U.S. patent application number 11/816787 was filed with the patent office on 2009-12-10 for tape with interlocking device.
Invention is credited to Yoshinori Nanba, Kenichi Tanaka.
Application Number | 20090300891 11/816787 |
Document ID | / |
Family ID | 36927334 |
Filed Date | 2009-12-10 |
United States Patent
Application |
20090300891 |
Kind Code |
A1 |
Nanba; Yoshinori ; et
al. |
December 10, 2009 |
TAPE WITH INTERLOCKING DEVICE
Abstract
A zipper-member-having tape 1 according to the present invention
includes a pair of male tape 11 and female tape 12, the male tape
11 and the female tape 12 having zipper members 10 engageable with
each other. The male tape and the like 11, 12 include a seal layer
111, 121 and a non-seal layer 112, 122, the non-seal layer 112, 122
being a portion excluding the seal layer 111, 121 and the zipper
members 10. A first convex thread 115, 125 is provided on a surface
of the seal layer 111, 121 of the male tape 11 and the female tape
12 while a second convex thread 116, 126 is provided on a surface
of the non-seal layer 112, 122 of the male tape 11 and/or the
female tape 12.
Inventors: |
Nanba; Yoshinori; (Chiba,
JP) ; Tanaka; Kenichi; (Chiba, JP) |
Correspondence
Address: |
MILLEN, WHITE, ZELANO & BRANIGAN, P.C.
2200 CLARENDON BLVD., SUITE 1400
ARLINGTON
VA
22201
US
|
Family ID: |
36927334 |
Appl. No.: |
11/816787 |
Filed: |
February 21, 2006 |
PCT Filed: |
February 21, 2006 |
PCT NO: |
PCT/JP2006/303040 |
371 Date: |
July 1, 2009 |
Current U.S.
Class: |
24/399 |
Current CPC
Class: |
B65D 33/2508 20130101;
Y10T 24/2532 20150115 |
Class at
Publication: |
24/399 |
International
Class: |
A44B 19/16 20060101
A44B019/16; A44B 19/32 20060101 A44B019/32 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 22, 2005 |
JP |
2005-045969 |
Claims
1. A zipper-member-having tape, comprising: a pair of a male tape
and a female tape, the male tape and the female tape having zipper
members engageable with each other, wherein the male tape and the
female tape include a seal layer and a non-seal layer, the non-seal
layer being a portion excluding the seal layer and the zipper
members, a resin material forming the seal layer is substantially
non-compatible with a resin material forming the non-seal layer, a
plurality of convex threads are provided on a surface of the seal
layer of the male tape and the female tape, and a plurality of
convex threads are provided on a surface of the non-seal layer of
the male tape and/or the female tape.
2. A zipper-member-having tape, comprising: a pair of a male tape
and a female tape, the male tape and the female tape having zipper
members engageable with each other, wherein the male tape and the
female tape include: a seal layer; and a non-seal layer formed of
multiple layers, the non-seal layer being a portion excluding the
seal layer and the zipper members, a resin material forming the
seal layer is substantially non-compatible with a resin material
forming the non-seal layer laminated to the seal layer, or at least
a pair of resin materials adjacently laminated in the non-seal
layer are substantially non-compatible with each other, a plurality
of convex threads are provided on a surface of the seal layer of
the male tape and the female tape, and a plurality of convex
threads are provided on a surface of the non-seal layer of the male
tape and/or the female tape.
3. The zipper-member-having tape according to claim 1, wherein the
convex thread provided on the surface of the seal layer is
substantially quadrangular in cross-section.
4. The zipper-member-having tape according to claim 1, wherein a
mounting width of the convex thread provided on the surface of the
seal layer is 0.5 mm or more and a height of the convex thread is
0.08 mm or more, and a summation of a mounting area of the convex
thread is 20 to 80% of a surface area of the seal layer.
5. The zipper-member-having tape according to claim 1, wherein the
convex thread provided on the surface of the non-seal layer is
substantially triangular shaped in cross-section.
6. The zipper-member-having tape according to claim 1, wherein a
height of the convex thread provided on the surface of the non-seal
layer is 0.03 mm or more.
7. The zipper-member-having tape according to claim 1, wherein a
combination of the resin materials that are substantially
non-compatible with each other is a combination of resin materials
whose sealing strength becomes 25 N/15 mm wide or less when both
the resin materials are laminated in form of a film and heat-sealed
to each other.
8. The zipper-member-having tape according to claim 7, wherein the
combination of the resin materials that are substantially
non-compatible with each other is a combination selected from a
group consisting of a combination of linear low-density
polyethylene using metallocene catalyst (metallocene LLDPE) and
polypropylene (PP); a combination of ethylene-vinyl-acetate
copolymer (EVA) and polypropylene (PP); and a combination of
ethylene-vinyl-acetate copolymer (EVA) and high-density
polyethylene (HDPE).
9. The zipper-member-having tape according to claim 1, wherein the
plurality of convex threads provided on the surface of the non-seal
layer of the male tape and/or the female tape are provided on a
first side demarcated by the zipper member when the first side is
seen from a width cross-section of the male tape and/or the female
tape, and the non-seal layer of the male tape and the non-seal
layer of the female tape on a second side forms a pseudo-adhesion
structure, the second side being demarcated by the zipper member
when the second side is seen from the width cross-section of the
male tape and the female tape.
10. A zipper-member-having bag, comprising a zipper-member-having
tape including a pair of a male tape and a female tape, the male
tape and the female tape having zipper members engageable with each
other, wherein the male tape and the female tape include a seal
layer and a non-seal layer, the non-seal layer being a portion
excluding the seal layer and the zipper members, a resin material
forming the seal layer is substantially non-compatible with a resin
material forming the non-seal layer, a plurality of convex threads
are provided on a surface of the seal layer of the male tape and
the female tape, a plurality of convex threads are provided on a
surface of the non-seal layer of the male tape and/or the female
tape, the plurality of convex threads provided on the surface of
the non-seal layer of the male tape and/or the female tape are
provided on a first side demarcated by the zipper member when the
first side is seen from a width cross-section of the male tape
and/or the female tape, the non-seal layer of the male tape and the
non-seal layer of the female tape on a second side forms a
pseudo-adhesion structure, the second side being demarcated by the
zipper member when the second side is seen from the width
cross-section of the male tape and the female tape, and the first
side of the zipper-member-having tape adheres to a side adjacent to
an opening of the bag while the second side of the
zipper-member-having tape adheres to a side opposite to the side
adjacent to the opening of the bag.
11. The zipper-member-having tape according to claim 2, wherein the
convex thread provided on the surface of the seal layer is
substantially quadrangular in cross-section.
12. The zipper-member-having tape according to claim 2, wherein a
mounting width of the convex thread provided on the surface of the
seal layer is 0.5 mm or more and a height of the convex thread is
0.08 mm or more, and a summation of a mounting area of the convex
thread is 20 to 80% of a surface area of the seal layer.
13. The zipper-member-having tape according to claim 2, wherein the
convex thread provided on the surface of the non-seal layer is
substantially triangular shaped in cross-section.
14. The zipper-member-having tape according to claim 2, wherein a
height of the convex thread provided on the surface of the non-seal
layer is 0.03 mm or more.
15. The zipper-member-having tape according to claim 2, wherein a
combination of the resin materials that are substantially
non-compatible with each other is a combination of resin materials
whose sealing strength becomes 25 N/15 mm wide or less when both
the resin materials are laminated in form of a film and heat-sealed
to each other.
16. The zipper-member-having tape according to claim 15, wherein
the combination of the resin materials that are substantially
non-compatible with each other is a combination selected from a
group consisting of a combination of linear low-density
polyethylene using metallocene catalyst (metallocene LLDPE) and
polypropylene (PP); a combination of ethylene-vinyl-acetate
copolymer (EVA) and polypropylene (PP); and a combination of
ethylene-vinyl-acetate copolymer (EVA) and high-density
polyethylene (HDPE).
