Konka Board: a cement-pumice-tow sheathing board

Konka board was a New Zealand invention which combined cement, pumice and flax fibre ("tow") into a fibre-cement board, replacing the imported asbestos-cement sheet. Sold soon after manufacture, Konka, it could be nailed or screwed, and over time it hardened. A waterproof plain or stucco plaster finish provided a resilient, borer proof, fireproof, low maintenance house. Three patents created the Konka system – 34,845 for the fibre-reinforced board, 37,354 for the stud and support system into which a concrete grout was poured to lock the panels in place, and finally 52,50 for metal strips to ensure a smooth final plaster surface. A waterproofing additive in the plaster provided the final part of the system.The company quickly setup a national series of agents, with manufacturing ultimately occurring in Wanganui, Gisborne, Christchurch and Timaru. Patent 34,845 was challenged in 1927, with the Privy Council finding in 1930 that it was invalid, opening the way for similar products to be made. The development in the 1930s of NZSS 95 Model Building By-law allowed Konka to be used nationally, without further evidence as to its performance. However, competitor other products were also included e.g. Excell, Rotorua, Thermax, Duro, Wangan, Walasco and the asbestos based Fibrolite.Konka survived until the 1960s, when flax production was in decline, the high labour costs and manufacturing time meant it was no longer competitive. Even so, in a twist of fate it was a Konka style approach which led to cellulose fibre replacing asbestos in fibre-cement sheeting. In the twenty-first century, Konka could even be considered a desirable product – a natural fibre reinforced, composite sheet.

Cellulose hydrocolloids in meat products: current status and challenges in developing functional food

Due to the growing health problems associated with the increased intake of saturated and trans fats, and the unbalanced n-6/n-3 ratio in the diet, in recent years numerous studies have focused on finding adequate substitutes for fat in meat products, while the meat industry made additional efforts to implement the obtained formulations (oleogels) in the standard production processes. Insoluble cellulose fibre in the form of microcrystalline cellulose has proven to be a promising ingredient in reduced fat, fibre-enriched functional food development, since it has been safely used as a food additive for many years with a known beneficial effect on human health. This review will discuss the recent advances of MCC application associated with alternative cellulose sources and processing technology, functional physico-chemical properties and potential as organogelator in fat mimetics. Finally, recently published data concerning its practical application in meat products as fat or starch substitutes will be presented.

Mapping humidity-dependent mechanical properties of a single cellulose fibre

Modelling of single cellulose fibres is usually performed by assuming homogenous properties, such as strength and Young’s modulus, for the whole fibre. Additionally, the inhomogeneity in size and swelling behaviour along the fibre is often disregarded. For better numerical models, a more detailed characterisation of the fibre is required. Herein, we report a method based on atomic force microscopy to map these properties along the fibre. A fibre was mechanically characterised by static colloidal probe AFM measurements along the longitudinal direction of the fibre. Thus, the contact stress and strain at each loading point could be extracted. Stress–strain curves were be obtained along the fibre. Additionally, mechanical properties such as adhesion or dissipation were mapped. Local variations of the effective fibre radius were recorded via confocal laser scanning microscopy. Scanning electron microscopy measurements revealed the local macroscopic fibril orientation and provided an overview of the fibre topography. By combining these data, regions along the fibre with higher adhesion, dissipation, bending ability and strain or differences in the contact stress when increasing the relative humidity could be identified. This combined approach allows for one to obtain a detailed picture of the mechanical properties of single fibres. Graphic abstract

Investigation of textile waste usage in stone mastic asphalt (SMA) mixtures

Stone mastic asphalt pavements are preferred worldwide as they are more resistant to heavy traffic loads. The stone mastic asphalt pavement design involves the use of 70-80% of coarse aggregate, 8-12% of filler, 5-7% of binder, and approximately 0.3-0.5% of fibre. The gap-graded structure and high binder content of stone mastic asphalt cause bitumen to drain down from aggregates. Marshall test and Schellenberg bitumen drainage test are performed in this research on samples prepared with different quantities of textile waste and cellulose fibre. The results of the research show that textile waste can be used instead of traditional fibres.

Response surface methodology optimization study on corncob pretreatment: reduction of sodium hydroxide usage and enhancement in pulpzyme HC biobleaching efficiency

Lignocellulosic rich corncob biomass possesses less complex structure, lignin and pigment content. As compared to wood pulp, it is considered to be a better alternative for the production of cellulose fibre. The present study was conducted to optimize both the alkaline (using sodium hydroxide) and biobleaching (using Pulpzyme HC) pretreatment process of corncob to promote lignin removal and cellulose swelling. It was the aim of this work to achieve mild processing conditions for corncob pretreatment in order to minimize the chemical usage. Results demonstrated that the mild pretreatment approach employed was found to successfully increase cellulose swelling and lignin removal from the corncob biomass. In alkaline pretreatment process, reaction temperature showed to be the most prominent effect in enhancing lignin removal and cellulose swelling as compared to sodium hydroxide concentration and reaction time. RSM optimized conditions for alkaline pretreatment process: 0.5 M NaOH, reaction temperature of 80°C and reaction time of 30 mins manage to increase the sedimentation index (indicate swelling of cellulose) from 0 to 30 and reduce the kappa number (represent lignin removal) from 82 to 32, respectively. Meanwhile, for biobleaching pretreatment using Pulpzyme HC, reaction time play a more significant role than the Pulpzyme HC concentration in promoting lignin removal and increasing cellulose swelling. RSM optimized conditions showed that the kappa number was reduced from 32 to 18 whereas the sedimentation index increased from 30 to 60 when the alkaline pretreated corncob was biobleached with Pulpzyme HC.

Brassinosteroids Influence Arabidopsis Hypocotyl Graviresponses through Changes in Mannans and Cellulose

The force of gravity is a constant environmental factor. Plant shoots respond to gravity through negative gravitropism and gravity resistance. These responses are essential for plants to direct the growth of aerial organs away from the soil surface after germination and to keep an upright posture above ground. We took advantage of the effect of brassinosteroids (BRs) on the two types of graviresponses in Arabidopsis thaliana hypocotyls to disentangle functions of cell wall polymers during etiolated shoot growth. The ability of etiolated Arabidopsis seedlings to grow upward was suppressed in the presence of 24-epibrassinolide (EBL) but enhanced in the presence of brassinazole (BRZ), an inhibitor of BR biosynthesis. These effects were accompanied by changes in cell wall mechanics and composition. Cell wall biochemical analyses, confocal microscopy of the cellulose-specific pontamine S4B dye and cellular growth analyses revealed that the EBL and BRZ treatments correlated with changes in cellulose fibre organization, cell expansion at the hypocotyl base and mannan content. Indeed, a longitudinal reorientation of cellulose fibres and growth inhibition at the base of hypocotyls supported their upright posture whereas the presence of mannans reduced gravitropic bending. The negative effect of mannans on gravitropism is a new function for this class of hemicelluloses. We also found that EBL interferes with upright growth of hypocotyls through their uneven thickening at the base.