Bottle washing for reusable bottles

Abstract

Compositions and methods for using a bottle washing composition. The composition comprises one or more organic acids, one or more organic and inorganic phosphates, one or more surfactants, and a hydrotrope. The compositions are free of chelating agents and compatible with glass and PET bottles. Washing bottles for reuse with the compositions and methods results in effective cleaning without cause ink or particles of labels to migrate into the solutions, and without stress cracking of the bottles after repeated reuse and wash cycles.

Description

BOTTLE WASHING FOR REUSABLE BOTTLESCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and priority7to U.S. Provisional Application No. 63 / 598,990, filed on November 15. 2023, the disclosure of which is hereby incorporated by reference in its entirety.FIELD

[0002] The present disclosure is related to compositions and methods of washing bottles for reuse. The disclosed compositions and methods clean bottles, such as glass and PET bottles, without the use of chelating agents like EDTA. The bottles are cleaned with effective label removal and minimized stress cracking and gushing.BACKGROUND

[0003] Bottle washing is an essential process in various industries, such as the food and beverage industry. The primary7purpose of bottle washing is to remove any contaminants, dirt, or debris from the inside and outside surfaces of bottles. This process ensures that bottles are clean and safe for reuse. Bottle washing typically involves several steps, including pre-rinsing, washing, rinsing, and dry ing. The ty pe of bottle washing equipment and cleaning solutions used will depend on the specific cleaning requirements of the relevant industry, the types of bottles being cleaned, and the soils on the bottles.

[0004] The pre-rinsing step may involve removing any large debris, such as labels or caps, from the bottles before they are washed. This is followed by the washing step, where the bottles may be cleaned using a combination of water, cleaning agents, and sometimes high-pressure jets or brushes. After the washing step, the bottles are rinsed with water to remove any remaining cleaning solution. Different compositions and methods have been used to clean various types of bottles.

[0005] It is against this background that the present disclosure is made.SUMMARY

[0006] A variety of additional inventive aspects will be set forth in the description that follows. The inventive aspects can relate to individual features and to combinations of features. It is to be understood that both the foregoing general description and the following detailed description are exemplary7and explanatory only and are not restrictive of the broad inventive concepts upon which the embodiments disclosed herein are based.

[0007] Disclosed herein is a method of cleaning glass and polyethylene terephthalate(PET) bottles comprising diluting a concentrate composition with a dilutant to form a use solution, the concentrate composition comprising one or more organic acids, one or more organic and inorganic phosphates, one or more surfactants, a hydrotrope, and water, wherein the concentrate composition is free of chelating agents; and applying the use solution to glass bottles, PET bottles, or combinations thereof.

[0008] Also disclosed herein is a method of cleaning a polyethylene terephthalate (PET) bottle comprising applying a use solution to PET bottles, the use solution comprising one or more organic acids, one or more organic and inorganic phosphates, one or more surfactants, a hydrotrope, and water, wherein the composition is free of chelating agents.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The accompanying drawings, which are incorporated in and constitute a part of the description, illustrate several aspects of the present disclosure. A brief description of the drawings is as follows:

[0010] FIG. 1 is a visual representation of results of Example 3.

[0011] FIGS. 2A-2B are visual representations of results of Example 4.

[0012] FIGS. 3A-3B are graphical representations of results of Example 5.

[0013] FIGS. 4A-4B are visual representations of results of Example 7.

[0014] FIGS. 5A-5B are visual representations of results of Example 7.DETAILED DESCRIPTION

[0015] As used herein, weight percent (wt. %), percent by weight, % by weight, and the like are synonyms that refer to the concentration of a substance as the weight of that substance divided by the total weight of the composition and multiplied by 100.

[0016] As used herein, the term “about” modifying the quantity of an ingredient in the compositions of the invention or employed in the methods of the invention refers to variation in the numerical quantity that can occur, for example, through typical measuring and liquid handling procedures used for making use solutions in the real world; through inadvertent error in these procedures; through differences in the manufacture, source, or purity of the ingredients employed to make the compositions or carry7out the methods; and the like. The term “about” also encompasses amounts that differ due to different equilibrium conditions for a composition resulting from a particular initial mixture. Whether or not modified by the term “about,” the claims include equivalents to the quantities.

[0017] As used herein, the terms "substantially free,’' “substantially free of,” and “free of’ of a particular substance means that the compositions of the instant specification contain less than 0.5 wt.% of the recited substance. When referring to “substantially free,” “substantially free of,” and “free of’ it is intended that the substance is not intentionally added to the compositions. The term “essentially free” of a particular substance means that the compositions of the instant specification contain less than 0. 1 wt.% of the recited substance. When referring to “essentially free” it is intended that the substance is not intentionally added to the compositions. The term “essentially completely free” of a particular substance means that the compositions of the instant specification contain less than 0.01 wt.% of the recited substance. When referring to “essentially completely free” it is intended that the substance is not intentionally added to the compositions. The term “completely free” of a particular substance means that the compositions of the instant specification contain less than 0.001 wt.% of the recited substance. When referring to “completely free” it is intended that the substance is not intentionally added to the compositions. Use of the term “completely free” allows for trace amounts of that substance to be included in compositions because they are present in another substance in the composition. However, it is recognized that only trace or de minimus amounts of a substance will be allow ed when the composition is said to be “completely free” of that substance.

[0018] It should be noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the content clearly dictates otherwise. Thus, for example, reference to a composition containing “a compound” includes a mixture of tw o or more compounds. It should also be noted that the term “or” is generally employed in its sense including “and / or” unless the content clearly dictates otherwise.

[0019] In the interest of brevity and conciseness, any ranges of values set forth in this specification contemplate all values within the range and are to be construed as support for claims reciting any sub-ranges having endpoints which are real number values within the specified range in question. By way of a hypothetical illustrative example, a disclosure in this specification of a range of from 1 to 5 shall be considered to support claims to any of the following ranges: 1-5; 1-4; 1-3; 1-2; 2-5; 2-4; 2-3; 3-5; 3- 4; and 4-5.

[0020] Bottle washing additives are substances added to a cleaning solution used in a bottle washing process. These additives can enhance the effectiveness of the cleaningsolution, making it easier to remove stubborn contaminants from the surfaces of the bottles. Some example bottle washing additives include surfactants, enzymes, and acids. Surfactants help to reduce the surface tension of the cleaning solution, which improves the solution’s ability' to remove dirt and debris. Enzy mes are biological molecules that can break down organic matter, such as protein or starch, making them easier to remove. Acids can help to dissolve mineral deposits, such as calcium or magnesium, which can build up on the surfaces of the bottles. Selecting suitable bottle washing additive components depends on the type of bottle and ty pe of soil to be removed from the bottle.

[0021] There are numerous ty pes of bottles commonly used, such as glass or plastic. Glass bottles may be used because of their ability to preserve the taste and quality' of the product, as well as their ability to be recycled or cleaned and reused. Plastic bottles are also commonly used because they are lightweight, shatterproof, and can be produced more easily in a variety7of shapes and sizes. Plastic bottles are also often more cost- effective than glass bottles and can be easily recycled. In some cases, plastic bottles can also be cleaned and reused.

[0022] One type of plastic bottle is a polyethylene terephthalate (PET) bottle. PET is a type of thermoplastic polymer that is lightweight, strong, and durable. PET bottles are commonly used for packaging beverages, such as water, soft drinks, and juices, as well as food products. PET bottles are popular due to their low cost, ease of manufacturing, and ability to be recycled. They are also resistant to impact and shatter, making them a safe option for packaging products.

