SOME STUDIES ON TEMPORARY AND PERMANENT FLAME RETARDANTS ON 100 % COTTON FABRIC V M Patil 1 and Anajali deshmukh 2 1 Principle, Bhonsala Coolege of Engineeing and Research, Akola, INDIA 2 HOD Home Sci. Dept. VMV Amravati, INDIA Abstract: To provide additional protection from fires and to increse escape time when fire occurs, methods to enhance the flame retardance of consumer goods have developed. Present work reports on process undertaken to prepare flame retardant cotton fabrics with well establised borex/boric acid mixture as temparary finished fabric and pyrovatex process for permanent finish in vary small laboratory scale. Fabric properties with permanent finishes and without permanent finishes were observed and compare. It was observed that 70/30 borex/boric acid combination is cheapar option for attaining flame retardancy but looses its handle, strength and feel. Pyrovatex results flame retardant fabric with almost no negative effect on fabric properties. 1. INTRODUCTION Modern fire-fighting techniques, equipment and building design has reduced the destruction due to fires. However, a fuel load in either a residential or a commercial building can offset even the best of building construction. To provide additional protection from fires and to increase escape time when a fire occurs, method to enhance the flame retardance of consumer goods have been developed. Present work report on process undertaken to prepare flame retardant cotton fabric with well established borax/boric acid mixture as temporary finished fabric and pyrovatex process for permanent finish in a very small laboratory Scale. An effective flame retardant should not affect other properties of the Base Fabric, hence apart from flame Retardant tensile, stiffness and crease recovery was also evaluated. 2. EXPERIMENTAL METHODS The main aim of our project was to prepare flame retardant fabric by chemical treatment of 100 % cotton fabric. Instead of industry Practice of Padding, Curing and Drying in padding mangle, drier and curing chamber, we used simple dipping in beaker, dripping and drying and curing in close oven for the entire process. We have optimesed Liquor concentration. dip[ping time to get the required pick up and add on%. Two Fabric sample with slightly different cloth parameter were taken for experimentation. Fabric A for temporary finish and Fabric B for permenant finish. Base Fabric Particulars Fabric A selected was with epi-44, ppi-38, warp count-10 Ne, Weft Count-15 Ne. Weight of cloth 5.75 oz./sq.yd. and fabric B selected was with epi-45, ppi-28, warp count-10 Ne, weft count-12 Ne, weight of cloth 5.44 oz./sq.yd. Chemicals Used: Laboratory grade Borax(Sodium Borate [Na2B4O7,10H2O]), Boric acid (H3BO3), Sodium Carbonate (Na2 CO3) & Phosphoric acid 85% was procured from Ranbaxy and Pyrovatex CP (Flame retardant), Alco print (cross linking agent), Dicrylane WK (silicon softener), Turpex CAN (strength retainer), Ultravon (wetting agent) was collected from CIBA chemicals.
Equipments & Instruments Used Laboratory glass equipments & distilled water was used for preparing solutions. Fabric samples of different sample size were dipped with required concentration of solution with optimized time. s were allowed to drip and dry in open air subsequently they were cured in laboratory drying oven at required temperature. Flame retardance test were carried out through ASTM D3659-semi restraint method Flame retardance was measured in terms of physical observation of flame propagation & mass loss %. Tensile strength of treated and untreated samples was measured in INSTRON 4311 model, crease recovery and stiffness test were carried out in EUREKA testers. Temporary Finish With 60% Borax A solution of 60% concentration of Borax with liquor ratio of 1:30 for 10 minutes of dipping time resulted highly flame retardant but very rough in handle and weak in strength fabric. With Borax and Boric acid The recommended add-on with borax boric acid mixture (70:30) was 10%. We carried out different hit and trial testing to reach to an optimized dipping duration for the desired add on %. s were given 4 after washes. It