A simple thin sheet self-heating element and its preparation method and application

Abstract

The present invention relates to the field of chemical technology, and in particular to a simple thin-sheet self-heating body and a preparation method and application thereof. The simple thin-sheet self-heating body comprises the following components: pig iron powder, activated carbon, polypropylene fiber, xanthan gum, sodium carboxymethyl cellulose and sodium polyacrylate, industrial salt, vermiculite and water, and the sum of the percentages of each component is 100%. The simple thin-sheet self-heating body is formed by mixing with industrial salt water, and the entire self-heating body is very thin and small in size; at the same time, a thin-sheet solid package is finally formed, which will not cause the problem of leakage of heating substances; furthermore, the content of polypropylene fiber, xanthan gum, sodium carboxymethyl cellulose and sodium polyacrylate in the self-heating body is relatively low, which greatly reduces the cost of the self-heating body. By adding vermiculite, the heat preservation effect of the self-heating body is increased.

Description

Technical Field

[0001] The invention relates to the technical field of chemical engineering, and in particular to a simple thin-sheet self-heating element and a preparation method and application thereof. Background Art

[0002] Self-heating body is a key material of a heat-keeping patch (commonly known as "heating patch", "warm baby", "one heat patch", "warm baby", etc.) used to keep the human body warm. Its basic principle is: iron powder, carbon powder, vermiculite, resin, salt, etc. are mixed in an appropriate proportion to make a self-heating body, which is then put into a bag made of non-woven fabric covered with a microporous oxygen-permeable film, and then packaged in an oxygen-insulated plastic outer bag. When in use, tear open the plastic outer bag, and after the non-woven inner bag contacts the air, oxygen enters from the micropores of the non-woven fabric and reacts with the iron powder to generate heat, achieving a warming effect.

[0003] Existing products have several significant deficiencies: (1) the self-heating body is too thick and bulky, which is not aesthetically pleasing when used to keep the human body warm; (2) the bagged powder material is easily damaged and leaks, thereby causing contamination and damage to the human body or clothing. Summary of the invention

[0004] The present invention provides a simple thin-sheet self-heating element and a preparation method and application thereof to solve the above-mentioned technical problems.

[0005] The technical solution of the present invention to solve the above technical problems is as follows:

[0006] A simple sheet-type self-heating element comprises the following components in percentage by weight:

[0007]

[0008]

[0009] The sum of the percentages of the individual components is 100%.

[0010] The working principle and beneficial effects of the present invention are as follows: a simple thin sheet-type self-heating body is formed by mixing industrial salt water, and the whole self-heating body is very thin and small in size; at the same time, a thin sheet-type solid package is finally formed, which will not cause the problem of leakage of heating substances; in addition, the content of polypropylene fiber, xanthan gum, sodium carboxymethyl cellulose and sodium polyacrylate in the self-heating body is relatively low, which greatly reduces the cost of the self-heating body. By adding vermiculite, the heat preservation effect of the self-heating body is increased.

[0011] Based on the above technical solution, the present invention can also be improved as follows.

[0012] Furthermore, the thickness of the self-heating element is 1 mm-3 mm.

[0013] The beneficial effect of adopting the above further solution is: the thickness of the self-heating body is 1mm-3mm, which takes into account both the heating performance and the overall weight of the self-heating body.

[0014] Based on the above technical solution, the present invention can also be improved as follows.

[0015] further,

[0016] The composition comprises the following weight percentages:

[0017]

[0018]

[0019] The sum of the percentages of the individual components is 100%.

[0020] The beneficial effect of adopting the above further solution is: the performance of the self-heating body is further improved.

[0021] Based on the above technical solution, the present invention can also be improved as follows.

[0022] Furthermore, the particle size of the pig iron powder is 120-180 meshes, the particle size of the activated carbon is 150-200 meshes, the length of the polypropylene fiber is 2mm-6mm, and the particle size of the sodium polyacrylate is 80-120 meshes.

[0023] The beneficial effect of adopting the above further scheme is: by setting the above, the mixing of each component during the mixing process is very uniform, and at the same time, the heating uniformity of the entire self-heating body is improved, and the situation of the heating body falling is avoided.

