Dual-Chamber Plastic Tubes

Plastic tubes are a preferred format for consumer packaging. Recent developments in tubes are requiring our attention, as they enhance consumer convenience.
A tube is a soft squeezable, basically, cylindrical, hollow piece with a round or oval profile, made of plastic or aluminium, which can be used for thick liquids such as glue, gel, crème and toothpaste. Both ends of the tube are treated differently during the manufacturing process and filling. In general, on one end of the tube body there is a round orifice, which can be closed by different caps and closures, while the other end is mostly sealed flat.

Recently World Wide Packaging LLC was honoured with the Skin Care Package Design Innovation for its new Tube-in-a-Tube created for Avon, which offers a unique approach to dispensing two separate products simultaneously. (See for details below)

But Avon’s Tube-in-a-Tube is not the first one. Dual-chamber tube packaging is not exactly new. Inventors and packaging developers have been working on the idea for more than 30 years, and a number of possible solutions have been patented. But surprisingly few solutions are commercialized as most of the inventions showed production problems or didn’t get the financial backing necessary to come to market. Let’s take a short historic journey and a look at the most striking innovations.

Dual chamber flexible tube dispensing
With US Patent 6063223 (1998) the inventors Christian Klauke and Igor Beaufils introduce a completely new idea for dual chamber tubes. In accordance with the invention the dual chamber flexible tube comprises two substantially identical tubes that are mirror images of one another, except for the finishes. Each tube includes a rigid half finish, a rigid half shoulder and a flexible tubular body extending from the shoulder. The cross sections are D-shaped such that each has a flat portion. The two tubes have the flat portions in abutting relation to one another so that the dual tube has a finish defined by the two half finishes. When the two tubes are brought into abutting relation a continuous thread is formed on the finish. The resultant dual chamber flexible tube packages are then filled with the respective viscous materials and the open ends are sealed to complete the package.

The inventors claim that among the advantages of this invention are ease of assembly and better filling and sealing line characteristics.
I never have seen this type of dual chamber tube commercialized so I have only some pictures from the patent to show you.

California Tan of Beverly Hills
In Nov 1999 California Tan introduced a new skin care and tanning emollient containing champagne and caviar. Called “Forbidden”, the product includes two formulations of these ingredients along with other more traditional tanning agents.
To protect the potency of the two formulations, the emollient is packaged in a dual-chamber package that keeps the materials separated until they are combined during application. The two formulations have different purposes.
The dual-chamber laminated flexible tube, developed and patented by CCL Container Tube Div., is formed from a five-layer construction containing one colour layer.
The tube’s centre layer is aluminium foil, with a copolymer layer on either side and a coextruded polyethylene (PE) film forming the inner and outer surface layers. The colour is in the copolymer layer above the aluminium, with the clear PE above it. Decorations are applied to the web stock before forming.
The dual-chamber is formed by inserting a polyethylene divider after the tube is formed. The divider is spot-welded at the shoulder and splits the entire tube into two isolated chambers, right up through the orifice. The two disparate products are mixed only when squeezed onto the consumer’s palm and rubbed into the skin according to directions.

Kawamata’s Dual-Chamber Tube
In the 2003 issue of the Japan Packaging Institute Journal Shigeyuki Kawamata of the Kao Corp., wrote about a new development in Japan, which obviously comes, as you will see, very close to the Avon Tube-In-A-Tube, mentioned above and detailed below. He writes: “This product is the first toothpaste in Japan that contains two kinds of fluoride (MFP and NaF) and Ca2+ to promote recalcification of initial caries-like enamel. In order to avoid the reaction of NaF and Ca2+ before using, the products are separated from each other in the same tube. This dual tube has an outer tube, an inner tube and a flip top cap. In order to simplify the construction, the inner tube is inserted into the outer tube and the mouth of the inner tube is fixed directly to the flip top cap by two undercuts. This tube container is a simple Dual Chamber Tube as two kinds of contents can be squeezed out in an almost equal dosage at the same time.”
I haven’t been able to find a picture of this innovation, but as I said it sounds very similar to the Avon Tube-in-a-Tube.

Simply White Dual Chamber Tube
In 2004 the Simply WhiteColgate Simply White Dual Chamber Tube was introduced by AISA Automation Industrielle SA, in Switzerland.
The tube is composed of a thin multilayer divider film welded onto the inner tube body walls and moulded onto the tube shoulder with separate orifices for each cavity. Since the thin divider film has minimal influence on the pressure distribution during squeezing, the nearly equal pressure applied on both component parts results into the most accurate dosing possible for such dual chamber tube packaging.

Aisa used a completely different approach to the dual chamber tube than the above mentioned innovators. They were able to do so as they use a laminate for the tubes.
Contrary to plastic tubes which are, in general, extruded through a set of sizing dies and made from a PE or PP film, laminate tubes are manufactured by using the laminate feed stock that is simply a poly-foil-poly structure that has polyethylene on either side of a thin gauge of foil. The material is taken in a flat state and fed through the forming rolls, which very gently turn the tube and form it into a cylinder of variable size. Heat generated by high frequency fuses the sides of the material together to form a solid cylindrical tube.

Within this production process Aisa developed the “Divider Tube Technology”, whereby the divider film (typically a 5-layer PE/EVOH/PE film) is welded onto the printed laminate.
In the second stage the laminate assembly with the divider film is formed into a tubular shape, and welded to create a side seam. During this operation the divider remains in its original position. At the end of the body-maker section the tube is cut to length and the divider inside the tube bodies is placed in position by several mechanical devices.

With the tube body and divider in the desired position and loaded onto the mandrels, a PE tube shoulder is compression-moulded and welded into place. The two half-moon shaped orifices are also formed during this operation.

And now the most recent development in Dual Tubes:

Avon’s Tube-in-a-Tube dispenser
Tube-in-a-Tube offers a tube containing one solution, while a second, smaller tube built into the larger tube holds a second solution. When the tube is squeezed, both products are dispensed at the same time, thereby activating both products.
Avon ANEW Dual Tube, manufactured by World Wide Packaging LLC, is the first mass produced commercial tube within a tube of this size. The packaging, ensuring the formulations stay separate until dispensed by the consumer, consists of a 50mm round outer tube containing a 35mm round inner tube. The tube heads and orifices have been globally patented. The tube is capable of dispensing two different products equally (50%/50%) at the same time.

What will be next in tube development.

One response to “Dual-Chamber Plastic Tubes

  1. Pingback: Tweets that mention Dual-Chamber Plastic Tubes « Best In Packaging -- Topsy.com·

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