Method for processing dairy bottle recycled material in the new production of dairy bottles (closed loop, bottle-to-bottle) and products obtained therefrom

Abstract

The present invention provides a method for processing dairy bottle recycling material in the new production of dairy bottles (closed loop; bottle-to-bottle).Furthermore, the present invention provides a multi-layer plastic bottle for containing and storing dairy products, obtainable by the method according to the present invention.

Description

[Technical field]

[0001] The present invention is located in the field of waste treatment and recycling, more particularly the reuse of product streams obtained from the processing of plastic packaging, and even more particularly dairy bottles.Furthermore, the present invention is located in the field of plastic preforms and bottles obtained from plastic preforms, in particular plastic dairy bottles. [Background technology]

[0002] Plastic packaging is widely known and widespread. Many types of plastic bottles are known in the state of the art, such as the so-called polypropylene, polycarbonate, polyethylene and polyester bottles. These bottles are used for a variety of purposes and are particularly suitable for containing beverages, including dairy products.

[0003] Beverage containers are usually transparent. This includes beverage bottles for water, soft drinks and alcoholic beverages. Transparent beverage containers, especially PET packaging, are well recycled. The material stream obtained from the processing of empty PET beverage containers can be reused to produce new beverage bottles.

[0004] A beverage bottle that is not reusable so far is the milk bottle. White-coloured polyolefin milk bottles are commonly known. White PET-based milk bottles with carbon black-based light blocking are becoming more and more common. The disposal of these milk bottles is problematic: shredding the bottles results in a stream of grey PET chips. There is no sales market for this food contact material. It is considered waste and is incinerated. The use of these plastic milk bottles is discouraged by environmental taxes.

[0005] Plastic packaging for non-drinking applications is also often opaque. Examples include plastic bottles for detergents, sauces, and oils. The opacity is achieved through the use of dyes and additives. Ketchup bottles, for example, are often colored red. PET is also increasingly used here. There is almost no sales market for colored waste streams (red, green, blue, yellow, other colors). "Non-colored" colors are white, gray, and black.

[0006] A further problem is the standardization of beverage bottles. Food contact regulations state that food or beverage packaging may only contain a maximum of 5% by weight of something that is not so-called food contact approved. Nowadays it is very difficult for bottle manufacturers to control the use and content of non-food recycled materials.

[0007] The present invention seeks to provide a solution to at least one of the above problems, in particular for the sustainable use of polyester, preferably PET, in plastic packaging, in particular beverage packaging, especially milk bottles. Summary of the Invention

[0008] In a first aspect, the present invention provides a method for processing dairy bottle recycled material for input into new production of dairy bottles, comprising the steps of: - shredding of used plastic dairy bottles and subsequent mechanical recycling to obtain dairy bottle recycled material in the form of granules; - forming an intermediate layer of a preform for a new multi-layer plastic dairy bottle by incorporating recycled dairy bottle material by injection molding, the preform having an inner layer that contacts the contents of the dairy bottle in use, an outer layer opposite the inner layer, and an intermediate layer between the inner layer and the outer layer; Contains the inner and outer layers are white and the middle layer is black, gray or colored; the interlayer has a light transmittance of less than 5% as measured by a spectrophotometer according to ASTM D1003 at 530 nm using a D65 lamp simulating natural lighting.

[0009] In a further aspect, the present invention provides a multi-layer plastic bottle for containing and storing dairy products, comprising an inner layer in contact with the contents of the bottle or preform, an outer layer opposite the inner layer, and an intermediate layer between the outer layer and the inner layer, The intermediate layer comprises opaque plastic pieces, the intermediate layer being black, gray or colored, and the multi-layer dairy plastic bottle can be obtained by a method according to an embodiment of the present invention, the intermediate layer having a light transmittance of less than 5% measured by a spectrophotometer according to ASTM D1003 at 530 nm using a D65 lamp simulating natural lighting.

[0010] As used herein, the term "opaque" or "opacity" refers to a measure of a material's light impermeability. Opacity is expressed as the ratio of transmitted luminous flux to incident luminous flux. The opposite of opacity is transmittance or transmission. Opacity and opacity refer to opaque materials. Transparent or slightly translucent plastic containers can be made opaque by adding fillers and / or pigments.

[0011] A transmittance of less than 20% is considered opaque, while a transmittance of more than 20% corresponds to a transparent or translucent material. Opaque bottles are used especially for milk bottles and detergent bottles. For dairy bottles, it is important to provide sufficient opacity to preserve the vitamins in the dairy product.