[0024] The present invention also provides a method for preparing a simple thin-sheet self-heating element, comprising the following steps:

[0025] Step 1, mixing pig iron powder, activated carbon, xanthan gum, sodium carboxymethyl cellulose, sodium polyacrylate, vermiculite and polyethylene fiber at room temperature and pressure to obtain a uniform powder;

[0026] Step 2, preparing a brine mixture with industrial salt and water, and pouring the uniform powder into the brine mixture for stirring and mixing to form a high-viscosity material body, which is then sealed and stored;

[0027] Step 3, the high-viscosity material after cooling is placed into a microporous oxygen-permeable film and an oxygen-isolating outer film, and heat-sealed and cut to form a simple sheet-type self-heating body.

[0028] The principle and beneficial effect of the preparation method of the present invention are as follows: the solid particle components are mixed separately to make the components evenly mixed, thereby avoiding the difference in local heating of the self-heating body.

[0029] Based on the above technical solution, the present invention can also be improved as follows.

[0030] Furthermore, the stirring and mixing conditions in step 2 are: pressure is normal pressure, temperature is 30° C., stirring direction is counterclockwise, stirring speed is 120 r / min, and stirring time is 10 min.

[0031] The beneficial effect of adopting the above further scheme is: by setting the above stirring and mixing conditions, the uniformity of the powder and brine mixture is ensured, so as to achieve the purpose of uniform heat release and sufficient steam; at the same time, the spontaneous heat of the self-heating body during the preparation process is reduced.

[0032] The present invention also provides an application of a simple thin-sheet self-heating body, which is used to prepare human body warming patches, medical surgery warming pads, medical and health care patches for heating and heat preservation, menstrual pain relief patches for women, breast health care, eye health care, lumbar vertebral disease medical care, and portable heating and warming equipment for instruments and meters or digital products.

[0033] The beneficial effects of the present invention are: by setting the above-mentioned self-heating body, the entire heating and warmth-keeping application product is very thin and small in size; it will not cause the problem of leakage of heating substances; and the cost of the self-heating body application product is greatly reduced.

[0034] Based on the above technical solution, the present invention can also be improved as follows.

[0035] Furthermore, a variable air permeability layer is provided on one side of the self-heating body.

[0036] The beneficial effect of adopting the above further scheme is that by setting a variable air permeability layer, the heating temperature and heating time length of the self-heating body application product can be adjusted.

[0037] Based on the above technical solution, the present invention can also be improved as follows.

[0038] Furthermore, the variable air permeability layer is a non-woven fabric layer, which includes a non-woven fabric base layer and a shielding layer arranged on the non-woven fabric base layer, and the shielding layer is used to cover part of the air permeability holes of the non-woven fabric base layer.

[0039] The beneficial effects of adopting the above further scheme are: the non-woven fabric has good air permeability and hygienic properties, which facilitates the wide application of self-heating body products in various fields; at the same time, it is also convenient to set a shielding layer to block some of the air holes of the non-woven fabric.

[0040] Based on the above technical solution, the present invention can also be improved as follows.

[0041] Furthermore, the non-woven fabric base layer is composed of two layers, and the blocking layer is composed of a plurality of non-breathable cotton threads, which are slidably arranged between the two layers of the non-woven fabric base layer and block at least half of the air holes, and at least one end of the non-breathable cotton threads is exposed from the non-woven fabric base layer.

[0042] The beneficial effect of adopting the above-mentioned further scheme is: multiple non-breathable cotton threads are slidably set between two layers of non-woven fabric base, which is convenient for setting the shielding layer. At the same time, the sliding non-breathable cotton threads can be easily pulled out from between the two layers of non-woven fabric base to adjust the air permeability of the variable permeability layer; furthermore, at least one end of the non-breathable cotton threads is exposed from the non-woven fabric base, which is convenient for users to use and operate. DETAILED DESCRIPTION

[0043] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0044] Example 1 Preparation of a simple thin sheet type self-heating body

[0045] The materials are taken in the following weight proportions (see Table 1 for details). Take 50 parts of pig iron powder (powder particle size 150 mesh), 17 parts of activated carbon (powder particle size 150 mesh), 0.2 parts of polypropylene fiber (length 4 mm), 1 part of xanthan gum, mixed powder of sodium carboxymethyl cellulose and sodium polyacrylate (including 0.2 parts of xanthan gum powder, 0.4 parts of sodium carboxymethyl cellulose powder and 0.4 parts of sodium polyacrylate powder, and the powder particle size of the three powders is 100 mesh), 9 parts of vermiculite powder (powder particle size 30 mesh) and mix them evenly at room temperature and pressure to form a uniform powder.