[0023] When bottles, such as glass and PET bottles, are to be cleaned and reused, all debris must be removed from the bottle, including any labels. Labels are often made of paper, plastic, or combinations thereof, and the adhesive used to attach labels can be difficult to remove without damaging the bottle. One method for removing labels is to soak the bottle in hot, soapy7water for several minutes to loosen the adhesive. Then, the label can be peeled off by hand or w ith a scraper. Another method removes labels in an automated process in a bottle washer with a combination of temperature and caustic solution. The label removal process may also use solvents that dissolve the adhesive. Once the label is removed, any remaining adhesive can be removed using rubbing alcohol or an adhesive remover.

[0024] In the last few years, a new bottle was introduced into the marketplace.Previous bottles typically had screen-printed ACL (applied ceramic label) labels, which can leave a fixed impression on the bottle and make removing the label for reuse of thebottle difficult. The new bottle uses paper labels, which allows companies to reuse and refill bottles more effectively and efficiently. In conjunction with the new bottle, companies have begun using paper labels in addition to, or instead of, traditional plastic labels. Paper labels are more environmentally friendly than plastic labels since they can be recycled along with the bottle, which is a more sustainable approach than using plastic labels, which are not typically recyclable. Additionally, paper labels can be printed with high-quality graphics and can be embossed or have a textured finish, providing opportunities for unique and eye-catching branding. Both paper and plastic labels are commonly used in the marketplace.

[0025] Despite the benefits of using bottles with paper labels, the switch presents operational challenges to existing bottle washing processes, especially for refillable PET bottles. Removal of paper labels can be challenging because paper labels are often coated with a varnish or laminate that protects the label from damage and makes the label more resistant to moisture and solvents. Plastic labels pose similar challenges to removal, such as difficulty of dissolving the adhesive and coating on labels. Sometimes, the label removal process may also require a longer soaking period of the bottle in a cleaning solution to remove adhesives or hot melts that attach the labels. Because of these challenges with label removal, labels are susceptible to ink and paper pulp fiber loss from the combination of temperature, the use of a caustic, and the chemicals used in the cleaners that are needed to promote thorough cleaning.

[0026] When labels lose ink and paper pulp fiber in the label removal process, the fibers and ink may mix with the washing solutions used for cleaning the bottles, which results in faster saturation of the washing solution with debris (i.e., the turbidity increases). This means that the bottle washing solution must be changed more frequently, which increases operative costs and reduces productivity. Ink and fiber loss may also reduce the efficacy of the cleaning solutions and result in debris left behind on the bottles. When the bottles are being cleaned, if ink and fiber debris are in the washing solution, gushing may occur during the cleaning process. Gushing may refer to the excessive foaming and overflow of the washing solution during the bottle washing process caused by the interaction of a caustic cleaning solution with ink and fibers from the label.

[0027] Gushing may also be present when the bottle is refilled after cleaning. If a bottle is not cleaned properly, gushing may also occur when a liquid product that fills the reusable PET bottle foams excessively and spills out of the bottle. In general, gushing can be caused by numerous factors such as carbonation of the liquid product,temperature, type of bottle, and the filling equipment and process. However, gushing may also occur due to the interaction of the liquid filling the bottles with any remaining ink and paper pulp fibers from the label that were not fully removed during the cleaning process. Therefore, a bottle that has not been thoroughly cleaned may undergo gushing at both the cleaning and filling stages. This is especially a problem at the filling stage because if the liquid filling the reused bottles gushes and spills out of the bottle, the bottle will not contain the appropriate amount of liquid. Such a bottle is likely to be rejected during the quality control process when the fill line of the bottle is checked, which leads to loss of revenue and productivity.

[0028] PET bottles are also more susceptible to damage than other types of bottles due to the pliable nature of the plastic. Heat and friction that may be used to remove labels can scratch or damage the bottle surface, rendering it unable to be refilled and reused. Stress cracking may also occur, which refers to damage caused to bottles, such as fine lines, cracks, leaks, or bursting of the bottle. Stress cracking also refers to hazing of the bottle, which appears as a cloudy appearance to the plastic. Hazing causes weakening of the polymer plastic in the bottle and is often particularly noticeable at the bottom of the bottle. Stress cracking may appear in any bottle that has undergone some sort of stress to weaken the bottle.

[0029] Without wishing to be bound by theory, it is believed that stress cracking may. at least in part, be caused by the shifting of one or more polymeric chains of the polymeric plastic in the bottle, like PET. The polymeric chains may shift due to the physical stressors such as heat, friction, caustic, other cleaning agents, and physical pressure, for example. When the polymeric chains shift, it is believed that this leads to the physical changes in the bottle such as fine lines, cracks, hazing, etc.

[0030] Disclosed herein are compositions and methods for cleaning bottles using a bottle washing additive that overcomes the difficulties of bottle washing described herein. In some examples, the bottles are glass or PET bottles. The compositions and methods disclosed herein mitigate gushing while cleaning bottles for reuse. The compositions and methods also remove labels with minimal migration of ink or particles from the labels into the washing solution. This bottle cleaning is also performed without stress cracking or damage to the bottles. In some examples, the bottle washing additive does not include chelating agents like EDTA, HEDTA, DPTA, or NT A.

[0031] In some examples, a bottle washing additive composition is disclosed that comprises water, one or more organic acids, one or more organic and inorganicphosphates, a hydrotrope, and one or more surfactants. In some examples, the composition further comprises sodium hydroxide. In some examples, the composition is created as a concentrate composition that is diluted. The concentrate composition may be diluted with a dilutant to form a use solution. In some examples, the dilutant is sodium hydroxide, potassium hydroxide, water, or a combination thereof. The concentrate solution may be created by combining one or more organic acids, one or more organic and inorganic phosphates, a hydrotrope, and one or more surfactants.

[0032] In some examples, the one or more organic acids comprises gluconic acid, citric acid, lactic acid, or combinations thereof. These acids can act as chelating agents that bind to metals and are dispersants, which aid in removal of labels and inorganic soils from bottles. The organic acids may also be easier to incorporate into a solution and remain stable with a longer shelf-life as compared to other acids. In some examples, the one or more organic acids is present in the concentrate composition from about 30 wt. % to about 50 wt. %. The one or more organic acids may be present in the concentrate composition from about 30 wt. % to about 45 wt. %, from about 30 wt. % to about 40 wt. %, from about 30 wt. % to about 35 wt. %. from about 35 wt. % to about 50 wt. %. from about 40 wt. % to about 50 wt. %, or from about 45 wt. % to about 50 wt. %.

[0033] In some examples, the one or more organic and inorganic phosphates comprises phosphoric acid, sodium phosphate, potassium phosphate, hydroxyethylidene diphosphonic acid (HEDP), amino trimethylene phosphonic acid (ATMP), phosphonobutane tricarboxylic acid (PBTC), or combinations thereof. The one or more organic and inorganic phosphates act as sequestering and anti-deposition agents that prevent the formation of white spots on the surface of bottles and within a bottle w ashing machine, which are formed by deposition of salts. In some examples, the one or more organic and inorganic phosphates are present in the concentrate composition from about 1 wt. % to about 10 wt. %. The one or more organic and inorganic phosphates may be present in the concentrate composition from about 1 wt. % to about 9 wt. %, from about 1 wt. % to about 8 wt. %, from about 1 wt. % to about 7 wt. %, from about 1 wt. % to about 6 wt. %. from about 1 wt. % to about 5 wt. %. from about I wt. % to about 4 wt. %, from about 1 wt. % to about 3 wt. %, from about 1 wt. % to about 2 wt. %, from about 1 wt. % to about 1.5 wt. %, from about 1.5 wt. % to about 10 wt. %, from about 2 wt. % to about 10 wt. %, from about 3 wt. % to about 10 wt. %, from about 4 wt. % to about 10 wt. %, from about 5 wt. % to about 10 wt. %, from about 6 wt. % to about 10 wt. %,from about 7 wt. % to about 10 wt. %, from about 8 wt. % to about 10 wt. %, or from about 9 wt. % to about 10 wt. %.

