Studi Kekuatan Lentur Bahan Komposit Sandwich Kayu Polyester Serat Gelas Untuk Lambung Perahu

Abstrak

The limitation of quality wood for the manufacture of fishing boats causes the lifespan of the boat to decrease. In addition, the wet boat operating environment and the effect of sunlight exposure accelerated the weathering of the boat. Some prevention methods that have been applied are painting and coating of boat hull wood using zinc. In this study, the wood material will be coated with polyester resin reinforced with glass fiber to form a sandwich composite as a boat hull material. The aim of the study was to study the flexural strength of sandwich composite materials using softwood cores and hardwoods using skins from glass fiber polyester composites. The flexural strength of sandwich composite materials will be compared with the flexural strength of wood materials. The study was designed by preparing Damar Laut and Merbau hardwood materials and Sengon and Damasui softwoods. Test specimens were made with a hand lay up process that is making a layer of skin on both wood surfaces (cores) by applying polyester resin reinforced with 1 layer of woven roving type glass fiber. The 3 point bending test refers to the ASTM C 1341 standard and using Galdabini Universal Testing Mechine (UTM). The test results take the average value of the normal distribution of 3 times of the test. The results show that Sengon wood sandwich composites produce a very significant increase in flexural strength up to 92% which shows that the process of strengthening the wood (core) by a glass fiber polyester layer occured well which is indicated by the appearance of the interface between the skin layer and the core which is still intact when broken test specimen. Whereas Damasui softwoods, the flexural strength only increased 5.1% after the sandwich process which indicated that there was no good reinforcement which was demonstrated by peeling at the interface when the test specimen was broken. While Merbau and Damar Laut hardwoods, the process of sandwiching with glass fiber polyester leather can increase its flexural strength by 13 % to 15% compared to the flexural strength without a sandwich which is already high as raw material for large size boats. In addition, the leather layer also provides an advantage over increased water resistance, so that the lifespan of the boat increases.

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