CONVERTING NON-BIODEGRADABLE POLYMERIC GRANULES AND COMPONENTS TO BIODEGRADABLE BY SURFACE COATING

Abstract

The present invention describes a process to convert non-biodegradable polymeric raw materials or pellets/granules into biodegradable raw materials/pellets/granules by applying enzyme-based coating, in water or suitable solvent or combination thereof, on their surfaces, before construction of the components from them.

Claims

1. A method of converting non-biodegradable polymeric raw material granules into biodegradable polymeric granules by applying coating on partial or complete surface of the granules and subsequently drying or curing.

2. The method as claimed in claim 1 is done during production of the granules on extrusion palletiser by mixing the enzyme-based composition in the recirculating cooling water in the underwater palletizer or in the strands cooling tank and then cutting the strands to granules.

3. The method as claimed in claim 1, the drying or curing the coating applied on the components online or offline individually or in batches.

4. The method as claimed in claim 1, wherein the concentration of the enzyme-based composition in water/solvent in the defined range is monitored by suitable sensors.

5. The method as claimed in claim 1, wherein the method further comprising a periodic dosing of the enzyme-based composition in water/solvent manual or automatic required maintaining concentration in a defined range.

6. A method of converting non-biodegradable polymeric components into biodegradable polymeric components, the method comprising: providing a moulded polymeric components to a coating station; applying a thin uniform layer of an enzyme based coating on partial or complete surface(s) of the components using a suitable coating process; and drying or curing the coating applied on the components online or offline individually or in batches.

7. The method as claimed in claim 1, wherein the polymeric components are made of at least one of PE, PP, PET, Nylon, Polystyrene, Polycarbonate and the like or combination thereof.

8. The method as claimed in claim 1, wherein the enzyme based coating is a formulation having natural peptides/enzymes/proteins obtained from edible biological sources such as plant or vegetables.

9. The method as claimed in claim 1, wherein the coating process is at least one of the group of spraying, dipping, wetting, by pressing between wet rollers, fluidized bed, manual or automated mixing in bags or tumbler, Physical, Chemical or Electrostatic vapour deposition and the like.

10. The method as claimed in claim 1, wherein the drying or curing is performed by hot air blower or radiation source.

11. The method as claimed in claim 1, wherein the enzyme-based composition in water or suitable solvent or combination thereof is applied on partial or complete surface of the polymeric components during or after manufacturing them by injection moulding, blow moulding, extrusion, casting or any other manufacturing process.

Description

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

[0009] While the present invention has been described in connection with what are currently considered to be the most practical and preferred embodiments, it is to be understood that various arrangements and alternative embodiments are intended to be included within the scope of the appended claims.

[0010] The present invention relates to biodegradability of polymers by applying enzyme-based coating on partial or complete surface of any polymer, polymer blend or composite granules and polymeric components manufactured therefrom.

[0011] The enzyme present in the enzyme-based composition are natural protein molecules that act as highly efficient catalysts in biochemical reactions, that is, they help a chemical reaction take place quickly and efficiently. Studies show that the enzymes present in the enzyme-based coating attracts microbes over the component surface and colonizes on the surface of the plastic forming a biofilm. Therefore, when the enzyme based additives are coated on the surface, the accumulation of microbes is increased and faster in comparison to components/granules with dispersed additives.

[0012] Once the microbes have colonized on the component/granules surface they secrete acids and/or enzymes that break down the polymeric chains.

[0013] The microbes utilize biodegradable polymeric as the component in unavailability of microbial nutrients.

[0014] The formulation of the enzyme based coating may include, but not limited to, natural peptides/enzymes/proteins obtained from edible biological sources such as plant or vegetables etc. The coating formulation may be solvent or water based.

[0015] Typical enzyme-based compositions are described in Indian patent Appl. Nos. 3104/mum/2015 and 201611028054, and U.S. Pat. No. 9,925,707/EP3162841, however any other similar/modified composition can also be used without deviating from the scope of the present invention.

