Note: Descriptions are shown in the official language in which they were submitted.
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FLEXIBLE ELECTROTHERMAL PLATE
BACKGROUND OF THE INVENTION
(a) Field of the Invention
The present invention relates to a flexible electrothermal plate and
more particularly to a flexible electrothermal plate which is constituted by
a flexible and insulative base film, a heating element, two electrodes, two
connection plates and an insulative and protective plastic film. The
flexible electrothermal plate provides all kinds of heating functions and
can be applied to heat preservation of clothing and shoes, heating and
warm keeping of foods and articles, as well as heating and warm keeping
in other areas, such as heavy electrical machinery, car and motorcycle
products, home appliances, medical products, freezing and
air-conditioning products, mountain climbing products, baby supplies,
cosmetic equipment, healthcare apparatuses and pet products.
(b) Description of the Prior Art
An ordinary heating element (plate) can be separated into a hard
element and a flexible element. The former is a conventional
electrothermal furnace and the latter includes a defogging wire used in a
car or an electrothermal blanket used in winter, etc. The flexible
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electrothermal device is generally in a plate shape and thus can be called
an electrothermal plate, which is provided with a special convenience in
application.
An insulative base film (substrate) used in the flexible electrothermal
plate can be divided into a silicone film, a polyimide (PI) film and a
polyester (PET) film. Using these three materials as the insulative base
film (substrate) is characterized in that (1) they can replace an ordinary
metal heater and are usually made into flexible, thin (standard thickness
of 1.5mm) and planar heating elements, with a good flexibility that they
can be tightly attached onto all kinds of curved surfaces or even surfaces
of heated objects in an irregular shape or in a cylindrical shape; (2) they
can resist with heat and are insulative to electricity, therefore they can be
broadly applied in parts or equipment of machinery, such as preheating a
toner in a photocopier or being used in a heating plate of a piping, etc.
FIG. 1 and FIG. 2 show the structure of flexible electrothermal plate
using the abovementioned three materials as the base film (substrate).
The flexible electrothermal plate is primarily constituted by a base film
1 Oa, a heating element 20, an adhesive layer 30 and a cover film 1 Ob.
The heating element 20 is a metallic heating wire formed by printing or
etching and is provided on a top surface of the base film 1 Oa after welding
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two ends of the metallic heating wire with. power lines 20a, 20b. In
addition, the heating element 20 is provided with the adhesive layer 30
which fixes the heating element 20 between the base film 10a and the
adhesive layer 30; whereas, a top surface of the adhesive layer 30 is then
attached with the cover film 10b to provide insulation, isolation and
protection to the heating element 20. The primary shortcoming of this
kind of structure that uses the metallic heating wire as the heating
element is that the electrothermal plate and a heated object can easily
accumulate heat, resulting in local overheating or burnout. Therefore, if
the issue of being easy to accumulate heat can be solved, then the
shortcoming of the flexible heating plate will be improved.
SUMMARY OF THE INVENTION
The primary object of the present invention is to provide a "plate-type"
flexible electrothermal plate to improve the shortcoming that an existing
flexible electrothermal plate may be locally overheated, burnt out or
non-uniformly heated as the heat-up is from a metallic heating wire.
The technical means utilized by the present invention is to provide a
flexible electrothermal plate including a base film which is a film substrate
with a good thermal conductivity, insulation and flexibility; a heating
element which is fixed on an inner side of a top surface of the base film
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and is a conductor that heats up totally by an impedance of current; two
electrodes which are combined with conductors at two sides of a top
surface of the heating element to transmit current to the heating element;
two connection plates which are combined and adhered at one end of the
two electrodes to be welded with power lines, transmitting the current of
the power lines to the conductors on the heating element through the
electrodes; and a plastic film which is fixed on the base film by press
bonding or adhesion and covers the heating element, the electrodes and
the connection plates for insulation and protection.
In the abovementioned flexible electrothermal plate, the said base film
includes a PI film, a polyamide film, a PET film or a silicone film.
