Abstract: A melt distribution block for a co-extrusion die has a generally annular body with opposed front and rear faces and opposed inner and outer faces. Inlets at the outer face have channel ports for accepting flow of melted polymer into the distribution block. Flow controlling valves independently control the melted polymer flow through each of the channel ports. Melt flow channels on the front and rear faces between the inner and outer faces are in fluid communication with the channel ports. A thermal insulation layer within the distribution block between the front and rear faces separate all or part of the melt flow channels on the front face from all or part of the melt flow channels on the rear face. The blocks, together with separator blocks, are axially stackable front to rear around a central mandrel to form an extrusion die for making blown films into tubular form.

Abstract: A melt distribution block for a co-extrusion die has a generally annular body with opposed front and rear faces and opposed inner and outer faces. Inlets at the outer face have channel ports for accepting flow of melted polymer into the distribution block. Flow controlling valves independently control the melted polymer flow through each of the channel ports. Melt flow channels on the front and rear faces between the inner and outer faces are in fluid communication with the channel ports. A thermal insulation layer within the distribution block between the front and rear faces separate all or part of the melt flow channels on the front face from all or part of the melt flow channels on the rear face. The blocks, together with separator blocks, are axially stackable front to rear around a central mandrel to form an extrusion die for making blown films into tubular form.

Abstract: A melt distribution block for a co-extrusion die has a generally annular body, for example in the shape of a conical frustum. The annular body has opposed front and rear faces and opposed inner and outer faces. Inlets at the outer face have channel ports for accepting flow of melted polymer into the distribution block. Flow controlling valves independently control the flow of the melted polymer through each of the channel ports. Melt flow channels on the front and rear faces between the inner and outer faces are in fluid communication with the channel ports. A thermal insulation layer within the distribution block between the front and rear faces separate all or part of the melt flow channels on the front face from all or part of the melt flow channels on the rear face. Such blocks together with separator blocks may be axially stacked front to rear around a central mandrel to form an extrusion die suitable for making blown films into tubular form.

Abstract: The envelope comprises layers of plain un-coated kraft paper and of bubble-wrap polyethylene. A stack of the layers is joined at the marginal edges of the envelope by squeezing the stack between a pair of points-dies, which are formed with points that puncture the kraft paper but do not puncture the polyethylene. The points push crowns of un-punctured polyethylene through the punctured boles in the paper. Then, the marginal edges are squeezed flat between flat-dies, the flat-dies being heated enough to cause fuse-bonding. The margins of the finished envelope are held together not only by fuse-bonding, but by the presence of the crowns, which, penetrating right through the holes in the paper, serve as mechanical rivets.

Abstract: The envelope comprises layers of plain un-coated kraft paper and of bubble-wrap polyethylene. A stack of the layers is joined at the marginal edges of the envelope by squeezing the stack between a pair of points-dies, which are formed with points that puncture the kraft paper but do not puncture the polyethylene. The points push crowns of un-punctured polyethylene through the punctured holes in the paper. Then, the marginal edges are squeezed flat between flat-dies, the flat-dies being heated enough to cause fuse-bonding. The margins of the finished envelope are held together not only by fuse-bonding, but by the presence of the crowns, which, penetrating right through the holes in the paper, serve as mechanical rivets.

Abstract: The insulated transit bag is made from bubble-wrap material, bonded to aluminum foil. The material is doubled-over, folded, and heat welded to form sealed seams. The bag is used for transporting heat-sensitive medicines etc.