Soap wrappers

Soap packaging materials

Full description

Background of the invention

This invention relates to soap wrappers, in particular, to a soap bar wrapped at least by a stiffening member and a package including a soap bar straw, a stiffining member, and a wrapper completely surrounding the soap bar and the stiffening member.

Considerable effort has been made in the past to develop fungicide-containing papers and backing sheets for soap packaging. Since cellulose, the main component of paper, is an excellent growth medium for mold especially under warm, humid conditions, the use of a fungicide (often known in the United States as “antimicotic”) is essential in soap packaging to prevent spoilage. These materials serve as fungistats, as they prevent the beginning of mold growth.

Unfortunately, the number of fungicides that can be safely used for soap packaging is limited, not least because some are very toxic to humans. In addition, mold may become resistant to fungicides after prolonged exposure, which requires changing the fungicide about every 7 years. Carbendazim and Thiabendazole were used in the past, but they are now ineffective under tropical conditions, and it is necessary

Paper makers have gone to great lengths to develop a suitable second generation fungicide. This requires a long program of tests and surveys, which, after the mold becomes resistant again, it is necessary to repeat this procedure to avoid mold growth.

It is well known to use plastic film to wrap soap. In particular, in a typical bar soap package, the soap is wrapped with a conventional paper backer, and the entire soap and hardener is encased in a packaging film which is typically a laminated film comprising two layers each of oriented polypropylene. However, in this approach the only concern is the appearance of the piece, which is enhanced by the high glossiness of the plastic films. It does not make any difference to the problem of mold infection, and the continued use of traditional stiffeners still leaves the stiffeners vulnerable to infection.

Mold is accelerated by warm, humid conditions, and just as a bar of soap contains free water at the time of packaging, the wrapper and hardener are initially very wet. With the use of paper covers this balances out relatively quickly as water is lost rapidly through the paper and the glued-folded edges of the cover.

General description of the invention

We have found that if a reinforcement is wrapped around a bar of soap, at least along its longitudinal length, the outer surfaces of which at least are equipped with a plastic material, then the growth of mold on and within it can be completely avoided.

Also when ordinary gusset becomes wet from moisture it will essentially lose its resistance. So the ability to protect the soap during transition will decrease. However, if the reinforcement consists of an inner panel and two surfaces of elastomeric material, moisture absorption by the panel will be reduced, and subsequent losses in the panel will be reduced. If, in addition, a wrap is wrapped around both the soap bar and the reinforcement, including a film material having at least its own outer surfaces equipped with a plastic material, mold growth on and within it can be completely eliminated.

Specifically, in microbiology laboratory tests used molds that were found to be resistant to Carbendazim, both elastomer films and elastomer-coated panels were selected for mold infestation, and both were found to be completely resistant.

Indeed, we found that, even with a double board reinforcement coated with a plastic material, the fungus did not extend beyond the edges.

Thus, according to one aspect, the present invention provides a bar of soap having, coiled laterally from the bar,

At least along its longitudinal extension, a reinforcement portion comprising a reinforced sheet material having at least its outer surfaces equipped with an elastomeric material, wherein at least a portion of the reinforcement material is transparent.

It is required for a hardening material, at least part of which is transparent, allowing the soap to be seen through the hardening material. Until now, the use of conventional paper loaded with stiffeners has prevented seeing through the stiffeners. In addition, the provision of elastic reinforcements provides improved resistance to mold.

Preferably, the stiffness for a piece of regular soap with a size of more than 50 grams for the stiffening part should be at least 3 Taber Stiffness Units in both directions.

Longitudinal (machine) and transverse (transverse), preferably at least 8 Taber stiffness units

Taber Stiffness Units

The reinforcement part should preferably have a gram weight (weight per unit area) of 100 to 200 g/

m2, with a thickness of 50 to 250 micrometres, preferably 160 to 180 micrometres.

In one embodiment of the invention the entire stiffening portion includes a transparent material, as may the entire cover.

According to another approach, the invention provides a package including a bar of soap and a packing material, the packing material comprising a reinforcing portion that wraps, laterally, of the piece, at least around a longitudinal extension of the piece, the reinforcement portion comprising a reinforced sheet material having at least its outer surfaces provided with an elastic material and including The least transparent portion, a wrapper wrapped around, in such a way as to completely enclose, both the bar of soap and the stiffener, the wrapper comprising a film material having at least a transparent portion. Ideally, at least its outer surfaces are prepared with a plastic material.

At a minimum, it is preferable to provide each of its external surfaces with a thermoplastic material. As an example, the board material for a stiffener may have a central layer of cardboard and each of its outer layers include a layer of thermoplastic material, each layer preferably having its own thickness, independent of the other, ranging from 5 to 35 micrometers. However, it is more preferable that the entire panel be of a thermoplastic material, containing perhaps 5 to 30%, preferably 10 to 35%, more preferably about 20%, by weight of the total weight of the filler reinforcement portion. Or a blowing agent, or the aggregate of a filler and a blowing agent. Typically, the filling is an inert inorganic filler such as talc or clay. Such fillers provide improved toughness.

