Materials and Methods for footwear industry
The NR (STR5L) rubber was purchased in block form from Chana Latex Co., Ltd. (Songkhla, Thailand), whereas CB (N-330, particles size 30 nm) and china clay (CC, C-400, mesh size 400) were acquired from GSP Products Co., Ltd. (Bangkok, Thailand). The CB and CC are generally considered as reinforcement and non-reinforcement fillers, respectively.
Paraffinic oil (PO, grade A no.15), added to NR as a plasticizer to facilitate filler dispersion, was likewise obtained from GSP Products Co., Ltd. (Bangkok, Thailand). Other crosslinking species (zinc oxide, stearic acid, Wingstay L, 2-mercaptobenzothiazole (MBT), and sulfur) were all provided by Kij Paiboon Chemical Co., Ltd. (Bangkok, Thailand). Table 1 lists the compound formulations examined here. Compound mixing was performed in two stages. First, the NR was masticated in a kneading machine (YFM Dispersion mixers 3L, Yong Fong Machinery Co., Ltd., Samutsakorn, Thailand) at 90 ◦C, at a roller speed of 30 rpm. Subsequently, the plasticizer and fillers were added according to the formulation in Table 1 within a mixing time of 30 min. In Panorama Global Trade Sdn Bhd we supply Styrene butadiene rubber which is directly use in sole shoe industry . Styrene-butadiene styrene is a popular material for footwear manufacturers. … SBS is an excellent material in footwear manufacturing for many of the same reasons that make it ideal for roofing. In shoe soles, styrene-butadiene styrene contributes to a strong yet flexible product that can be waterproofed.
Second, the modified NR was mixed with the remaining ZnO, Stearic acid and Wingstay L on a two-roll mill (YFM 400B, Yong Fong Machinery Co., Ltd., Samutsakorn, Thailand). After the compound was cooled to ambient temperature, it was mixed with MBT and sulfur and held at that temperature for 24 h to allow stress relaxation to proceed before vulcanization. The optimal curing time was chosen on the basis of prior reports [13,14,17] andin-house NR experience. Each test piece was molded at the same conditions of 150 ◦C and 150 kg/cm2 for 10–15 min and subsequently cooled at ambient temperature for 24 h prior to testing. Rubber compound formulations examined here:
Concentration (phr a)
Wingstay L b
CB (X1) c
10 ≤ X1 ≤ 100
PO (X2) c
5 ≤ X2 ≤ 100
CC (X3) c
0 ≤ X3 ≤ 200
Parts per hundred rubber. b Antioxidant. c
Independent experimental variables (designation in parentheses)