Pultron Composites Ltd.

Gisborne, New Zealand

Pultron Composites Ltd.

Gisborne, New Zealand

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Sawpan M.A.,Pultron Composites Ltd. | Pickering K.L.,University of Waikato | Fernyhough A.,Scion Research
Composites Part A: Applied Science and Manufacturing | Year: 2012

In this work, flexural strength and flexural modulus of chemically treated random short and aligned long hemp fibre reinforced polylactide and unsaturated polyester composites were investigated over a range of fibre content (0-50 wt%). Flexural strength of the composites was found to decrease with increased fibre content; however, flexural modulus increased with increased fibre content. The reason for this decrease in flexural strength was found to be due to fibre defects (i.e. kinks) which could induce stress concentration points in the composites during flexural test, accordingly flexural strength decreased. Alkali and silane fibre treatments were found to improve flexural strength and flexural modulus which could be due to enhanced fibre/matrix adhesion. © 2011 Elsevier Ltd. All rights reserved.


Sawpan M.A.,University of Waikato | Sawpan M.A.,Pultron Composites Ltd. | Pickering K.L.,University of Waikato | Fernyhough A.,Scion Research
Composites Part A: Applied Science and Manufacturing | Year: 2011

In this work, mechanical properties of chemically treated random short fibre and aligned long hemp fibre reinforced PLA composites were investigated over a range of fibre content (0-40 wt.%). It was found that tensile strength, Young's modulus and impact strength of short hemp fibre reinforced PLA composites increased with increased fibre content. Alkali and silane fibre treatments were found to improve tensile and impact properties which appears to be due to good fibre/matrix adhesion and increased matrix crystallinity. A 30 wt.% alkali treated fibre reinforced PLA composite (PLA/ALK) with a tensile strength of 75.5 MPa, Young's modulus of 8.18 GPa and impact strength of 2.64 kJ/m2 was found to be the best. However, plane-strain fracture toughness and strain energy release rate decreased with increased fibre content. The mechanical properties of the PLA/ALK composites were increased further due to alignment of long fibres. © 2010 Elsevier Ltd. All rights reserved.


Sawpan M.A.,Pultron Composites Ltd. | Pickering K.L.,University of Waikato | Fernyhough A.,Scion Research
Composites Part A: Applied Science and Manufacturing | Year: 2011

Industrial hemp fibres were treated with sodium hydroxide, acetic anhydride, maleic anhydride and silane to investigate the influence of treatment on the fibre structure and tensile properties. It was observed that the average tensile strength of sodium hydroxide treated fibres slightly increased compared with that of untreated fibres, which was believed to be as a result of increased cellulose crystallinity. The average tensile strength of acetic anhydride, maleic anhydride, silane and combined sodium hydroxide and silane treated fibres slightly decreased compared with that of untreated fibres, which was believed to be as a result of decreased cellulose crystallinity. However, the average Young's modulus of all treated fibres increased compared with untreated fibres. This was considered to be as a result of densification of fibre cell walls due to the removal of non-cellulosic components during treatment. © 2011 Elsevier Ltd. All rights reserved.


Sawpan M.A.,Pultron Composites Ltd | Holdsworth P.G.,Pultron Composites Ltd | Renshaw P.,Pultron Composites Ltd
Materials and Design | Year: 2012

The changes that can occur in glass fibre reinforced polymer (GFRP) composites with ageing can affect its application, performance and lifetime. Hygrothermal ageing (i.e. accelerated ageing by moisture absorption and temperature change) is a very useful technique to evaluate durability as well as development of GFRP composites in a reasonable timeframe. Dynamic mechanical thermal analysis (DMTA) is essentially able to detect all changes in the state of molecular motion in polymer composites as temperature is scanned. In this work, pultruded GFRP rebars were accelerated aged in an alkaline aqueous environment at 60 °C for 1, 2, 3, 4 and 6. months to evaluate the changes in glass transition of viscoelastic GFRP rebars by DMTA. Five different glass transitions in an average temperate range from 110 to 165 °C were observed at storage modulus, loss modulus and damping factor traces of DMTA. It was also found that glass transition temperature (Tg) of the aged samples changed up to maximum 6 °C compared with that of controlled sample. This change in Tg with ageing time was believed to be due to moisture absorption by rebars. © 2012 Elsevier Ltd.