17. The zipper-member-having tape according to claim 2, wherein the
plurality of convex threads provided on the surface of the non-seal
layer of the male tape and/or the female tape are provided on a
first side demarcated by the zipper member when the first side is
seen from a width cross-section of the male tape and/or the female
tape, and the non-seal layer of the male tape and the non-seal
layer of the female tape on a second side forms a pseudo-adhesion
structure, the second side being demarcated by the zipper member
when the second side is seen from the width cross-section of the
male tape and the female tape.
18. A zipper-member-having bag, comprising a zipper-member-having
tape including a pair of a male tape and a female tape, the male
tape and the female tape having zipper members engageable with each
other, wherein the male tape and the female tape include: a seal
layer; and a non-seal layer formed of multiple layers, the non-seal
layer being a portion excluding the seal layer and the zipper
members, a resin material forming the seal layer is substantially
non-compatible with a resin material forming the non-seal layer
laminated to the seal layer, or at least a pair of resin materials
adjacently laminated in the non-seal layer are substantially
non-compatible with each other, a plurality of convex threads are
provided on a surface of the seal layer of the male tape and the
female tape, a plurality of convex threads are provided on a
surface of the non-seal layer of the male tape and/or the female
tape, the plurality of convex threads provided on the surface of
the non-seal layer of the male tape and/or the female tape are
provided on a first side demarcated by the zipper member when the
first side is seen from a width cross-section of the male tape
and/or the female tape, the non-seal layer of the male tape and the
non-seal layer of the female tape on a second side forms a
pseudo-adhesion structure, the second side being demarcated by the
zipper member when the second side is seen from the width
cross-section of the male tape and the female tape, and the first
side of the zipper-member-having tape adheres to a side adjacent to
an opening of the bag while the second side of the
zipper-member-having tape adheres to a side opposite to the side
adjacent to the opening of the bag.
Description
TECHNICAL FIELD
[0001] The present invention relates to a zipper-member-having tape
for unsealing and resealing a bag, the tape being provided at an
opening of the bag.
BACKGROUND OF THE INVENTION
[0002] As a packaging material for packaging various articles such
as foods, pharmaceutical and medical products and groceries, there
has been typically used a packaging bag that is openable and
resealable by a zipper-member-having tape provided at an opening of
the bag. The zipper member of the tape, which is belt-like shaped,
includes a pair of a male member and a female member that are
engaged with each other. As a typical method for manufacturing such
a packaging bag as allows the opening of the bag to be opened and
resealed, there is typically and widely used a method including
making the zipper-member-having tape in advance and heat-sealing
the zipper-member-having tape to a sealant layer of a base film
forming a bag body.
[0003] In heat-sealing the zipper-member-having tape to the sealant
layer of the base film, the zipper-member-having tape is generally
double-layered in order to improve a heat-sealing speed. In this
case, a melting point of a resin material forming a non-seal layer
(on which the zipper member is provided) is generally set to be
higher than that of a resin material forming a seal layer (a layer
heat-sealed to the sealant layer of the base film). The
zipper-member-having tape is manufactured by coextrusion. Although
the tape is formed as a laminate body of different resins, an
interlaminar intensity of a certain degree is obtainable without
using any adhesives, and the degree of the intensity poses no
practical disadvantage.
[0004] When the zipper-member-having tape is used as the tape,
there is a sufficient interlaminar intensity applied between the
seal layer and the non-seal layer that form the tape with the
zipper member. However, when the zipper-member-having tape is
heat-sealed with the base film, heat of heat-sealing by a seal-bar
is applied to the tape via the base film, and a force for adhering
non-compatible resins, which is applied on an interface between the
seal layer and non-seal layer, is lost due to the heat of the
heat-sealing. Accordingly, there has been a risk that the
zipper-member-having tape may be detached from between the seal
layer and the non-seal layer.
[0005] Further, there has been another problem that the non-seal
layer of the male tape may be welded with that of the female tape
due to the heat applied by the seal-bar in the above-described
manner when heat-sealed, and there has been a demand for
improvements.
[0006] In order to prevent the zipper-member-having tape and a
bag-forming film from being distorted and to firmly heat-seal the
both layers, it has been suggested to provide a plurality of ribs
on the seal layer in a double-layered zipper-member-having tape
(for example, see Patent Document 1).
[0007] [Patent Document 1] JP-A-2000-287718 (Claim 1, FIG. 4)
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
[0008] However, although the zipper-member-having tape disclosed in
Patent Document 1 can prevent the tape and the bag-forming film
from being distorted when heat-sealed, the zipper member-having
tape can neither sufficiently prevent an interlaminar separation
between the seal layer and the non-seal layer nor prevent the
welding of the non-seal layers. Thus, the zipper-member-having tape
is not practically applicable.
[0009] An object of the present invention is to firmly heat-seal a
zipper-member-having tape that has a multi-layer of a seal layer
and a non-seal layer with a sealant layer of a bag-forming base
film, and to provide a zipper-member-having tape that can prevent
an interlaminar separation of a multi-layered zipper-member-having
tape formed from different resins (e.g., an interlaminar separation
between the seal layer and the non-seal layer) and that can prevent
the non-seal layers from being welded with each other.
Means for Solving the Problems
[0010] In order to achieve the object described above, a
zipper-member-having tape according to a first aspect of the
present invention is a zipper-member-having tape including: a pair
of a male tape and a female tape, the male tape and the female tape
having zipper members engageable with each other, in which the male
tape and the female tape include a seal layer and a non-seal layer,
the non-seal layer being a portion excluding the seal layer and the
zipper members, a resin material forming the seal layer is
substantially non-compatible with a resin material forming the
non-seal layer, a plurality of convex threads are provided on a
surface of the seal layer of the male tape and the female tape, and
a plurality of convex threads are provided on a surface of the
non-seal layer of the male tape and/or the female tape.
[0011] The zipper-member-having tape according to the aspect of the
present invention is formed by the male tape and the female tape.
The male tape and the female tape include the seal layer and the
non-seal layer that is the portion excluding the seal layer and the
zipper member, in which the non-seal layer is provided on a side on
which the zipper member is provided. The plurality of convex
threads (first convex thread) are formed on the surface of the seal
layer of the male tape and the female tape while the plurality of
convex threads (second convex thread) are formed on the surface of
the non-seal layer of the male tape and/or the female tape.
[0012] Since the first convex thread formed on the surface of the
seal layer is fused to be heat-sealed to the base film when a
heated seal-bar applies heat to the tape via the base film in a
heat-sealing operation, a sealing strength of the tape and the base
film is maintained at a high level, and the heat and pressure
applied to a concave portion between the convex threads (i.e., a
portion excluding the first convex threads of the seal layer) are
relaxed, such that a deformation and flexure of the zipper member
and an interlaminar separation between the seal layer and the
non-seal layer can be prevented to a certain degree.
[0013] The second convex thread formed on the non-seal layer
surface laminated to the seal layer provides a desired space
between the male tape and the female tape on the zipper member side
even in the heat-sealing operation. Thus a contact area between the
non-seal layer of the male tape and the female tape can be made
smaller, such that the heat applied in the heat-sealing operation
can be radiated (heat-radiating effect) and the heat and pressure
applied to one of the zipper-member-having tape (i.e., one of the
male tape and the female tape) can be prevented from transmitted to
the other (the other of the male tape and the female tape)
(heat-insulating effect), thereby preventing the male tape from
being welded to the female tape in the heat-sealing operation.
