A u-shaped binding element comprising a u-shaped element main body made of steel material or aluminium alloy which is molded by a tension process, wherein one or two up ends of the u-shaped element main body is or are wrapped with anti-drop adhesive tape; wherein if one up end of the u-shaped element main body is winded with the anti-drop adhesive tape, a single-side molding body is formed; if two ends of the u-shaped element main body are covered with are respectively winded with the anti-drop adhesive tape, a double-side molding body is formed, a wrapage is covered on an external surface of the single-side molding body or the double-side molding body to form the u-shaped binding element. Utilizing the binding sleeve and a binding machine is capable of quickly completing text sheet binding and effectively solving the first requirement of binding: convenient and reliable, so as to make the binding more reliable, fast and convenient.

A hook-and-loop fastening structure for a clipboard contains: a cover and an accommodation box rotatably connecting with the cover. The accommodation box includes an accommodating chamber, a fixing slot defined on one of two inner peripheral sides of the accommodating chamber, and two opposite insertions portions, wherein each insertion portion is arranged on each of two inner ends of the accommodating chamber. Said each insertion portion has a recess and a through hole defined between and communicating with a bottom of the recess and the accommodating chamber. The fixing slot of the accommodating chamber is configured to house a clamper for clamping papers/documents, and a hook-and-loop fastener is connected with the two opposite insertions portions so as to fix an object (such as a mobile device or a tablet PC) in the clipboard, after inserting the hook-and-loop fastener into the recess and the through hole.