[0034] In some examples, the hydrotrope comprises sodium xylene sulfonate, sodium cumenesulfonate, ethylene glycol, propylene glycol, or combinations thereof. Hydrotropes help to dissolve and stabilize all of the components in the composition, which prevents separation of the concentrate composition over time. In some examples, the hydrotrope is present in the concentrate composition from about 1 wt. % to about 20 wt. %. In some examples, the hydrotrope may be present in the concentrate composition from about 1 wt. % to about 15 wt. %, from about 1 wt. % to about 12 wt. %, from about 1 wt. % to about 10 wt. %, from about 1 wt. % to about 9 wt. %, from about 1 wt. % to about 8 wt. %. from about 1 wt. % to about 7 wt. %, from about 1 wt. % to about 6 wt. %, from about 1 wt. % to about 5 wt. %, from about 1 wt. % to about 4 wt. %, from about 1 wt. % to about 3 wt. %, from about 1 wt. % to about 2 wt. %, from about 2 wt. % to about 20 wt. %, from about 3 wt. % to about 20 wt. %, from about 4 wt. % to about 20 wt. %, from about 5 wt. % to about 20 wt. %, from about 6 wt. % to about 20 wt. %. from about 7 wt. % to about 20 wt. %. from about 8 wt. % to about 20 wt. %. from about 9 wt. % to about 20 wt. %, from about 10 wt. % to about 20 wt. %, from about 12 wt. % to about 20 wt. %, or from about 15 wt. % to about 20 wt. %.

[0035] In some examples, the one or more surfactants are nonionic surfactants comprising alkyl polyglycosides, alkyl polyethylene glycol ethers, alkoxylated fatty alcohols, and combinations thereof. In some examples, the one or more surfactants include cationic, anionic, and zwitterionic surfactants. In some examples, the one or more surfactants includes alky l polyglycoside, which is a nonionic surfactant that provides hard detergency and has wetting, dispersing, and surface tension reduction properties that aid in soil removal and emulsification. The alkyl polyglycoside may work in synergy with other surfactants in the composition, as discussed below .

[0036] The alkoxylated fatty7alcohols may be selected from the group consisting of C12-15 alcohol alkoxylates, C12-C15 alcohol ethoxylates, C12-C15 alcohol propoxylates, and combinations thereof. The alkoxylated alcohols are low foaming nonionic surfactants that act as wetting agents and have emulsifying properties. Alkoxylated alcohols help to remove soils from the surface of bottles and may have synergy when combined with alkyl polyglycoside. The composition may include one or more surfactants selected from any of the surfactants discussed herein.

[0037] The inventors found that surfactants with cloud points greater than 40 °C with 0-20 EO moles (preferably 4-12 EO moles) and low PO moles (< 5 PO moles) exhibited a decrease in surface tension when used in the compositions described herein. It was further found that the surfactants provided good cleaning properties while avoiding penetration of the ink layer of a paper label that would inhibit cleaning (discussed more below). Nonionic surfactants, such as amine ethoxylated and alkoxylated fatty alcohols that have higher PO mole content (> 5 PO moles) and cloud points of less than 40 °C are too aggressive and penetrate the ink layer of paper labels, which leads to ink migration and increased turbidity of the compositions. In some examples, EO refers to ethylene oxide, and PO refers to propylene oxide. The one or more surfactants may comprise any other surfactants not named herein that fit these parameters for cloud points. EO moles, and PO moles.

[0038] The one or more surfactants may be present in the concentrate composition from about 1 wt. % to about 25 wt %. In some examples, the one or more surfactants is present in the concentrate composition from about from about 1 wt. % to about 25 wt. %, from about 1 wt.% to about 20 wt.%. from about 1 wt. % to about 15 wt. %. from about 1 wt. % to about 10 wt. %, from about 1 wt. % to about 8 wt. %, from about 1 wt. % to about 6 wt. %, from about 1 wt. % to about 5 wt. %, from about 1 wt. % to about 4 wt. %, from about 1 wt. % to about 3 wt. %, from about 1 wt. % to about 2 wt. %, from about 2 wt. % to about 25 wt. %. from about 3 wt. % to about 25 wt. %. from about 4 wt. % to about 25 wt. %, from about 5 wt. % to about 25 wt. %, from about 6 wt. % to about 25 wt. %, from about 8 wt. % to about 25 wt. %, from about 10 wt. % to about 25 wt. %, from about 15 wt. % to about 25 wt. %, or from about 20 wt. % to about 25 wt. %.

[0039] In some examples, the composition may optionally comprise sodium hydroxide as a constituent of the composition in an amount from about 0. 1 wt. % to about 5 wt. %. In some examples, the sodium hydroxide may be added in an amount from about 0.1 wt. % to about 4.5 wt. %, from about 0.1 wt. % to about 4 wt. %, from about 0.1 wt. % to about 3.5 wt. %, from about 0.1 wt. % to about 3 wt. %, from about 0.1 wt. % to about 2.5 wt. %. from about 0.1 wt. % to about 2 wt. %, from about 0.1 wt. % to about 1.5 wt. %, from about 0.1 wt. % to about 1 wt. %, from about 0.1 wt. % to about 0.5 wt. %, from about 0.5 wt. % to about 5 wt. %, from about 1 wt. % to about 5 wt. %, from about 1.5 wt. % to about 5 wt. %, from about 2 wt. % to about 5 wt. %, from about 2.5 wt. % to about 5 wt. %, from about 3 wt. % to about 5 wt. %, from about 3.5 wt. % to about 5 wt. %, from about 4 wt. % to about 5 wt. %, or from about 4.5 wt. % to about 5wt. %. In some examples, sodium hydroxide is added to the composition in an amount of 1.5 wt. % to about 3.5 wt. %.

[0040] In some examples, the concentrate composition optionally comprises water as a constituent of the composition. In some examples, water is present from about 0.1 wt. % to about 67 wt. %, from about 0. 1 wt. % to about 65 wt. %, from about 0. 1 wt. % to about 60 wt. %, from about 0. 1 wt. % to about 55 wt. %, from about 0. 1 wt. % to about 50 wt. %, from about 0.1 wt. % to about 45 wt. %, from about 0.1 wt. % to about 40 wt. %, from about 0. 1 wt. % to about 35 wt. %, from about 0. 1 wt. % to about 30 wt. %, from about 0. 1 wt. % to about 25 wt. %, from about 0. 1 wt. % to about 20 wt. %, from about 0. 1 wt. % to about 15 wt. %, from about 0. 1 wt. % to about 10 wt. %, from about 0. 1 wt. % to about 5 wt. %, from about 0. 1 wt. % to about 2 wt. %, from about 0. 1 wt. % to about 1 wt. %, from about 0. 1 wt. % to about 0.5 wt. %, from about 0.5 wt. % to about 67 wt. %, from about 1 wt. % to about 67 wt. %, from about 2 wt. % to about 67 wt. %, from about 5 wt. % to about 67 wt. %, from about 10 wt. % to about 67 wt. %, from about 15 wt. % to about 67 wt. %. from about 20 wt. % to about 67 wt. %, from about 25 wt. % to about 67 wt. %, from about 30 wt. % to about 67 wt. %. from about 35 wt. % to about 67 wt. %, from about 40 wt. % to about 67 wt. %, from about 45 wt. % to about 67 wt. %, from about 50 wt. % to about 67 wt. %, from about 55 wt. % to about 67 wt. %, from about 60 wt. % to about 67 wt. %, or from about 65 wt. % to about 67 wt. %.

