U.S. patent application number 10/665497 was filed with the patent office on 2004-03-25 for film winding method and apparatus, and lay-on roll for the film winding apparatus.
Invention is credited to Shigemura, Takashi.
Application Number | 20040056139 10/665497 |
Document ID | / |
Family ID | 31986936 |
Filed Date | 2004-03-25 |
United States Patent
Application |
20040056139 |
Kind Code |
A1 |
Shigemura, Takashi |
March 25, 2004 |
Film winding method and apparatus, and lay-on roll for the film
winding apparatus
Abstract
In a film winding method, continuous polymer film of cellulose
acetate being supplied is wound into a form of a film roll. During
the winding step, looseness of outer turns of the film roll is
prevented by pressing a rotatable lay-on roll against the film
roll. The lay-on roll includes a surface material, formed in a
cylindrical shape, for contacting the film roll. The surface
material includes rubber, has volume resistivity of
10.sup.2-10.sup.12 .OMEGA.cm, and hardness of 30-70.
Inventors: |
Shigemura, Takashi;
(Kanagawa, JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
31986936 |
Appl. No.: |
10/665497 |
Filed: |
September 22, 2003 |
Current U.S.
Class: |
242/547 |
Current CPC
Class: |
B65H 27/00 20130101;
B65H 2404/185 20130101; B65H 2401/111 20130101; B65H 18/26
20130101 |
Class at
Publication: |
242/547 |
International
Class: |
B65H 018/26 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 19, 2002 |
JP |
2002-273848 |
Claims
What is claimed is:
1. A film winding method comprising steps of: winding continuous
polymer film into a form of a film roll; and during said winding,
preventing looseness of outer turns of said film roll by pressing a
rotatable lay-on roll against a peripheral surface of said film
roll; wherein said lay-on roll includes a surface material, formed
in a cylindrical shape, and including rubber which has volume
resistivity of 10.sup.2-10.sup.12 .OMEGA.cm, and hardness of
30-70.
2. A film winding method as defined in claim 1, wherein said lay-on
roll further includes a roll body about which said surface material
is disposed in a cylindrical form.
3. A film winding method as defined in claim 2, wherein said roll
body is formed from metal.
4. A film winding method as defined in claim 1, wherein said
surface material has said volume resistivity of 10.sup.4-10.sup.8
.OMEGA.cm.
5. A film winding method as defined in claim 4, wherein said
surface material has said hardness of 30-60.
6. A film winding method as defined in claim 1, wherein said
surface material has high resistance to ozone.
7. A film winding method as defined in claim 1, wherein a winding
speed of said polymer film is 30 meters per minute or more.
8. A film winding method as defined in claim 1, wherein said
polymer film has a thickness of 125 microns or less.
9. A film winding method as defined in claim 8, wherein said
polymer film has said thickness of 85 microns or less.
10. A film winding method as defined in claim 1, wherein a pressing
force of said lay-on roll to said film roll is 10-100 N.
11. A film winding method as defined in claim 10, wherein said
pressing force is 20-80 N.
12. A film winding method as defined in claim 11, wherein said
pressing force is decreased in a range from 60 N down to 30 N
according to an increase in a radius of said film roll.
13. A film winding method as defined in claim 1, wherein said
polymer film is cellulose acylate or polyester.
14. A film winding method as defined in claim 1, wherein said
surface material further includes carbon.
15. A film winding method as defined in claim 1, wherein said
polymer film has a width of 600-3,500 mm.
16. A film winding method as defined in claim 1, wherein a length
of winding of said polymer film into said film roll is 500-10,000
meters.
17. A lay-on roll for a film winding apparatus for winding
continuous polymer film into a form of a film roll, said lay-on
roll being pressed against said film roll while said polymer film
is wound by said film winding apparatus, for preventing looseness
of outer turns of said film roll, said lay-on roll comprising: a
rotatable roll body; and a surface material, disposed about said
roll body, and including rubber which has volume resistivity of
10.sup.2-10.sup.12 .OMEGA.cm, and hardness of 30-70.
18. A lay-on roll as defined in claim 17, wherein said surface
material has high resistance to ozone.
19. A lay-on roll as defined in claim 17, wherein a pressing force
of being pressed to said film roll is 10-100 N.
20. A lay-on roll as defined in claim 17, wherein said polymer film
is cellulose acylate or polyester.