[0014] In addition to the heat-radiating and heat-insulating
effects by the second convex thread on the non-seal layer, the
concave portion between the first convex threads on the seal layer
relaxes the heat and pressure, such that the male tape and the
female tape are prevented from being excessively heated, whereby
the interlaminar separation between the seal layer and the non-seal
layer during the heat-sealing operation can be prevented.
[0015] A zipper-member-having tape according to a second aspect of
the present invention is a zipper-member-having tape including: a
pair of a male tape and a female tape, the male tape and the female
tape having zipper members engageable with each other, in which the
male tape and the female tape include: a seal layer; and a non-seal
layer formed of multiple layers, the non-seal layer being a portion
excluding the seal layer and the zipper members, a resin material
forming the seal layer is substantially non-compatible with a resin
material forming the non-seal layer laminated to the seal layer, or
at least a pair of resin materials adjacently laminated in the
non-seal layer are substantially non-compatible with each other, a
plurality of convex threads are provided on a surface of the seal
layer of the male tape and the female tape, and a plurality of
convex threads are provided on a surface of the non-seal layer of
the male tape and/or the female tape.
[0016] The zipper-member-having tape according to the second aspect
is provided by modifying the zipper-member-having tape according to
the first aspect such that the non-seal layer is multi-layered.
When the non-seal layer is multi-layered as described above, it is
necessary to take into consideration not only the interlaminar
separation between the seal layer and the non-seal layer when a
resin material forming the seal layer is substantially
non-compatible with that of the non-seal layer to be laminated to
the seal layer but also an interlaminar separation within the
non-seal layer when at least a pair of resin materials adjacently
laminated in the non-seal layer are substantially non-compatible
with each other.
[0017] As in the tape according to the first aspect, by forming the
first convex thread on the surface of the seal layer, the
deformation and flexure of the zipper member, the interlaminar
separation between the seal layer and non-seal layer, or the
interlaminar separation within the multi-layered non-seal layer can
be prevented to a certain degree while the sealing strength of the
tape and the base film is maintained at a high level.
[0018] In addition, the second convex thread formed on the non-seal
layer surface laminated to the seal layer can radiate the heat
applied in the heat-sealing operation (heat-radiating effect), and
prevent the heat and pressure applied to one of the
zipper-member-having tape from being transmitted to the other
(heat-insulating effect), thereby preventing the male tape from
being welded to the female tape in the heat-sealing operation.
[0019] In addition to the heat-radiating and heat-insulating
effects by the second convex thread on the non-seal layer, the
concave portion between the first convex threads on the seal layer
relaxes the heat and pressure, such that the male tape and the
female tape are prevented from being excessively heated, whereby
the interlaminar separation between the seal layer and the non-seal
layer or the interlaminar separation within the multiple-layered
non-seal layer can be appropriately prevented.
[0020] Since the zipper-member-having tape according to the present
invention can be heat-sealed to the sealant layer of the base film
forming the bag and prevent the interlaminar separation between the
seal layer and the non-seal layer during the heat-sealing operation
(or the interlaminar separation within the multi-layered non-seal
layer) and the welding of the non-seal layer, the
zipper-member-having tape can exert the advantages to the maximum
extent not only when being applied to a general flat bag such as a
bag sealed along three edges but also when being applied to a bag
product such as a side-gusset bag in which the tape cannot be
conveyed in an MD direction of the base film and needs to be
inserted in a TD direction of the base film without using a
separator.
[0021] In the zipper-member-having tape according to the aspect of
the present invention, it is preferable that the convex thread
provided on the surface of the seal layer is substantially
quadrangular in cross-section.
[0022] According to the aspect, since the convex thread (first
convex thread) provided on the surface of the seal layer is
substantially quadrangular in cross-section, a contact area between
the first convex thread and the sealant layer of the base film, to
which the tape is welded, can be appropriately enlarged and the
sealing strength can be reinforced.
[0023] In the zipper-member-having tape according to the aspect of
the present invention, it is preferable that a mounting width of
the convex thread provided on the surface of the seal layer is 0.5
mm or more and a height of the convex thread is 0.08 mm or more,
and a summation of a mounting area of the convex thread is 20 to
80% of a surface area of the seal layer.
[0024] Since the convex thread (first convex thread) formed on the
surface of the seal layer has the mounting width of 0.5 mm or more
and the height of 0.08 mm or more, the first convex thread can be
fused to be welded to the sealant layer of the base film on a
larger area when heat-sealed, whereby the sealing strength of the
tape and the base film can be reliably enhanced.
[0025] In addition, since the summation of the mounting area of the
first convex thread is 20 to 80% of the surface area of the seal
layer, the zipper-member-having tape can contact the base film on
an appropriately larger area when heat-sealed. Accordingly, the
sealing strength of the tape and the base film to which the tape is
sealed is enhanced and the proportion of the concave portion
between the first convex threads becomes a desired value, thereby
reliably preventing the interlaminar separation between the seal
layer and the non-seal layer in the heat-sealing operation (or the
interlaminar separation within the multi-layered non-seal
layer).
[0026] In the zipper-member-having tape according to the aspect of
the present invention, it is preferable that the convex thread
provided on the surface of the non-seal layer is substantially
triangular shaped in cross-section.
[0027] According to the aspect of the present invention, since the
convex thread formed on the non-seal layer (second convex thread)
is triangular in cross-section, the second convex thread can
contact the non-seal layer facing the second convex thread on a
smaller area, thereby efficiently preventing the welding of the
second convex thread and the non-seal layer facing the second
convex thread in the heat-sealing operation.
[0028] In the zipper-member-having tape according to the aspect of
the present invention, it is preferable that a height of the convex
thread provided on the surface of the non-seal layer is 0.03 mm or
more.
[0029] According to the aspect of the present invention, since the
height of the convex thread formed on the surface of the non-seal
layer (second convex thread) is 0.03 mm or more, the heat and
pressure applied to one of the zipper-member-having tapes (one of
the male tape and female tape) is reliably prevented from being
transmitted to the other tape (the other of the male tape and
female tape), thereby efficiently preventing the interlaminar
separation between the seal layer and the non-seal layer of the
zipper-member-having tape in the heat-sealing operation (or the
interlaminar separation within the multi-layered non-seal layer)
and the welding of the non-seal layer provided on the pair of the
zipper-member-having tape.
[0030] In addition, when a combination of the resin materials that
are substantially non-compatible with each other is a combination
of resin materials Whose sealing strength becomes 25 N/15 mm wide
or less when both the resin materials are laminated in form of a
film and heat-sealed to each other, the zipper-member-having tape
according to the present invention is free from a problem such as
the interlaminar separation described above, whereby a practically
applicable zipper-member-having tape is provided. By appropriately
selecting the resin materials that are on the above-described
relationship with each other for the seal layer and non-seal layer,
the seal layer and non-seal layer each may be arranged to have a
different property and function. Accordingly, a wide variety of
tape product designs becomes possible by selecting appropriate
materials.
[0031] Note that the "heat-sealing" operation in the present
invention is performed, for example, under the following conditions
(i) to (iv) (in the description below, one of the resin materials
is referred to as the "seal layer" while the other resin material
is referred to as the "non-seal layer" for a convenience. When the
non-seal layer is multi layered, the "seal layer" and the "non-seal
layer" are respectively equivalent to the mutually non-compatible
resin materials forming the non-seal layers.).
(i) Obtaining by a general method (a) a film using a resin material
forming the seal layer (thickness: approximately 0.06 to 0.12 mm),
(b) a film formed of the resin material forming the seal layer
(thickness: approximately 0.01 to 0.04 mm), (c) a film formed of a
resin material forming the non-seal layer (thickness: approximately
0.15 to 0.18 mm) and (d) a film using the resin material forming
the non-seal layer (thickness: 0.04 to 0.10 mm), and laminating the
films in this order. (ii) Pressing the seal-bar to the laminated
layers from (a) side, and sealing (a) to (b) by heat-sealing under
the following conditions.
