title: Effect of stearic acid treatment on the properties of aligned short hemp fibre mats and their potential use as reinforcement in polypropylene matrix composites

authors: Pickering, Kim L.

subjects: Science & Technology

abstract: The main objective of this study was to assess the effect of stearic acid vapour treatment on hemp fibre mats produced using dynamic sheet forming, and the potential use of these treated mats as reinforcement in polypropylene matrix composites. Stearic acid was successfully applied through vapour treatment, appearing to form a layer on fibre surfaces. It was found that the presence of stearic acid increased hydrophobicity and thermal stability of fibre mats. It was also found to increase thermal stability of polypropylene matrix composites as well as their strength.

text: Effect of stearic acid treatment on the properties of aligned short hemp fibre mats and their potential use as reinforcement in polypropylene matrix composites The main objective of this study was to assess the effect of stearic acid vapour treatment on hemp fibre mats produced using dynamic sheet forming, and the potential use of these treated mats as reinforcement in polypropylene matrix composites. Stearic acid was successfully applied through vapour treatment, appearing to form a layer on fibre surfaces. It was found that the presence of stearic acid increased hydrophobicity and thermal stability of fibre mats. It was also found to increase thermal stability of polypropylene matrix composites as well as their strength.

year: 2021

title: A study of polyvinyl butyryl based binder system in titanium based metal injection moulding

authors: Thavanayagam, Gnanavinthan

subjects: Binders

abstract: Metal injection moulding (MIM) is an innovative injection moulding technique widely used to produce complex shaped components from feedstock composed of metal powders and thermosetting or thermoplastic binders. In MIM, binder selection and formulation are considered as critical processes since binder characteristics dictate the success of MIM. The purpose of this study is to determine the feasibility of polyvinyl butyryl (PVB) based binder system in Ti-6Al-4V(wt.%)/binder feedstock, as well as to understand the effects of key parameters, such as powder loading and mixing conditions on the rheological properties of a feedstock. In this study, PVB, polyethylene glycol (PEG), and stearic acid (SA) were chosen to formulate a multi-component binder system to prepare Ti-6Al-4V based feedstock with the aid of three types of mixers: a compounder, a modified mechanical mixer and a twin screw extruder. Further, morphological analysis was performed using optical microscopy and scanning electron microscopy. Thermal analysis was performed using simultaneous differential thermal analysis and thermogravimetric analysis. Results showed that binder formulation was reasonably successful with the aid of both mechanical mixer and a twin screw extruder under certain mixing conditions, and the critical powder loading was 68 vol.%, resulting in an optimum powder loading of 63 vol.%.

text: A study of polyvinyl butyryl based binder system in titanium based metal injection moulding Metal injection moulding (MIM) is an innovative injection moulding technique widely used to produce complex shaped components from feedstock composed of metal powders and thermosetting or thermoplastic binders. In MIM, binder selection and formulation are considered as critical processes since binder characteristics dictate the success of MIM. The purpose of this study is to determine the feasibility of polyvinyl butyryl (PVB) based binder system in Ti-6Al-4V(wt.%)/binder feedstock, as well as to understand the effects of key parameters, such as powder loading and mixing conditions on the rheological properties of a feedstock. In this study, PVB, polyethylene glycol (PEG), and stearic acid (SA) were chosen to formulate a multi-component binder system to prepare Ti-6Al-4V based feedstock with the aid of three types of mixers: a compounder, a modified mechanical mixer and a twin screw extruder. Further, morphological analysis was performed using optical microscopy and scanning electron microscopy. Thermal analysis was performed using simultaneous differential thermal analysis and thermogravimetric analysis. Results showed that binder formulation was reasonably successful with the aid of both mechanical mixer and a twin screw extruder under certain mixing conditions, and the critical powder loading was 68 vol.%, resulting in an optimum powder loading of 63 vol.%.

year: 2012

title: The Long Bay Restaurant site, R10/1374: Volume 1, the archaeology (HNZPTA authorities 2015/19 and 2016/81): Report to Heritage New Zealand Pouhere Taonga and Auckland Council

authors: Campbell, M

abstract: Auckland Council had proposed refurbishing the Long Bay Restaurant at Long Bay Regional Park (Lot 2 DP 54616), amounting to a near full rebuild of the structure apart from the in situ foundations. Council began the project in mid-2013 with the partial demolition of the existing structure and sawing of the concrete floor slab to install new utilities. Following the discovery of human remains beneath the floor slab on 2 July 2013, work was halted. The remains were inspected by the New Zealand Police who confirmed that they were pre-European kōiwi tangata. An assessment of the site was then undertaken by Beatrice Hudson of ArchOs Archaeology (Hudson 2013) and the find was recorded as site R10/1374 in the New Zealand Archaeological Association (NZAA) Site Recording Scheme (SRS) (this site number applies to any other archaeological features associated with the wider area). Auckland Council applied to the New Zealand Historic Places Trust (now Heritage New Zealand Pouhere Taonga, HNZPT) for an archaeological authority under section 18 of the Historic Places Act 1993 to undertake archaeological test excavations to investigate the nature, extent and condition of the site, and how it would be affected by the proposed development project. Authority 2014/506 was granted on 28 November 2013 and the investigation was carried out on the 20th and 21st of January 2014 (Campbell et al. 2014) (the 2014 excavation is summarised in Chapter 3).