[0012] The use of opaque plastic pieces for the intermediate layer, preferably the opaque intermediate layer, has the advantage that the intermediate layer contributes to making the bottle impermeable to light.

[0013] In a third aspect, the present invention provides a multi-layer dairy product package comprising a multi-layer plastic bottle according to a preferred embodiment of the present invention and a sterilized dairy product contained in the multi-layer plastic bottle, preferably the sterilized dairy product is milk. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Unless otherwise specified, all terms used in the description of the present invention, including technical and scientific terms, are intended to have the meanings commonly understood by workers in the art to which the present invention pertains. Furthermore, definitions of terms are included to better understand the description of the present invention.

[0015] As used herein, the following terms shall have the following meanings. As used herein, "A," "a," and "the" refer to both the singular and the plural unless the context clearly indicates otherwise. For example, "a compartment" refers to one or more compartments.

[0016] As used herein, "about" referring to a measurable value such as a parameter, amount, duration, etc., means including a variation of the stated value of + / -20% or less, preferably + / -10% or less, more preferably + / -5% or less, even more preferably + / -1% or less, even more preferably + / -0.1% or less, insofar as such variation is appropriate for implementing the described invention. However, it will be clear that the value to which the term "about" refers is also specifically described. As used herein, the terms "include", "including" and "included" are synonymous with "comprise", "comprising" and "comprises", and include those followed by these terms, such as open terms indicating the presence of components and not excluding the presence of further unmentioned components, properties, elements, components, steps that are well known or described in the state of the art.

[0017] The recitation of a numerical interval by endpoints includes all integers and fractions contained within that interval, including those endpoints.

[0018] As used herein, the term "wt. %" refers to a weight percentage that is the ratio of the weight of a component to the total weight of the bottle, not including the closure, expressed as a percentage.

[0019] In a first aspect, the present invention provides a method for processing dairy bottle recycled material for input into new production of dairy bottles, comprising the steps of: - shredding of used plastic dairy bottles and subsequent mechanical recycling to obtain dairy bottle recycled material in the form of granules; - forming an intermediate layer of a preform for a new multi-layer plastic dairy bottle by incorporating recycled dairy bottle material by injection molding, the preform having an inner layer that contacts the contents of the dairy bottle in use, an outer layer opposite the inner layer, and an intermediate layer between the inner layer and the outer layer; Contains the inner and outer layers are white and the middle layer is black, gray or colored; the interlayer has a light transmittance of less than 5% as measured by a spectrophotometer according to ASTM D1003 at 530 nm using a D65 lamp simulating natural lighting.

[0020] The very limited light transmission provided by the middle layer is favorable for reducing the degradation of vitamin B2 in dairy products. 530 nm is the UV-visible light absorption maximum of riboflavin (vitamin B2). Riboflavin is found primarily in dairy products such as milk.

[0021] Shreds of plastic dairy bottles can be obtained by cutting or crushing.

[0022] The term "particulate" refers to solid material in granular form.

[0023] Preferably the dairy bottle recycle material is pigmented, meaning having a color and thus not black, white or grey.

[0024] Preferably, the intermediate layer comprises opaque pigmented plastic pieces, more preferably opaque pigmented polyester pieces.

[0025] Even more preferably, the intermediate layer comprises opaque green polyester flakes. Opaque green plastic flakes are currently hardly recycled. The use of these materials has a beneficial environmental impact. Incineration as a solution for processing opaque green polyester flakes can be reduced and in some cases even avoided.

[0026] Preferably, the intermediate layer has a light transmittance of less than 1%, more preferably less than 0.5%, most preferably less than 0.1%. This has the advantage that the intermediate layer provides light protection for the preservation of vitamin B2 in dairy products. These products are typically stored in plastic dairy bottles.

[0027] Preferably, up to 5% of the non-food recycle material is processed in dairy bottles, more preferably up to 3%, even more preferably up to 1%, and most preferably 0% of the non-food recycle material is processed in dairy bottles.

[0028] In a method according to a preferred embodiment of the present invention, the dairy bottle recyclates are recycled milk bottles, and the new dairy bottles are preferably milk bottles.

[0029] The dairy bottle recycle material is preferably polyester plastic shredder. More preferably, the dairy bottle recycle material is PET shredder.

[0030] The plastic preform is preferably obtained by injection molding.

[0031] The multi-layer structure of the preform is preferably obtained by co-injection. The simultaneous use of different raw materials is advantageous for time utilization in the manufacturing process. Preforms obtained from the co-injection process have improved adhesion of the layers.

