title: Fibre orientation of novel dynamically sheet formed discontinuous natural fibre PLA composites

authors: Efendy, M.G. Aruan

subjects: Science & Technology

abstract: This paper describes work carried out to fabricate and to assess the fibre orientation in PLA reinforced by aligned discontinuous harakeke and hemp fibre mats produced using a dynamic sheet former (DSF). These mats were combined with PLA sheets to make composites with fibre contents of 5–40 wt% using a hot press. It was found that the fibre orientation factors (Kθ) for both harakeke and hemp fibre composites were higher than those values seen in the literature for composites prepared using injection moulding and hot pressed using randomly oriented fibre mats, but slightly lower than the highest values obtained with aligned fibre nonwoven preform composites utilising more processing stages. The highest Kθ values for harakeke and hemp fibres in this work were found to be 0.58 and 0.44 respectively. Kθ decreased, reflecting increased fibre misalignment as fibre content increased, believed to be due to fibre agglomeration and the higher pressure required during processing.

text: Fibre orientation of novel dynamically sheet formed discontinuous natural fibre PLA composites This paper describes work carried out to fabricate and to assess the fibre orientation in PLA reinforced by aligned discontinuous harakeke and hemp fibre mats produced using a dynamic sheet former (DSF). These mats were combined with PLA sheets to make composites with fibre contents of 5–40 wt% using a hot press. It was found that the fibre orientation factors (Kθ) for both harakeke and hemp fibre composites were higher than those values seen in the literature for composites prepared using injection moulding and hot pressed using randomly oriented fibre mats, but slightly lower than the highest values obtained with aligned fibre nonwoven preform composites utilising more processing stages. The highest Kθ values for harakeke and hemp fibres in this work were found to be 0.58 and 0.44 respectively. Kθ decreased, reflecting increased fibre misalignment as fibre content increased, believed to be due to fibre agglomeration and the higher pressure required during processing.

year: 2016

title: Accelerated weathering of unbleached and bleached Kraft wood fibre reinforced polypropylene composites

authors: Beg, Mohammad Dalour Hossen

subjects: natural fibre composites

abstract: In this paper, combined moisture/ultraviolet (UV) weathering performance of unbleached and bleached Kraft wood fibre reinforced polypropylene (PP) composites was studied. Composites containing 40 wt% fibre with 3 wt% of a maleated polypropylene (MAPP) coupling agent were fabricated using extrusion followed by injection moulding. Composite mechanical properties were evaluated, before and after accelerated weathering for 1000 h, by tensile and impact testing. Differential scanning calorimetry (DSC), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) were also carried out to assess the changes occurring during accelerated weathering. Bleached fibre composites initially showed higher tensile and impact strengths, as well as higher thermal stability and greater crystallinity. During accelerated weathering, both unbleached and bleached fibre composites reduced tensile strength (TS) and Young's modulus (YM), with the extent of the reduction found to be similar for both unbleached and bleached fibre composites. Evidence supported that the reduction of TS and YM was due to PP chain scission, degradation of lignin and reduced fibre–matrix interfacial bonding.

text: Accelerated weathering of unbleached and bleached Kraft wood fibre reinforced polypropylene composites In this paper, combined moisture/ultraviolet (UV) weathering performance of unbleached and bleached Kraft wood fibre reinforced polypropylene (PP) composites was studied. Composites containing 40 wt% fibre with 3 wt% of a maleated polypropylene (MAPP) coupling agent were fabricated using extrusion followed by injection moulding. Composite mechanical properties were evaluated, before and after accelerated weathering for 1000 h, by tensile and impact testing. Differential scanning calorimetry (DSC), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) were also carried out to assess the changes occurring during accelerated weathering. Bleached fibre composites initially showed higher tensile and impact strengths, as well as higher thermal stability and greater crystallinity. During accelerated weathering, both unbleached and bleached fibre composites reduced tensile strength (TS) and Young's modulus (YM), with the extent of the reduction found to be similar for both unbleached and bleached fibre composites. Evidence supported that the reduction of TS and YM was due to PP chain scission, degradation of lignin and reduced fibre–matrix interfacial bonding.

year: 2008

title: An exploration of wellbeing in Hapū Wānanga through a Te Wheke framework analysis

authors: Hawaikirangi, Lena

subjects: Antenatal education

abstract: Before colonisation, Māori had comprehensive knowledge and practices around pregnancy and childbirth. With colonisation, traditional maternity knowledge and practices were replaced by western medical practices. In more recent times, antenatal education classes have played an essential role in providing information on pregnancy, birth and caring for newborns. Research reports that Māori are less likely to attend antenatal programmes and  have suggested that culturally responsive programmes may encourage better engagement by Māori. Hapū Wānanga is a kaupapa Māori antenatal education programme. No previous research has explored how whānau experience wellbeing through Hapū Wānanga. This research explores how participants experience wellbeing within the Kia Wana  Lakes Baby Service Hapū Wānanga. Three participants, including one couple, and three facilitators were interviewed. Transcripts were analysed through a framework analysis using the Te Wheke model (Pere, 1997), a comprehensive Māori model of health. Findings showed that Hapū Wānanga caters to Māori holistic views of wellbeing, as demonstrated through the Te Wheke Model (Pere, 1997). All participants reported negative experiences with mainstream antenatal services; however, whānau enjoyed their experience at Hapū Wānanga. The two dimensions that influenced participants most were whānaungatanga (kinship ties) and hā ā koro mā ā kuia mā (cultural heritage). Although whānau were empowered by their experience at Hapū Wānanga, they wanted to learn more about parenting and postpartum, mental health. Overall, my findings highlighted that culturally adapted programmes that cater to  holistic models of wellbeing could engage Māori service users in an enjoyable and empowering way. If healthcare providers are to be successful in improving indigenous peoples' wellbeing, they need to prioritise culturally adapted programmes based on holistic models of wellbeing.

text: An exploration of wellbeing in Hapū Wānanga through a Te Wheke framework analysis Before colonisation, Māori had comprehensive knowledge and practices around pregnancy and childbirth. With colonisation, traditional maternity knowledge and practices were replaced by western medical practices. In more recent times, antenatal education classes have played an essential role in providing information on pregnancy, birth and caring for newborns. Research reports that Māori are less likely to attend antenatal programmes and  have suggested that culturally responsive programmes may encourage better engagement by Māori. Hapū Wānanga is a kaupapa Māori antenatal education programme. No previous research has explored how whānau experience wellbeing through Hapū Wānanga. This research explores how participants experience wellbeing within the Kia Wana  Lakes Baby Service Hapū Wānanga. Three participants, including one couple, and three facilitators were interviewed. Transcripts were analysed through a framework analysis using the Te Wheke model (Pere, 1997), a comprehensive Māori model of health. Findings showed that Hapū Wānanga caters to Māori holistic views of wellbeing, as demonstrated through the Te Wheke Model (Pere, 1997). All participants reported negative experiences with mainstream antenatal services; however, whānau enjoyed their experience at Hapū Wānanga. The two dimensions that influenced participants most were whānaungatanga (kinship ties) and hā ā koro mā ā kuia mā (cultural heritage). Although whānau were empowered by their experience at Hapū Wānanga, they wanted to learn more about parenting and postpartum, mental health. Overall, my findings highlighted that culturally adapted programmes that cater to  holistic models of wellbeing could engage Māori service users in an enjoyable and empowering way. If healthcare providers are to be successful in improving indigenous peoples' wellbeing, they need to prioritise culturally adapted programmes based on holistic models of wellbeing.

year: 2021