Polyvinyl alcohol is on the up as more applications are mooted and a plethora of patents are filed. Pauline Covell reports

Understated for decades, polyvinyl alcohol has been somewhat of a dark horse in the packaging world. After all what on earth can you do with a water soluble film? However, it is just that property – coupled with a vast amount of research and development work over the past 20 years and the desire of brand owners and retailers to heed the calls for consumer convenience – that has led today to far more than just a passing interest in the material.

Indeed PVOH, a polymer that was regarded as something of a chemical oddity some 40 years ago, has been growing at a faster usage rate than probably any other material of its type over the past couple of years. That, anyway, is the view of the man who almost certainly has more patents in the field bearing his name than anyone else – David Edwards, project development director of water soluble packaging research and solutions provider Aquasol.

When the Co-op, Persil and Ariel brands of clothes washing liquids hit the retail shelves in PVOH capsules the polymer was on the map. “During the past three years demand has gone through the roof,” he says. Aquasol is highly unusual in the packaging industry in that it does not manufacture any materials or film itself, but concentrates on research and application development.

“There has been a massive fight for the film. Its conversion is no longer a cottage industry,” says Edwards, and one of the latest success stories is Electrasol – a new dish washing product from Reckitt Benckiser Inc. Developed in conjunction with Aquasol, the thermoform, fill and seal Gelpacs were launched last autumn in the USA and are said have “taken off with massive success.”

The material was really only of interest to academics and chemists in the 50s and 60s. There was no converting equipment developed and little was known about sealing the material. The Holy Grail for PVOH was the discovery and development by Edwards and the team at Rhone Poulenc in the late 80s of a material that could hold solvent based liquids. That discovery allowed liquid crop spray pesticides to be packed in a convenient and safe way for the farmer and, being able to throw a water-soluble pouch in the spray tank, let RP steal a march.

Innovation recognition

When David Edwards was hailed as Packaging Innovator of the Year for his work, the Financial Times reported in 1990 that it was “worth watching” as it could have applications in many other industries. How perceptive that was.

Two years later the team at Rhone Poulenc staged a management buyout of all the patents and founded Aquasol. “The discovery of being able to hold liquids and the original Rhone Poulenc stipulation that we could not touch the agrochemical market provided the launch pad for everything that has happened in the PVOH market. The irony is that it forced us to look at other markets and that is when it all started to happen,” he reveals. “The plus points of convenience and safety for the consumer were picked up by the detergent producers.”

Expanding on the benefits for brand owners Edwards says: “All the big players in home laundry and dishwasher cleaners traditionally competed through packaging – the graphics, a different liner in the bag, a different way of opening the box. It was not exactly rocket science.

“The introduction of unit dosing of liquid through capsules of PVOH was so radical for the industry. Lever took an enormous gamble with Persil. But they did it. The consumers liked it and they won. It is all around Europe now. He who dares wins – the precedent was set and, if the others didn’t follow suit, they could have lost significant market share.

“I can tell you that every product that comes out in a new water soluble configuration puts fear and trepidation in the boards of rival companies,” comments Edwards. “Following the very successful launch of Electrasol dishwasher in the US, Lever has launched Sun in its flying saucer capsule in Europe.

“Since the competitive stakes are so high there is continual frenzied research and development by some of the world’s biggest players, causing a systematic domino effect. This results in increased innovation and, subsequently, advanced technology for the end user. Patents are crawling out of the woodwork with a new one almost on a fortnightly basis.”

Development of the converting processes has had much to do with the recent successes. “They include vertical and horizontal form, fill and seal, preforming of bags, injection moulding and thermoforming. They all have their place and can be intermixed, but I consider the real future to lie in thermoforming and injection moulding,” he forecasts.

“The end user will benefit from more convenience and better products. The converters who were historically in the food business now find themselves in new market places. They are having a field day.”

&#8220I consider the real future to lie in thermoforming and injection moulding ”

David Edwards, project development director, Aquasol

Independent operation

Edwards stresses that Aquasol is independent and not in bed with any one film supplier. “They know they are seeing a massive demand for film with different and incredible properties. Film is needed that will hold borates and acids. Imagine if you can develop a film that holds bleach or chlorine – you could lock up the future with a massive order of magnitude. We are forcing the film producers to innovate.”

And the future? “I can safely say it is very exciting. We will see delivery systems of a highly sophisticated nature. We will see increased performance of products, controlled release of products, greater convenience to the consumer and greater protection for the operator, particularly where hazardous liquids are concerned.

“The impetus is being accelerated here by European environmental legislation so that the secondary packaging is very important too. We have some very exciting carrier technology. When the thermoformings are produced they are made on an APET carrier with the PVOH on top. We have also invested in cutting technology – up until now cutting has been very difficult.

“Films and equipment are changing radically. Not only are demands on the film manufacturers for properties tremendous but also for the amount of film needed and the thickness.”

So just what sort of applications can we expect? “We will have multi-activity within one unit dose. There will be different dividers, specially thinned areas, different hydrolysis triggers at different temperatures within the thermoforming. So different things can happen at different times.

“In injection mouldings similar things could happen. You could put a capsule containing concentrate down a drain. You can’t put the same sort of concentrate in a bottle.”

Edwards says there is potential in the drugs and medical market too. “The moulding could also allow for different release times. We are, for example, working on a medical application – the perforate capsule – that is currently going through the FDA process.”

Slow release pond chemicals or slick removers – with built in buoyancy designed into the pack – may also provide applications for moulded material.

In addition, the film can be used in skin packaging formats. Aquaskin, developed with the help of Arthur W Clowes, enables consumers to twist off the product from the backing board and allows product and film to be deposited in water as a whole or the skin to be removed easily.

“Geographically, we are seeing developments all over Europe like the toilet block freshener in Italy. The material is taking Canada by storm and the USA will overtake the lot,” predicts Edwards.

And the future for Aquasol? “We are piling all our money back into research, developing new patents all the time,” he says. “Where the business is, if you like, is at the Mark 2 level. We are already at Mark 8. Whereas all the current fascination is with detergents, I am now working on other areas of application.”

Packaging for electronics is also a potential area, given the non-static and high puncture resistant properties of PVOH. It really is a case of “definitely watch this space,” concludes Edwards.