[0032] Sealing temperature: the melting point of the resin material
forming the seal layer +10.degree. C.
[0033] Sealing pressure: 0.2 Mpa
(iii) Pressing the seal-bar to the laminated layers from (c) side,
and sealing (c) to (d) by heat-sealing under the following
conditions.
[0034] Sealing temperature: 200.degree. C. Sealing temperature: the
melting point of the resin material forming the non-seal layer
+10.degree. C.
[0035] Sealing pressure: 0.2 Mpa
(iv) Measuring the sealing strength of (b) and (c) having been
simultaneously sealed in accordance with the above described (ii)
and (iii) (i.e., the sealing strength of the film formed of the
resin material forming the seal layer and the film formed of the
resin material forming the non-seal layer), and using the resin
materials whose sealing strength becomes 25 N/15 mm wide or less.
Incidentally, the measurement of the sealing strength may be
performed using a commercially available autograph tensile testing
machine under a measuring condition of 300 mm/min at 180.degree.
peeling.
[0036] When the combination of the resin materials that are
substantially non-compatible with each other is a combination
selected from a group consisting of a combination of linear
low-density polyethylene using metallocene catalyst (metallocene
LLDPE) and polypropylene (PP); a combination of
ethylene-vinyl-acetate copolymer (EVA) and polypropylene (PP); and
a combination of ethylene-vinyl-acetate copolymer (EVA) and
high-density polyethylene (HDPE), the above-described advantages
can be reliably obtained.
[0037] As one embodiment of the zipper-member-having tape according
to the first and second aspects of the present invention, the
plurality of convex threads provided on the surface of the non-seal
layer of the male tape and/or the female tape are provided on a
first side demarcated by the zipper member when the first side is
seen from a width cross-section of the male tape and/or the female
tape, and the non-seal layer of the male tape and the non-seal
layer of the female tape on a second side forms a pseudo-adhesion
structure, the second side being demarcated by the zipper member
when the second side is seen from the width cross-section of the
male tape and the female tape. The "pseudo-adhesion" is not
particularly limited as long as the adhesive force thereof is so
weak as to allow the pseudo-adhesion to be easily released by
hands, and the adhesive force of the pseudo-adhesion is generally 5
to 20 N/15 mm.
[0038] With this arrangement, it is possible to prevent a
mal-adhesion of the non-seal layers when the tape is heat-sealed to
the film in a bag manufacturing operation. In addition, since the
other side of the non-seal layer surface of the
zipper-member-having tape, which faces a downstream side of a bag
manufacturing line, forms the pseudo-adhesion structure during the
heat-sealing operation, it is possible to prevent a bag product
from being defected by a peeling of the zipper-member-having tape
in the bag manufacturing operation, whereby the bag manufacturing
efficiency is improved. A bag manufacturing operation in which the
zipper-member-having tape is inserted from a direction
perpendicular to a flow direction of the bag manufacturing line can
be performed with a dramatically-improved efficiency as compared
with an operation using a conventional zipper-member-having
tape.
[0039] When the zipper-member-having tape is applied to a bag, it
is preferable that the first side of the zipper-member-having tape
adheres to a side adjacent to an opening of the bag while the
second side of the zipper-member-having tape adheres to a side
opposite to the side adjacent to the opening of the bag (i.e., a
side adjacent to a non-opening of the bag, a side adjacent to a
content). Since convex thread ribs are provided on the non-seal
layer surface of the zipper-member-having tape facing the opening
side of the bag, the bag is easily opened by hands. Although the
non-seal layer of the zipper-member-having tape forms the
pseudo-adhesion structure on the non-opening side of the bag (i.e.,
a content side), the adhesive force thereof is so weak as to allow
the bag to be easily opened by hands and thus does not impair an
openability of the bag.
BRIEF DESCRIPTION OF THE DRAWING(S)
[0040] FIG. 1 is a cross-sectional view showing a
zipper-member-having tape according to an embodiment of the present
invention;
[0041] FIG. 2 is a fragmentary enlarged view of FIG. 1;
[0042] FIG. 3 is a front view showing a male tape seen from a seal
layer direction;
[0043] FIG. 4 is a front view showing a male tape seen from a
non-seal layer direction; and
[0044] FIG. 5 is a cross-sectional view showing the
zipper-member-having tape heat-sealed to a base film according to
the present invention.
EXPLANATION OF CODES
[0045] 1: zipper-member-having tape [0046] 10: zipper member [0047]
11: male tape [0048] 12: female tape [0049] 111, 121: seal layer
[0050] 112, 122: non-seal layer [0051] 113: head [0052] 114:
connector [0053] 123: first hook [0054] 124: second hook [0055]
115, 125: first convex thread [0056] 116, 126: second convex thread
[0057] 40: base film [0058] 401: sealant layer [0059] 402: outer
layer
BEST MODE FOR CARRYING OUT THE INVENTION
[0060] Embodiments of the present invention will be described below
with reference to the attached drawings.
[0061] FIG. 1 is a cross-sectional view showing a
zipper-member-having tape according to the present embodiment.
[0062] Codes in FIG. 1 respectively represent a
zipper-member-having tape (1), a zipper member (10), a male tape
(11), a female tape (12), a seal layer (111, 121), a non-seal layer
(112, 122), a head (13), a connector (114), a first hook (123) and
a second hook (124).
[0063] FIG. 1 is a cross-sectional view showing the
zipper-member-having tape 1 in engagement, which is formed by the
head 113 of the male tape 11, the first hook 123 and the second
hook 124 of the female tape 12.
[0064] The zipper-member-having tape 1, whose cross-section is
shown in FIG. 1, includes a pair of a male tape 11 and a female
tape 12 formed of thermoplastic resins.
[0065] The male tape 11 includes: the seal layer 111 welded to an
opening of a bag body (not shown); the non-seal layer 112 laminated
to the seal layer 111 and provided on a side where the zipper
member 10 is arranged; the head 113 substantially arrow-tip shaped
in cross section; and the connector 114 for connecting the non-seal
layer 112 and the head 113, all of which are integrally formed.
[0066] Similarly to the above-described male tape 11, the female
tape 12 includes: a seal layer 121 welded to the opening of the bag
body (not shown); the non-seal layer laminated to the seal layer
121; and the first hook 123 and the second hook 124 connected with
the non-seal layer 122 and circular-arc shaped in cross section,
the first hook 123 and the second hook 124 facing each other.
[0067] In the zipper-member-having tape 1, the head 113 and the
connector 114 of the male tape 11 and the first hook 123 and the
second hook 124 of the female tape 12 form the zipper member 10,
and the bag is opened and resealed by engaging and disengaging
these members.
[0068] In the present embodiment, the non-seal layer 112, the head
113 and the connector 114 of the male tape 11 are integrally formed
from one material while the non-seal layer 122, the first hook 123
and the second hook 124 of the female tape 12 are integrally formed
from another material.
[0069] Resin materials forming the seal layers 111, 121 and the
non-seal layers 112, 122 are respectively selected from
thermoplastic resins such that the resin materials are
non-compatible with each other. The resin materials may be selected
such that a melting point of the resin material forming the
non-seal layers 112, 122 are higher than that of the resin material
forming the seal layers 111, 121. When the melting point of the
resin material forming the non-seal layers 112, 122 are not higher
than that of the resin material forming the seal layers 111, 121,
surfaces on the zipper member 10 side of the male tape 11 and the
female tape 12 (surfaces of the non-seal layers 112, 122) may be
welded with each other when heat-sealed, which is detrimental to
heat-sealing and product yield.
[0070] On the other hand, when the difference between the melting
points of the resin materials are large, a heat-sealing speed can
be easily increased. Thus, it is preferable that the melting point
of the resin material forming the non-seal layer 112, 122 is higher
than that of the resin material forming the seal layer 111, 121 by
20.degree. C. or more.
