JP2005077321A - Evaluation method of folding aptitude of sheet-shaped material and measuring device used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method applicable even to a sheet-shaped material to which ruled line processing is applied, and capable of evaluating properly folding aptitude from a practical side view. <P>SOLUTION: A rotation moment when the sheet-shaped material is folded up to a designated angle selected in the range of 90°-180° at the folding position set within the surface of the sheet-shaped material is measured, and a repulsion angle of a packing material when a constant rotation moment smaller than the rotation moment when folding the material up to the designated angle is applied continuously to the sheet-shaped material folded up to the designated angle is measured, and the folding aptitude of the sheet-shaped material is evaluated based on the measured rotation moment and repulsion angle. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for evaluating the bendability of a sheet-like material such as paperboard and a measuring apparatus for use in the method.

  It is frequently performed to process a packaging material by bending a sheet-like material such as paperboard. In order to bend a sheet-like material at a specific position, ruled lines such as a line push, a half cut, and a sewing line are often processed in advance or in combination in advance. It is empirically known that, in order to improve the bendability of the ruled line, it is desirable that the packaging material itself has a high bending rigidity (bending stiffness) and that the ruled line should have an appropriate bending rigidity.

  As a method for evaluating the bending rigidity of the packaging material itself, a Taber stiffness test method defined in JIS P-8125 is generally known. On the other hand, there is no fixed evaluation method for ruled line processing. In ruled line processing, there are many control factors that can be intentionally controlled, such as the depth of the line pushing, the half cut depth, and the sewing machine line pitch. Therefore, it is necessary to establish an appropriate evaluation method for the ruled line processing.

  Therefore, it is conceivable to apply the above Taber stiffness test to the evaluation of ruled line processing. However, the Taber stiffness test is a test method in which a repulsive force due to elastic deformation when a test piece having a width of 38 mm and a length of 70 mm is bent by an angle of 15 ° is measured and converted into a bending moment. The test piece must be uniform, and is unsuitable for plastic deformation from a ruled line such as half-cut or streak and to evaluate the processing state.

  When the ruled line processing is half cut, if the packaging material is paperboard, only the half cut layer is peeled off with a finger, and the thickness of the remaining portion (so-called remaining thickness) is measured with a micrometer or dial gauge. The method is known. However, it is common to make multiple layers of paperboard. For example, in the case of a circular net method, 3 to 9 layers are combined according to the paper thickness. For this reason, this method has a problem that accuracy is lacking because a place where peeling easily occurs is determined. In addition, when the packaging material is other than paperboard (for example, a resin sheet), this method cannot be used.

On the other hand, in order to be able to bend a sheet-like material smoothly when producing a finished product, the sheet-like material is preliminarily folded in advance and developed into an original state. Paperboard that is difficult to fold has a large repulsion to return to its original state when folded for temporary folding. For this reason, when evaluating the bendability of a sheet-like material, it is necessary to consider not only the force required for temporary folding but also the degree of repulsion after temporary folding.
JIS P-8125

  As described above, conventionally, there has been no method for appropriately evaluating the bendability of a sheet-like material. Therefore, the present invention has an object to provide a method that can be applied even to a sheet-like material subjected to ruled line processing, and that can appropriately evaluate bending suitability from a practical side. And It is also an object of the present invention to provide an apparatus that can be used to carry out this method. In particular, it is possible to measure the rotational moment required to bend sheet-like materials, measure the repulsion angle under a certain rotational moment smaller than the rotational moment, and measure the mechanical resistance of the measuring system with simple operations. The object is to provide a possible device.

  As a result of intensive studies, the present inventor has found that the object can be achieved by the present invention having the following configuration.

  The present invention measures the rotational moment when the sheet material is bent to a specified angle selected within the range of 90 ° to 180 ° at the bending position set in the plane of the sheet material. Measure the repulsion angle of the packaging material when applying a constant rotation moment smaller than the rotation moment when bending to the specified angle to the sheet material bent at an angle, and the measured rotation moment and repulsion angle It is the evaluation method of the bendability of a sheet-like material characterized by evaluating the bendability of a sheet-like material based on this. In the evaluation method of the present invention, for example, the rotational moment applied to the sheet material when measuring the repulsion angle can be selected so that the repulsion angle is in the range of 5 ° to 90 °.

  The present invention also measures the rotational moment and repulsion angle when a specific type of sheet-like material is bent at a specified angle by the above method, and previously obtains a relational expression between the rotational moment and the repulsion angle based on the measurement result. In addition, the rotational moment when a new sheet-like material is bent at a specified angle is measured, the repulsion angle is calculated from the relational expression, and the new repulsion angle is calculated based on the measured rotational moment and the calculated repulsion angle. There is also provided a method for evaluating the bendability of a sheet-like recording material, characterized by evaluating the bendability of a sheet-like material.

  Moreover, the present invention measures the maximum bending moment and Taber stiffness (JIS P-8125) of a sheet-like material, and evaluates the ratio (maximum bending moment / Taber stiffness) of the sheet-like material. A method for evaluating the bending aptitude is also provided. For example, a sheet-like material having a ratio (maximum bending moment / Taber stiffness) in the range of 0.3 to 1.5 can be evaluated as being suitable. Examples of the sheet-like material to be measured according to the present invention include paperboard and packaging materials.

