Frequently Asked questions

FAQ about Aquapak polymer (called Hydropol)

What is a polymer?

A polymer is a large molecule, made from connecting many small molecules called monomers. Polymers are very common and can be naturally occurring, like starch, cellulose, rubber and protein – or can be man-made, like plastic and some fibres.

Is there a quick overview of Aquapak polymer?

Here is a 2 minute introduction to Aquapak Polymer explaining its properties and benefits:

What makes Aquapak’s polymer soluble?

Aquapak’s polymer, Hydropol™is made from a range of different PVOH blends, formulated using Aquapak’s proprietary process, which can be designed to be soluble in water at controllable temperatures.

The temperature at which products made from Hydropol™ dissolve in water can be varied by the type of PVOH used, the thickness and surface area of the product, the temperature, agitation and the amount of water present. Hot water soluble grades, for example, are more robust at cold temperatures, but dissolve rapidly at temperatures above 70℃. The water solubility is an important feature for the end of life, as it causes the product to soften and break-down in the environment over time into mineralised biomass, CO2 and water. Warm water soluble grades will break-down rapidly at temperatures above 40℃. These features of Hydropol™ make it a very useful material in its own right for certain applications, but would need to be combined with another more impervious material, if more resistance to water is required.

Video: Watch this video to see a bag made from Hydropol™ hold cold water but then dissolve rapidly in very hot water.

Please note that the bag was held in a controlled situation to give a clearer video but to avoid potential burns we advise that bags are placed in a sink and that hot water is poured over them. 

What is a hydrophilic polymer?

Aquapak polymers are hydrophilic. A hydrophilic polymer is attracted to water and in the right conditions (temperature, agitation etc.) will be dissolved in water. This property is important in enhancing biodegradation and other properties such as compatibility with other materials such as cellulose.

Aquapak polymer is designed to replace traditional hydrophobic polymer from which nearly all other plastics are made – and are certainly the most used. Hydrophobic (water-hating) materials not only take hundreds-thousands of years to break down, but often produce toxic breakdown products as they do.

What is Aquapak’s Hydropol™ made from?

Aquapak polymer, including HydropolTM is made from PVOH. Aquapak has, after 10 years of R&D, perfected a method of thermally processing PVOH allowing the production of pellets, which is the standard form for secondary processing in the plastics industry. Aquapak’s global patent is a combination of process know-how and chemistry.

Aquapak’s materials, being based on PVOH a hydrophilic and water-soluble polymer, are inherently biodegradable, that is, given the right balance of environment and microbial presence it will biodegrade to carbon dioxide, water and mineralised natural biomass.

What is PVOH (Polyvinyl Alcohol)?

Polyvinyl alcohol (PVOH) is a water-soluble polymer, sold in both fully and partially hydrolyzed forms. Its technical properties vary depending on molecular weight (degree of polymerization) and fraction of acetate groups that are removed (degree of hydrolysis).

In what form is Aquapak’s polymer supplied?

Aquapak’s products are in pelletised form at all hydrolysis levels, including high hydrolysis to maximise application potential. As they are available as standard plastic pellets, stability and storage is not an issue.

What has HydropolTM been tested against?

A full list of our testing is available in our white paper. Examples of some of the more pertinent tests and Standards are listed below:
1. Determination of biobased content: CEN/TS 16137; ASTM D6866
2. Composability: EN 14995; EN13432; ASTM D6400; ISO 17088; AS4736; ISO18606; ASTM D6868
3. Anaerobic Digestion: ISO 15985; ASTM D5511
4. Soil: ISO 17556
5. Freshwater: ISO 13975; EN14987
6. Landfill: ASTM D 5526
7. Aerobic wastewater & sewage sludge: EN14851; EN14852
8. Anaerobic wastewater: EN14853
9. Marine: ASTM D6691; OK Marine; ISO 18830 (floating); ISO 19679 (sediment)
10. Recycling: ISO 15270 Guidelines for the recovery and recycling of plastics waste
11. Plastic waste: EN15347


FAQ about Hydropol's end-of-life

Does HydropolTM form microplastics?