[0071] In this Description, "substantially non-compatible" not only
means that the resin material forming the seal layer 111, 121 is
non-compatible with the resin material forming the non-seal layer
112, 122 at all, but also means that the resin material forming the
seal layer 111, 121 is slightly compatible with the resin material
forming the non-seal layer 112, 122. The resin materials may be
slightly compatible with each other, where, for example, the resin
materials are a combination of resin materials whose sealing
strength becomes 25 N/15 mm wide or less when both the resin
materials are laminated in form of a film and heal sealed to each
other under predetermined conditions (the above described
conditions (i) to (iv)).
[0072] Combinations of such resin materials forming the seal layer
111, 121 and the non-seal layer 112, 122 (seal layer 111,
211/non-seal layer 112, 122) are exemplified as follows: a
combination of linear low-density polyethylene using metallocene
catalyst (metallocene LLDPE) and polypropylene (PP); a combination
of ethylene-vinyl-acetate copolymer (EVA) and polypropylene (PP);
and a combination of ethylene-vinyl-acetate copolymer (EVA) and
high-density polyethylene (HDPE).
[0073] Incidentally, a melt flow rate (MFR) of the resin material
forming the non-seal layer 112, 122 of the zipper-member-having
tape 1 is preferably 3 to 10 g/10 minutes, more preferably 5 to 9
g/10 minutes. When the MFR of the resin material is less than 3
g/10 minutes, it may be difficult to extrude the head 113 (and the
connector 114) as a component of the zipper member 10 of the male
tape 11 and the first hook 123 and the second hook 124 as a
component of the zipper member 10 of the female tape 12, both of
which are integrally formed with the non-seal layers 112, 122. On
the other hand, when the MFR of the resin material is more than 10
g/10 minutes, tip ends of the first hook 123 and the second hook
124 of the female tape 12 may be easily closed and the connector
114 of the male tape 11 may be easily tumbled, which makes it
difficult to extrude the zipper member 10 into a predetermined
reopenable and resealable shape.
[0074] According to the present invention, as shown in FIG. 1, a
plurality of convex threads (first convex threads 115, 125) are
provided along a longitudinal direction of the tape 1 on a surface
of the seal layer 111, 121 (a surface that is heat-sealed to a
sealant layer 401 of the base film 40 shown in FIG. 5, as will be
described below). With this arrangement, the first convex thread
115, 125, which is provided on the surface of the seal layer 111,
121, is fused to be heat-sealed to the base film when the heated
seal-bar applies heat to the tape 1 via the base film during the
heat-sealing operation.
[0075] The seal-bar applies the heat and pressure to the first
convex thread 115, 125 when heat-sealing the tape 1 to the sealant
layer of the base film, and the heat and the pressure applied to a
concave portion between the first convex threads 115, 125 on the
seal layer 111, 121 are relaxed until the first convex thread 115,
125 is welded and leveled. Accordingly, while the sealing strength
of the tape and the base film can be maintained to be high, an
interlaminar separation between the seal layer 111, 121 and the
non-seal layer 112, 122 and a deformation and flexure of the zipper
member can be prevented.
[0076] The concave portion between the first convex threads 115,
125 relaxes the heat and pressure, such that the male tape 11 and
the female tape 12 are prevented from being excessively heated and
pressurized. The concave portion between the first convex threads
115, 125, as well as heat-radiating and heat-insulating effects of
a below-described second convex thread 116, 126 provided on the
non-seal layer 112, 122, can prevent the interlaminar separation
between the seal layer 111, 121 and the non-seal layer 112, 122 in
the heat-sealing operation.
[0077] In FIG. 1, the first convex thread 115, 125 is
isosceles-trapezoid shaped in cross-section. The cross-sectional
shape of the first convex thread 115, 125 provided on the surface
of the seal layer 111, 121 may not be trapezoidal but may be
substantially quadrangular such as rectangular and quadrate,
whereby a contact area of the first convex thread 115, 125 with the
sealant layer of the base film (see FIG. 5), to which the tape is
welded, can be appropriately enlarged and the sealing strength can
be reinforced.
[0078] The first convex thread 115, 125 may have any other
cross-sectional shape and may be exemplarily formed to be
substantially triangular and polygonal (e.g. pentagonal and
semicircular).
[0079] On the other hand, a plurality of convex threads (the second
convex thread 116, 126) are provided along the longitudinal
direction of the tape 1 on a surface of the non-seal layer 112, 122
that is laminated to the seal layer 111, 121 (a surface on which
the zipper member 10 is provided). The second convex thread 116,
126 provided on the surface of the non-seal layer 112, 122,
provides an appropriate space between the male tape 11 and the
zipper-member 10 side of the female tape 12 so as to prevent the
non-seal layer 112 of the male tape 11 from contacting the non-seal
layer 122 of the female tape 12 in the heat-sealing operation. In
addition, the second convex thread 116, 126 can radiate the heat
applied in the heat-sealing operation, thereby preventing the male
tape 11 from being welded to the female tape 12 in the heat-sealing
operation.
[0080] In FIG. 1, the second convex thread 116, 126 is triangular
in cross-section. By making the second convex thread 116, 126
triangular, the contact area of the second convex thread 116, 126
with the non-seal layer 112, 122 facing the second convex thread
116, 126 can be made small, thereby efficiently preventing the
welding of the non-seal layers 112, 122 facing each other in the
heat-sealing operation.
[0081] The second convex thread 116, 126 may have any other
cross-sectional shape and may be exemplarily substantially
quadrangular (e.g. trapezoidal, rectangular and quadrate),
polygonal (e.g. pentagonal) and semicircular in cross-section.
[0082] FIG. 2 is a fragmentary enlarged view of FIG. 1 (the male
tape 11), FIG. 3 is a front view showing the male tape 1 seen from
a seal-layer-111 direction, and FIG. 4 is a front view showing the
male tape seen from a non-seal-layer-112 direction. Although FIGS.
2 to 4 exemplarily shows the male tape 11, the female tape 12 is
similarly arranged in the present embodiment.
[0083] A height h.sub.1 of the first convex thread 115 formed on
the seal layer 111 is preferably 0.08 mm or more (FIG. 2), and more
preferably 0.1 to 0.3 mm or more. With the height h.sub.1 being
0.08 mm or more, the first convex thread 115 formed on the seal
layer 111 can contact the sealant layer of the base film to which
the tape is heat-sealed (see FIG. 5) on a larger area, whereby the
sealing strength of the tape and the base film can be reliably
enhanced.
[0084] A mounting width d of the first convex thread 115 (a surface
contacting the seal layer surface on which the first convex thread
115 is mounted; hereinafter the same shall apply) is preferably 0.5
mm or more, and more preferably 0.7 to 2 mm. With the mounting
width d being 0.5 mm or more, the first convex thread 115 can
contact the sealant layer of the base film to which the tape is
heat-sealed on a larger area, whereby the sealing strength of the
tape and the base film can be enhanced.
[0085] According to the present invention, a proportion of the
first convex thread 115 to the surface of the seal layer 111 may
influence the sealing strength of the tape and the base film to
which the tape is heat-sealed and on an effect to prevent the
interlaminar separation between the seal layer 111 and the non-seal
layer 112, the effect being entailed by heat-insulating performed
by the concave portion between the first convex threads 115.
[0086] The proportion of the first convex portion 115 to the
surface of the seal layer 111 is preferably such that a summation
of the mounting area of the first convex threads 115 is 20 to 80%
of the surface area of the seal layer 111, and more preferably such
that the summation is 40 to 60% the surface area of the seal layer
111. With the summation of the mounting area of the first convex
threads 115 being 20 to 80% of the surface area of the seal layer
111, the sealing strength of the tape and the base film to which
the tape is heat-sealed is enhanced, and the interlaminar
separation between the seal layer 111 and the non-seal layer 112 in
the heat-sealing operation can be reliably prevented.