[0041] In some examples, the concentrate composition described herein is diluted. In some examples, the concentrate composition is mixed with a dilutant in a bottle washing machine, meaning that both the concentrate composition and the dilutant are added separately to the bottle washing machine to mix together in the machine. In other examples, the concentrate composition is diluted with dilutant prior to being added to a bottle washing machine.

[0042] In examples where the composition is a concentrate composition that is diluted with a dilutant, the dilutant may be sodium hydroxide, potassium hydroxide, water, or combinations thereof. In some examples, the dilutant is a combination of water and sodium hydroxide. The dilutant may be added in addition to any presence of sodium hydroxide, potassium hydroxide, or water already in the concentrate solution. For example, in some examples the concentrate solution comprises sodium hydroxide, and the concentrate solution may be diluted with additional sodium hydroxide. The dilutant is added to the concentrate composition to form a diluted use solution. In some examples, the dilutant is present in use solution from about 90 wt. % to about 99.99 wt. %. In someexamples, the dilutant is present in an amount of about 90 wt. % to about 99.99 wt. %, about 90 wt. % to about 98 wt. %. about 90 wt. % to about 97 wt. %, about 90 wt. % to about 96 wt. %, about 90 wt. % to about 95 wt. %, about 90 wt. % to about 94 wt. %, about 90 wt. % to about 93 wt. %, about 90 wt. % to about 92 wt. %, about 90 wt. % to about 91 wt. %, about 91 wt. % to about 99.99 wt. %, about 92 wt. % to about 99.99 wt. %, about 93 wt. % to about 99.99 wt. %, about 94 wt. % to about 99.99 wt. %, about 95 wt. % to about 99.99 wt. %, about 96 wt. % to about 99.99 wt. %. about 97 wt. % to about 99.99 wt. %, about 98 wt. % to about 99.99 wt. %, or from about 99 wt. % to about 99.99 wt. %.

[0043] When the concentrate composition and the dilutant are mixed, the concentrate composition may be mixed with the dilutant in an amount from about 0.01 wt. % to about 10 wt. % to create the diluted use solution. In some examples, the concentrate solution may be mixed with the dilutant in an amount from about 0.01 wt. % to about 9 wt. %, from about 0.01 wt. % to about 8 wt. %, from about 0.01 wt. % to about7 wt. %, from about 0.01 wt. % to about 6 wt. %. from about 0.01 wt. % to about 5 wt. %, from about 0.01 wt. % to about 4 wt. %, from about 0.01 wt. % to about 3 wt. %, from about 0.01 wt. % to about 2 wt. %, from about 0.01 wt. % to about 1 wt. %, from about 0.01 wt. % to about 0.5 wt. %, from about 0.5 wt. % to about 10 wt. %, from about 1 wt. % to about 10 wt. %. from about 2 wt. % to about 10 wt. %. from about 3 wt. % to about 10 wt. %, from about 4 wt. % to about 10 wt. %, from about 5 wt. % to about 10 wt. %, from about 6 wt. % to about 10 wt. %, from about 7 wt. % to about 10 wt. %, from about8 wt. % to about 10 wt. %, or from about 9 wt. % to about 10 wt. %.

[0044] In examples where the concentrate composition is diluted with the dilutant, the diluted use solution comprises the following components and concentrations.

[0045] In some examples, the use solution that has been diluted comprises from about 0.003 wt. % to about 5 wt. % of one or more organic acids. In some examples, the one or more organic acids is present in the use solution from about 0.003 wt. % to about4.5 wt. %, from about 0.003 wt. % to about 4 wt. %, from about 0.003 wt. % to about 3.5 wt. %, from about 0.003 wt. % to about 3 wt. %, from about 0.003 wt. % to about 2.5 wt. %, from about 0.003 wt. % to about 2 wt. %, from about 0.003 wt. % to about 1.5 wt. %, from about 0.003 wt. % to about 1 wt. %, from about 0.003 wt. % to about 0.5 wt. %, from about 0.003 wt. % to about 0.01 wt. %, from about 0.01 wt. % to about 5 wt. %, from about 0.5 wt. % to about 5 wt. %, from about 1 wt. % to about 5 wt. %, from about1.5 wt. % to about 5 wt. %, from about 2 wt. % to about 5 wt. %, from about 2.5 wt. %to about 5 wt. %, from about 3 wt. % to about 5 wt. %, from about 3.5 wt. % to about 5 wt.%, from about 4 wt. % to about 5 wt. %, or from about 4.5 wt. % to about 5 wt. %.

[0046] In some examples, the use solution comprises from about 0.0001 wt. % to about 1 wt. % of one or more organic and inorganic phosphates. In some examples, the one or more organic and inorganic phosphates is present in the use solution from about 0.0001 wt. % to about 0.5 wt. %, from about 0.0001 wt. % to about 0. 1 wt. %, from about 0.0001 wt. % to about 0.01 wt. %. from about 0.0001 wt. % to about 0.001 wt. %. from about 0.001 wt. % to about 1 wt. %, from about 0.01 wt. % to about 1 wt. %, from about 0.1 wt. % to about 1 wt. %, or from about 0.5 wt. % to about 1 wt. %.

[0047] In some examples, the use solution comprises from about 0.0001 wt. % to about 2 wt. % hydrotrope. In some examples, the hydrotrope is present in the use solution in amounts from about 0.0001 wt. % to about 1.5 wt. %, from about 0.0001 wt. % to about 1 wt. %, from about 0.0001 wt. % to about 0.5 wt. %, from about 0.0001 wt. % to about 0.1 wt. %, from about 0.0001 wt. % to about 0.01 wt. %, from about 0.0001 wt. % to about 0.001 wt. %, from about 0.001 wt. % to about 2 wt. %, from about 0.01 wt. % to about 2 wt. %, from about 0. 1 wt. % to about 2 wt. %. from about 0.5 wt. % to about 2 wt. %, from about 1 wt. % to about 2 wt. %, or from about 1.5 wt. % to about 2 wt. %.

[0048] In some examples, the use solution comprises from about 0.0001 wt. % to about 2.5 wt. % of one or more surfactants. In some examples, the one or more surfactants is present in the use solution from about 0.0001 wt. % to about 2 wt. %, from about 0.0001 wt. % to about 1 .5 wt. %, from about 0.0001 wt. % to about 1 wt. %, from about 0.0001 wt. % to about 0.5 wt. %, from about 0.0001 wt. % to about 0. 1 wt. %, from about 0.0001 wt. % to about 0.01 wt. %. from about 0.0001 wt. % to about 0.001 wt. %, from about 0.001 wt. % to about 2.5 wt. %, from about 0.01 wt. % to about 2.5 wt. %, from about 0.1 wt. % to about 2.5 wt. %, from about 0.5 wt. % to about 2.5 wt. %, from about 1 wt. % to about 2.5 wt. %, from about 1.5 wt. % to about 2.5 wt. %, or from about 2 wt. % to about 2.5 wt.%.