21. A film winding apparatus comprising: a spindle for winding
continuous polymer film into a form of a film roll thereabout; and
a lay-on roll, pressed against a peripheral surface of said film
roll while said polymer film is wound about said spindle, for
preventing looseness of outer turns of said film roll; said lay-on
roll including: a rotatable roll body; and a surface material,
disposed about said roll body, and including rubber which has
volume resistivity of 10.sup.2-10.sup.12 .OMEGA.cm, and hardness of
30-70.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a film winding method and
apparatus, and a lay-on roll for the film winding apparatus. More
particularly, the present invention relates to a film winding
method and apparatus suitable for efficient production of a film
roll without degrading polymer film, and a lay-on roll for the film
winding apparatus.
[0003] 2. Description Related to the Prior Art
[0004] Cellulose acetate film as a type of cellulose acylate films
is widely used for various purposes, including an electronic
display panel, a support of a photosensitive material, and other
optical equipments. Because of great development in techniques in
the field of the electronic display panel, further reduction in the
thickness of polymer film has been desired in the industrial use.
So higher productivity of the polymer film is required.
[0005] In general, the cellulose acylate film is manufactured by a
method of solution casting film forming. According to this,
cellulose acylate is dissolved in solvent with additives including
plasticizer, ultraviolet absorber, and lubricant, to obtain
high-density solution. The solution is caused through a die to flow
to an endless support such as a band, a drum or the like. The
solvent is dried and hardened, and removed from the support.
Furthermore, the solvent is dried to obtain the polymer film.
[0006] According to considerable highness in the producing speed,
stable winding in a station for the winding the polymer film
becomes more difficult because of air between turns. Occurrence of
inclusion of air between turns is likely to create low tightness in
the winding, sinking failure and other failures. The term of the
low tightness in the winding or looseness is used to refer to a
failure of an excessively great difference between upper and lower
radii of a film roll. The term of the sinking failure is used to
refer to an accidental sink or recess in an upside of the film
roll. This difficulty is specifically frequent in the case of a
very high producing speed, or a very small thickness of the polymer
film.
[0007] JP-A 2002-068538 discloses elimination of air from between
turns of the polymer film. In winding the polymer film, a lay-on
roll is used to press the polymer film toward a spindle for the
film roll. According to this, it is possible to produce the film
roll with regularly thick air layers between the turns of the
polymer film.
[0008] However, the use of the lay-on roll electrifies the polymer
film being wound because of the contact and separation between the
polymer film and the lay-on roll. Foreign material or particles
flowing in air are attracted by electrostatic charge. So failure of
foreign material is likely to occur. Also, a voltage application
type of static eliminator for the polymer film is used to generate
ion, which is applied to the film roll as a product so as to
eliminate static charge. However, this method has a problem in
creation of gas of ozone in a winding chamber in the film winding
apparatus. The ozone seriously degrades the surface material of
rubber in the lay-on roll. This causes an increase in the volume
resistivity of the rubber surface. The amount of electrification
rises. Also, black belt-shaped failure occurs, in which a surface
of the film roll comes to have failure in deformation of the base
in a belt shape of the black color in a circumferential direction
of the film roll. This is because of rise in the hardness of the
rubber.
SUMMARY OF THE INVENTION
[0009] In view of the foregoing problems, an object of the present
invention is to provide a film winding method and apparatus in
which electrification due to a lay-on roll in winding polymer film
is suppressed, a status of a film roll in high-speed production is
stabilized, and the polymer film can be produced with high quality
and with high reliability.
[0010] In order to achieve the above and other objects and
advantages of this invention, a film winding method includes a step
of winding continuous polymer film being supplied into a form of a
film roll. During the winding step, looseness of outer turns of the
film roll is prevented by pressing a rotatable lay-on roll against
the film roll. The lay-on roll includes a surface material, formed
in a cylindrical shape, for contacting the film roll, wherein the
surface material includes rubber, has volume resistivity of
10.sup.2-10.sup.12 .OMEGA.cm, and hardness of 30-70.
[0011] The lay-on roll further includes a roll body about which the
surface material is wound in a cylindrical form.
[0012] The roll body is formed from metal.
[0013] Preferably, the surface material has the volume resistivity
of 10.sup.4-10.sup.8 .OMEGA.cm.
[0014] Preferably, the surface material has the hardness of
30-60.
[0015] The surface material has high resistance to ozone.
[0016] A winding speed of the polymer film in the winding step is
30 meters per minute or more.