[0046] 4 parts of industrial salt powder (powder particle size 40 mesh) and 18.8 parts of water are prepared into a salt water mixture, and the above uniform powder is poured into the above salt water mixture for stirring and mixing to form a high viscosity material body, which is sealed for storage. The stirring and mixing conditions are: pressure is normal pressure, temperature is 25°C, stirring direction is clockwise, stirring speed is 60r / min, and stirring time is 10min.

[0047] The cooled high-viscosity material is placed in a microporous oxygen-permeable film and an oxygen-isolating outer film, and then heat-sealed and cut to form a simple thin-film self-heating body. The thickness is 2 mm, and it is cut into rectangular sheets with a length of 10 cm and a width of 6 cm. Take out the above sample and test the heating temperature and heating time of the sample. The total heating time is 51 minutes, and the average heating temperature is 42.2°C. See Table 2 for specific results.

[0048] Example 2 Preparation of a simple thin sheet type self-heating body

[0049] The materials are taken in the following weight portions (see Table 1 for details). Take 52 parts of pig iron powder (powder particle size 150 mesh), 14.6 parts of activated carbon (powder particle size 200 mesh), 0.5 parts of polypropylene fiber powder (powder particle size 100 mesh), 2.5 parts of xanthan gum, mixed powder of sodium carboxymethyl cellulose and sodium polyacrylate (including 0.8 parts of xanthan gum powder, 1 part of sodium carboxymethyl cellulose powder and 0.7 parts of sodium polyacrylate powder, and the powder particle size of the three powders is 100 mesh), and 7.4 parts of vermiculite powder (powder particle size 40 mesh) and mix them evenly at room temperature and pressure to form a uniform powder.

[0050] 3.5 parts of industrial salt powder (powder particle size 40 mesh) and 19.5 parts of water are prepared into a salt water mixture, and the above uniform powder is poured into the above salt water mixture for stirring and mixing to form a high viscosity material body, which is sealed and stored. The stirring and mixing conditions are: pressure is normal pressure, temperature is 23°C, stirring direction is counterclockwise, stirring speed is 120r / min, and stirring time is 10min. .

[0051] The cooled high-viscosity material is placed in a microporous oxygen-permeable film and an oxygen-isolating outer film, and then heat-sealed and cut to form a simple thin-sheet self-heating body. The thickness is 2.5 mm, and it is cut into rectangular sheets with a length of 10 cm and a width of 6 cm. The above sample is taken out, and the heating temperature and heating time of the sample are tested. Among them, the total heating time is 51 minutes, and the average heating temperature is 42. See Table 2 for specific results.

[0052] Example 3 Preparation of a simple thin sheet type self-heating body

[0053] The materials are taken in the following weight portions (see Table 1 for details). Take 55 parts of pig iron powder (powder particle size 150 mesh), 14.2 parts of activated carbon (powder particle size 200 mesh), 0.5 parts of polypropylene fiber powder (powder particle size 100 mesh), 1.5 parts of xanthan gum, mixed powder of sodium carboxymethyl cellulose and sodium polyacrylate (including 0.6 parts of xanthan gum powder, 0.5 parts of sodium carboxymethyl cellulose powder and 0.4 parts of sodium polyacrylate powder, and the powder particle size of the three powders is 100 mesh), and 6.4 parts of vermiculite powder (powder particle size 20 mesh) and mix them evenly at room temperature and pressure to form a uniform powder.

[0054] 3.5 parts of industrial salt powder (powder particle size 80 mesh) and 18.9 parts of water are prepared into a salt water mixture, and the above uniform powder is poured into the above salt water mixture for stirring and mixing to form a high viscosity material body, which is sealed and stored. The stirring and mixing conditions are: pressure is normal pressure, temperature is 21°C, stirring direction is counterclockwise, stirring speed is 120r / min, and stirring time is 10min.

