conventional hand lay-up technique followed by light compression moulding process. Experimental results show that aluminium powder as a filler material influences the mechanical properties. Density and void fraction in composites increase whereas steady decrease of tensile strength is recorded with aluminium powder addition. Micro hardness, flexural strength, inter laminar shear strength (ILSS) of 5 and 10 wt% aluminium content composites are improved compared to unfilled glass epoxy composite and with further addition of aluminium up to 15 wt% decreasing trends are observed. Glass epoxy with 5 wt% aluminium concentration shows the highest improvement. Tensile modulus for aluminium addition of 5 wt% decreases whereas 10 wt% aluminium filled composite shows improvement in tensile modulus. These are explained on the basis of material properties, void fractions and bonding strength among the constituents.

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Experimental investigations and optimization of processibility of sheet moulding compound

Journal of Polymer Engineering ◽

10.1515/polyeng.2011.062 ◽

2011 ◽

Vol 31 (2-3) ◽

Cited By ~ 2

Author(s):

Bhaskara J.C. Babu ◽

Sachin Waigaonkar ◽

Amit Rajput

Keyword(s):

Penetration Depth ◽

Flow Behavior ◽

Glass Fibers ◽

Zinc Stearate ◽

Experimental Investigations ◽

Compression Moulding ◽

Maturation Time ◽

Moulding Process ◽

Moulding Compound ◽

Sheet Moulding Compound

Abstract Sheet moulding compound (SMC) is a combination of glass fibers and filled polyester resin. It is processed by a compression moulding process and finds extensive applications in structural, automotive, electrical and electronic industries. The compression moulding process is characterized by the flow behavior of SMC under heat and pressure in the press mould. This paper is focused on the prediction of ideal processibility conditions of SMC. The qualitative aspect of a properly thickened (matured) moulding compound could be seen from its tack-free nature, which was quantitatively calibrated in terms of penetration depth, measured by a specially constructed softness indicator. The weight (wt)% of calcium carbonate (CaCO3) as filler, magnesium oxide (MgO) as thickener, graphite (C) and zinc stearate [Zn (C18H35O2)2] (ZnSt) as lubricants along with the maturation time (Tm) were selected as process variables. Taguchi’s scheme of experimental design was adapted to perform the experiments. It was found that the higher levels of MgO and CaCO3 were favorable for a good penetration depth as well as a reduced maturation time. We have also found that a penetration depth of at least 5 mm was required for achieving good processability conditions of SMC. An optimization study was under taken to find the right blend of additives and fillers, at their minimal weights and in the least possible maturation time, to achieve the desired processability. This study is particularly useful in a production run to make moulded parts from SMC.

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Aging of novel membranes made of PVA and cellulose nanocrystals extracted from Egyptian rice husk manufactured by compression moulding process

International Journal of Environmental Studies ◽

10.1080/00207233.2018.1456862 ◽

2018 ◽

Vol 75 (5) ◽

pp. 750-762 ◽

Cited By ~ 9

Author(s):

E. M. Abdel Bary ◽

Yaser A. Soliman ◽

Ahmed Fekri ◽

Ammar N. Harmal

Keyword(s):

Rice Husk ◽

Cellulose Nanocrystals ◽

Compression Moulding ◽

Moulding Process

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3D Printing of Fibre-Reinforced Thermoplastic Composites Using Fused Filament Fabrication—A Review

Polymers ◽

10.3390/polym12102188 ◽

2020 ◽

Vol 12 (10) ◽

pp. 2188

Author(s):

Andrew N. Dickson ◽

Hisham M. Abourayana ◽

Denis P. Dowling

Keyword(s):

3D Printing ◽

Polymer Composites ◽

Mechanical Performance ◽

Polymer Processing ◽

Thermoplastic Composites ◽

Fused Filament Fabrication ◽

Compression Moulding ◽

Processing Technologies ◽

Reinforced Polymer ◽

Fibre Reinforced Polymer

Three-dimensional (3D) printing has been successfully applied for the fabrication of polymer components ranging from prototypes to final products. An issue, however, is that the resulting 3D printed parts exhibit inferior mechanical performance to parts fabricated using conventional polymer processing technologies, such as compression moulding. The addition of fibres and other materials into the polymer matrix to form a composite can yield a significant enhancement in the structural strength of printed polymer parts. This review focuses on the enhanced mechanical performance obtained through the printing of fibre-reinforced polymer composites, using the fused filament fabrication (FFF) 3D printing technique. The uses of both short and continuous fibre-reinforced polymer composites are reviewed. Finally, examples of some applications of FFF printed polymer composites using robotic processes are highlighted.

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