[0087] In contrast, when the proportion of the first convex thread
115 is less than 20%, a less portion of the first convex thread 115
is fused in the heat-sealing operation to be heat welded to the
sealant layer of the base film, which may pose a risk that an
enhancement of the sealing strength of the tape and the base film
may be impaired. On the other hand, when the proportion of the
first convex thread 115 exceeds 80%, the arrangement of the tape
becomes substantially the same as an arrangement in which no first
convex thread 115 is formed on the seal layer 111 and the tape
thickness is increased. Thus, the heat and the pressure applied by
the seal-bar to the tape is hardly relaxed, which may cause the
interlaminar separation between the seal layer 111 and the non-seal
layer 112.
[0088] In the present embodiment, the surface area of the seal
layer 111 is obtained by multiplying a tape width shown in FIG. 3
by a length of the tape 1. The mounting area of the first convex
thread 115 is obtained by multiplying the mounting width d of the
first convex thread 115 shown in FIGS. 1 and 3 by the length of the
tape 1.
[0089] A height h.sub.2 of the second convex thread 116 formed on
the non-seal layer 112 is preferably 0.03 mm or more, and more
preferably 0.05 mm or more. An upper limit of the height h.sub.2 of
the second convex thread is preferably 0.3 mm. With the height
h.sub.2 of the second convex thread 116 of the non-seal layer 112
being 0.03 mm or more, the heat and the pressure applied to one of
the male tape 11 or the female tape 12 can be reliably prevented
from being transmitted to the other. With this arrangement, it is
possible to efficiently prevent the seal layer 111, 121 and the
non-seal layer 121, 122 of the zipper-member-having tape 1 from
being interlaminarly separated during the heat-sealing operation,
and the pair of non-seal layers 112, 122 of the
zipper-member-having tape 1 from being welded with each other.
[0090] A thickness t.sub.1 of the seal layer 111 (the portion
excluding the first convex thread 115) is not particularly limited
but may be 0.01 to 0.04 mm, and a thickness t.sub.2 of the non-seal
layer 112 (the portion excluding the second convex thread 116) is
not particularly limited but may be 0.1 to 0.2 mm.
[0091] As shown in FIGS. 1 and 3, the thickness sum t.sub.1+t.sub.2
of the seal layer 111, 121 and the non-seal layer 112, 122, the
height h.sub.1, h.sub.2 respectively of the first convex thread
115, 125 formed on the seal layer 111, 121 and the second convex
thread 116, 126 formed on the non-seal layer 112, 122, and a
thickness T of the a portion of the zipper-member-having tape 1 at
which the zipper member 10 is provided are preferably on a
relationship represented by a formula (I) as shown below. When the
relationship is not satisfied, either of the convex threads is so
high as to cause a practical problem that the position of the
zipper member 10 may not be easily conceived when the
zipper-member-having tape is to be engaged by hands (incidentally,
although FIG. 1 shows h.sub.1, h.sub.2 and t.sub.1+t.sub.2 with
respect to the male tape 11, the same is true with respect to the
female tape 12).
[0092] [Formula 1]
0.5TV.gtoreq.2h.sub.1+2(t.sub.1+t.sub.2)+h.sub.2 (I)
[0093] Although FIG. 1 shows the first convex thread 115, 125 and
the second convex thread 116, 126 according to the present
invention in an exaggerated manner, the maximum thickness of the
actual tape 1 can be usually found at the portion at which the
zipper member 10 is provided.
[0094] The male tape 11 as a component of the zipper-member-having
tape 1 has a cross-section as shown in FIG. 1. The male tape 11 is
obtained by integrating the seal layer 111 on which the first
convex thread is formed, the non-seal layer 112 on which the second
convex thread is formed, and the head 112 and the connector 114
continuously formed from the non-seal layer 112 by a known
coextrusion method. Likewise, the female tape 12 is obtained by
integrating the seal layer 121 on which the first convex thread is
formed, the non-seal layer 122 on which the second convex thread is
formed and the first hook 123, and the second hook 124 continuously
formed from the non-seal layer 122 by a known coextrusion method.
When the zipper-member-having tape 1 is formed by such a
coextrusion-forming method, the tape 1 can be manufactured in a
simplified process at low cost. In addition the
zipper-member-having tape 1 can be stably manufactured in a
continuous manner.
[0095] The seal layer 111, 121 of the zipper-member-having tape 1
is welded to the base film 40 that forms a bag body (not shown),
the base film 40 being transformed into a bag to obtain a package
bag with the zipper-member-having tape 1.
[0096] FIG. 5 is a cross-sectional view showing the
zipper-member-having tape 1 heat-sealed to the base film 40
according to the present invention. When the zipper-member-having
tape 1 is heat-sealed to the base film 40, the first convex thread
115, 125 formed on the surface of the seal layer 111, 121 is fused
to be welded to the sealant layer 401 of the base film 40.
[0097] Welding conditions (temperature, pressure, etc.) can be
determined as desired in accordance with types of the resins used
for the zipper-member-having tape 1 and the base film 40 for
forming the bag body.
[0098] The arrangement of the bag body having an opening to which
the zipper-member-having tape 1 according to the present invention
is heat-sealed is not particularly limited but may include a known
bag shape such as a bag sealed along four edges, a side-gusset bag
and a bottom-gusset bag.
[0099] Particularly, the zipper-member-having tape 1 is preferably
usable even when the zipper-member-having tape cannot be conveyed
in a MD direction of the base film but needs to be inserted in a TD
direction of the base film without using a separator in a bag
product such as the side-gusset bag.
[0100] Although FIG. 5 shows a laminate film in which the sealant
layer 401 is laminated over an outer layer 402 as the base film 40
for forming the bag body, a laminate film in which a middle layer
(not shown) such as a gas barrier layer, a light-shielding layer
and a strength-reinforcing layer is provided between the outer
layer 402 and the sealant layer 401 may be used depending on a
required performance. Incidentally, the outer layer 402, the middle
layer (not shown) and the sealant layer 401 may be respectively
formed of a single layer, or at least one of these layers may be
formed of a plurality of layers.
[0101] The plurality of convex threads (first convex threads 115,
125), which are formed on the seal layers 111, 121 in the
zipper-member-having tape 1 as described above, are fused to be
heat-sealed to the base film 40 when applied with the heat by the
heated seal-bar via the base film 40 in the heat-sealing operation.
While the sealing strength of the tape 1 and the base film 40 is
maintained at a high level, the concave portion between the first
convex threads 111, 125 relaxes the heat and pressure, such that a
deformation and flexure of the zipper member 10 is suppressed,
thereby desirably preventing the interlaminar separation between
the seal layer 111, 121 and the non-seal layer 112, 222. Further,
the second convex threads 116, 126, which are provided on the
surface of the non-seal layer 112, 122, provide an appropriate
space between the male tape 11 and the zipper-member 10 side of the
female tape 12 so as to prevent the non-seal layer 112 of the male
tape 11 from contacting the non-seal layer 122 of the female tape
12 in the heat-sealing operation. In addition, the second convex
thread 116, 126 can radiate the heat transmitted in the
heat-sealing operation (heat-radiating effect) and can prevent the
heat and pressure applied to one of the male tape 11 or the female
tape 12 from being transmitted to the other (heat-insulating
effect), thereby preferably preventing the male tape 11 from being
welded to the female tape 12 in the heat-sealing operation.