[0032] In a method according to a preferred embodiment of the present invention, the method comprises the following steps: - injecting a quantity of a first material into a mold cavity in an injection mold and injecting a quantity of a second material into the mold cavity to form a core within the injected first material to produce a preform. Further comprising: - in a main phase, in successive injections, a first material is completely injected into the mould cavity, followed by a second material completely injected; - during successive injections, a first material is injected so as to provide an inside and an outside of the preform, and a second material is injected into a region located at the level of the injection openings of the injection mold so as to provide an intermediate layer of the preform located between the inside and the outside of the preform; in the final stage, the first material is pushed towards the preform mouth by injecting the second material, the second material always being injected into the intermediate layer without the possibility of penetrating from the outside of the preform to the inside, The first material is polyester and the second material is an opaque plastic piece, excluding black opaque plastic pieces, preferably the second material is an opaque colored polyester plastic piece.

[0033] In another method according to a preferred embodiment of the present invention, the method comprises the following steps: - injecting a quantity of a first material into a mold cavity in an injection mold and injecting a quantity of a second material into the mold cavity to form a core within the injected first material to produce a preform. Further comprising: in parallel injection, a first material is injected inside and outside and a second material is injected into the middle layer in the area located at the level of the injection openings of the injection mold; - in a preliminary step, only a predetermined amount of a first material is injected into the injection mould, - in a final step, a predetermined amount of the first material is injected and, if necessary, the second material is further forced towards the front of the injection mould; The first material is polyester and the second material is an opaque plastic piece, excluding black opaque plastic pieces, preferably the second material is an opaque colored polyester plastic piece.

[0034] In a method according to a preferred embodiment of the present invention, a preform is blown to form a new dairy bottle containing recycled dairy bottle material in an intermediate layer.

[0035] The multi-layer plastic bottle is preferably obtained by coinjection blow molding, in which a coinjection molding process for producing a preform is followed by blowing the preform into a bottle shape.

[0036] Preferably, the material of the interlayer is additionally pigmented to enhance the opacity of the interlayer.

[0037] Preferably, the intermediate layer contributes at least 5% of the wall thickness. Wall thickness can be measured using techniques well known to those skilled in the art.

[0038] The middle layer incorporates recycled opaque plastic fragments obtained from the processing of used plastic bottles or plastic preforms for dairy bottles. In this way, dairy bottle material is reused to produce dairy bottles. This so-called closed-loop system, or bottle-to-bottle recycling system, is part of the present invention. The dairy bottles thus obtained are durable and reusable.

[0039] In a method according to a preferred embodiment of the present invention, dairy bottles from a dairy bottle filler are reprocessed into new dairy bottles for the same filler. This method provides bottles that are reprocessed into new bottles containing bottle recycle material; the so-called "bottle-to-bottle" principle.

[0040] In a method according to a preferred embodiment of the present invention, used dairy bottles from pre-identified dairy bottle fillers are collected separately and processed into new dairy bottles for pre-identified dairy bottle fillers. This method provides material control; the so-called "closed loop" principle.

[0041] Preferably, the intermediate layer provides at least 5% of the wall thickness of the multilayer preform or plastic bottle. Even more preferably, the intermediate layer provides at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50% of the wall thickness. Preferably, the entire intermediate layer is opaque.

[0042] Said recycled material is preferably PET recycled material, more preferably opaque PET recycled material, most preferably opaque green PET recycled material.This has the advantage of increasing the reuse of PET materials, especially opaque PET materials, which have limited recycling applications due to their visual aspects.Another advantage is that the environmental tax on opaque pieces can be reduced by recycling them.

[0043] Preferably, the bottle outer wall forms a light shield. The multi-layer plastic bottle or preform preferably has a white outer layer. In combination with an intermediate layer with opaque plastic pieces, less dye can be used in the outer layer. The use of new materials is reduced.

[0044] The multi-layer dairy plastic bottle is preferably a bottle for containing pasteurized milk, milk drink, pasteurized yogurt (drink), creamer, coffee milk.

[0045] In a further aspect, the present invention relates to a multi-layer plastic bottle for containing and storing dairy products, characterized in that it comprises an inner layer in contact with the contents of the bottle or preform, an outer layer located opposite the inner layer, and an intermediate layer located between the outer layer and the inner layer, the intermediate layer comprising opaque plastic pieces, excluding the black and grey intermediate layers, the multi-layer plastic bottle being obtainable by a method according to an embodiment of the present invention.