Microplastics are simply small pieces of plastic, defined in 2009 as “plastic particles smaller than 5mm in size”.

Depending on the environment, Hydropol™ in solid form may break down to small particles but without the formation of toxins or the subsequent absorption of toxins associated with traditional plastics. These small particles will not persist in the environment unlike conventional plastics whose long lasting hydrophobic micro-particles absorb and concentrate toxins. When in solution Hydropol™ cannot form microplastics.

How can Hydropol™ be Recycled?

Recyclability depends upon what Hydropol™ is made into and whether it is mixed with other materials. For example:

  • Single materials
    • Soluble in warm or hot water (40°C or >70°C)
    • Sortable with infrared signature
  • Coated paper
    • Paperboard re-pulping
    • HydropolTM recovered or left in pulp
  • Bi-layer laminates
    • HydropolTM dissolves > recycle other material
    • Traditional recyclable plastics – PE, PET
  • Compostables – cellulose, Polylactic acid
    • HydropolTM dissolves > recycle or compost other material

What does HydropolTM biodegrade into?

HydropolTM  polymer biodegrades into carbon dioxide, water and mineralised biomass.

Why is carbon dioxide produced during its disposal?

CO2 is a natural bi-product of living organisms, hence it is produced when micro organisms breakdown HydropolTM

What is mineralised biomass?

In this case of polymer degradation, the term mineralisation indicates a natural biological breakdown step of the carbon in the polymer to carbon dioxide and water. So, via a process of oxidation the polymer breaks down via chain breaking to form smaller oxidised polymer chains (mineralised biomass) which then break down further to carbon dioxide and water. HydropolTM does not yield any harmful products in any stage of breakdown and biodegradation.

What do you mean by a plastic for the circular economy?

The drive towards a Circular Economy means the development of a sustainable materials chain which has all the advantages of modern highly functional materials in their primary and secondary uses but combines it with real end of life options.

FAQ about Finisterre's Leave No Trace garment bags

What are Finisterre’s leave no trace bags made from?

Finisterre has partnered with Aquapak, whose Hydropol™ range is based on specialty hydrophilic (water-liking) polyvinyl alcohol.

Can Finisterre’s Leave No Trace bags be recycled?

Yes. The material can be readily identified by sorting methods such as infra-red and laser sorting and can therefore be separated and reprocessed.

In less sophisticated waste handling facilities, the use of a hot water wash enables HydropolTM to be taken into solution. Once in solution the polymer can either be recovered or the solution allowed to go to normal waste water treatment or anaerobic digestion.

Are Finisterre’s Leave No Trace bags biodegradable?

By its nature Aquapak’s base polymers are inherently biodegradable and there is a large amount of historical work undertaken by academic and other researchers in this area detailing the microorganisms which breakdown the polymer in various conditions.

Are Finisterre’s Leave No Trace bags safe in waste water treatment systems?

The base polymer has been used for many years in applications where the disposal route is through the waste water system and there are no reported problems, and this has been confirmed by a historical literature review as well as work conducted at two UK Universities on Hydropol™  film.

Are Finisterre’s Leave No Trace bags safe in the sea?

Aquapak and Finisterre are very much aware of the ocean plastics problem and are in touch with several organisations looking at this problem. Work has already been undertaken with a renowned university in toxicology testing using standardised marine fauna and no deleterious effects were found. Read more

If a turtle eats a leave no trace bag, what happens?

The work undertaken so far by independent laboratories including the OK Marine certification scheme indicates that Hydropol™  is non-toxic to marine species which would include turtles. The mechanism of breakdown would also decrease the possibility of the turtle accumulating levels which would be harmful unlike most conventional plastics.

FAQ about Hydropol's sustainability

Where can I get a repulpability data on HydropolTM on coated paper?

This report assesses the re-pulpability of Hydropol™ on a variety of coated papers using standard paper industry assessment methods.

Where can I get a scientific paper on HydropolTM for my sustainability team?

This White Paper provides a more technical summary of the latest test data on HydropolTM at End of Life and an overview of the regulatory environment governing Hydropol’s routes to market.

Want to know more?

Speak to our team