[0102] The heat-radiating and heat-insulating effects of the second
convex threads 116, 126 on the non-seal layer 112, 122,
synergistically with the heat-radiating effect of the concave
portion between the first convex threads 115, 125 on the seal layer
111, 121, prevent the male tape 11 and the female tape 12 from
being excessively heated, thereby preventing the interlaminar
separation between the seal layer 111, 121 and the non-seal layer
112, 122 in the heat-sealing operation.
[0103] The zipper-member-having tape 1 according to the present
invention, as arranged in the above-described manner, is applicable
to wide variety of products where the tape 1 is attached to an
opening of a package bag for packaging various articles such as
foods, pharmaceutical and medical products and groceries.
MODIFICATION OF EMBODIMENTS
[0104] It should be noted that the above-described embodiment
merely shows an embodiment of the present invention, and the
present invention is not limited to the above-described embodiment,
where modifications and improvements are included within the scope
of the present invention as long as an object and an advantage of
the present invention can be achieved. In addition, specific
arrangements and profiles when implementing the present invention
may be altered as long as an object and an advantage of the present
invention can be achieved.
[0105] For example, in above-described FIG. 1, ribs 116, 126 that
are provided on a side of the non-seal layer surface at which the
"T" representing the thickness of the zipper-member-having tape 1
is shown ("the other side" described in Claim 9) may be omitted
(omission of total fourteen ribs), and a pseudo-adhesion layer may
be provided to the other side end(s) of the male tape 11 and/or the
female tape 12 of the zipper-member-having tape 1 so that the two
layers are pseudo-adhered with each other.
[0106] For example, when the non-seal layer of the male tape is of
polypropylene, a layer of low-density polyethylene and a
composition of polypropylene and polyethylene (polyethylene-rich)
may be provided to the non-seal layer surface of the female
tape.
[0107] On the other hand, when the non-seal layer of the male tape
is of high-density polyethylene, a layer of polypropylene and a
composition of polypropylene and polyethylene (polypropylene-rich)
may be provided to the non-seal layer surface of the female
tape.
[0108] Such a zipper-member-having tape 1 is attached to the bag
such that the side at which the "T" representing the thickness of
the zipper-member-having tape 1 ("the other side" described in
Claim 9) faces a non-opening side of the bag (a content side).
Since the convex thread ribs 116, 126 are provided on the non-seal
layer surface of the zipper-member-having tape 1 facing the opening
side of the bag, the bag is easily opened by hands. Although the
non-seal layers of the zipper-member-having tape 1 are
pseudo-adhered with each other on the non-opening side (i.e., the
content side) of the bag, the adhesive force is so weak as to allow
the bag to be easily opened by hands thus does not impair an
openability of the bag.
[0109] Although the non-seal layer 112, 122 of the male tape 11 and
the female tape 12 is a single layer, with which the zipper member
10 is integrally formed in the above-described embodiment, the
non-seal layer 112, 122 may be formed of multiple layers, in which
the zipper member 10 is provided on the innermost layer of the
multiple layers of the non-seal layer 112, 122.
[0110] Although the second convex thread 116, 126 is formed on the
non-seal layer of 112, 122 of the male tape 11 and the female tape
12 in the above-described embodiment, the second convex thread 116,
126 may be provided on either of the male tape 11 or the female
tape 12.
[0111] Although six of the first convex threads 115, 125 are
provided on each of the content side (upper side in FIG. 1. the
same is true hereinafter.) and the opening side (lower side in FIG.
1. the same is true hereinafter) of the seal layer 111, 121 (total
twelve threads) while seven of the second convex thread 116, 126
are provided on each of the content side and the opening side of
the non-seal layer 121, 122 (total fourteen threads) in the above
embodiment, the present invention is not limited thereto, but the
number of the first convex thread 115, 125 and the second convex
thread 116, 126 may be determined as desired.
[0112] In the zipper-member-having tape 1 in the above-described
embodiment, the components of the zipper member 10, i.e., the head
113 having a substantially arrow-tipped shape of the male tape 11
and the first and second hooks 123, 124 each having a substantially
arc shape of the female member 12, are engaged with and disengaged
from each other to unseal and reseal the bag. However, the shape of
the zipper member 10 is not limited to the one as in the
above-described embodiment but may be any shape as long as the
zipper member 10 can perform unsealing and resealing. The shape and
the number of the heads 113 and the first and second hooks 123, 124
may be arbitrarily determined.
[0113] Although the seal layer 111, 121, the first convex thread
115, 125 formed on the seal layer 111, 121, the non-seal layer 112,
122 and the second convex thread 116, 126 formed on the non-seal
layer 112, 122 are preferably integrally formed of the same resin
material, the seal layer 111, 121 and the non-seal layer 112, 122
may be formed of a resin material different from that of the first
convex thread 115, 125 and the second convex thread 116, 126
respectively as long as an object and an effect of the present
invention is not impaired.
[0114] Although the non-seal layer 112, 122 is laminated over the
seal layer 111, 121 to be integrated with the zipper member 10 in
FIG. 1, the zipper member 10 (including the connecter 114 of the
male tape 11) and the seal layer 111, 121, for example, may be
separately formed to be integrally adhered with each other using an
adhesive and the like. In addition, a middle layer (not shown) with
which the zipper member is integrally formed may be provided
between the seal layer 111, 121 and the non-seal layer 112, 122 to
be laminated to the non-seal layer 112, 122.
[0115] Although the non-seal layer 112, 122 is single-layered and
the resin material forming the seal layer 111, 121 is substantially
non-compatible with that of the non-seal layer 112, 122 in the
above-described embodiment, the non-seal layer may be
multiple-layered. In this case, not only when the resin material
forming the seal layer is substantially non-compatible with that of
the non-seal layer 112, 122 laminated to the seal layer but also
when at least a pair of layers adjacently laminated in the non-seal
layer are substantially non-compatible with each other, effects of
the present invention can be obtained.
[0116] Specifically, with the first convex thread being formed on
the surface of the seal layer (the resin material forming the seal
layer) as in the above-described embodiment, the sealing strength
of the tape and the base film is maintained at a high level and the
heat and the pressure applied to the concave portion between the
convex threads (portion of the seal layer other than the convex
thread) is relaxed. Accordingly, it is possible to desirably
prevent the deformation and flexure of the zipper member, the
interlaminar separation between the seal layer and the non-seal
layer, and an interlaminar separation inside the multiple-layered
non-seal layer. With the second convex thread being formed on the
non-seal layer surface laminated to the seal layer, the contact
area between the non-seal layers of the male tape and the female
tape can be reduced, such that the heat applied in the heat-sealing
operation can be radiated (heat-radiating effect) and the heat and
the pressure applied to one of the male tape and the female tape
can be prevented from being transmitted to the other
(heat-insulating effect), thereby preventing the male tape from
being welded to the female tape in the heat-sealing operation.
[0117] Also as in the above-described embodiment, the
heat-radiating and heat-insulating effects by the second convex
thread on the non-seal layer, as well as the relaxation of the heat
and pressure by the concave portion between the first convex
threads on the seal layer, can prevent the male tape and the female
tape from being excessively heated, whereby the interlaminar
separation between the seal layer and the non-seal layer or the
interlaminar separation in the multiple-layered non-seal layer can
be prevented as desired.
[0118] The specific arrangement, the profile and the like described
in the embodiment of the present invention can be altered as long
as an object of the present invention can be attained.
Example
[0119] Now, the present invention will more specifically be
described below by providing examples and comparisons, the content
of which by no means limits the scope of the present invention.
[0120] In the examples and the like described below, resin
properties were measured with the melt flow rate (MFR) being based
on JIS K7210 (21.1 N load at 230.degree. C.) and a melting point
being based on JIS K7121.