[0046] Preferably, the intermediate layer of the multi-layer plastic bottle provides at least 5 or at least 10% of the wall thickness, more preferably at least 15% of the wall thickness, even more preferably at least 20% of the wall thickness, and most preferably at least 25% of the wall thickness.

[0047] Preferably, the outer layer and the middle layer of the multi-layer plastic bottle are white.

[0048] Preferably, the intermediate layer comprises recycled PET.

[0049] The multi-layer plastic bottle or preform according to one embodiment of the present invention preferably has an intermediate layer that comprises at least 10% recycled material by weight. More preferably, the intermediate layer comprises at least 15, 20, 25, 30, 35, 40, 45, 50% recycled material by weight. Even more preferably, the intermediate layer comprises at least 55, 60, 65, 70, 75, 80, 85, 90% recycled material by weight.

[0050] Preferably, the multi-layer plastic bottle or preform according to one embodiment of the present invention comprises up to 98% recycled content by weight, more preferably up to 95, 90, 85, 80, 75, 70, 65, 60, 55, 50% recycled content by weight.

[0051] Preferably, multi-layer plastic bottles or preforms according to embodiments of the invention contain 25-40% by weight (endpoints included) recycled material calculated based on the total weight of the preform or dairy bottle.

[0052] In the context of the present invention, a dairy bottle refers to any bottle suitable for containing pasteurized dairy products. The shape may vary from a typical dairy bottle to a dairy carton. Smaller packages such as small beverage bottles and cartons are not excluded. The dairy bottle according to the present invention may be equipped with any suitable closure ranging from a cap to a breakable membrane.

[0053] Preferably, the outer layer of the dairy bottle comprises a polyester material containing a white pigment such as titanium dioxide, calcium carbonate, or zinc oxide. Preferably, the outer layer comprises titanium dioxide. The polyester material is preferably PET. The incorporation of the white pigment gives the bottle a white appearance.

[0054] Preferably, the outer layer contains 0.5 to 10% by weight of the white pigment, more preferably, the outer layer contains 1.0 to 8% by weight of the white pigment, and most preferably, the outer layer contains 3.0 to 7.0% by weight of the white pigment.

[0055] Preferably, the intermediate layer of the dairy bottle comprises a polyester material. The polyester material is preferably PET. A dye is preferably added to the intermediate layer to adjust the opacity of the intermediate layer and the dairy bottle. The use of coal black is preferably excluded. The incorporation of a dye gives the intermediate layer a colored appearance. Preferably, the intermediate layer comprises 0.01-10% by weight of a dye.

[0056] A multi-layer dairy bottle according to an embodiment of the present invention preferably comprises: a) an outer layer containing 0.5 to 7% titanium dioxide and having a thickness of 30 to 250 micrometers; b) an opaque intermediate layer containing 0.01 to 10% by weight of a dye and having a thickness of 50 to 800 micrometers; c) an inner layer, which optionally contains 0.5-7% titanium dioxide and has a thickness of 30-250 micrometers, and which is in contact with the dairy product; Includes.

[0057] In a third aspect, the present invention provides a multi-layer dairy product package comprising a multi-layer plastic bottle according to a preferred embodiment of the present invention and a sterilized dairy product contained in the multi-layer plastic bottle, preferably the sterilized dairy product is milk.

[0058] Preferably, the intermediate layer provides at least 10% of the wall thickness.

[0059] If necessary, the material of the interlayer is additionally tinted to provide the desired opacity. Preferably, the additional tinting is with a dark dye, with the exception of carbon (black), which by definition is not a dye.

[0060] The intermediate layer contributes significantly to the light blocking. This is measured by determining the opacity of the bottle or preform at 540 nm. For this purpose, the residual light transmission is measured spectrophotometrically according to standard measurement procedures such as ASTM D1003, using a D65 lamp that simulates natural lighting. The residual transmission at 540 nm is preferably less than 4%, more preferably less than 2%, and most preferably less than or equal to 0.1%.

[0061] If the residual light transmission is higher than desired, additional dye can be added to achieve the required opacity.

[0062] Color determination is performed by obtaining L*a*b* measurements from the CIELAB system using a spectrophotometer. The L* value is a measure of lightness, where an L* value of 0 is equal to all black and an L* value of 100 is equal to all white. The L* value must be 65 or greater. The a* and b* values ​​are a scale of color and should preferably lie between -2 and +2, more preferably between -1.5 and +1.5, and most preferably between -1 and 1.

