Fibres, additives

Grigelmo-Miguel, N. and Martin-Belloso, O. (1999). Influence of fruit dietary fibre addition on physical and sensorial properties of strawberry jams. ]. Food Eng. 41,13-21. 

Analysis of DTA, DTG, TG curves of modified and unmodified PETP - fibres has shown, that though all additives - modifiers being used belong to one class of compounds, they have different effect on PETP - fibre. Additives HC-2 and HC-1, being isomers of phenyldiamine (HC-1 - para-product HC-2 - meta-product), have different effect on PETP -fibre. Additive HC-2 has greater plasticizing effect, then HC-1 (Table 29), though they have small difference in structure. 

Recipes for the positive and negative active masses are well known and are aimed at achieving a positive mass that is as porous as possible and a negative mass that can withstand the formation process, which can involve very high temperatures. The majority of separators are pure glass-mats, but present research is focusing on the use of synthetic fibre additives to make manufacturing simpler and cheaper. 

Fibres of the above types (3 mm in length) and polypropylene fibres are introduced into the paste with the aim to provide mechanical stability to the structure of NAM. Because of the poor adhesion between lead and fibre particles, the role of mechanical strengthener of the NAM structure is not always very pronounced. Beyond any douht, however, fibre additions reduce substantially the waste during the pasting process and throughout the technological process of negative plate manufacture, which provides very important economical effect. 

In the case where PA (CEN EN 13108-7 2008) is to be used, the surface layer thickness should be 50 mm and the asphalt must be modified with polymer or fibre additive. Its contribution to the material design thickness is only 20 mm hence, an increase by 30 mm of the total asphalt thickness is necessary. Additionally, a 60 mm dense binder course is required to be laid beneath PA surfacing. 

If a porous asphalt (CEN EN 13108-7 2008) surface course is used over CRCB, it must be modified with a polymer or fibre additive and laid over a dense binder course. The porous asphalt should be 50 mm thick over a 90 mm binder course or 50 mm thick over a 60 mm binder course with the CRCB thickness increased by 10 mm. 

Woodside A.R., W.D.H. Woodward and A. Graham, 2011. The use of glass fibre addition to reinforce a road patch. Proceedings, 5th International Conference Bituminous Mixtures and Pavements. Thessaloniki, Greece AUTh. 

The effect of SWCNTs and carbon fibre additions on the tensile ductility of silicone rubber is shown that the strain to failure drops from 325 (RTV) to 275% upon loading with 1 wt% SWCNTs, corresponding to 15% reduction. ... 

The processing characteristics and acoustic properties are further advantages of the natural fibres. Additional advantages like good life-cycle assessment and industrial medicine relating advantages compared with glass fibres are also to be... 

Peressini D, Sensidoni A. Effect of soluble dietary fibre addition on rheological and breadmaking properties of wheat doughs.J Cereal Sci 2009 49(2) 190-201. 

Fibre Additive Tensile strength Modulus Flexural strength Impact strength... 

Figure 15.1 (Brown et al., 2002) shows the behaviour of fibre-reinforced concrete under loading. The plain concrete (with no fibre reinforcement) cracks into two pieces when the stmcture is subjected to the peak tensile load and cannot withstand further load or deformation. An analogous fibre-reinforced concrete (FRC) structure cracks at the same peak tensile load however, it usually maintains large deformations as a single element. The area under the curve represents the energy that the FRC absorbed when subjected to tensile load, usually described as the post-cracking response of FRC. The best performance of fibre addition takes place when fibres not only bridge the cracks but also undergo pullout processes. In those cases, the deformation continues only with employment of further loading energy (Brown et al., 2002 ACI, 2002).

The fatigue strength is increased with the fibre addition and the conclusions may be summarized as follows ... 

The main advantages of using foam concrete is that the density of the material can be varied between 300 and 1600 kg/m, and the foam provides good insulation properties and it is easy to handle by pumping. However, several properties still need to be modified in order to make foam concrete an even more competitive material. There is a need to decrease the shrinkage and the water uptake, and to increase the strength and the insulation ability. At present, the foam structures can be enhanced by the use of various additives, such as microsilica or superplasticizers which reduce the cement/water ratio and improve the stability. Polyester fibre additives enhance the hardening and also improve the tensile properties. 

It must be remembered that, when examining or describing the effects of fibre additions, changes in SFRC properties are always expressed in terms of average fibre content. It is implicitly assumed that the fibres are uniformly distributed throughout the matrix, and, moreover, that they are randomly oriented. Unfortunately, neither assumption is likely to be correct after the SFRC has been placed and compacted by vibration [23], and this leads not only to a considerable amount of scatter in the test data, but also to a considerable variability in measured values due to the direction of loading (in relation to the direction of casting). 

Particular attention was given to the enhancement in the first crack stress due to the glass fibre addition (Figures 8.12 and 8.18). This could be predicted on the basis of the crack suppression equation (Eq. 4.49) developed by Aveston et al. [66] by using bond strength values in the range of 1-3 MPa [46,55], the perimeter of the strand in direct contact with the matrix, and an efficiency coefficient in the range of 1/2-3/8. 

PHBV combined with various cellulosic fibres. In general, die addition of fibres increased the polymer crystallisation rate from the glass and the melt however, the ultimate erystallinity as determined from the heat of crystallisation in MDSC experiments was the same in reinforced and unreinforced materials. Straw fibre addition was found to have a similar effect on PHBV crystallisation (Avella et al, 2000a). Optical microscopy has also been used to show the increased nucleation oeeurring in PHB or PHBV as a result of fibre addition and the use of a silane eoupling agent (Shanks et al, 2004). 

Comments Lubricomp has bronze and Thermocomp has glass fibre additions, M0S2 = molybdenum disilicide, Br = bronze. ... 

Comments Lubricomp has PTFE and Stat-Kon has carbon fibre additions. GF = glass fibres, CF = carbon fibres. ... 

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