[0055] The cooled high-viscosity material is placed in a microporous oxygen-permeable film and an oxygen-isolating outer film, and then heat-sealed and cut to form a simple thin-film self-heating body. The thickness is 3 mm, and it is cut into rectangular sheets with a length of 10 cm and a width of 6 cm. Take out the above sample and test the heating temperature and heating time of the sample. Among them, the total heating time is 54 minutes, and the average heating temperature is 43.8°C. See Table 2 for specific results.

[0056] Example 4 Preparation of a simple thin sheet type self-heating body

[0057] The materials are taken in the following weight proportions (see Table 1 for details). Take 40 parts of pig iron powder (powder particle size 150 mesh), 20 parts of activated carbon (powder particle size 200 mesh), 1 part of polypropylene fiber powder (powder particle size 100 mesh), 3 parts of xanthan gum, mixed powder of sodium carboxymethyl cellulose and sodium polyacrylate (including 1 part of xanthan gum powder, 1 part of sodium carboxymethyl cellulose powder and 1 part of sodium polyacrylate powder, and the powder particle size of the three powders is 100 mesh), and 10 parts of vermiculite powder (powder particle size 30 mesh) and mix them evenly at room temperature and pressure to form a uniform powder.

[0058] 5 parts of industrial salt powder (powder particle size 80 mesh) and 21 parts of water are prepared into a salt water mixture, and the uniform powder is poured into the salt water mixture for stirring and mixing to form a high viscosity material body, which is sealed for storage. The stirring and mixing conditions are: pressure is normal pressure, temperature is 25°C, stirring direction is clockwise, stirring speed is 120r / min, and stirring time is 10min.

[0059] The cooled high-viscosity material is placed in a microporous oxygen-permeable film and an oxygen-isolating outer film, and then heat-sealed and cut to form a simple thin-sheet self-heating body. The thickness is 1.5 mm, and it is cut into rectangular sheets with a length of 10 cm and a width of 6 cm. The above sample is taken out, and the heating temperature and heating time of the sample are tested. Among them, the total heating time is 69 minutes, and the average heating temperature is 42. See Table 2 for specific results.

[0060] Example 5 Preparation of a simple thin sheet type self-heating body

[0061] The materials are taken in the following weight proportions (see Table 1 for details). Take 45 parts of pig iron powder (powder particle size 150 mesh), 18 parts of activated carbon (powder particle size 150 mesh), 0.8 parts of polypropylene fiber powder (powder particle size 100 mesh), 2 parts of xanthan gum, mixed powder of sodium carboxymethyl cellulose and sodium polyacrylate (including 0.6 parts of xanthan gum powder, 0.8 parts of sodium carboxymethyl cellulose powder and 0.6 parts of sodium polyacrylate powder, and the powder particle size of the three powders is 80 mesh), and 9 parts of vermiculite powder (powder particle size 30 mesh) and mix them evenly at room temperature and pressure to form a uniform powder.

[0062] 4.5 parts of industrial salt powder (powder particle size 60 mesh) and 20.7 parts of water are prepared into a salt water mixture, and the uniform powder is poured into the salt water mixture for stirring and mixing to form a high viscosity material body, which is sealed for storage. The stirring and mixing conditions are: pressure is normal pressure, temperature is 25°C, stirring direction is clockwise, stirring speed is 120r / min, and stirring time is 10min.

[0063] The cooled high-viscosity material is placed in a microporous oxygen-permeable film and an oxygen-isolating outer film, and then heat-sealed and cut to form a simple thin-sheet self-heating body. The thickness is 1.5 mm, and it is cut into rectangular sheets with a length of 10 cm and a width of 6 cm. Take out the above sample and test the heating temperature and heating time of the sample. Among them, the total heating time is 63 minutes, and the average heating temperature is 42.1. See Table 2 for specific results.

[0064] Table 1, weight percentage of components in each embodiment

[0065]

[0066]

[0067] Table 2, heating temperature (unit: °C) and heating time (unit: minutes) of samples in various embodiments

[0068]

[0069] The method for testing the heating time and temperature is as follows: under the conditions of laboratory atmospheric conditions of (23±2)°C and relative humidity RH of (50±5)%, the above-mentioned simple thin sheet type self-heating element is made into a self-heating eye mask pattern, and then the elastic ears of the sample are torn off and lightly fixed on the surface of a constant temperature water bath with a surface temperature of (35±0.5)°C, the heating time and temperature are recorded, and the heating process is observed.

