A na-akpọkwa osisi hpl dị ka osisi refractory, aha sayensị bụ thermosetting resin impregnated paper high pressure laminated board, bụ ihe ịchọ mma n'elu nke ihe ụlọ refractory, osisi hpl bụ akwụkwọ ntọala site na melamine na phenolic resin impregnation process, site na elu t.. .
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