FR2612931A1 - Process for the manufacture of plastic packaging and packaging obtained by making use of the process - Google Patents

Abstract

The process is noteworthy in that a certain quantity of a master batch consisting of a product which has properties that are capable of making the packaging obtained degradable under the effect of an external atmospheric phenomenon is incorporated into the starting polymer before conversion.

Description

 The invention relates to a method of manufacturing plastic packaging and packaging obtained by the implementation of the method.

 The object of the invention is related to the technical sector of plastics processing.

 It is known that the use of packaging, in the form of films, bags, plastic bags, in particular based on polyethylene, is becoming increasingly important. Indeed, a large part of the consumed products are packaged, grouped and / or transported in such packaging. It has been found that very often after their use and primary function, these different types of packaging are left in the nature, of a significant pollution.

 The problem being thus posed, the purpose of the invention is to remedy these drawbacks. in a simple and effective way, by making these different self-degradable packaging.

 In this respect, it has been designed and developed a specific manufacturing process to control the degradation of polyethylenes used for packaging foodstuffs or various consumer goods.

 In order to achieve this result, a certain amount of a mixture-ma-lter consisting of a product having properties capable of rendering the packages obtained degradable under the effect of a phenomenon is incorporated into the starting polymer before transformation. outside atmosphere.

The process according to the invention is applicable to all types of polyethylene-based packaging such as
- Neutral or printed films and sleeves. in rolls, used in automatic or manual packaging,
- Films, sheaths and retractable covers used for bundling and bundling, - - Open mouth bags,
- Shoulder bags,
- Heaped bags,
- Bags in pre-cut rolls,
- Etc ...

The invention is described below in more detail with the aid of the accompanying drawings in which
FIG. 1 is a purely schematic view illustrating an example of an installation for carrying out the method,
- Figure 2 is a block diagram of the main phases of the manufacturing process.

 In order to make more concrete the object of the invention, it is now described in a non-limiting manner with reference to the embodiments of the figures of the drawings.

 The various types of polyethylene packaging are obtained, in a perfectly known manner, by the tubular extrusion process. To this end, as is shown schematically in FIG. 1, the thermoplastic compound (P>) is generally present in billets or aggregates in a hopper (T) surmounting a box (C) heated to maintain the temperature required for satisfactory state of viscosity of the polymer The granules are driven by means of a cooling screw (A) which successively comprises a feed zone, a compression zone and a dosing zone. output comprises a die section appropriate to the desired shape and then different means and workstations given the type of packaging to obtain.

 According to a characteristic underlying the invention, is incorporated into the starting polymer (polybenthylbne mixture), a certain amount of a masterbatch (M> consisting of a product capable of ensuring the self-degradability of the packaging got.

 The quantities and proportions of this masterbatch can be variable to obtain a more or less rapid controlled degradability. This masterbatch is a concentrated material integrated at a certain percentage of the order of 5; 6.

 In a preferred manner, this masterbatch consists of a product capable of ensuring the photodegradation of the wrap under the influence of the ultraviolet rays. As an indicative example, the product can be in this case a mixture based on sulfur and iron.

 It is obvious that other mixing agents capable of ensuring the biodegradability of the packaging under the action, for example, should not be excluded. air, water and other external atmospheric phenomena.

The polyethylene film thus obtained is then processed on conventional printing and welding machines depending on the type of packaging desired. The method according to the invention is therefore characterized by the following essential steps:
- incorporation into the starting polymer (polyethylene) of a certain amount of mblange-maltre (step 1),
extrusion of the mixture of polyethylene mixed with the masterbatch (step 2),
- Transformation of the plastic film obtained according to the desired final packaging product (step 3).

 For example, the homogeneous mixture obtained is blown to obtain a sheath and then possibly impressed. This sheath, printed or not, is then properly cut and welded for the realization of shoulder bags, smooth bags, bags roui waters.

 it follows therefore that the bags or other types of packaging obtained according to the invention, are likely to kill automatically destroyed if they are left for a variable time variable, ranging from a few days to several months, in contact with the external atmospheric agents.

Claims (1)

- i - A process for manufacturing plastics packaging especially polyethylene, characterized in that is incorporated in the starting polymer before processing, a certain amount of a mxlange-maltre consisting of a product having pro pieties apt to to render the packaging obtained degradable, under the effect of an external atmospheric phenomenon. The process according to claim 1, characterized by the following essential steps  - is incorporated in the starting polymer, namely polyethylene, a certain amount of masterbatch  the polyethylene mixture containing a masterbatch is extruded,  the plastic film obtained is converted according to the desired packaging product. - 3 - Process according to claim i, characterized in that the concentrated masterbatch results from a mixture shaped to ensure photo-degradation of the package under the influence of ultraviolet rays. - 4 - A method according to claim 1, characterized in that one incorporates the mix-maltre variable amount depending on the desired time for the packaging becomes degradable. - 5 - Packaging obtained directly by the implementation of the process according to any one of claims 1 to 4! characterized in that it has chemical characteristics capable of rendering it degradable after a given time. under the effect of external atmospheric phenomena. Packaging according to claim 5, because it is in the form of bags.