[0016] According to an embodiment, the present invention describes a process to convert non-biodegradable polymeric raw materials or pellets/granules into biodegradable raw materials/pellets/granules by applying enzyme-based coating, in water or suitable solvent or combination thereof, on their surfaces, before construction of the polymeric components from them.

[0017] The coating formulation may be water or solvent based or combination thereof. The enzyme-based coating may be applied using any known method in the art such as, but not limited to, spraying, dipping, wetting, by pressing between wet rollers, fluidized bed, manual or automated mixing in bags or tumbler, Physical, Chemical or Electrostatic vapour deposition etc. Details of the aforesaid coating mythologies, in the art, have not been provided herein for brevity of the present disclosure.

[0018] According to another embodiment, the present invention describes a method of coating granules during production of the granules on extrusion palletiser by mixing the enzyme-based composition in the recirculating cooling water in the underwater palletizer or in the strands cooling tank and then cutting the strands to granules.

[0019] A periodic dosing of the enzyme-based composition in water/solvent manual or automatic may be required to maintain concentration in a defined range. Suitable sensors may be used to monitor the concentration. Details of the aforesaid coating methodologies, in the art, have not been provided herein for brevity of the present disclosure.

[0020] According to still another embodiment, the present invention describes bio-degradable polymeric components, made from non-biodegradable polymeric materials, having enzyme-based coating on their surfaces and a method of coating the enzyme-based composition on the surface(s) of polymeric components to convert them into biodegradable. The enzyme-based composition in water or suitable solvent or combination thereof is applied on the surface of the polymeric components during or after manufacturing them by injection moulding, blow moulding, extrusion, casting or any other manufacturing process.

[0021] According to an embodiment, the aforesaid method of applying thin layer of enzyme-based coating on the surface of the polymeric components comprises the steps of providing a moulded polymeric component to a coating station; applying a thin uniform layer of an enzyme based coating on partial or complete surface(s) of the component at the coating station using a suitable coating process; and drying/curing the coating applied on the component online/offline individually or in batches.

[0022] The non-biodegradable polymeric component is introduced to the aforesaid process using continuous feeding mechanism, known in the art, to the coating station. The feeding mechanism holds the component to be coated and provides the component to the coating station in line or offline. The coating station(s) apply the enzyme based coating on complete or partial surfaces of the component. Thereafter the coated component is passed through a suitable process to dry/cure the coating applied on the surface of the component online/offline individually or in batches. The coating may also be applied on the surface(s) of the component in-line during the production of component at any suitable location. The coating is cured by drying/curing process that may be a hot air blower and/or radiation source such as but not limited to Electron Beam or UV lamp/LED.

[0023] The enzyme-based coating may be applied on all type of polymeric pellets/granules or components made of polymeric materials such as, but not limited to, PE, PP, PET, Nylon, Polystyrene, Polycarbonate etc. The coated products are various polymeric products such as, but not limited to, PET preforms, bottles, furniture, rigid packaging including trays, and boxes, sheets or any other articles made thereof.

[0024] The thin layer of enzyme-based coating, applied by the aforesaid method of the present invention, on complete or partial surface of the polymeric granules or pellets induces biodegradation without loss of physical strengths, structural characteristics or aesthetics.

[0025] The enzyme-based coating formulations may include a bio marker or any other type of covert marker to incorporate a mechanism to detect/identify/differentiate biodegradable polymeric granules/component from non-biodegradable granules/polymeric component, using suitable means after application.

[0026] The present invention requires substantially low quantity of enzyme-based composition compared to that in the prior art as the formulations are only coated on the surface of the granules/component and thus make the process cost effective.

[0027] While the present invention has been described in connection with what are currently considered to be the most practical and preferred embodiments, it is to be understood that various arrangements and alternative embodiments are intended to be included within the scope of the appended claims.