Brief explanation of the drawings

Furthermore, as shown by reference to Appendix 1, since only the folded ends of the wrap provide an escape route for moisture, the rate of water loss is greatly reduced to provide a desired amount of water within the piece. On the other hand, the membrane cover made of elastic material gives a very effective moisture barrier.

Detailed description of the invention

It is preferable to choose a thermoplastics material for the reinforcement plate from among the many types of films suitable for this application. Typically this would be polypropylene, acrylic/butadiene/styrene copolymer, polystyrene and polyethylene terephthalate and PVC. These films may be either single or double directed to improve the properties like clarity, blocking, strengthening etc. which are usually imparted by these processes. On the other hand, a simple membrane system can be used. It is preferable that the membranes be in a form that gives maximum reinforcement, therefore it is preferable that the suitable polystyrene be either BOPS or HIPS and the suitable PET is A-PET.

It is particularly preferable for the hardboard material to be non-returnable, so that it does not separate from the language on which it is stored, and so that it can be folded around the bar of soap, preferably around the longitudinal surface of the perimeter of the soap bar. After that, the stiffener part will remain in the folded state until it is stretched. A sleeve wrapper surrounds the bar of soap. Preferably, the longitudinal ends of the bar of soap are not surrounded by the stiffener, so that the bar of soap can easily be removed for use.

The cover may be a film material including a paper core coated on the surface with an elastic material. However, it is preferable that the cover be made of a film material that is entirely plastic, preferably more thermoplastic, with at least parts that are transparent.

Optionally the membrane can have a single surface with a metallic appearance to enhance the visual appearance or improve blocking properties. Additionally this can be partially removed to create a transparent area forming a window, through which the bar of soap can be viewed.

The film material for the covers is preferably 5 to 50 micrometers thick.

Preferably, the wrapper, when wrapped around the bar of soap and the stiffener, should have end parts in an overlapping relationship with each other. This allows these end parts to lock together. This may be accomplished by applying an adhesive between different corresponding corresponding surface areas, for example, by coating the adhesive at different areas of the end parts, folding the wrap and applying pressure. However, it is preferable that the end parts be secured together by heat-tight welding, so that at least the outer layers of the covering film material are, preferably, of a ductile material capable of being heat-tight welded.

Moreover, it is preferable that the peripheral parts be kept free of printing materials, etc.

Thus, preferably, the cover film material shall include at least one layer of biaxially oriented, heat-tight weldable polypropylene. It is more preferable to have the membrane attached from a biaxially oriented polypropylene layer with a low density polyethylene membrane.

Preferred examples of optional shell configurations are:

(a) a laminate foil of a heat-weldable film whose inner face may bear printing material and between which a foil of an adhesive, such as hot melt, may be applied;

(b) Special BOPP membrane which is capable of heat welding; And

(c) Wafer bonded with nylon, PET or low-density polyethylene, eg hot melt adhesive, to a heat-weldable film.

A package, according to the invention, containing a bar of soap may be produced by a method including the steps:

Folding around at least a longitudinal extension of a bar of soap a reinforcing portion such that the reinforcing portion wraps sideways around the bar;

Wrapping both the soap bar and the reinforcement portion with a wrap in such a manner as to completely surround the soap bar and the reinforcement portion and provide overlapping end portions of the film; And

Gluing together, preferably by heat welding, at least the respective portions of the overlapping end parts to secure the casing in position.

It is preferable to form the stiffening part by casting a molten film of a thermoplastic material such as polypropylene or polystyrene.

Typically the soap packaging system for a package embodying the invention may include:

1- A cover that may be made entirely of a plastic material or of paper coated with a plastic material. It is preferable for the finished shell to be heat weldable on both sides for high-speed machines; However, hot melt adhesive can be used for welding in lower speed packaging lines.

2- A hardener that can be either 100% plastic, a stuffed plastic film, or paper or cardboard coated on both sides with a plastic material, provided that at least part of the hardener is transparent. Particularly popular examples of both packaging and reinforcement materials that can provide a mold-proof soap package are as follows:

Wrapper Materials

1- Synchronous extrusion polypropylene (BOPP) films, biaxially oriented, 15-55 micrometer thick, printed on the surface and varnished with areas of the end parts free of ink and varnish to adhere to each other. If desired, the print can be narrowed on the back to avoid damage due to wear during Transport.

2- BOPP films 15-35 µm thickness, back-printed and over-ink coated with 12-35 µm low-density polyethylene (LDPE), or a mixture thereof. Instead of a homopolymer of LDPE or LLDPE, a copolymer containing each of these may be used for the coating. However, such homopolymer or copolymer may additionally contain 2-

10% ethylene vinyl acetate (EVA) copolymer units, especially in LDPE to improve welding.

3- Two or more films, preferably 10-35 micrometer thick, laminated together on the front and back surfaces, capable of hot welding. Interlayer printing may occur between layers of the membrane.

4- BOPP film with thickness of 10-35 micrometers laminated with LDPE or LLDPE film in thickness

10-50 µm. A combination of LDPE or LLDPE can be used in the membrane, and adding 2-10% ethylene vinyl acetate copolymer to the LDPE membrane can improve welding.

