Compositions for removal of starch

Abstract

A composition for the removal of resin-injected starch from a surface, the composition comprising: an enzyme present in an amount in the range of about 15 - 30% w / w to break down the starch into water soluble units; at least one solvent in an amount in the range of about 2 - 4% w / w, effective to liquify resins present in the starch; a cofactor present in an amount in the range of about 5 - 10% w / w to function as an enhancer to assist the enzyme to break down the starch into water soluble units; at least one surfactant in an amount in the range of about 14 - 25% w / w to retain the enzyme in solution; and a bacteriocide in an amount in the range of 0.01 – 0.04% w / w, effective to protect the enzyme from bacteria.

Description

[0001] COMPOSITIONS FOR REMOVAL OF STARCH

[0002] RELATED APPLICATIONS

[0003] The present application claims priority from Australian provisional patent application no. 2024904256 filed 20 December 2024, the entire contents of which are incorporated herein by reference.

[0004] FIELD OF INVENTION

[0005] The present application relates generally to compositions for the removal of starch and in particular, to compositions for use in the removal of starch from surfaces in the industrial printing, paper and the corrugated box industry.

[0006] BACKGROUND ART

[0007] Starches are used extensively for industrial applications, including for paper strength and brightness for the paper industry and as a highly effective adhesive for all board grades, from corrugated packaging to plasterboard. Starch is by far the most important surface sizing agent. In the size press the dilute starch solution is applied to the surface where it cements the body of the paper and thus increases the paper strength.

[0008] Starch is widely used in the paper manufacturing industry at different stages of the paper making process. Common starches used for the paper making industry are potato and cassava, and in particular countries some forms of starch predominate, such as wheat starch in Australia, tapioca starch in New Zealand and com starch in the USA. The main processes of sizing, printing, and finishing need starch in sub stantial quantitie s .

[0009] Some starches may be water soluble, however most starches used in many packaging applications and in particular in the corrugating packaging industry, often include resin and are not water soluble or at least not sufficiently water soluble to be able to be cleaned effectively with water alone. It can also be problematic to use high pressure spraying of water as this may cause damage to components such as bearings in the equipment which may in turn substantially affect the operation of the equipment. Manual scrubbing, as an alternative, is too time consuming and costly, due to labour requirements and long machine downtimes.

[0010] The regular removal of starch from equipment in a commercial chemical process is required as the starch resin used to impart water resistance to corrugating adhesives is retained on the surfaces of the machinery. However, often machinery is allowed to continue to be used in a fouled or excess starch build-up condition which decreases the effectiveness of the equipment in further chemical processing. By keeping the machinery and particularly the starch applicators clean, this can encourage an even spread of starch which in turn means that less starch is used and also less heat is required to cure the starch. This can translate to energy and cost savings, and also reduce the negative impact that unnecessarily high heat conditions may have, in particular in relation to the strength of the paper or board which may weaken under high temperatures.

[0011] In the operation of a paperboard converting plant, tens of thousands of feet of paperboard move through converting equipment on a daily basis, with corrugators capable of producing up to 350 - 450 meters of board per minute. As the paperboard comes into contact with feed rollers within the converting equipment, any starch present on the paperboard will collect from the paperboard onto the feed rollers. Also, as any anilox rolls will apply ink to the paperboard, traces of ink will remain on the anilox rolls during use. The residues of ink and starch can detract from efficient operation of the machinery as they may cause a smearing effect and / or cause slippage of the rollers. Accordingly, it is desirable to clean the rollers from time to time to ensure such adverse effects are minimised.

[0012] It is known for rollers to be cleaned by spraying them with soap or other cleaning chemicals. Typically, soap is delivered to a paperboard converting plant in totes of concentrated soap. The concentrated soap then is diluted to its working strength. Often, dilution is a manual operation that involves galoshes, other personal protective equipment, and a hand-held hose.