[0049] In some examples, the use solution further comprises from about 0. 1 wt. % to about 5 wt. % of sodium hydroxide or potassium hydroxide. The sodium hydroxide or potassium hydroxide may be added in addition to the dilutant to form the use solution. In some examples, the sodium hydroxide or potassium hydroxide is present in the use solution in amounts from about 0.1 wt. % to about 4.5 wt. %, from about 0.1 wt. % to about 4 wt. %, from about 0.1 wt. % to about 3.5 wt. %. from about 0. 1 wt. % to about 3 wt. %, from about 0. 1 wt. % to about 2.5 wt. %, from about 0.1 wt. % to about 2 wt. %,from about 0.1 wt. % to about 1.5 wt. %, from about 0.1 wt. % to about 1 wt. %, from about 0. 1 wt. % to about 0.5 wt. %, from about 0.5 wt. % to about 5 wt. %, from about 1 wt. % to about 5 wt. %, from about 1.5 wt. % to about 5 wt. %, from about 2 wt. % to about 5 wt. %, from about 2.5 wt. % to about 5 wt. %, from about 3 wt. % to about 5 wt. %, from about 3.5 wt. % to about 5 wt. %, from about 4 wt. % to about 5 wt. %, or from about 4.5 wt. % to about 5 wt. %.

[0050] Any of the above-described compositions, including the concentrate composition and use solution, may be applied to glass, PET bottles, or combinations thereof to clean the bottles. This application often occurs in a bottle washing machine but may also occur in other suitable washing mediums or applied by hand.

[0051] In some examples, a pre-wash and / or pre-rinse is used on an uncleaned bottle before it is contacted with the compositions and solutions disclosed herein. Any suitable pre-wash or pre-rinse may be used, such as those know n in the art of bottle washing and dishw are cleaning.

[0052] In some examples, the concentrate compositions and the use solutions disclosed herein do not include the chelating agents EDTA, HEDTA, DPTA, NT A, and the like. In some examples, the concentrate compositions and use solutions disclosed herein are free of, or substantially free of, EDTA, HEDTA, DPTA, NTA, and combinations thereof. In some examples, the concentrate compositions and use solutions disclosed herein are essentially free of EDTA. HEDTA. DPTA. NTA, and combinations thereof. In some examples, the concentrate compositions and use solutions disclosed herein are essentially completely free of EDTA, HEDTA, DPTA, NTA, and combinations thereof. In some examples, the concentrate compositions and use solutions disclosed herein are completely free of EDTA, HEDTA, DPTA, NTA, and combinations thereof.

[0053] EDTA (ethylenediaminetetraacetic acid) is a chelating agent commonly used in bottle washing solutions because it helps remove mineral deposits and other contaminants that can build up on the surface of the bottle over time, which can cause staining and odors. These deposits can be particularly problematic in reusable bottles since they can accumulate over multiple uses and can be difficult to remove with traditional cleaning methods. EDTA works by binding to the minerals and other contaminants, which helps to break down and remove the deposits. Additionally, some labels have previously included trace heavy metals, which chelating agents, such as EDTA, would bind to during cleaning to prevent contamination of the bottle with heavymetals. EDTA is also effective at removing organic compounds, such as bacteria and other microorganisms, which can grow inside the bottle and cause odors or health concerns.

[0054] While EDTA is effective at removing these deposits, there are downsides to using it in cleaning compositions. EDTA is not readily biodegradable and can persist in the environment for an extended period. Additionally, EDTA can bind to heavy metals, such as lead and cadmium, and prevent them from being removed from wastewater during treatment. This can lead to the accumulation of these toxic substances in the environment. Other chelating agents such as EIEDTA (hydroxyethyl ethylenediamine triacetic acid), DPTA (diethylenetriaminepentaacetic acid), and NTA (nitrilotriacetic acid) have similar downsides as EDTA.

[0055] In some examples, other chelating agents may be used. In some examples, aminocarboxylates other than EDTA, HEDTA, DPTA, and NTA may be added. Aminocarboxylates and / or their salt forms (e.g., alkali metal salts) may be included. In some examples, the aminocarboxylates may comprise MGDA, GLDA. or combinations thereof. High soluble polymer compounds, including but not limited to, sodium polyacrylate, may be included as chelating agents. Other chelating agents may also be included in the compositions.

[0056] The compositions and methods described herein are PET bottle compatible, meaning that labels are removed from PET bottles without significant ink or label particles migrating to the use solution during washing. In some examples, PET- compatibility also means that the compositions and methods can be used with PET bottles for 25 or more washing cycles. Additionally, the compositions and methods described herein do not cause stress -cracking of PET bottles during the washing process.

[0057] PET bottles can be challenging to clean compared to other types of bottles. PET is a relatively soft plastic, and the surface of the bottles can be easily scratched or damaged, which can create areas for bacteria to grow. Additionally, PET bottles have a high surface area-to-volume ratio, meaning that there is more surface area for contaminants to adhere to. The narrow neck of the bottles can also make it difficult to clean the interior surfaces thoroughly. PET bottles are often used for carbonated beverages, which can leave behind a residue that can be difficult to remove. PET is also more easily damaged than other bottles from forces such as temperature and exposure to chemicals, which can cause porosity of the bottle surface, hazing, and stress cracking.

[0058] PET bottles have also become lighter over time (e.g., about 93 grams to about 126 grams for a 2L bottle) because the bottles are thinner, which makes them more susceptible to damage during cleaning.

[0059] PET bottles are also subject to repeated changes in pressure and temperature that may compromise the plastic. A PET bottle undergoes expansion and contraction of internal pressure throughout its life cycle. For example, the bottle may be filled at 4 °C and at a pressure of 28 psi. Throughout the bottle’s life cycle, it may be subject to pressures up to 70 psi and temperatures above 30 °C during storage and distribution, which puts stress on the bottle and weakens it. Additionally, washing of PET bottles must be done at lower temperatures than glass bottles, so the compositions used to clean PET bottles must be effective to clean at lower temperatures without relying on increased temperature. For example, glass bottles are typically washed at 75 °C to 80 °C, while PET bottles are washed about 55 °C to 65 °C. At temperatures above 65 °C, the plastic of the PET bottles will begin to deform.

[0060] The compositions and methods described herein are effective at cleaning glass and PET bottles with compositions free from chelating agents and that are PET- compatible. The efficacy of the compositions and solutions can be measured by evaluating label compatibility with the solutions (efficacy of removing labels without ink migration or particles in the solution), turbidity of the solution after cleaning, foam formation during washing and rinsing, label removal, cleaning performance, and stress cracking.

