Water-soluble and biodegradable plastic – Injection Moulding products

Funeral Urn example:

Leading directly from the development of compounded injection mouldable water soluble products (PVOH), a commercial opportunity arose involving the production of biodegradable / water soluble funeral urns.

The required urns consisted of 3 parts:  the first part was the main body, the second part the lid, and the third part was a water-soluble bag.  The brief for the production of the funeral urns was that the urn:

  1. had to hold the ashes from the cremation
  2. had to be formulated from water-soluble/biodegradable material,
  3. be completely soluble in water,
  4. dissolving and/or breaking down leaving no harmful residues of any nature.

The urn can be produced with a standard finish in a choice of several colours.  A more recent addition has been seen with the production of an urn with an attractive sand finish, which enhances the appearance of the urn, producing no adverse effects on this eco-friendly product.  The ashes obtained from the cremation are placed in the water-soluble tie bag provided with the urn, the bag is sealed with the help of a water soluble tape and the lid of the urn is placed on top forming a secure seal.  The bottom of the urn has 2 small holes which allows the urn to be used in “burial at sea” applications or land burial including mountain top for example.  At a dissolution temperature of 5 – 10°C, the urn will dissolve in under 48 hours at sea and, if the urn is left exposed to the atmosphere, at 21°C then the biodegradation time is 35 days.

For full technical data, see the data table below.

The urns may be manufactured in 3 colours – natural, terracotta and granite grey – with the fourth option of an attractive sand coating being recently made available.

The water-soluble bag provided is 300 x 400 x 25mm, with a tie tape which is water soluble.

EEC accredited Green Eco-Certifications are as follows:

  • Biodegradability according to UNE-EN-ISO 14851
  • Compostibility in accordance with EN13432
  • Non-toxicity accreditation according to UNE-EN-ISO 7346-1 and UNE EN ISO 6341

The compounded water-soluble resin is formulated in such a way to give the correct melt flow index (MFI) allowing the material to operate with traditional injection moulding technology, utilising both hot and cold runner systems.  Cycle times are dependent on the end size and shape thickness, etc, of the injection-moulded product but the two piece capsules shown in the picture were produced with cycle times of approximately 11 seconds.

Water-soluble/biodegradable injection moulded products can now be produced with the use of the compounded poly vinyl alcohol (PVOH) resins.

Pictures of injection moulded water-soluble biodegradable products will be uploaded soon

Pictures to show products here or produce schematic animation will be uploaded soon