[0013] The present applicant has developed a composition, method and system for cleaning rollers that is disclosed in the Applicant’s US Patent No. 11,034,908. The patent discloses a composition that removes starch from surfaces by using surfactants and solvents at appropriate percentages to react at the interface of the starch and surface to which it is attached, to liquify the resins. Such a composition was proven to provide a greater surface area for the enzyme present in the composition to break down the starch molecules into smaller water-soluble units.

[0014] Whilst such a composition and method of applying the composition has been effective in removing the starch from the surfaces of the machinery, the enzyme has proven difficult to maintain in solution and the solvent present in the composition can limit the effective working life of the enzyme. Thus, there is a need to provide an improved composition that works faster and more effectively in breaking down the starch molecules for cleaning.

[0015] The above references to and descriptions of prior proposals or products are not intended to be, and are not to be construed as, statements or admissions of common general knowledge in the art. In particular, the above prior art discussion does not relate to what is commonly or well known by the person skilled in the art, but assists in the understanding of the inventive step of the present invention of which the identification of pertinent prior art proposals is but one part.

[0016] SUMMARY OF THE INVENTION

[0017] Accordingly, in one aspect of the invention there is provided a composition for the removal of resin-injected starch from a surface, the composition comprising: an enzyme present in an amount in the range of about 15 - 30% w / w to break down the starch into water soluble units; at least one solvent in an amount in the range of about 2 - 4% w / w, effective to liquify resins present in the starch; a cofactor present in an amount in the range of about 5 - 10% w / w to function as an enhancer to assist the enzyme to break down the starch into water soluble units; at least one surfactant in an amount in the range of about 14 - 25% w / w to retain the enzyme in solution; and a bacteriocide in an amount in the range of 0.01 - 0.04% w / w, effective to protect the enzyme from bacteria.

[0018] The enzyme may be alpha amylase.

[0019] The at least one solvent may include Ethylene Glycol Mono Butyl Ether.

[0020] The cofactor may be Alkyl Poly Glucoside (APG).

[0021] The at least one surfactant may include Sodium laureth sulfate (SLES).

[0022] The bacteriocide may be Sodium benzoate.

[0023] The composition may further include a pH control agent to control the acidity of the composition in the range of about 6 to 8 pH, more preferably of between 5.6 - 7.6 pH. The pH control agent may be one of citric acid or Citrate.

[0024] DETAILED DESCRIPTION

[0025] The composition according to the present invention will be described below in relation to its application for removing starch from surfaces in the industrial printing, paper industry and the corrugated box industry. However, it will be appreciated that the composition could be employed across a wide variety of industries for the removal of starch and similar products from a variety of different surfaces and components, as will be appreciated by those skilled in the art.

[0026] The composition of the present invention seeks to remove starch from surfaces by using a combination of surfactants and solvents to create a reaction at the interface of the starch and the surface to which it is attached to liquify the resins present in the starch on the surface to which it is attached. This allows for the enzyme present in the formulation to act across a greater surface area of the starch molecules to break down the starch molecules into smaller water-soluble units. Such a basis of operation was discussed in the Applicant’s US Patent No. 11,034,908, which is incorporated herein by reference.

[0027] In the formulation disclosed in the Applicant’s earlier US Patent No. 11,034,908, the enzyme alpha amylase was present in a range of about 5 - 15%. Whilst this formulation percentage was sufficient to achieve the purpose of the invention, the action time of the formulation is relatively slow. To increase the action time the percentage of enzyme in the formulation needs to increase; however, through experimentation the Applicant has found that to increase the percentage of enzyme to a more preferred 15 - 30%, the enzyme will not stay in solution and the increased percentage of enzyme is more likely to be attacked by bacteria that consume the enzyme as food, thereby creating a formulation that is less stable and more prone to spoiling. To address this the Applicant has developed an improved formulation as follows.

