| 摘要 |
A refrigerant transportation hose includes an innermost layer primarily of a polyamide resin, a low-permeability layer provided on the outer periphery of the innermost layer and made of polyvinyl alcohol, and a rubber layer (including an inner rubber layer and an outer rubber layer) provided on the outer periphery of the low-permeability layer. The innermost layer is formed with a multiplicity of through holes each extending in a direction of thickness of the innermost layer. The refrigerant transportation hose is produced by: extruding a material of the inner layer in the form of a hose to form a hose element; pressing a roll with spikes mounted on the surface thereof against an outer peripheral surface of the hose element to form in the hose element the multiplicity of through holes each extending in a direction of thickness of the hose element; and forming the low-permeability layer and the rubber layer (including the inner rubber layer and the outer rubber layer) in sequential order on the outer periphery of the hose element.
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