[0017] The polymer film has a thickness of 125 microns or less
during the winding step.
[0018] Preferably, the polymer film has the thickness of 85 microns
or less during the winding step.
[0019] A pressing force of the lay-on roll to the film roll in the
preventing step is 10-100 N.
[0020] Preferably, the pressing force is 20-80 N.
[0021] The pressing force is decreased in a range from 60 N down to
30 N according to an increase in a radius of the film roll.
[0022] The polymer film is cellulose acylate or polyester.
[0023] The surface material further includes carbon.
[0024] The polymer film has a width of 600-3,500 mm.
[0025] A length of winding of the polymer film into the film roll
is 500-10,000 meters.
[0026] According to one aspect of the invention, a lay-on roll for
a film winding apparatus winds continuous polymer film being
supplied into a form of a film roll, the lay-on roll being
rotatable, and pressed against the film roll while the polymer film
is wound by the film winding apparatus, for preventing looseness of
outer turns of the film roll. The lay-on roll includes a surface
material, formed in a cylindrical shape, for contacting the film
roll, wherein the surface material includes rubber, has volume
resistivity of 10.sup.2-10.sup.12 .OMEGA.cm, and hardness of
30-70.
[0027] According to another aspect of the invention, a film winding
apparatus includes a spindle for winding continuous polymer film
being supplied into a form of a film roll thereabout. A rotatable
lay-on roll is pressed against the film roll while the polymer film
is wound about the spindle, for preventing looseness of outer turns
of the film roll. The lay-on roll includes a surface material,
formed in a cylindrical shape, for contacting the film roll,
wherein the surface material includes rubber, has volume
resistivity of 10.sup.2-10.sup.12 .OMEGA.cm, and hardness of
30-70.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The above objects and advantages of the present invention
will become more apparent from the following detailed description
when read in connection with the accompanying drawings, in
which:
[0029] FIG. 1 is an explanatory view in elevation, illustrating a
film winding apparatus;
[0030] FIG. 2 is a front elevation, partially broken, illustrating
a lay-on roll in the film winding apparatus;
[0031] FIG. 3 is a side elevation illustrating a film roll;
[0032] FIG. 4A is a perspective illustrating a state of a film roll
having a sinking failure;
[0033] FIG. 4B is a front elevation illustrating the same as FIG.
4A; and
[0034] FIG. 5 is a front elevation illustrating a state of a film
roll having a belt-shaped failure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) OF THE PRESENT
INVENTION
[0035] In FIG. 1, a film winding apparatus of the invention is
illustrated. A spindle 10 is incorporated in the film winding
apparatus. A motor (not shown) causes the spindle 10 to rotate. A
supply unit supplies continuous polymer film 11, which the spindle
10 winds, to form a film roll 12.
[0036] A lay-on roll 13 is disposed in a rotatable manner, and
positioned to contact the film roll 12. A pressing mechanism 14
presses the polymer film 11 toward the spindle 10. In the course of
winding of the polymer film 11, air is removed from between turns
of the polymer film 11. The film roll 12 can be formed with
regularly thick air layers between the turns of the polymer film
11.
[0037] In FIG. 2, the lay-on roll 13 is constituted by a roll body
13a and a surface material or liner material 13b overlaid on the
periphery of the roll body 13a in a cylindrical form. The roll body
13a is formed from metal, of which examples are SS, SUS and the
like. An example of the surface material 13b is NBR rubber.
Additive agent is mixed in the surface material 13b to impart
rubber hardness of 40, and volume resistivity of 10.sup.8
.OMEGA.cm. An example of the lay-on roll 13 having the surface
material 13b of this characteristic is White EC 240NS, manufactured
by Katsura Roller Mfg. Co., Ltd. Note that the rubber hardness is
measured according to JIS K6253, and that the volume resistivity is
measured according to JIS K6271.
[0038] The surface material 13b in the lay-on roll 13 has the
volume resistivity in a range from 10.sup.2 .OMEGA.cm to 10.sup.12
.OMEGA.cm, and preferably in a range from 10.sup.4 .OMEGA.cm to
10.sup.8 .OMEGA.cm. Also, the surface material 13b has the rubber
hardness of 30-60, and preferably 35-50. Furthermore, the surface
material 13b is formed from a material having high resistance to
ozone.
