J. Environ. Res. Develop. Journal of Environmental Research And Development Vol. 8 No. 3, January-March 2014

Transcription

1 LAMINATED COMPOSITE OF FILLER LOADED PAPER SHEETS MANUFACTURED USING RICE STRAW FIBERS AND UREA FORMALDEHYDE RESIN Sinha Sanjay Kumar Akhouri* and Samarjeet Singh Department of Chemical Technology, SLIET, Longowal, Sangrur, Punjab (INDIA) Received October 2, 213 Accepted January 25, 214 ABSTRACT This research study is based on finding environment friendly economical process for manufacturing of paper laminate composites. Rice straw an agro residue based fibrous raw material has been used for paper manufacturing. The paper industries are facing pressure for reducing the consumption of forest based wood raw materials in paper making. Rice straw can prove to be an important established fibrous raw material for paper industries. But higher percentage of ash and silica which is the main constituent of ash causes problems. The rice straw contains nearly 16-2 % ash. Nearly 75 % portion of ash is silica. The paper sheets have been prepared using natural fibers of rice straw and fillers with different percentages. The paper sheets coated with paste of urea formaldehyde resins are combined together and treated at high pressure and temperature for composite formation. The different conditions have been explored for better properties and economical production. This study will provide a process for manufacturing of thin sheets of paper based laminated products which can be used in place of plastic bags. This will give environment friendly flexible paper based bags and wrappers along with hard sheets if higher number of sheets of paper is used. Key Words : UF resin, Laminates, Composites, Rice straw, Silica, Ash INTRODUCTION A composite is viewed as a laminate if the reinforcing fibres are arranged in layered fashion such as in the form of webs, mats or fabrics. Increasing performance demands in chemical industries, electrical appliance and energy industries is the main concern for finding the alternate to high cost materials like metals and concrete. This motivates process and design engineers to consider new thermoset composite materials as a replacement for existing materials. Thermoset composite materials have extraordinary properties of corrosion resistance, very high strength, light weight, electrical nonconductance and required thermal properties. For instance, these structural composites can be used for outdoor applications and in extreme environments due to no rusting or corrosion problem. Many components can be moulded along with the part and require no *Author for correspondence final finishing, thermoset moulding compounds are often more economical considering design and construction. Thermoset composites are a reliable substitute for traditional materials due to better strength-to-weight ratio than conventional materials like metals. Gokay Nemli 1 has done experiments to find the effect on important properties of continuous pressed laminates with some changes in thickness and press parameters. Overlay laminates with a combination of kraft paper and alpha cellulose base decorative paper were manufactured to maintain property of resistance to surface abrasion, scratch, cigarette burns, staining. The study was done as a function of manufacturing variables. It was found that the press temperature and press cycle influenced both scratch and abrasion resistances. Paul and A. P. Mamza 2 has studied the mechanical properties of ureaformaldehyde particle boards. A gradual 418