Auckland Council then applied to HNZPT for an authority under section 44 of the Heritage New Zealand Pouhere Taonga Act 2014 to modify or destroy any further material found during the refurbishment project, including associated car parks and footpaths. Authority 2015/19 was granted on 7 August 2014 and works resumed. On 6 November 2014 further kōiwi were found within the project footprint and work once again ceased. 

Following extensive consultation with mana whenua and HNZPT, Auckland Council determined that the refurbishment would continue but it was agreed that the entire footprint of the development would be cleared archaeologically in order to provide assurance that no further kōiwi would remain within the project area. As the scope of the archaeological investigation had changed, a new archaeological authority, superseding authority 2015/19, was required and a full archaeological assessment of efects was also required in support of the authority application (Campbell and Hudson 2015). Authority 2016/81 was granted by HNZPT on 25 August 2015. This report fulfils the conditions of both authority 2015/19 and 2016/81.

Excavation began on 5 October 2015 with site clearance and removal of the concrete pad but not the ground beam foundations, while full excavation commenced on 12 October under the direction of Matthew Campbell (Excavation Director, CFG Heritage) and Beatrice Hudson (Osteologist, ArchOs Archaeology). Excavation continued until 3 November, by which stage kōiwi of a further 10 individuals had been found, bringing the total to 12. Following an onsite hui on 4 November between representatives of mana whenua, HNZPT, Auckland Council and the excavation team, the excavation was halted but mana whenua requested that the 3 possible burials that had been located but not excavated be lifted, and on 9 November the site was shut down. At a second on site hui on 9 December Auckland Council announced that they had resolved to cancel the restaurant project, but mana whenua expressed a desire that the 13 x 12 m excavation area opened up at the time be excavated to a sterile layer to lift all kōiwi. Excavation resumed on 18 January 2016 and continued until 4 March, when all kōiwi and archaeological deposits and features had been excavated.

text: The Long Bay Restaurant site, R10/1374: Volume 1, the archaeology (HNZPTA authorities 2015/19 and 2016/81): Report to Heritage New Zealand Pouhere Taonga and Auckland Council Auckland Council had proposed refurbishing the Long Bay Restaurant at Long Bay Regional Park (Lot 2 DP 54616), amounting to a near full rebuild of the structure apart from the in situ foundations. Council began the project in mid-2013 with the partial demolition of the existing structure and sawing of the concrete floor slab to install new utilities. Following the discovery of human remains beneath the floor slab on 2 July 2013, work was halted. The remains were inspected by the New Zealand Police who confirmed that they were pre-European kōiwi tangata. An assessment of the site was then undertaken by Beatrice Hudson of ArchOs Archaeology (Hudson 2013) and the find was recorded as site R10/1374 in the New Zealand Archaeological Association (NZAA) Site Recording Scheme (SRS) (this site number applies to any other archaeological features associated with the wider area). Auckland Council applied to the New Zealand Historic Places Trust (now Heritage New Zealand Pouhere Taonga, HNZPT) for an archaeological authority under section 18 of the Historic Places Act 1993 to undertake archaeological test excavations to investigate the nature, extent and condition of the site, and how it would be affected by the proposed development project. Authority 2014/506 was granted on 28 November 2013 and the investigation was carried out on the 20th and 21st of January 2014 (Campbell et al. 2014) (the 2014 excavation is summarised in Chapter 3).

Auckland Council then applied to HNZPT for an authority under section 44 of the Heritage New Zealand Pouhere Taonga Act 2014 to modify or destroy any further material found during the refurbishment project, including associated car parks and footpaths. Authority 2015/19 was granted on 7 August 2014 and works resumed. On 6 November 2014 further kōiwi were found within the project footprint and work once again ceased. 

Following extensive consultation with mana whenua and HNZPT, Auckland Council determined that the refurbishment would continue but it was agreed that the entire footprint of the development would be cleared archaeologically in order to provide assurance that no further kōiwi would remain within the project area. As the scope of the archaeological investigation had changed, a new archaeological authority, superseding authority 2015/19, was required and a full archaeological assessment of efects was also required in support of the authority application (Campbell and Hudson 2015). Authority 2016/81 was granted by HNZPT on 25 August 2015. This report fulfils the conditions of both authority 2015/19 and 2016/81.

Excavation began on 5 October 2015 with site clearance and removal of the concrete pad but not the ground beam foundations, while full excavation commenced on 12 October under the direction of Matthew Campbell (Excavation Director, CFG Heritage) and Beatrice Hudson (Osteologist, ArchOs Archaeology). Excavation continued until 3 November, by which stage kōiwi of a further 10 individuals had been found, bringing the total to 12. Following an onsite hui on 4 November between representatives of mana whenua, HNZPT, Auckland Council and the excavation team, the excavation was halted but mana whenua requested that the 3 possible burials that had been located but not excavated be lifted, and on 9 November the site was shut down. At a second on site hui on 9 December Auckland Council announced that they had resolved to cancel the restaurant project, but mana whenua expressed a desire that the 13 x 12 m excavation area opened up at the time be excavated to a sterile layer to lift all kōiwi. Excavation resumed on 18 January 2016 and continued until 4 March, when all kōiwi and archaeological deposits and features had been excavated.

year: 2019