Sawpan M.A.,Pultron Composites Ltd | Mamun A.A.,University of Kassel | Holdsworth P.G.,Pultron Composites Ltd | Renshaw P.,Pultron Composites Ltd
Materials and Design | Year: 2013

Due to the increased use of glass fibre reinforced polymer composite (GFRP) rebar in concrete structures, the durability performance of GFRP rebar has been an important research topic in recent years. This paper presents elastic modulus of alkaline environment (pH ≈ 13) aged pultruded GFRP rebar as evaluated by three different methods, namely, quasi-static tensile, quasi-static flexural and dynamic mechanical thermal tests. It was found that elastic modulus of the GFRP rebar samples did not change significantly due to exposure in alkaline environment at 60 °C for 1, 2, 3, 4, 6 and 14. months when compared with that of control sample. Elastic modulus was found to be in the range of 52.5-56.5. GPa irrespective to testing methods and ageing time. In addition, it was estimated from the long time projected results that quasi-static tensile, quasi-static flexural and dynamic mechanical moduli will be retained by about 93%, 95% and 85%, respectively, after 100. years in alkaline environment at 60 °C. Microscopic analysis indicated that quasi-static tensile and flexural failure was mainly due to matrix cracking and shear failure of fibre/matrix interface. © 2012 Elsevier Ltd.


Sawpan M.A.,University of Waikato | Sawpan M.A.,Pultron Composites Ltd. | Pickering K.L.,University of Waikato | Fernyhough A.,Scion Research
Composites Part A: Applied Science and Manufacturing | Year: 2011

Surface treatment of hemp fibres was investigated as a means of improving interfacial shear strength (IFSS) of hemp fibre reinforced polylactide (PLA) and unsaturated polyester (UPE) composites. Fibres were treated with sodium hydroxide, acetic anhydride, maleic anhydride and silane. A combined treatment using sodium hydroxide and silane was also carried out. IFSS of PLA/hemp fibre samples increased after treatment, except in the case of maleic anhydride treatment. Increased IFSS could be explained by better bonding of PLA with treated fibres and increased PLA transcrystallinity. The highest IFSS was 11.4 MPa which was obtained for the PLA/alkali treated fibre samples. IFSS of UPE/hemp fibre samples increased for all treated fibres. This is believed to be due to the improvement of chemical bonding between the treated fibres and the UPE as supported by FT-IR results. The highest IFSS (20.3 MPa) was found for the combined sodium hydroxide and silane treatment fibre/UPE samples. © 2011 Elsevier Ltd. All rights reserved.


Pickering K.L.,University of Waikato | Sawpan M.A.,Pultron Composites Ltd. | Jayaraman J.,University of Waikato | Fernyhough A.,Scion Research
Composites Part A: Applied Science and Manufacturing | Year: 2011

Plane-strain fracture toughness (KIc) of random short hemp fibre reinforced polylactide (PLA) bio-composites was investigated along with the effect of loading rate, fibre treatment and PLA crystallinity. Fracture toughness testing was carried out at loading rates varying from 0.5 to 20 mm/min using single-edge-notched bending specimens with 0 to 30 wt.% fibre. K Q (trial KIc) of composites decreased as loading rate increased, until stabilising to give KIc values at a loading rate of 10 mm/min and higher. The reduction of crazing and stress whitening, as well as a more direct crack path observed in PLA samples combined with reduced plastic deformation observed in composites provided explanation for this reduction. KIc of composites was found to decrease with increased fibre content and fibre treatment with sodium hydroxide. Studies controlling the degree of PLA crystallinity by heat treatment or "annealing" showed that reduction of KIc can be attributed to increased crystallinity. © 2011 Elsevier Ltd. All rights reserved.


Sawpan M.A.,Pultron Composites Ltd | Mamun A.A.,University of Kassel | Holdsworth P.G.,Pultron Composites Ltd
Materials and Design | Year: 2014

Pultruded glass fibre reinforced polymer (GFRP) composite rebar was immersed in alkaline concrete environment for 0, 1, 2, 3, 4, 6, 14 and 24 months at 60 °C to evaluate its durability in concrete structure. Moisture absorption of the rebar was found to be only 0.76%. It was also found that both the glass transition temperature (Tg) and the short beam shear strength were retained by about 91.5%; and the above properties were remained almost unchanged during the ageing period from 1 month to 24 months. Design tensile strength and tensile elastic modulus of the rebar were retained by 100% after 24 months exposure in concrete environment. Degradation of GFRP rebar was not evident in the FT-IR results as supported by scanning electron micrographs and energy dispersive X-ray analysis. Moisture absorption was found to be a critical factor that controlled thermal and mechanical properties of GFRP rebar. © 2014 Elsevier Ltd.


Patent
Bellingham Marine Industries Inc. and Pultron Composites Ltd | Date: 2015-07-10

In one aspect the invention provides a nut and tie rod assembly which includes a composite material tie rod defining a main shaft with an exterior surface. The tie rod is formed from reinforcing fibres encapsulated within a matrix material, and at least a portion of the exterior surface of the shaft defines an engagement structure. The assembly also includes at least one nut which includes an internal cavity with an interior surface defining an engagement structure which is complimentary to the engagement structure defined on the exterior surface of the shaft of the tie rod.


Trademark
Pultron Composites Ltd | Date: 2012-01-24

Non-metal building materials, namely, composite reinforcing bars and composite dowels. Non-metal fasteners, namely, bolts and nails; non-metal bolts, namely, rock bolts and anchor bolts; and non-metal soil nails.

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