[0061] The following non-limiting Examples are provided as illustrative embodiments of the invention. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical values, however, inherently contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements. The Examples are illustrative and may only show limited numerical quantities of the components described above. Only some Examples are shown for the sake of brevity, but the full quantity ranges of components described above are contemplated.EXAMPLESExample 1: Preparation of Concentrate Composition and Diluted Use Solution

[0062] The methods of cleaning PET and glass bottles described herein use a concentrate composition in some examples. In this Example, a concentrate compositionwas prepared by combining the components described below in Table 1. The components were added in the order indicated in Table 1 to form a concentrate solution.TABLE 1 : Preparation of Concentrate Composition

[0063] After the concentrate composition was prepared, two example use solutions were prepared with different amounts of the concentrate composition and water as a dilutant. In one use solution, 0. 1 wt. % of the concentrate composition was added to 1 wt. % to 4 wt. % of sodium hydroxide (the remainder being water) to create a diluted use solution. In the other use solution, 1.0 wt. % of the concentrate composition was added to 1 wt. % to 4 wt. % of sodium hydroxide (the remainder being water) to create another diluted use solution. The formulas of these two solutions is shown in Table 2.TABLE 2: Dilution to Form Use SolutionsExample 2: Preparation of a Ready-to-Use Formula

[0064] A ready-to-use (RTU) formula was prepared where all components were added together into a use solution that is ready to be used to clean glass and PET bottles.The RTU formula is a use solution that has already been diluted with sodium hydroxide, though other RTU formulas may include other dilutants as disclosed herein. The RTU formula was prepared in accordance with Table 3.TABLE 3: RTU formulaExample 3: Evaluation of Label Compatibility

[0065] Label compatibility is a measure of how effective the compositions and solutions are at removing labels from bottles by measuring the loss of ink on the removed labels and turbidity of the cleaning solution.

[0066] Four different common label suppliers (Supplier A, Supplier B, Supplier C, and Supplier D) were evaluated to account for differences between labels produced by different sources. Suppliers A, C, and D use engraved labels, while supplier B uses flexible labels. A use solution was prepared that comprised 0.4 wt. % of the concentrate composition described in Table 1 of Example 1 with 2.8 wt. % of caustic soda (sodium hydroxide) in water. A control solution was also prepared that comprised a control cleaning solution. The control cleaning solution was a commercially used cleaning composition commonly used for bottle washing. Examples 3-5 and 7 herein measure the performance of the control solution as compared to the use solution comprising the compositions and solutions descnbed herein.

[0067] One of each of the 4 labels was submerged in the use solution and one of each of the 4 labels was submerged in the control solution for 5 minutes at 60 °C with mechanical vigorous agitation. At the end of the 5 -minute period, all labels were removed from the solutions and dried.

[0068] The above-described method simulates effective label extraction conditions, but certain situations may require additional contact time or agitation to a label forremoval. An extended test was performed to simulate such conditions. The test solutions described above (the use solution and control solution) were maintained at 60 °C, and labels from each supplier were submerged and agitated in the solutions for 2 hours. At the end of 2 hours, the labels were removed from the solutions, and the solutions were allowed to cool. The final turbidity' of the solutions was measured.

[0069] After the labels were dried, they were digitized, as shown in FIG. 1. The digitized images were analyzed using software that quantified the increase of white areas of the label by comparing the treated labels to labels that were not treated by the solutions. An increase in the percentage of white area meant that there was a greater loss of ink on the label during the extraction process. The software used to analyze the labels detected pixels with lost pigmentation and highlighted those pixels as white to be assessed in the final quantification of ink loss.

[0070] The white regions in the software-processed labels were quantified to measure how' much white region was present on each label after soaking in each of the solutions. These quantities were compared to the amount of white space (measured by the software) on labels that were not soaked in any solution. Table 4 show s the percent increase in white area for each of the 4 labels in the control solution and the use solution as compared to an untreated label. An acceptable degree of ink loss that will not significantly interfere with bottle reuse is less than 3 % ink loss.TABLE 4: Percent increase in white areas after extraction in solution

[0071] For Supplier A labels soaked in the control solution, there was a 20.62 % increase in white areas after soaking, meaning that there was a 20.62 % increase in ink loss from the label during an extraction (label removal) process with the control solution. As described above, ink loss contributes to gushing and inhibits proper cleaning. For Supplier A labels soaked in the use solution, there was only a 1.95 % increase in white areas, resulting in a 90.5 % reduction in label ink loss by using the use solution (prepared in accordance with the compositions described herein) compared to the control solution (commercial product).

[0072] A similar trend is seen for Supplier C labels. There was an 83. 1 % reduction in ink label loss using the use solution compared to the control solution. Supplier D labels demonstrated a slight reduction in ink loss with the use solution.Example 4: Measurement of Solution Turbidity

[0073] The results of Example 3 demonstrate that the use solution results in less ink loss with extraction that simulates label removal. The extended test described in Example 3 where the labels were soaked in the solutions for 2 hours provided an additional measurement of label removal. When the labels tested in Example 3 experienced ink loss, the ink lost from the labels was deposited in the solutions. The turbidity of each solution was tested in this Example.

[0074] Turbidity is the cloudiness or haziness of a liquid caused by the presence of suspended particles, which scatter light that passes through the liquid. Turbidity can be measured using a turbidimeter, which is an instrument that measures the amount of light scattered by the suspended particles in the liquid. A beam of light is directed through the liquid, and a sensor measures the amount of light scattered at a 90-degree angle from the direction of the light beam. The amount of scattered light is proportional to the amount of suspended particles in the liquid and is measured in units of nephelometric turbidity units (NTU).

[0075] The turbidity of each of the control solution and the use solution was measured for each of the 4 types of labels tested. The turbidity measurements in NTU are shown in Table 5. FIGS. 2A-2B show visual representations of the control solution and the use solution after removal of each of the 4 types of labels. The solutions that have larger and more closely oriented particles correspond to high turbidity levels (i.e., higher NTUs).TABLE 5: Turbidity of Solutions

[0076] The use solution had a much lower turbidity in each solution for all 4 types of labels. This indicated that the control solution (a conventional bottle washing additive) resulted in significant ink loss during extraction, which would lead to gushing duringfilling and problems cleaning. In contrast, the use solution (prepared in accordance with the compositions and methods described herein) significantly reduced the amount of ink lost.Example 5: Measuring Foam Formation

[0077] F oam generation under normal w ashing and rinsing conditions w as evaluated for the control solution and the use solution.

[0078] One liter of a washing solution was prepared by mixing 0.4 wt. % of the use solution from Example 3 and 2.8 % caustic soda with the remainder as water at 60 °C. One liter of the control solution was also prepared using 0.4 wt. % of a control product and 2.8 % caustic soda with the remainder as water at 60 °C. The solutions were placed in a foam test apparatus and the height (in centimeters) of foam produced by each solution was measured. Table 6 shows the foam height produced by each solution during w ashing, and FIG. 3A is a graphical representation of the dynamic change in foam height over the course of 20 minutes at 60 °C.TABLE 6: Foam height during washing at 60 °C

[0079] As shown in Table 6 and FIG. 3A, the control solution exhibits significant foaming that increases over 20 minutes, while the use solution maintains a low amount of foaming over the entire 20-minute period.

[0080] Foaming was also measured under rinse conditions at room temperature using each of the solutions. 0.04 wt. % of each of the control solution and the use solution w ere added to soft w ater (as the remainder) at room temperature, and the foam heightwas measured over 20 minutes. Table 7 and FIG. 3B show illustrate the foaming during rinsing at room temperature.TABLE 7: Foam height during rinsing at room temperature

[0081] Similarly to the washing step, the control solution produced significantly more foam during rinsing over the course of 20 minutes, while the use solution produced much less foam at a substantially consistent height.

[0082] Overall, foam generation was reduced by using the use solution in both washing and rinsing. This foam reduction optimizes the water consumption by avoiding false level measurements during the caustic wash and rinse sections of a bottle washing machine.Example 6: Measuring Label Removal

[0083] The efficacy of label removal from bottles was evaluated using the use solution of Example 3. 3-liter refillable PET bottles that each had 2 paper labels glued with a synthetic adhesive were cleaned with the use solution. Each test was performed by submerging bottles in each respective solution for 5 minutes to evaluate the label removal.