was observed that after 6 washes flame retardance was completely removed. We tried with different dipping time and liquor concentrations to achieve it. Table-1 exibits value of different add on with varying process production. Table 1: Test to Optimize The Time of Dipping and Concentration For Achieving An add on of 10% Table 1 Test to optimize the time of dipping and concentration for achiving an add on 10% Conc. 5% 10% Time of Dipping 1 min. 5 min. 10 min. 1 min. 5 min. 10 min. Dry samples wt(gms) 1.99 2.00 1.72 2.00 2.00 2.03 Wet samples wt(gms) 4.49 4.93 4.45 4.29 5.26 5.27 Dry wt(gms) 2.07 2.10 1.79 2.18 2.23 2.26 Pick up% 125 146 159 114 163 160 Add on% 4.0 5.0 4.0 9.0 11.5 11.3 It was observed that sample treated with 10 % conc, liquor with 5 mins dipping and 15 min dripping resulted 10 % add-on (approx). After optimization all treatment was carried out with recipe as : liquor ratio : 1:20, dipping time: 5 mins, dripping time:15 mins, Conc of solution: 10% and temperature at : 60 at room temperature. After washing was carried out with soda ash :
2%, temperature: 60 C and for 10 min duration. After every soda wash sample were rinsed with cold water. Permanent Finish Pyrovatex CP CIBA S Pyrovatex CP has become very popular for imparting durable flame retardant finish for all cotton material. It is modified form of Pyroset CP that was developed in America using Dimethylol dicynamide and phosphoric acid by pad-dry-cure method. This Pyrovatex CP is based on N- methylol compound of Diethyl and diethyl phosphonopropionamide. The final basic product is 3-(dimethylphosphono)-propionoic acid methylolamide with chemical formula of (Ca3O)2P(o)(CH2CH2CONHCH2OH). The Fabric to be treated was free from on finished as was made highly absorbent by scouring and subsequently freed from alkalinity by acid steeping. Fabric sample was desized with o.6 % HCL for 30 min and scoured with 3 % NAOH for 30 minutes. The Scoured sample was again dipped into an acid solution to bring PH value to 5-6.5. The recommended recipe for FR Treatment was as follow:- 1) Pyrovatex CP (flame retardant): 400 gpl 2) Alcoprint PFL (cross linking agent): 75 gpl 3) Dicrylane WK (silicon softener): 30 gpl 4) TorpexACN (Strength retainer): 40 gpl 5) Phosporic acid 85% (catalyst)l: 25 gpl 6) Ultraviolet (wetting agent): 1 gpl Recommended pick up : 70-90 % To get the required pick up and add on % we started with following parameter given in table -2 Table -2: The Effect of Dipping time on pick up % : Dipping Time Pick Up % 30 sec 284 4 mins 365 After the initial trial it was found that the pick up % so obtain was almost four times than what was actually recommended so we had to optimize dipping time. To get required pick up % & desired retention of properties, we maintained dipping time as 5 secs, dripping time as 12
minute, and curing time was 5 minutes. We obtained average add on as 15.5 %(approx) with 5 sec dipping as shown in the table -2 Sr. No Wt(gms) Desized wt(gms) Table 3- Desized Scoured & Pick up % Desize % Scoured wt(gms) Scour % Wet sample Wt(gms) Pick up % Dry wt(gms) Add on (after curing)% Avg 11.375 10.935 3.84 10.345 5.39 20.775 100.8 13.13 15.48 Process The desized and scoured fabric sample is dipped in the FR chemical solution for just 5 sec in order to get the desired pick up %. Then allowed the sample to drip for 12 min and dried it at room temperature. After drying curing was done in Oven at 150 C for 5 min. Then the fabric was washed off after curing. Washing was done with 10 gpl soda ash at 60 C for 20 min. followe with two cold rinses and allowed to dry in the air. This immediate wash off is compulsory to bring the PH to neutral value. Drying with the help of iron was avoided. 3. TESTING RESULTS AND DISCUSSIONS:- All the sample belonging to durable and non durable were tested for the following properties: 1) Crease recovery. 2) Bending Length. 3) Tensile Strength. 1) Crease Recovery :- The value of crease recovery increase after the Borax and Boric treatment because of the surface deposition of Borax and Boric acid layer. But after washing when those layer dissolved out rectulin of crease resistance observed. Further reduction of crease recovery is due to hydrocellulose formation which is observed in table-3. But for permanent finished sample no significant changes are observed (table -4). Table -4 Temporary Finish Table- 5 Permanent Finish Type Warp way Weft way Control 93 76 Finished 107 102