[0039] A preferable winding speed of the polymer film 11 is 30 or
more meters per minute. The thickness of the polymer film 11 while
wound is 125 microns or less, which is very preferable in view of
the effect of the invention because of low rigidity and easy
deformation. The thickness of the polymer film 11 while wound is
preferably 85 microns or less, and desirably 65 microns or less. A
pressing force applied by the lay-on roll 13 to the polymer film 11
when the polymer film 11 is wound is 20-80 N, and desirably 30-60
N. It is also preferable to change the pressing force of the lay-on
roll 13 from 60 N down to 30 N according to the change in the
diameter of the film roll 12.
[0040] The lay-on roll 13 can have any suitable shape. For example,
the lay-on roll 13 may have an inclined portion or tapered portion.
It is preferable also in this structure to set the pressing force
between the polymer film 11 and the lay-on roll 13 in a range of
30-60 N.
[0041] The polymer film 11 used in the invention may be any
suitable type. Examples of the polymer film 11 are plastic
materials, which are cellulose acetates, such as cellulose
triacetate, and polyesters, such as polyethylene terephthalate and
polyethylene naphthalate. When the film roll 12 as a product is
obtained, a width of the film roll 12 is 600-3,500 mm, preferably
1,000-1,600 mm. A thickness of the polymer film 11 in the film roll
12 is 25-250 microns, preferably 30-100 microns. A winding length
of the film roll 12 is 500-10,000 meters, preferably 2,000-6,000
meters.
[0042] Both selvedge portions of the polymer film 11 to be wound is
provided with knurling constituted by projections or recesses known
in the art. Shapes of the knurling can be varied in a suitable
manner.
[0043] Examples of the invention are hereinafter described. Of
course, modifications are possible in relation to the preferred
examples of the invention.
EXAMPLE 1
[0044] In the film winding apparatus of FIG. 1, cellulose acetate
film as the polymer film 11 was wound by use of the lay-on roll 13.
The cellulose acetate film was wound at a winding speed of 35
meters per minute. The cellulose acetate film was 40 microns thick
and 1,336 mm wide. The pressing force of the lay-on roll 13 was 35
N. The surface material 13b of the lay-on roll 13 was NBR rubber,
which was White EC 240NS (trade name), manufactured by Katsura
Roller Mfg. Co., Ltd., with rubber hardness of 40, and volume
resistivity of 10.sup.8 .OMEGA.cm.
EXAMPLE 2
[0045] The surface material 13b of the lay-on roll 13 was NBR
rubber in which carbon was added. The NBR rubber was 37H50S (trade
name), manufactured by Kinyosha Co., Ltd., with rubber hardness of
50, and volume resistivity of 10.sup.5 .OMEGA.cm. Except for this
feature, the characteristics of Example 2 were the same as those of
Example 1.
COMPARATIVE EXAMPLE 1
[0046] The surface material 13b of the lay-on roll 13 was NBR
rubber without carbon. The NBR rubber was 31G40W (trade name),
manufactured by Kinyosha Co., Ltd., with rubber hardness of 40, and
volume resistivity of 10.sup.16 .OMEGA.cm. Except for this feature,
the characteristics of Comparative example 1 were the same as those
of Example 1.
COMPARATIVE EXAMPLE 2
[0047] The surface material 13b of the lay-on roll 13 was NBR
rubber in which carbon was added. The NBR rubber was 37H80S (trade
name), manufactured by Kinyosha Co., Ltd., with rubber hardness of
80, and volume resistivity of 10.sup.5 .OMEGA.cm. Except for this
feature, the characteristics of Comparative example 2 were the same
as those of Example 1.
COMPARATIVE EXAMPLE 3
[0048] The lay-on roll 13 was not used. Except for this feature,
the characteristics of Comparative example 3 were the same as those
of Example 1.
[0049] [Evaluation of the Film Roll]
[0050] The film roll 12 according to Examples 1 and 2 and
Comparative examples 1, 2 and 3 was prepared. The polymer film 11
was cellulose acetate film. The film roll 12 was evaluated for the
quality in relation to the electrification, the tightness in
winding, the sinking failure, the black belt-shaped failure, the
deposition of foreign material, the degradation of the lay-on roll
13.
[0051] [Evaluation of Electrification]
[0052] To measure an amount of electrification, an electrostatic
tester STATIRON-DZ3 (trade name) manufactured by Shishido
Electrostatic, Ltd was used. Note that the film roll 12 is the
better according to the smallness of the electrification. According
to measured results of amounts of electrification, evaluation was
conducted according to the ranks in Table 1.