[0028] COMPOSITION EXAMPLE

[0029] In accordance with a preferred embodiment of the composition, the composition contains the following active ingredients:

[0030]

[0031] The formulation includes the enzyme, alpha amylase, at a higher concentration of 15 - 30% to provide for quicker hydrolysation of the bonds between the glucose molecule in the starch chain that were disrupted by the solvent. To increase the rate of reaction of the enzyme with the glucose molecules in the starch chain, the cofactor, APG, is included. The cofactor is a surfactant that functions as a co-factor or enhancer with the enzyme to enhance the reaction and speed up the hydrolysation process at a concentration of 5 - 10% w / w.

[0032] To cater for the increase in enzyme concentration, the surfactant SLES has been introduced into the formulation at a concentration of around 14 - 25% w / w to hold the enzyme in solution. The surfactant functions as a foaming agent and has larger bubbles to also assist in cleaning process.

[0033] To maintain the pH of the solution at the desired level for optimal enzyme activity, Citric acid is added to obtain a pH range of around 5.6 - 7.6.

[0034] With the increased concentration of the enzyme in the composition, the composition is more attractable to bacteria growth as the bacteria see the enzyme as protein food, which can spoil the composition and render the composition ineffective if the bacteria growth is too great. For this reason, the composition comprises a bacteriocide, such as sodium benzoate, to a concentration of around 0.01 - 0.04%, which is sufficient to prevent bacteria growth in the composition.

[0035] The present formulation can be applied using the system and method as described in the Applicant’s US Patent No. 11,034,908.

[0036] It will be appreciated by those skilled in the art that the present formulation has a considerably higher enzyme strength than compared to that disclosed in US Patent No. 11,034,908. To achieve this, the solution has been adapted to ensure that the enzyme remains in solution and has pH control for best enzyme activity. Further, a biocide has been included to prevent bacteria growth to protect the enzyme.

[0037] Throughout the specification and claims the word “comprise” and its derivatives are intended to have an inclusive rather than exclusive meaning unless the contrary is expressly stated or the context requires otherwise. That is, the word “comprise” and its derivatives will be taken to indicate the inclusion of not only the listed components, steps or features that it directly references, but also other components, steps or features not specifically listed, unless the contrary is expressly stated or the context requires otherwise.

[0038] Orientational terms used in the specification and claims such as vertical, horizontal, top, bottom, upper and lower are to be interpreted as relational and are based on the premise that the component, item, article, apparatus, device or instrument will usually be considered in a particular orientation, typically with the apparatus uppermost.

[0039] It will be appreciated by those skilled in the art that many modifications and variations may be made to the methods of the invention described herein without departing from the spirit and scope of the invention.

Claims

The claims defining the invention are as follows:

1. A composition for the removal of resin-injected starch from a surface, the composition comprising: an enzyme present in an amount in the range of about 15 - 30% w / w to break down the starch into water soluble units; at least one solvent in an amount in the range of about 2 - 4% w / w, effective to liquify resins present in the starch; a cofactor present in an amount in the range of about 5 - 10% w / w to function as an enhancer to assist the enzyme to break down the starch into water soluble units; at least one surfactant in an amount in the range of about 14 - 25% w / w to retain the enzyme in solution; and a bacteriocide in an amount in the range of 0.01 - 0.04% w / w, effective to protect the enzyme from bacteria.

2. The composition according to claim 1, wherein the enzyme is alpha amylase.

3. The composition according to claim 1, wherein the at least one solvent includes Ethylene Glycol Mono Butyl Ether.

4. The composition according to claim 1, wherein the cofactor is Alkyl Poly Glucoside (APG).

5. The composition according to claim 1, wherein the at least one surfactant is Sodium laureth sulfate (SLES).

6. The composition according to claim 1, wherein the bacteriocide is Sodium benzoate.

7. The composition according to any one of the preceding claims, wherein the composition further includes a pH control agent to control the acidity of the composition in the range of about 5.6 to 7.6 pH.

8. The composition according to claim 13, wherein the pH control agent is one of citric acid or Sodium Citrate.

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