[0063] The plastic bottle is a dairy bottle, more preferably a milk bottle. In the present method, light protection is incorporated for this purpose. Preferably, the light protection is incorporated in an intermediate layer. More preferably, the light protection is incorporated in a polyester intermediate layer, most preferably a PET intermediate layer.

[0064] Light-proofing a dairy bottle means essentially sealing the bottle against ultraviolet and visible light, especially light with wavelengths shorter than 550 nm, which is favorable for reducing the degradation of vitamin B2 in dairy products.

[0065] Preferably, the dairy bottles are filled with sterilized dairy products by aseptic filling methods, which is advantageous to avoid bacterial contamination.

[0066] Preferably, the dairy bottle is impermeable to oxygen, and therefore the method includes incorporating an oxygen barrier, for example, by using nylon, polyester, ethyl vinyl alcohol (EVOH), or polyamide.

[0067] Preferably, the intermediate layer is made of recycled material obtained from the processing of used plastic beverage bottles or plastic preforms for bottles. This bottle-to-bottle process is advantageous as it has a low impact on the environment. Sustainable reuse is guaranteed.

[0068] The opaque recycled material may be part of the inner and / or outer layer, preferably mixed with the raw materials for the production of the inner and / or outer layer in an amount of at least 10% by weight, more preferably up to 20% by weight, most preferably more than 20%.

[0069] The present invention is further illustrated by examples which are not meant to be limiting. EXAMPLES

[0070] Opaque bottle fragments are collected and then sorted by color. An analysis is performed to separate food and non-food bottles. The purpose of the separation is, among other things, to remove HDPE plastic bottles used for non-food applications. The remaining bottles are shredded into chips. The chips are placed in a flotation bath where the PET material is separated from the polyethylene (PE) and other non-PET materials such as polyolefin caps and labels. The PET material fragments are then washed. If desired, the chips can be further sorted by color. The washed PET material fragments are then extruded into granules. If desired, a solid-state step is performed, whereby the material is kept at high temperature and reduced pressure. This affects the viscosity of the processed material. It is also a requirement that the material be food grade.

[0071] The resulting plastic PET material is incorporated into a dairy bottle. In an injection molding process, a multi-layer preform for a dairy bottle is produced. The middle layer comprises at least 9% by weight of recycled PET material expressed based on the total weight of the preform. The preform comprises 25% by weight of PET recycled material expressed based on the total weight of the preform. EXAMPLES

[0072] A multi-layer plastic dairy bottle according to an embodiment of the invention comprises, for example, white inner and outer layers and a middle layer that provides sufficient light blocking for the preservation of dairy products. The inner and outer layers are made of the same material, preferably PET with a white dye and at least 15% by weight of opaque PET recycle material expressed based on the total weight of the multi-layer dairy bottle. The middle layer also preferably consists of PET obtained from opaque PET recycle material and dark dye. This middle layer has a thickness corresponding to 10% of the wall thickness of the bottle. This recycle material comes from recycled dairy bottles, preferably recycled milk bottles. This recycle material already contains an opaque dye and provides a certain blocking of incident light. This can be improved by adding a dark dye if desired. The multi-layer dairy bottle preferably contains at least 9% by weight, more preferably 25% by weight of recycled material expressed based on the total weight of the dairy bottle. EXAMPLES

[0073] A multi-layer plastic dairy bottle according to an embodiment of the invention comprises, for example, white inner and outer layers and a middle layer that provides sufficient light blocking. The inner and outer layers are made of the same material, preferably PET with a white dye. The middle layer is also made of PET, preferably an opaque PET recycle. This is achieved by using a colored PET recycle. This middle layer has a thickness corresponding to at least 10% of the bottle wall. The thickness of the middle layer can be increased in a controlled manner up to 40% of the wall thickness. This colored recycle already contains an opaque dye and provides a certain blocking of incident light. This can be improved by adding a dark dye if desired.

Claims

1. 1. A method for processing recycled dairy bottle material for input into new production of dairy bottles, comprising: - shredding used plastic dairy bottles and subsequent mechanical recycling to obtain recycled dairy bottle material in the form of granules; - incorporating the recycled dairy bottle material by injection molding to form an intermediate layer of a preform for a new multi-layer plastic dairy bottle, the incorporated preform comprising an inner layer that contacts the contents of the dairy bottle in use, an outer layer opposite the inner layer, and an intermediate layer located between the inner and outer layers; It contains - said inner and outer layers are white and said middle layer is black, grey or tinted; - a method wherein said interlayer has a light transmittance of less than 5% measured by a spectrophotometer according to ASTM D1003 at 530 nm using a D65 lamp simulating natural lighting.

