| 摘要 |
<p>Process for the opening of envelopes made of cellulosic paper in which there is applied to at least one envelope edge as the sole reactant with the cellulose therein a non-noxious organic acid having at least one pK value at room temperature between about 1.5 and about 5, followed by the application of heat and mild mechanical action to the envelope edge. </p> |