After 2 Wash After 4 Wash 90 88 77 66 Type Warp way Weft way Control 94 75 Finished 108 80 After 5 Wash 103 81 2) Bending Length (cms):- In temporary finished fabric it is observed that after finish application blending length decreased. With washes reduction of Bending Length increased. This happened partially due to increased in weight and partly due to loss in degree of Polymerization. But in case of permanently finished Fabric in Wrap Way bending length decreased but along weft way bending length increased. Cross linking of polymer played significant role Warp way Weftway behind this. type Control 2.84 2.49 Table 6: Bending Length of Warp way Weftway type Finished 2.69 2.91 Control 2.54 2.21 After 2 2.39 2.63 Finished wash 2.42 2.48 After 4 2.49 2.57 After wash 5 2.46 2.51 wash Table 7: Bending Length of Permanent Temporary finished Fabric finished Fabric
3) Tensile Strength Test:- Tensile strength test shows (Table-8) that both in warp and weft way both tensile strength and elongation% decrease after treatment with finishing chemicals. These loss in strength can be explained due to loss of degree of polymerization on hydrolysis of celluloses. But the reason for gain in strength and elongation properties after Na2Co3 solution can not be explained. Same test was repeated three times and similar results was observed. Work is going on to study the reasons. Table 8 : Tensile strength for temporary finish type Warp way Weftway Load(lb/inch) Elongation% Load(lb/inch) Elongation% Control 16.91 18.33 10.75 9.39 Finished 7.15 14.71 5.84 6.84 After 4 wash 15.36 20.85 11.58 11.45 Table 9 Tensile Strength for Permanent Finished s Type Warpway Weftway Load (lb/ Inch) Elongation % Laod (lb/ Inch) Elongation % Control 16.91 18.33 10.75 9.39 Finished 15.26 19.43 10.03 12.91 After 5 Wash 14.40 18.89 10.00 11.20 Test For Flame Retardance:- All Fabric sample of standers size were tested for flame retardance as per ASTM D3659- semi restraint method. Control base sample completely burned. Where as sample treated with temporary finished as Borax and Boric acid without any washing remained almost unburnt. These after 5 washes exhibited almost zero flame retardancy. In Case of permanent finished sample both sample just treated and thoroughly washed exhibited very high degree of flame retardancy. Table 10 exhibit s data for the same. Table-10 Mass loss Temporary Finish Permanent Finish
Treated After 5 Wash Treated After 5 Wash 0.44% 100% 0.7% 0.6% 4. CONCLUSION Present work reported on laboratory technique of one temporary and one Permanent flame retardant on 100% cotton Fabric. We observed that 70:30 borax/boric acid combination is a cheaper option for attaining flamr retardancy. But Fabric looses it s handle,strength and feel. More over as chemical remains on surface as well as inside of the fibre, this finished fabric never can be thougth for apparel purpose. With washing it almost looses all it s flame retardance. Whereas permanent finish with CIBA Pyrovatex result flame retardant fabric with almost no negative effect on Fabric properties. For producing consistent and reproducible result one must use padding Masle with all contain. REFERENCES 1) www.google.com/ flame retardant finishes on cotton/ research paper on flame retardancy/durable & non durable flame retardant finishes for pure cotton/ EHC (1992). 2) Dr. A.A. Vaidya & Dr. S.S. Trivedi, Textile Auxiliaries & Finishing Chemicals. 3) Dr. V.A. Shenai, Technology Of Textile Processing, Sevak Publication, Mumbai. 4) Mr. Fikry A. Abdel-Mohdy & Mr.Galal A.M.Nawar, Journal Of textile. 5) Association, Vol 60,Page-121, Sept.- Oct. 1999 6) Mr. Subramanian,Senthil Kannan & r. Geethamalini, Man Made Textile In India, Page 59, Feb 2005. 7) Ms.Ashwini K. Agarwal & Ms. Pushpa Bajaj, Ecofriendly Finishes For Textile, Page 113,1995.