2 increase in mechanical properties was observed from 22% to 3% ureaformaldehyde resins concentration, but at 32% and 34% compositions, increase in resins concentrations in the sawdust did not significantly affect the mechanical properties of the particleboards obtained. A comparison between the various compositions showed that 3% urea-formaldehyde resins compositions have better mechanical properties. J. B. Zhong 3 has studied on mechanical properties of sisal fibre reinforced ureaformaldehyde resin composites. Alkali-treated sisal fibres were used as novel reinforcement to obtain composites with self-synthesized urea-formaldehyde resin as matrix phase. The composites were prepared by means of compression moulding and then the effects of sisal loading on mechanical properties such as impact strength, flexural strength and wear resistance were investigated. The composite with 3 wt% sisal fibres gives excellent flexural strength, water absorption and especially the wear resistance showing that it has the most superior bonding and adhesion of all the composites. In particular, the highest value 9.42 kj/m 2 of impact strength is observed in the composite with 5 wt% sisal fibre. A. K. Mohanty 4 has studied on jute composites a literature review polymerplastics technology and engineering. Jute fibre is an important agricultural product. Jute fibre use in the area of fibre-reinforced composites has been studied. Narendra Reddy 5 has studied on the properties of high-quality long natural cellulose fibres from rice straw. This paper reports the structure and properties of novel natural cellulose fibres obtained from rice straw. Rice straw fibres have 64% cellulose with 63% crystalline cellulose strength of 3.5 g/denier (45 MPa), elongation of 2.2%, and modulus of 2 g/denier (26 GPa), similar to that of linen fibres. A.S.K. Sinha 6-11 has done research works on the agro residue based cellulosic fibre separation methods using acetic acid pulping, characteristics of fibres, optical and mechanical strength properties of paper made from these fibres. This has been found that the rice and wheat straw based fibres have good fibre length and strength properties for manufacturing of different composite sheets. High silica content in rice straw (16-2%) is the main concern causing problem in separation and use of rice straw fibres. MATERIAL AND METHODS Urea formaldehyde resin having density of gm/cc, manufactured by Samrat Plywood Pvt. Ltd. was used. Kaolin Clay Powder with mean particle size of 7µm, bulk density of 71 kg/m 3, brightness of 9.4 % ISO was used (Table 1). TiO 2 powder of lab purity was used as filler which has high brightness and refractive index. (Table 2) Preparation of composite sheet We laminate the paper sheets which made from the above formulation and then dry it in hot air oven at 1 C for 5 minute. After that we put these sheets in in compression moulding machine at different pressure and temperature. The steel plates were first cleaned with toluene and thereafter coated with release agent usually, silicon oil. Here steel plates we are using as a mold which have the area 2 cm 2. A very thin layer of the release agent was applied to facilitate easy removal of the cured sheet from the mold and then required amount of crosslinked urea formaldehyde resin laminated on the resin fiber composite sheet, then mold is inserted in compression moulding machine under a load of 5-15 Kg/cm 2. The temperature is set around 95 C. Sheet is finally ejected. Total time of sheet formation is 2 hour. 419

3 Table 1 : The manufacturing condition for making thermoset composite of Kaolin clay and its thickness S/N Sample Ply 1. C C C C-4 2 Initial weight(gm.) Hydraulic press condition Press.-5 Kg/cm 2 Press.-75 Kg/cm 2 Press.-1 Kg/cm 2 Press.-15 Kg/cm 2 42 Final wt.(gm.) Thickness(µm) Table 2 : The manufacturing condition for making thermoset composite of TiO 2 and its thickness S/N Sample Ply 1. T T T T-4 2 Initial Weight (gm.) RESULTS AND DISCUSSION Tensile strength It is a key material property of composite material. Fig. 1 indicates the values of tensile strength of the filler loaded resin fiber composite at different pressure. But temperature is constant i.e. 95 C for all composition. As we increase the pressure the tensile strength also increases but in case of Kaolin clay composite after 1 Kg/cm 2 it is decreases because of that Hydraulic press condition Press.-5 Kg/cm 2 Press.-75 Kg/cm 2 Press.-1 Kg/cm 2 Press.-15 Kg/cm 2 Final weight(gm.) Thickness (µm) this is the optimum pressure for the kaolin clay composite. Elongation At break is also the key material property of composite material. Fig 2 indicates the values of elongation at break of the filler loaded resin fiber composite at different pressure. But temperature is constant i.e. 95 C for all composition. As we increase the pressure the elongation at break also increases but in case of Kaolin clay composite after 1 Kg/cm 2 it

4 is decreases because of that this is the optimum pressure for the Kaolin clay composite. i.e. after the 1 Kg/cm 2 pressure Kaolin clay loaded composite will be decomposed. Tensile strength (MPa) TiO2 2 composite Fig. 1 : Tensile strength Elongation at break (%) TiO2 composite TiO 2 Tensile strength and elongation at break Table 3 indicates the value of tensile strength (MPa) and elongation at break (%) of both filler at different temperature but the pressure is 1 Fig. 2 : Elongation at break 421 Kg/cm 2. When we increase the temperature the tensile strength is decreased in both filler. So it is shows that at high temperature the strength of filler loaded resin fiber composite is decreases. Table 3 : Tensile strength and elongation at break Sample Tensile strength (MPa) Elongation at break(%) C-6(temp.-15 C) C-7(temp.-85 C) T-6(temp.-15 C) T-7(temp.-85 C) Opacity Opacity is the measure of impenetrability to electromagnetic or other kinds of radiation, especially visible light. The composite samples with 26% filler show opacity of 99.6 % ISO. Thickness We study that the thickness of resin fiber composite is decreasing with increase of Pressure 1ml as we increase the pressure from 5 to 15 Kg/cm 2 due to the flexibility in the composite which comes from the urea formaldehyde resin and the filler which we are using. Fig. 3 shows the thickness of TiO 2 and kaolin clay filler loaded resin fiber composite at different pressure.