[0084] Two washing solutions were prepared with 0.4 wt. % of the use solution of Example 3. Bottles with labels from two different soft drinks, Label A and Label B. were submerged in each washing solution. The time it took for each label to detach from the bottle was measured, and the bottles were examined for any undesired remaining adhesive residue.

[0085] Table 8 shows the results of the label removal tests. In all four tests, the use solution was effective in removing both Label A and Label B in less than 3 minutes. Additionally, no adhesive residue was observed on any of the bottles after 5 minutes of immersion in the solutions.TABLE 8: Label removalExample 7 : Evaluating Cleaning Performance

[0086] The cleaning performance of the control solution and the use solution of Example 3 was evaluated. Bottles often have different levels of dirtiness, and a higher number indicates a bottle that is dirtier (e.g., a bottle with dirt level 3 is dirtier than a bottle with dirt level 2). Dirtiness can include debris, sediment, mold, or odor of the bottles. Bottles from dirtiness level 2 and bottles from dirtiness level 3 were photographed to evaluate the initial condition of the bottles. The top row of both FIGS. 4A and 5 A show representations of the initial condition of bottles with dirt level 2 before any cleaning. The top row of both FIGS. 4B and 5B show representations of the initial conditions of bottles with dirt level 3 before any cleaning.

[0087] A washing solution and a control solution were prepared in accordance with Table 9 and Example 3. Both solutions were heated to 60 °C.TABLE 9: Washing solution and control solution

[0088] Five bottles at dirt level 2 were submerged in a washing tank containing the control solution to clean the bottles. The bottles were then removed from the control solution and thoroughly rinsed with hard water, then rinsed with soft water. The bottleswere allowed to dry completely. The bottles were then evaluated for cleanliness, and representations of the final condition of the bottles are shown in the bottom row of FIG. 4 A. The bottom row of FIG. 4 A shows that the dirt level 2 bottles cleaned with the control solution were all adequately cleaned.

[0089] The experiment was repeated with bottles at dirt level 3. Five bottles at dirt level 3 were submerged in a washing tank containing the control solution. The bottles were removed from the control solution, rinsed with hard water, rinsed with soft water, and allowed to dry completely. The bottom row of FIG. 4B shows a representation of the final condition of the bottles after washing. With the control solution, only two of the bottles at dirt level 3 were adequately cleaned, while the other three had remaining debris.

[0090] Therefore, while all of the bottles with dirt level 2 were adequately cleaned with the control solution, all of the bottles with dirt level 3 were not adequately cleaned with the control solution.

[0091] The experiment was repeated with the washing solution that comprises the compositions and solutions disclosed herein. Five bottles at dirt level 2 were submerged in a washing tank containing the washing solution. The bottles were removed from the washing solution, rinsed with hard water, rinsed with soft water, and allowed to dry completely. The bottom row of FIG. 5 A shows a representation of the final condition of the bottles after washing in the washing solution. All five bottles at dirt level 2 were adequately cleaned with the washing solution.

[0092] The experiment was repeated using bottles at dirt level 3. Five bottles at dirt level 3 were submerged in a washing tank containing the washing solution. The bottles were removed from the washing solution, rinsed with hard water, rinsed with soft water, and allowed to dry completely. The bottom row of FIG. 5B shows a representation of the final condition of the bottles after washing in the washing solution. Three of the five bottles at dirt level 3 were adequately cleaned with the washing solution, and two were not adequately cleaned.

[0093] Therefore, all bottles at dirt level 2 were adequately cleaned with both the control solution and the washing solution. However, at dirt level 3, the bottles were more effectively cleaned using the washing solution as compared to the control solution.

[0094] The soil removal from the bottles cleaned with the control solution and the use solution was also evaluated by assigning a grade indicating the final level of cleanliness. A bottle with 50-70% soil removal is graded as “good,” which is represented by one plus sign (+). A bottle with 70-99% soil removal is graded as “better,” which isrepresented by two plus signs (++). A bottle with 100% soil removal is graded as “best,” which is represented by three plus signs (+++). The gradings for each of the control and use bottles cleaned in this Example is shown below in Table 10.TABLE 10: Grading of level of cleanliness after control and use solutionsExample 8: Measuring Stress Cracking

[0095] Stress-cracking of bottles washed in the control solution and the washing solution was measured. Stress cracking was measured by exposing bottles to conditions that accelerate bottle stress, specifically by subjecting the bottles to pressure variations that simulate the internal pressure changes that a bottle is subject to as its temperature varies during its shelf life.

[0096] Five, three-liter reusable PET bottles were selected and weighed before any testing was performed. The average bottle weight was 126 grams. A washing solution according to Table 9 was prepared.

[0097] The five bottles were submerged in the washing solution at 58 °C for 10 minutes. Then, the bottles were rinsed, and then filled with water and subjected to a pressure tamp from 45 psi to 75 psi, which constituted 1 wash cycle (also referred to as 1 life cycle). This test was repeated 25 times to replicate 25 wash cycles. As described above, stress cracking may be caused by physical stressors that may lead to changes in the bottle appearance such as fine lines, cracks, and hazing. Simulating numerous wash cycles exposes the bottles to stressors that may induce stress cracking.

[0098] The five bottles that were washed 25 times with the washing solution endured all 25 wash cycles with only slight stress formation at the bottom of the bottles, and no hazing of the bottle was observed.

[0099] The stress of the washed bottles was visually graded using a 1 to 5 scale. Level 0 represents no stress to the bottle, Level 1 represents slight stress. Level 2 represents moderate stress. Level 3 represents high stress, and Level 4 represents bottle leaking / bursting. Prior to any washing cycles, all of the bottles were at a Level 0 with no stress. After the washing cycles, all of bottles washed in the washing solution were at a Level 2 with moderate stress. The washing solution provided adequate cleaning while withstanding stress for 25 wash cycles.

[0100] The suitability of a washing solution can be evaluated based on the ability of a bottle washed with the washing solution to withstand numerous wash cycles without demonstrating stress cracking or hazing. For example, a bottle washed with the washing solution may exhibit no stress cracking or hazing after 1 wash cycle, after 5 wash cycles, after 10 wash cycles, after 15 wash cycles, after 20 wash cycles, or after 25 wash cycles. In some examples, a PET bottle washed with the bottle can be cleaned at least 5 times, at least 10 times, at least 15 times, at least 20 times, or at least 25 times without exhibiting stress cracking or hazing.

[0101] PET compatibility of the washing solution can be tested on the PET bottles by submersing the bottles in the washing solution at 8°C for 10 minutes, rinsing the bottles, and filling the bottles with carbonated water to create a pressure of 45 psi to 75 psi. The bottles may then be observed for signs of stress cracking or hazing. This cycle can be repeated to determine the PET compatibility of the washing solution over numerous wash cycles. For example, this test may be repeated at least 5 times, at least 10 times, at least 15 times, at least 20 times, or at least 25 times without the bottles exhibiting stress cracking or hazing.Example 9: Label removal with different surfactants

[0102] Several surfactants were tested in cleaning compositions to evaluate their effectiveness at removing labels. Table 10 shows six different compositions, each containing a different surfactant, their cloud point, EO (ethylene oxide) and PO (polyethylene oxide) moles, and their efficacy at removing labels.TABLE 10: Efficacy of different surfactants at removing labels

[0103] Surfactants with higher PO moles (i.e., about 5 PO moles) and cloud points of less than 40 °C causes ink loss from the ink layer on paper labels, resulting in bad label removal. However, surfactants with cloud points of greater than 40 °C, 0-20 EO moles, and low PO moles (i.e., < 5 PO moles) decreased the surface tension of the solution and provided good cleaning properties to the composition while avoiding penetration of the ink layer. Thus, such surfactants, like Surfactant A, resulted in an effective label removal with minimal ink loss.