Example 1
[0121] With respect to the zipper-member-having tape as shown in
FIG. 1, materials forming the seal layer and the non-seal layer
(including the zipper member) were coextruded using a commercially
available extrusion-molding machine in a manner described below,
such that twelve convex threads of an isosceles-trapezoid shape
with a height of 0.1 mm (first convex thread) were provided on the
seal layers (thickness: 0.02 mm) of the male tape and the female
tape respectively and fourteen equilateral-triangular convex
threads with a height of 0.06 mm and a mounting width per thread of
0.15 mm were provided on the non-seal layers (thickness: 0.16
.mu.m) of the male tape and the female tape respectively. By this
method, the zipper-member-having tape according to the present
invention was obtained.
[0122] The summation of the mounting width of the first convex
threads was 5 mm and the mounting area of the first convex threads
was 30% of the surface area of the seal layer. In addition, the
thickness T of the zipper-member-having tape 1 at the portion where
the zipper member was provided shown in FIG. 1 was 1.5 mm.
[0123] (Material: Seal Layer)
[0124] Linear low-density polyethylene using metallocene catalyst
was used (7P12A: Manufactured by Tosoh Corporation, MFR: 12 g/10
minute, Melting Point: 93.degree. C., Density: 900
kg/cm.sup.3).
[0125] (Material: Non-Seal Layer)
[0126] Random polypropylene was used (F-744NP: Manufactured by
Idemitsu Kosan Co., Ltd., MFR: 7 g/10 minute, Melting Point:
133.degree. C., Density: 900 kg/cm.sup.3).
Example 2
[0127] In the zipper-member-having tape obtained by the method
described in the example 1, the shape of the first convex thread
formed on the seal layer was modified to a triangle with a height
of 0.1 mm from the isosceles-trapezoid shape with the height of 0.1
mm. Except for the modification, a zipper-member-having tape was
obtained by the same method as in the example 1.
[0128] [Comparison 1]
[0129] In the zipper-member-having tape obtained by the method
described in the example 1, the shape of the first convex thread
formed on the seal layer was modified to a triangle with a height
of 0.1 mm from the isosceles-trapezoid shape with the height of 0.1
mm, and no second convex thread was formed on the non-seal layer.
Except for these modifications, a zipper-member-having tape was
obtained by the same method as in the example 1.
[0130] [Comparison 2]
[0131] In the zipper-member-having tape obtained by the method
shown in the example 1, no first convex thread was formed on the
seal layer. Except for the modification, a zipper-member-having
tape was obtained by the same method as in the example 1.
[0132] [Comparison 3]
[0133] In the zipper-member-having tape obtained by the method
described in the example 1, the shape of the first convex thread
formed on the seal layer was modified to a triangle with a height
of 0.06 mm from the isosceles-trapezoid shape with the height of
0.1 mm, and no second convex thread was formed on the non-seal
layer. Except for these modifications, a zipper-member-having tape
was obtained by the same method as in the example 1.
[0134] [Comparison 4]
[0135] In the zipper-member-having tape obtained by the method
shown in the example 1, no convex thread was formed on either of
the seal layer and the non-seal layer. Except for the modification,
a zipper-member-having tape was obtained by the same method as in
the example 1.
[0136] [Examination 1]
[0137] The zipper-member-having tapes obtained in Examples 1, 2 and
Comparative Examples 1 to 4 were heat-sealed three times to a
linear low-density polyethylene side of the base film arranged as
below (by touching the seal-bar to the tape two times from the male
tape side and one time from the female tape side) under the
following sealing conditions of sealing pressure of 2 kg/cm.sup.2;
sealing temperature of 150.degree. C.; and sealing time of 1
second, set by a commercially available heat-sealing tester,
whereby a gusset bag was obtained.
[0138] After being heat-sealed in this manner, the sealing strength
of the zipper-member-having tape and the base film, the welding of
the non-seal layers of the zipper-member-having tape and the
interlaminar separation between the seal layer and non-seal layer
were checked, compared and evaluated. The results are shown in
Table 1 together with the arrangements of Examples 1, 2 and
Comparative Examples 1 to 4.
[0139] Measurement of the sealing strength was performed in the
following manner.
[0140] (Arrangement of Base Film)
[0141] Multi-layered film (total thickness: 85 .mu.m) of Nylon film
(Ny) (thickness: 15 .mu.m) and linear low density polyethylene
(LLDPE) (thickness: 70 .mu.m) was used as the base film.
[0142] (Evaluation of Sealing Strength)
[0143] The base film and the zipper-member-having tape heat-sealed
to each other were cut into a piece with 15 mm wide to obtain a
test sample, and the test sample was measured with an autograph
tensile testing machine under a measuring condition of 300 mm/min
at 180.degree. peeling. In addition, the evaluation was conducted
in accordance with the following evaluation criteria.
[0144] (Evaluation Criteria)
TABLE-US-00001 Evaluation Contents Excellent: Sealing Strength of
30 N/15 mm wide or more. Good: Sealing Strength of 25 N/15 mm wide
or more, less than 30 N/15 mm wide. Not Good: Sealing Strength of
less than 25 N/15 mm wide.
TABLE-US-00002 TABLE 1 (Result) [Example 1] [Example 2] [Comparison
1] [Comparison 2] [Comparison 3] [Comparison 4] Convex Shape
Isosceles- Triangle Triangle none Triangle none Threads of
Trapezoid Seal Layer Height (mm) 0.1 0.1 0.1 0.06 (First Summation
of 5 5 5 5 Convex Mounting Thread) width (mm) Proportion of 30 30
30 30 Summation of Mounting Area (%) Convex Shape Triangle Triangle
None Triangle None None Threads of Height (mm) 0.06 0.06 0.06
Non-Seal Mounting 0.15 0.15 0.15 Layer Width (mm) (Second (Per
Thread) Convex Thread) Evaluation Sealing Excellent: Good: Good:
Not Good: Good: Not Good: Result Strength Welding Not Observed Not
Observed Observed Not Observed Observed Observed Interlaminar Not
Observed Not Observed Observed Observed Observed Observed
Separation
[0145] As is understood from the results shown in Table 1, the
zipper-member-having tape according to the present invention
obtained in Examples 1 and 2 was sealed to the base film with a
high sealing strength, where neither welding of the non-seal layers
during the heat-sealing operation nor interlaminar separation
between the seal layer and non-seal layer was caused in the
zipper-member-having tape.
[0146] As compared with Example 2 in which the shape of the first
convex thread was equilateral-triangular in cross-section, the tape
was sealed to the base film with a higher sealing strength in
Example 1 in which the shape of the first convex thread was
isosceles-trapezoid in cross-section.
[0147] On the other hand, in Comparative Examples 1 and 3 in which
the tape in Example 1 was modified such that the shape of the first
convex thread was triangular in cross-section while no second
convex thread was provided on the non-seal layer, the tape was
sealed to the base film with a less seal strength as compared with
Example 1, and the welding of the non-seal layers during the
heat-sealing operation and the interlaminar separation between the
seal layer and non-seal layer were observed.
[0148] In Comparative Example 2 in which the tape in Example 1 was
modified such that no first convex thread was provided on the seal
layer, the tape was sealed to the base film with a much less seal
strength as compared with Example 1, and although the welding of
the non-seal layers during the heat-sealing operation was not
confirmed, the interlaminar separation between the seal layer and
non-seal layer was observed.
[0149] In Comparative Example 4 in which the tape in Example 1 was
modified such that no convex thread was provided on either the seal
layer or the non-seal layer, the tape was sealed to the base film
with a much less seal strength as compared with Example 1, and the
welding of the non-seal layers during the heat-sealing operation
and the interlaminar separation between the seal layer and non-seal
layer were observed.
INDUSTRIAL APPLICABILITY
[0150] The present invention is applicable to a wide variety of
zipper-member-having tapes that are heat-sealed to an opening of
the package bag that packages various articles such as foods,
pharmaceutical and medical products and groceries in an openable
and resealable manner.
* * * * *