5- High-density polyethylene film with a thickness of 10-50 micrometers is printed on the surface and varnished with welding areas free of ink and varnish.

15-55 µm PET, PVC, polyethylene, polyethylene films with a hot weld coating (typically hot melt wax) applied to the back side. Optionally the coating can be of the cold seal type, when heat application is not used in the welding process.

Reinforcement materials, which at least have transparent parts:

1- Casting films made entirely of 100% plastic material, or casting films produced from a plastic material filled with inert inorganic fillers or intermediate blowing agents to increase strengthening. Examples of this type of membrane are 50-250 µm polypropylene,

PET, acrylic/butadiene/styrene, polystyrene or PET. Filler materials such as talc or 10-30% clay may be present.

2- Cardboard coated on both sides with 5-35 micrometer polyethylene. A combination of LDPE and LLDPE can be used. Cardboard quality is not critical for white striped particle board, Triplex, Duplex or 100% bleached or unbleached Kraft cardboard as it is suitable for weights from 100-200 g/m2.

The above special strengthening and packing materials can be used in any combination with each other.

It is especially preferable for the entire packaging system to be paperless.

Preferred embodiments of the invention will now be described by reference to the following examples and the attached graphical representation of weight loss due to moisture loss during the post-packaging period of a newly prepared bar of soap.

Examples A to H

The following packaging systems were tested for fungal growth and weight loss.

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Notes

1 biaxially oriented polypropylene (BOP) shell consisting of a sheet of two layers of BOP with printing material in between. The outer layer of the shell has a melting index greater than that of the inner layer for hot melting during heat welding. The outer layer has an acrylic polymer coating to additionally assist in heat welding. .

2 A cover with a paper core laminated with an acrylic-based varnish, forming an outer layer, and a hot-melted layer of waxy material, forming an inner layer.

3 special reinforcement materials made of paper and plastic material, both with a stiffness value, when measured as described below in the longitudinal direction of the machine, of 15 Taber Stiffness units.

4 After wrapping a newly manufactured bar of soap, the ends of the wrapping paper are either left flat (no soldering), folded and held together by applying adhesive tape (partial soldering), or folded and held together with sufficient adhesive tape to provide a tight seal (full solder).

5 Paper backing materials and paper pulp packaging are pre-treated with Carbendazim as an insecticide

innate.

The above hardness values were determined using a 5-Taber V digital hardness laboratory (model 150-D) on ten specimens cut to size 40 mm x 70 mm, five in the transverse direction and five in the machine direction. Before testing, condition samples at 35°C/50% relative humidity for twenty-four hours. For the meaning of Taber Stiffness Units, see TAPP Standard Specification 86-T489 om.

All of the above sheathing and reinforcing materials have been evaluated for their resistance to fungal growth. It was the evaluation method

as follows.

As a growth medium for mold growth, Sabouraud Dextrose Agar is used. This consists of a mixture of fungal peptone (commercially available from Oxoid Ltd, England as Oxoid L40) (10 g), dextrose (40 g) and agar (15 g). This mixture is commercially available from Oxoid Ltd in the form of powder (CM40) or tablets (CM42). For use, mix with 1000 milliliters of distilled water, sterilize for twenty minutes at 100 C and cool to give a growth medium with a pH of 5.6.

Small squares of test packing material were cut using scissors dipped in alcohol, exposed to flame and cooled. The squares were placed right side up and upside down on the surface of Sabourauds dextrose agar petri dishes using tweezers dipped in alcohol and exposed to a flame.

Using a sterile pipette, dispense 0.1 milliliter of mold inoculum (approximately 810 spores mL-1) onto the center of the packing box. Using a sterile plastic hockey stick, spread the inoculum evenly over the surface of the agar and packing material.

Petri dishes were incubated at 28°C for one week and fungal growth levels on the packing material and agar were visually assessed.

The following statement is used for visual sanitization.

Zero = no growth

10 = slight growth

20 = patchy, light growth

30 = Moderate growth on the entire sample

40 = Heavy growth on most of the sample

50 = Completely excessive growth

As a control, the test included Sabourauds dextrose agar without packaging material and Sabourauds dextrose agar with preservative-free paper. These plates showed a reading of 50, but both the reinforcement and packing materials in Examples A-H showed zero fungal growth.

The results of these tests showed that when using flexible packaging and reinforcement materials, it was possible to achieve zero fungal growth without the need for pre-treatment with the fungicide Carbendazim. As opposed to paper backing and packaging materials for which such pre-treatment was necessary.

After packaging the freshly prepared sample soap bars for the packaging systems of Examples A-H, the samples were stored at 37°C and 70% relative humidity and were weighed regularly to determine the weight loss (in grams) due to moisture loss. The results obtained are shown in Figure 1.

As can be seen, these plastic-coated samples suffered significantly less moisture loss over a 60-day period than the paper-wrapped samples, even after the paper was coated on the absorbent sides with acrylic paint and wax.