In the abovementioned flexible electrothermal plate, the said heating
element is an electric conductive film made of graphene, graphite or
carbon.
In the abovementioned flexible electrothermal plate, the said
electrode includes silver which is provided with a good electric
conductivity, such as a silver colloid or a silver plate.
In the abovementioned flexible electrothermal plate, the said
connection plate is a metal with a good electric conductivity, such as a
copper foil or an aluminum foil.
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In the abovementioned flexible electrothermal plate, the said plastic
film includes a top film and a lower film which tightly enclose the base film,
the heating element, the electrodes and the connection plates by hot
press bonding.
The flexible electrothermal plate disclosed by the present invention is
provided with following benefits that: (1) the heating element heats up
from a plate, which is different from the conventional heating element that
heats up from a metallic heating wire; (2) the present invention can be
bended freely to be attached on a heated object, increasing a contact
area.between the heated object and the flexible electrothermal plate,
such that an irregular-shaped object can be heated up uniformly and
quickly, thereby improving the electrothermal efficiency.
To enable a further understanding of the said objectives and the
technological methods of the invention herein, the brief description of the
drawings below is followed by the detailed description of the preferred
embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a top view of a conventional assembly.
FIG. 2 shows a cutaway view along the line A-A in FIG. 1.
FIG. 3 shows a three-dimensional perspective view of a first embodiment
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of the present invention.
FIG. 4 shows a top view of FIG. 3.
FIG. 5 shows a cutaway view along the line B-B in FIG. 4.
FIG. 6 shows a cutaway view along the line C-C in FIG. 4.
FIG. 7 shows a top view of a second embodiment of the present
invention.
FIG. 8 shows a cutaway view along the line D-D in FIG. 7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 3 through 6, it shows a first embodiment of the
flexible electrothermal plate which comprises primarily a base film 40, a
heating element 41, two electrodes 42, 43, two connection plates 44, 45
and a plastic film 48.
The said base film 40 is a flexible and insulative film substrate and can
be a polyimide film, a polyamide film, a polyester film or a silicon film,
preferably the polyimide film.
The said heating element 41 can be attached on an inner side of a top
surface of the base film 40 by spray coating, printing or other means, and
is fixed on the top surface of the base film 40 to form a layer of electric
conductive film after drying, so as to produce heat energy. The said
heating element 41 can use graphene, graphite or carbon as an electric
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conductive material.
The said electrodes 42, 43 are combined on two sides of a top surface
of the heating element 41 to transmit current to the heating element 41
which is combined totally on the base film 40 to produce heat in a plane,
which is able to improve the shortcoming that the metallic heating wire
will be locally overheated and non-uniformly heated. The said electrodes
42, 43 are silver which is provided with a good electric conductivity.
The said connection plates 44, 45 are combined at one end of the two
electrodes 42, 43 to provide welding with power lines 46, 47, thereby
transmitting the current from the power lines 46, 47 to the heating
element 41 through the electrodes 42, 43. The said connection plates 44,
45 include copper foils which are provided with a good electric
conductivity.
The said plastic film 48 covers the heating element 41, the electrodes
42, 43 and the connection plates 44, 45 by press bonding or adhesion
and is then fixed on the base film 40 to prevent the heating element 41
from oxidation and provide insulation and protection.
Referring to FIG. 7 and FIG. 8, it shows a second embodiment of the
flexible electrothermal plate. The difference from the first embodiment
lies in that the plastic film is changed into a top plastic film 49 and a
lower
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plastic film 50 which tightly enclose the base film 40, the heating element
41, the electrodes 42, 43, the connection plates 44, 45 and the welding
portions between the two ends of the power lines 46, 47 and the
connection plates 44, 45 by hot press bonding, thereby providing a better
water-proofing and insulation function.
It is of course to be understood that the two embodiments described
herein is merely illustrative of the principles of the invention and that a
wide variety of modifications thereto may be effected by persons skilled in
the art without departing from the spirit and scope of the invention as set
forth in the following claims.
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