[0104] The use solution and washing solution disclosed herein is prepared in accordance with the compositions and methods described herein. The solution demonstrates effective cleaning with full label removal, minimal foam formation, and less stress-cracking when tested on PET bottles.

[0105] The performance of the solutions described herein may additionally be impacted by other mechanical conditions such as conditions of a bottle washing machine, pressure in rinse streams, and the control of operating variables, such as concentration, time, and temperature.

[0106] Having described the preferred aspects and implementations of the present disclosure, modifications and equivalents of the disclosed concepts may readily occur to one skilled in the art. However, it is intended that such modifications and equivalents be included within the scope of the claims which are appended hereto.

Claims

What is claimed is:

1. A method of cleaning glass and polyethylene terephthalate (PET) bottles comprising:(a) diluting a concentrate composition with a dilutant to form a use solution, the concentrate composition comprising one or more organic acids, one or more organic and inorganic phosphates, one or more surfactants, a hydrotrope, and w ater, wherein the concentrate composition is free of chelating agents; and(b) applying the use solution to glass bottles, PET bottles, or combinations thereof.

2. The method of claim 1, wherein the one or more surfactants is selected from the group consisting of alkyl polyglycosides, alkyl polyethylene glycol ethers, alkoxylated fatty alcohols, and combinations thereof.

3. The method of claim 1 or claim 2, wherein the one or more surfactants is selected from the group consisting of C12-15 alcohol alkoxylates, C12-C15 alcohol ethoxylates, C12-C15 alcohol propoxylates. and combinations thereof.

4. The method of any one of claims 1-3, the concentrate composition comprising: 30 to 50 wt.% of the one or more organic acids;1 to 10 wt.% of the one or more organic and inorganic phosphates;1 to 25 wt.% of the one or more surfactants; and1 to 20 wt.% of the hydrotrope.

5. The method of any one of claims 1-4, wherein the dilutant is sodium hydroxide.

6. The method of any one of claims 1-5, wherein 0.1% to 1.0% of the concentrate composition is mixed with the dilutant.

7. The method of any one of claims 1-6, wherein a PET bottle cleaned with the method exhibits no stress cracking or hazing.

8. The method of any one of claims 1-7, wherein a PET bottle can be cleaned with the method at least 15 times without exhibiting stress cracking or hazing.

9. The method of any one of claims 1-8, wherein a PET bottle can be cleaned with the method at least 20 times without exhibiting stress cracking or hazing.

10. The method of any one of claims 1-9, wherein a PET bottle can be cleaned with the method at least 25 times without exhibiting stress cracking or hazing.

11. The method of any one of claims 1-10, wherein after the applying to the glass bottles. PET bottles, or combinations thereof, the turbidity of the use solution after applying is lower than 130 NTU.

12. The method of claim 11, wherein after the applying to the glass bottles, PET bottles, or combinations thereof, the turbidity of the use solution after applying is lower than 100 NTU.

13. The method of claim 12, wherein after the applying to the glass bottles, PET bottles, or combinations thereof, the turbidity of the use solution after applying is lower than 80 NTU.

14. The method of claim 13, wherein after the applying to the glass bottles, PET bottles, or combinations thereof, the turbidity of the use solution after applying is lower than 60 NTU.

15. The method of claim 14, wherein after the applying to the glass bottles, PET bottles, or combinations thereof, the turbidity of the use solution after applying is lower than 40 NTU.

16. The method of any one of claims 1-15, wherein the concentrate composition is free of EDTA, HEDTA, DPTA, and NTA.

17. The method of any one of claims 1-16, wherein the dilutant is sodium hydroxide, potassium hydroxide, or water.

18. The method of any one of claims 1-17, wherein the concentrate composition and the use solution do not comprise sodium hydroxide.

19. The method of any one of claims 1-18, wherein the applying results in a label being removed from the glass bottles, PET bottles, or combinations thereof in less than 5 minutes.

20. The method of claim 19, wherein the applying results in a label being removed from the glass bottles, PET bottles, or combinations thereof in less than 3 minutes.

21. A method of cleaning a polyethylene terephthalate (PET) bottle comprising: applying a use solution to PET bottles, the use solution comprising one or more organic acids, one or more organic and inorganic phosphates, one or more surfactants, a hydrotrope, and water, wherein the composition is free of chelating agents.

22. The method of claim 21, wherein the one or more surfactants is selected from the group consisting of C12-15 alcohol alkoxylates, C12-C15 alcohol ethoxylates, C12- C15 alcohol propoxylates, and combinations thereof.

23. The method of claim 21 or claim 22, wherein the use solution comprises:0.003 to 5 wt.% of the one or more organic acids;0.0001 to 1 wt.% of the one or more organic and inorganic phosphates;0.0001 to 2.5 wt.% of the one or more surfactants; and0.0001 to 2 wt.% of the hydrotrope.

24. The method of any one of claims 21-23, wherein the use solution further comprises sodium hydroxide.

25. The method of claim 24, wherein the use solution further comprises 0.1 to 5 wt.% of sodium hydroxide.

26. The method of any one of claims 21-25. wherein a PET bottle can be cleaned with the method at least 10 times without exhibiting stress cracking or hazing.

27. The method of any one of claims 21-26, wherein a PET botle can be cleaned with the method at least 15 times without exhibiting stress cracking or hazing.

28. The method of any one of claims 21-27, wherein a PET botle can be cleaned with the method at least 20 times without exhibiting stress cracking or hazing.

29. The method of any one of claims 21-28, wherein a PET botle can be cleaned with the method at least 25 times without exhibiting stress cracking or hazing.

30. The method of any one of claims 21-29. wherein after the applying to the glass botles, PET botles, or combinations thereof, the turbidity of the use solution after applying is lower than 130 NTU.

31. The method of claim 30, wherein after the applying to the glass botles. PET botles, or combinations thereof, the turbidity of the use solution after applying is lower than 100 NTU.

32. The method of claim 31, wherein after the apply ing to the glass bottles. PET botles, or combinations thereof, the turbidity of the use solution after applying is lower than 80 NTU.

33. The method of claim 32, wherein after the applying to the glass botles, PET botles, or combinations thereof, the turbidity of the use solution after applying is lower than 60 NTU.

34. The method of claim 33, wherein after the applying to the glass botles, PET botles, or combinations thereof, the turbidity of the use solution after applying is lower than 40 NTU.

35. The method of any one of claims 21-34, wherein the concentrate composition is free of EDTA, HEDTA, DPTA, and NTA.

36. The method of any one of claims 21-35, wherein the applying results in a label being removed from the glass bottles, PET bottles, or combinations thereof in less than 5 minutes.

37. The method of claim 36, wherein the applying results in a label being removed from the glass bottles, PET bottles, or combinations thereof in less than 3 minutes.

38. The method of any one of claims 21-37, wherein the dilutant is sodium hydroxide, potassium hydroxide, or water.

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