[0070] In the above embodiment, the soluble powder is relatively small, which avoids the problem that the particle size of the water-insoluble powder is not too large, which may easily cause the heating element to fall off; at the same time, it also avoids the problem that the particle size of the water-soluble powder is too large, which may easily lead to uneven dispersion.

[0071] Example 6 Application of a simple thin sheet type self-heating body. This example uses an eye mask as an application of a simple thin sheet type self-heating body.

[0072] A variable air permeability layer is arranged on one side of the self-heating body, that is, the variable air permeability layer is located on the side of the eye mask in contact with the human body; the variable air permeability layer is a non-woven fabric layer, and the non-woven fabric layer includes a non-woven fabric base layer and a blocking layer arranged on the non-woven fabric base layer, and the blocking layer is used to cover part of the air permeability holes of the non-woven fabric base layer; wherein the non-woven fabric base layer is two layers, and the blocking layer is a plurality of non-breathable cotton threads, and the plurality of non-breathable cotton threads are slidably arranged between the two layers of the non-woven fabric base layer and block at least half of the air permeability holes, and at least one end of the non-breathable cotton thread is exposed from the non-woven fabric base layer.

[0073] Specifically, when making a variable air permeability layer, first cut two layers of non-woven fabric into non-woven fabric base layers of set sizes, overlap the two layers of non-woven fabric base layers together, and then test the air permeability of the overlapped non-woven fabric base layers. Then separate one of the non-woven fabric base layers, and arrange non-breathable cotton threads on one side of the non-breathable cotton thread at intervals, where the interval is 1.2 to 2.0 times the diameter of the non-breathable cotton thread, ensuring that one end of the non-breathable cotton thread is exposed from the non-woven fabric base layer, and then overlap another non-woven fabric base layer on the non-breathable cotton thread, and press the two layers of non-woven fabric base layers in the area without non-breathable cotton thread to form a variable air permeability layer, from which the non-breathable cotton thread can be pulled out by external force, so as to adjust the heating temperature and heating time length of the self-heating body product.

[0074] In this embodiment, two layers of non-woven fabric base layers are stacked together, and then the air permeability of the stacked non-woven fabric base layer is tested, and its air permeability is: 18.13L / h.m2; the diameter of the non-air-permeable cotton thread is: 0.8mm, and the spacing between two adjacent non-air-permeable cotton threads is set to 1.2mm, and the spacing is set at an equal distance. After completion, the air permeability of the variable air permeability layer is tested, and its air permeability is: 8.75L / h.m2.

[0075] This embodiment takes a self-heating eye mask used for eye health as an example, and uses the simple thin sheet type self-heating body in Embodiments 1 to 5 of the present invention for the self-heating eye mask. One side of the eye mask is used to contact with human eyes, and a variable air permeability layer is provided on the side in contact with human eyes. In specific tests, the variable air permeability layer corresponding to each embodiment is divided into four cases, the first case is to retain all non-breathable cotton threads, the second case is to retain 3 / 4 of the non-breathable cotton threads, the third case is to retain 1 / 2 of the non-breathable cotton threads, and the fourth case is to retain 1 / 4 of the non-breathable cotton threads. The heating time and heating temperature in these four cases are tested respectively, and the method for testing the heating time and temperature is the same as the aforementioned method. Through the above experimental tests, due to the provision of the variable air permeability layer, the amount of oxygen entering the product and contacting the self-heating body is controlled, and the heating temperature and time are further controlled. Among them, the heating time length of the first case is increased by 22.8% on average, and the heating temperature is reduced by 18.6% on average compared with the eye mask without a variable air permeability layer; the heating time length of the second case is increased by 16.6% on average, and the heating temperature is reduced by 14.3% on average compared with the eye mask without a variable air permeability layer; the heating time length of the third case is increased by 11.0% on average, and the heating temperature is reduced by 9.5% on average compared with the eye mask without a variable air permeability layer; the heating time length of the fourth case is increased by 5.2% on average, and the heating temperature is reduced by 4.8% on average compared with the eye mask without a variable air permeability layer. See Table 3 for details.