1 TABLE 1 Electrification Results Lower than .+-.1.0 kV AA .+-.1.0
kV or higher, and lower than .+-.3.0 kV A .+-.3.0 kV or higher, and
lower than .+-.7.0 kV B .+-.7.0 kV or higher F
[0053] In FIG. 3, a film roll 20 had an upper radius LU of windings
and a lower radius LD. To evaluate the tightness in turns being
wound, a difference LD-LU between the radii LU and LD was
calculated and evaluated. Note that the tightness of the film roll
12 is the higher and the better according to the smallness of the
difference between the radii. According to measured results of the
radius difference, evaluation was conducted according to the ranks
in Table 2.
2 TABLE 2 Difference LD-LU between the two radii Results Less than
3 mm A 3 mm or more, and less than 10 mm B 10 mm or more F
[0054] In FIG. 4A, it is likely that a sinking failure 22 occurs
accidentally in a film roll 21. In FIG. 4B, a depth D1 of the
sinking failure 22 was measured to evaluate the sinking failure 22.
The depth D1 was defined as a distance between a deepest position
of a sunken surface of the sinking failure 22 and a position of a
normal surface without a sink as indicated by the phantom line.
Note that the film roll 21 is the better according to the smallness
of the depth D1 of the sinking failure 22. According to measured
results of the depth D1 of the sinking failure 22, evaluation was
conducted according to the ranks in Table 3.
3 TABLE 3 Depth of the sinking failure 22 Results Less than 3 mm A
3 mm or more, and less than 10 mm B 10 mm or more F
[0055] In FIG. 5, a film roll 25 was inspected by human eyes for
occurrence of a belt-shaped failure 26 in a black color. Evaluation
was conducted as to existence or lack of the belt-shaped failure
26. Note that the film roll 25 without the belt-shaped failure 26
is desired.
[0056] [Evaluation of Deposition of Foreign Material]
[0057] Stroboscopic light was applied to the outermost turn of the
film roll 12. The number of particles as foreign material on the
one outermost turn of the film roll 12 were inspected by human
eyes. Preference is higher according to the highness of the number
of particles. According to measured results of the numbers of the
particles, evaluation was conducted according to the ranks in Table
4.
4 TABLE 4 No. of particles as foreign material Results 0-2 AA 3-5 A
6-10 B 11 or more F
[0058] [Evaluation of Degradation of the Lay-On Roll]
[0059] Regarding degradation of the lay-on roll 13, it was checked
whether cracks had occurred in the lay-on roll 13 after the use for
one month. It was also checked whether the belt-shaped failure had
occurred in the film roll 12 after the use of the lay-on roll 13
for six months. Evaluation was conducted according to the existence
or lack of the cracks and the belt-shaped failure. Note that the
evaluation of the ozone degradation of the rubber was according to
JIS K6259 in conditions of the ozone density of 50 pphm (parts per
hundred million), temperature of 40.degree. C., and exposure time
of 48 hours. However, in the process of the present evaluation,
existence or lack of cracks was evaluated after the use for one
month. Note that the preference is higher when no cracks and no
belt-shaped failure occurs.
[0060] [Total Evaluation of the Film Roll]
[0061] The film roll 12 according to Examples 1 and 2 and
Comparative examples 1, 2 and 3 was observed and evaluated for the
above-described items, to obtain the following results.
5 TABLE 5 Comp. Comp. Comp. Ex. 1 Ex. 2 Ex. 1 Ex. 2 Ex. 3
Electrification A AA F AA A Tightness in winding A A A B F Sinking
failure A A A B F Black belt-shaped None None None Found None
failure Deposition of A A F A A foreign material Degradation of the
None Found Found Found -- lay-on roll
[0062] In Example 1, good results were obtained for all of the
items of the evaluation. In Example 2, the lay-on roll was
degraded. The black belt-shaped failure occurred after the long
use. However, it is concluded that the film roll 12 can be formed
by Example 2 if the long use is avoided. In contrast, no good
results for the film roll 12 were obtained from Comparative
Examples 1-3.
[0063] Although the present invention has been fully described by
way of the preferred embodiments thereof with reference to the
accompanying drawings, various changes and modifications will be
apparent to those having skill in this field. Therefore, unless
otherwise these changes and modifications depart from the scope of
the present invention, they should be construed as included
therein.
* * * * *