Laminate tubes are manufactured from rolls of laminate feed stock commonly called web stock made of different polymers and a barrier layer.
The web stock in rolled form is first printed by offset/letterpress, flexographic or digital means before being delivered to a manufacturing line to produce the tubes.
In the tube making process, the printed web stock is unrolled and continuously fed through forming rolls, which very gently turn the flat material and form it into a cylinder of different diameters depending on the end customer’s needs. Heat generated by high frequency fuses the sides of the material together to form a long cylindrical sleeve or tube. After the cylindrical sleeve has been formed, it advances to a cutting station where the long sleeve is cut into smaller sleeves of a uniform length.
After the tube has been formed into the desired cylindrical length, the sleeve is transferred to the heading operation. Several different heading methodologies are possible depending on the type of production machine employed to make tubes. There are three common possibilities to make the shoulders – shoulders made by in-line injection or compression molding of the shoulder or by introducing a preformed shoulder which has been produced in a separate, offline operation. For the in-line molding operations, the plastic resin to be used for the specification is heated and the molten plastic forms the tube head in a mold which is then fused to the tube body. With the preformed shoulder, the tube sleeve is placed onto a mandrel and the preformed shoulder is fed onto the mandrel with the sleeve and the two are fused together at the top of the sleeve by heat generated by high frequency energy or hot air.
After the complete tube has been formed, it goes to the capping station where the closure is applied. The cap is applied and torqued to the desired torquing requirements. The tube is then ejected onto a conveyor and taken to a packing operation where it is packed into a carton and is ready for filling with product at the customer’s site.
Depending on the product to be packaged, laminate tubes can have a barrier layer of aluminum, plastic or ceramic. The most common tubes can either be Aluminum Barrier Laminate (ABL) or Plastic Barrier Laminate (PBL) depending on the materials used in the construction of the tubes. For ABL, aluminum foil in thickness of 9µ to 30µ are typically used. PBL tubes are all plastic and can include a barrier layer or be made without a specific barrier. The barrier layer, if required, typically involves different thickness of Ethylene Vinyl Alcohol (EVOH) copolymer added to limit oxygen permeation into the product through the tube sleeve.
Laminate tubes combine the beneficial properties of different materials: excellent barrier effect to protect the contents and high-end print quality using essentially all printing techniques to produce packages with aesthetic appeal.
M. Hoard
Albea Americas, Inc.