[0076] It can be seen from the above embodiments that users can adjust the appropriate usage temperature according to their own conditions, thereby improving the user experience.

[0077] In the above embodiment, the method for manufacturing the self-heating eye mask is a conventional technical means in the art and will not be described in detail here.

[0078] Table 3. Average temperature and average time of heating in four states of eye masks with variable air permeability layer

[0079]

[0080] In a specific embodiment, the variable permeability layer is arranged on the side in contact with the human body for a human body warming patch, a medical surgical warming pad, a medical care patch for heating and insulation, a female menstrual pain relief patch, a breast care patch, an eye care patch, or a lumbar spondylosis medical care patch, that is, the temperature of the human body is regulated through the variable permeability layer; for portable heating and warming equipment for instruments or digital products, the variable permeability layer is arranged on the side in contact with the object, and the temperature of the object is regulated through the variable permeability layer.

[0081] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A sheet-type self-heating element, characterized in that: The composition comprises the following weight percentages: The sum of the percentages of the individual components is 100%; A variable air permeability layer is provided on one side of the self-heating body; The variable air permeability layer is a non-woven fabric layer, the non-woven fabric layer comprises a non-woven fabric base layer and a shielding layer arranged on the non-woven fabric base layer, the shielding layer is used to cover part of the air permeability holes of the non-woven fabric base layer; The non-woven fabric base layer is composed of two layers, and the shielding layer is composed of a plurality of non-breathable cotton threads, which are slidably arranged between the two layers of the non-woven fabric base layers and shield at least half of the air holes, and the plurality of non-breathable cotton threads are arranged at intervals, and the intervals are 1.2 to 2.0 times the diameter of the non-breathable cotton threads, and at least one end of the non-breathable cotton threads is exposed from the non-woven fabric base layer, and the two layers of the non-woven fabric base layers are pressed tightly in an area without the non-breathable cotton threads, and the non-breathable cotton threads can be pulled out of the non-woven fabric base layer by an external force to adjust the heating temperature and heating time length of the self-heating body; and The particle size of the pig iron powder is 120-180 meshes, the particle size of the activated carbon is 150-200 meshes, the length of the polypropylene fiber is 2mm-6mm, and the particle size of the sodium polyacrylate is 80-120 meshes.

2. A sheet-type self-heating element according to claim 1, characterized in that: The thickness of the self-heating element is 1 mm to 3 mm.

3. A sheet-type self-heating element according to claim 2, characterized in that: The composition comprises the following weight percentages: The sum of the percentages of the individual components is 100%.

4. A method for preparing a sheet-type self-heating body according to any one of claims 1 to 3, characterized in that: The steps include: Step 1, mixing pig iron powder, activated carbon, xanthan gum, sodium carboxymethyl cellulose and sodium polyacrylate, vermiculite and polypropylene fiber according to the weight percentage of the components described in any one of claims 1 to 3 at room temperature and pressure to obtain a uniform powder; Step 2, preparing a brine mixture by mixing industrial salt and water according to the weight percentage of the components described in any one of claims 1 to 3, and pouring the uniform powder into the brine mixture for stirring and mixing to form a high-viscosity material body, which is then sealed and stored; Step 3, the high-viscosity material after cooling is placed into a microporous oxygen-permeable film and an oxygen-isolating outer film, and heat-sealed and cut to form a simple sheet-type self-heating body.

5. The method for preparing a sheet-type self-heating body according to claim 4, characterized in that: The stirring and mixing conditions in step 2 are: pressure is normal pressure, temperature is 23±2° C., stirring direction is clockwise, stirring speed is 60 r / min, and stirring time is 10 min.

6. Use of the sheet-type self-heating element according to any one of claims 1 to 5, characterized in that: Used for preparing human body warming patches, medical surgical warming pads, medical care patches, and portable heating and warming equipment for instruments and meters.

7. The use of the sheet-type self-heating element according to any one of claims 1 to 5, characterized in that: The invention relates to a device for preparing breast health care, eye health care, and lumbar and cervical spondylosis health care.

8. The use of the sheet-type self-heating element according to any one of claims 1 to 5, characterized in that: Used for preparing menstrual pain relief patches for women.

9. The use of the sheet-type self-heating element according to any one of claims 1 to 5, characterized in that: Portable heating and warming equipment used for preparing digital products.

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