ACTIVATABLE ADHESIVE WEBS AND ARTICLES MADE THEREFROM

Concrete Column Forming Tube Having a Smooth Inside Coated Surface and Method of Making Same

CONCRETE COLUMN FORMING TUBE HAVING A SMOOTH INSIDE COATED SURFACE AND METHOD OF MAKING SAME

A concrete column forming tube and method of making same for receiving poured concrete column therein to produce a concrete column is characterized by a smooth inside coated surface in the forming tube to eliminate spiral seam lines and other undesirable characteristics on the outside surface of the formed concrete column. The tube is formed from spirally-wound plies of paper adhered together and has a centrifugally-cast epoxy resin coating sprayed onto the inside surface of the spirally-wound tube while the tube is rotating to produce a smooth inside coated surface on the forming tube.

Activatable adhesive webs and articles made therefrom

Activatable adhesive webs and articles made therefrom

The present invention relates to activatable webs having fibrous substrates coated with activatable adhesive and methods of forming the webs into articl es by indirectly activating the adhesive using microwave energy. The activatabl e web may further include a protective coating of a material that is compatibl e with the adhesive. One or more activatable webs can be formed into the shape of an article such as by wrapping the activatable webs around a mandrel. The activatable webs can be subjected to microwave energy shortly before being formed into the shape of the article or while they are held in the appropria te shape. The microwave energy is absorbed by moisture retained within the fibrous substrate, which becomes heated. The heated moisture activates the adhesive, causing it to bond to any webs in which the activatable web has be en brought into contact and to stiffen.

Composite core

A composite core tube is provided for the winding of a web of material. A hollow cylindrical core is covered by a water-resistant rigid sleeve in a heat fit manner to provide a winding surface. The sleeve is selected and finished to control the winding characteristics of the core.