5 Thickness (µm) Fig. 3 : Thickness of resin fiber composite at different pressure Reflectance Reflectance is the study of light that has been reflected or scattered from a solid, liquid or gas. Fig. 4 shows the reflectance at 457 nm. at different pressure of both filler loaded resin fiber composite. Tio2 TiO 2 composite Lower gsm of TiO Tio2 2 Lower gsm of clay Smoothness Smoothness means having a texture that lacks friction. Not rough. In this chart we see that what is the difference of smoothness between both filler loaded composite. Here this is clear that TiO 2 loaded resin Reflectance (%ISO) Pressure (kg./ sq.cm.)) TiO Tio2(457 2 nm) Clay(457 nm) fiber composite have the high smoothness comparison to the Kaolin clay composite. The reason is that TiO 2 have high temperature resistance comparison to the kaolin clay by which TiO 2 filler loaded composite have high smoothness. The optimum pressure for getting Fig. 4 : Reflectance at 457 nm the best result is 1 Kg/cm 2 on which result is best. After that if increase the pressure then composite will be burned and it will be decomposed. Fig. 5 shows the smoothness of both filler loaded composite at different pressure. Smoothness (min./1ml) Fig. 5 : Smoothness at different pressure 422 TiO2 2 composite

6 Density The mass density or density of a material is defined as its mass per unit volume. Here we see that in Kaolin clay filler loaded resin fiber composite has a constant density comparison to the TiO 2. But when the pressure reached to the 1 Kg/cm 2 the TiO 2 filler loaded composite goes to the high dense than the Kaolin clay composite. It is because of that TiO 2 have high temperature resistance. The composite have maximum density ( to Kg/m 3 ) at the pressure of 1kg/cm 2. Fig. 6 shows the density of both filler loaded composite at different pressure. Density (Kg/m 3 ) TiO2 composite TiO Fig. 6 : Density at different pressure Ash contents An ash test is used to determine if a material is filled. The test will identify the total filler ash test cannot be used to determine the percent carbon fiber or percent carbon black since carbon burns off during the Ash test. We content. It cannot identify individual can find out the % ash by muffle furnace of percentages in multi-filled materials without additional test procedures being performed. An both filler loaded resin fiber composite (Table 4). Table 4 : Shows the ash content of different filler loaded resin fiber composite Sample % Ash Kaolin clay TiO CONCLUSION The optimum pressure for Kaolin clay loaded composite is 1 kg/cm 2 on which the mechanical properties observed are maximum but for TiO 2 composite it increases till the 15 kg/cm 2 pressure. The thickness of resin fiber composite is decreasing with increase of pressure and smoothness also increases from 64 to 144 min/1ml as we increase the pressure from 5 to 15 Kg/cm 2. The composite samples with 26% filler show opacity of 99.6 % ISO. Reflectance of the composite is increasing with increase of pressure for all the three wavelengths (36, 457 and 78 nm) of visible light. The composite have maximum density ( to Kg/m 3 ) at the pressure of 1kg/cm 2. The resin fiber composite is showing improvement in tensile strength and elongation 423 properties with increase in pressure till pressure of 1 Kg/cm 2. The higher pressures are causing the decrease in the strength and bursting of sample surface. Urea-formaldehyde resin and filler loaded paper composite having good tensile strength, elongation, very high opacity, good brightness and good surface properties can be used in a number of industrial and domestic applications of environment friendly packaging materials and decorative laminates. ACKNOWLEDGEMENT Author give special thanks to Mr. Ramnik Agarwal,Senior Lab. Technician for his supports. REFERENCES 1. Nemli G., Gezer E. D. and Hiziroglu S., The changes in important quality properties of Continuous Pressed

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