Abstract: Provided are scratch-resistant blow moldings of crystalline resin having good surface gloss of at least 80% and high surface hardness of at least HB. A crystalline resin melt parison is blown in a blow mold into a blow-molded article, where the temperature of the inner wall of the mold falls between 20° C. lower than the crystallization temperature of the crystalline resin and 5° C. lower than the melting point of the crystalline resin; then, a pressure fluid is introduced into the pinched parison; then the mold is heated to a temperature lower by 10° C. than the melting point of the crystalline resin and a temperature below the melting point of the crystalline resin.

Abstract: The invention relates to a method for producing blow moldings, especially to a blow-molding method capable of efficiently producing blow moldings of crystalline thermoplastic resin having good surface gloss and good mold transferability of, for example, embossed patterns and, not warped, having a good appearance with no sinkmarks. The method comprises blowing and shaping a parison of a crystalline thermoplastic resin at a mold temperature falling between (the crystallization point of the resin −10° C.) and (the melting point of the resin), then keeping the thus-blown parison at a temperature falling between (the crystallization point of the resin −15° C.) and (the crystallization point thereof −45° C.) for a dwell time of from 30 to 300 seconds, and thereafter cooling it in an ordinary manner.

Abstract: Provided are scratch-resistant blow moldings of crystalline resin having good surface gloss of at least 80% and high surface hardness of at least HB. A crystalline resin melt parison is blown in a blow mold into a blow-molded article, where the temperature of the inner wall of the mold falls between 20° C. lower than the crystallization temperature of the crystalline resin and 5° C. lower than the melting point of the crystalline resin; then, a pressure fluid is introduced into the pinched parison; then the mold is heated to a temperature lower by 10° C. than the melting point of the crystalline resin and a temperature below the melting point of the crystalline resin.