2. The method of claim 1 , wherein the recycled dairy bottle material is colored.

3. 10. The method of claim 1, wherein the interlayer has a light transmittance of less than 1% as measured by a spectrophotometer according to ASTM D1003 at 530 nm using a D65 lamp that simulates natural lighting.

4. 10. The method of claim 1, wherein recycled material from non-food applications is not processed into the dairy bottle.

5. 10. The method of claim 1, wherein the recycled dairy bottle material is recycled milk bottle material and the new dairy bottles are new milk bottles.

6. 10. The method of claim 1, wherein the dairy bottle recycled material is polyester plastic shredder, more preferably PET shredder.

7. 10. The method of claim 1, wherein blowing the preform forms the new dairy bottle, the new dairy bottle including recycled dairy bottle material encased in the intermediate layer.

8. - injecting a predetermined amount of a first material into a mold cavity in an injection mold and injecting a predetermined amount of a second material into said mold cavity to form a core within said injected first material to produce a preform; Including, - in a main phase, the first material is completely injected into the mould cavity, followed by the second material, in successive injections; - during said successive injections, said first material is injected so as to provide an inside and an outside of the preform, and said second material is injected into an area located at the level of the injection opening of the injection mould so as to provide an intermediate layer of the preform located between said inside and outside of the preform; in a final step, the first material is pushed towards the preform mouth by injecting the second material, the second material always being injected into the intermediate layer without the possibility of penetrating from the outside of the preform to the inside, the first material is polyester and the second material is an opaque plastic piece, excluding black opaque plastic pieces, preferably the second material is an opaque colored polyester plastic piece; 2. The method of claim 1 .

9. - injecting a predetermined amount of a first material into a mold cavity in an injection mold and injecting a predetermined amount of a second material into said mold cavity to form a core within said injected first material to produce a preform; Including, in parallel injection, the first material is injected into the inside and outside and the second material is injected into the intermediate layer in the area located at the level of the injection openings of the injection mold; - in a preliminary step, only a predetermined amount of said first material is injected into said injection mould, - in a final step, a predetermined amount of the first material is injected and, if necessary, the second material is further forced towards the front of the injection mould; the first material is polyester and the second material is an opaque plastic piece, excluding black opaque plastic pieces, preferably the second material is an opaque colored polyester plastic piece; 2. The method of claim 1 .

10. The method of claim 1 , wherein the material of the interlayer is further pigmented to increase the opacity of the interlayer.

11. The method of claim 1 , wherein the intermediate layer contributes at least 5% of the wall thickness.

12. 10. The method of claim 1, wherein dairy bottles of a dairy bottle filler are reprocessed into new dairy bottles for the same filler ("bottle-to-bottle").

13. 10. The method of claim 1, wherein used dairy bottles from pre-identified dairy bottle fillers are separately collected and processed into new dairy bottles for the pre-identified dairy bottle fillers ("closed loop").

14. A multi-layer plastic bottle for containing and storing dairy products, comprising an inner layer in contact with the contents of the bottle or preform, an outer layer opposite the inner layer, and an intermediate layer between the outer layer and the inner layer; 14. The multi-layer dairy plastic bottle according to claim 1, wherein the intermediate layer comprises opaque plastic pieces, and the intermediate layer is black, gray, or colored. The multi-layer dairy plastic bottle can be obtained by the method according to claim 1, wherein the intermediate layer has a light transmittance of less than 5% as measured by a spectrophotometer according to ASTM D1003 at 530 nm using a D65 lamp that simulates natural lighting.

15. 15. The multi-layer plastic bottle of claim 14, wherein the intermediate layer contributes at least 5% of the wall thickness.

16. 15. The multi-layer plastic bottle of claim 14, wherein the intermediate layer comprises at least 25% recycled material by weight, calculated based on the total weight of the preform or dairy bottle.

17. 15. The multi-layer plastic bottle of claim 14, wherein the outer and inner layers are colored white.

18. 15. The multi-layer plastic bottle of claim 14, wherein the middle layer comprises recycled PET material.

19. A multi-layer dairy product package comprising the multi-layer plastic bottle of claim 14 and a sterilized dairy product contained in the multi-layer plastic bottle, preferably wherein the sterilized dairy product is milk.