  Furthermore, the present invention provides a clamp for pressing and fixing the vicinity of a fold line of a sheet-like material, an arm fixed to a rotatable rotating shaft, and a fixing for fixing one end of the sheet-like material installed on the arm. There is also provided a measuring apparatus for performing the above-described evaluation, characterized by having a power mechanism for applying moment to the rotating shaft. The apparatus of the present invention includes a transmission pulley fixed to the rotating shaft, a weight A that applies a moment that is hung on the transmission pulley and rotates the bending arm in the folding direction, and a folding arm that is hung on the transmission pulley and that extends the folding arm. The weight B that gives the moment to rotate, the mechanism that can act and release the rotational moment in the deployment direction by the weight B, the moment that rotates the bending arm in the folding direction can be given, and the moment is adjusted and measured You may have further the moment adjustment mechanism which can be performed. In the apparatus of the present invention, for example, the moment adjusting mechanism can apply a rotational moment to the bending arm through a thread on which the weight A is suspended. The apparatus of the present invention may have a bed for placing the sheet-like material, and the clamp may fix the sheet-like material by pressing the sheet-like material toward the bed. .

  According to the method for evaluating the bendability of a sheet-like material of the present invention, the bendability can be appropriately evaluated from a practical side. Moreover, the evaluation method of the bendability of the sheet material of the present invention can also be applied to the evaluation of the sheet material subjected to ruled line processing.

  Moreover, if the apparatus of this invention is used, the measurement required for said evaluation can be performed. In addition, the measurement of the rotational moment necessary for bending the sheet-like material, the measurement of the repulsion angle under a constant reverse rotational moment, and the measurement of the mechanical resistance of the measurement system can be performed with simple operations.

BEST MODE FOR CARRYING OUT THE INVENTION

  Below, the evaluation method of the bendability of the sheet-like material of this invention and the apparatus used for it are demonstrated in detail. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

  The evaluation method of the present invention measures a rotational moment when the sheet material is bent to a specified angle selected within a range of 90 ° to 180 ° at a bending position set in the plane of the sheet material. Step (first step), a step of measuring the repulsion angle of the packaging material when the sheet-like material bent at the specified angle is continuously subjected to a rotation moment smaller than the rotation moment when bent to the specified angle ( (2nd process), It has the process (3rd process) which evaluates the bendability of a sheet-like material based on the rotational moment measured at the 1st process, and the repulsion angle measured at the 2nd process. .

  The sheet-like material to be evaluated in the present invention is a material premised on bending, and other conditions are not particularly limited as long as the shape is sheet-like. For example, a paperboard for making a packaging box for storing a photosensitive material can be exemplified. The material is not limited to the papermaking material, but may be synthetic paper. Moreover, the evaluation method of the present invention is particularly preferably applied to the evaluation of a sheet-like material in which a ruled line is processed at the bending position. As the ruled line processing, there are a line push, a half cut, a sewing line, and the like, and a combination of these may be used. The bending position is determined according to the shape of the finished product.

  In the first step, the unfolded sheet-like material is bent to a specified angle selected within a range of 90 ° to 180 ° at the bending position. The angle here is an angle at which the sheet-like material in the folded portion has moved, and is 0 ° before folding. The designated angle is preferably 110 to 160 °, more preferably around 150 °. The bending is preferably performed at a constant speed, that is, an angular speed, that is, a tensioning / measuring mechanism. Also, care should be taken that the bending speed does not vary greatly depending on the measurement target to be compared. Further, the rotational moment may be applied by pulling only the end portion of the sheet-like material in the rotational direction, or may be applied by pulling the entire part to be bent.

  The rotational moment when bent to a specified angle can be measured by a method such as reading a power display attached to a power mechanism that gives the rotational moment. Specifically, it can be performed by measuring the tensile force of a tension / measuring mechanism incorporated in an apparatus to be described later.

  In the second step, the repulsion angle of the packaging material is measured when the sheet-like material bent at a specified angle is continuously applied with a rotation moment smaller than the rotation moment when bent to the specified angle. The repulsion angle here refers to an angle that returns from a specified angle by repulsion. Therefore, for example, when it is bent to 150 ° in the first step and then returned to 100 ° in the second step, the rebound angle is 50 °.

  The rotational moment applied in the second step is desirably selected so that the repulsion angle is within a range of preferably 5 to 90 °, more preferably 10 to 80 °, and still more preferably 10 to 70 °. The method of applying the rotational moment in the second step is not particularly limited, but it is preferable to reduce the rotational moment in the first step in a short time to such an extent that no impact is applied to the measurement target. Also, care should be taken that the method of applying the rotational moment in the second step does not change greatly depending on the measurement object to be compared. When the rotational moment is applied by pulling only the end portion of the sheet-like material in the rotational direction in the first step, the rotational moment can be applied by pulling only the end portion with a small force in the rotational direction also in the second step. preferable.

  In the third step, the bendability of the sheet-like material is evaluated based on the rotational moment measured in the first step and the repulsion angle measured in the second step. A specific method of evaluation can be appropriately determined based on an empirical rule or physical calculation. An evaluation calculation formula using two measured values may be created to quantify the evaluation.

  The evaluation criteria for the third step differ depending on the mechanism and driving environment of the device used when folding the sheet-like material, the usage mode of the finished product manufactured by folding, the usage purpose, the usage environment, the inclusions, etc. is there. For example, a sheet-like material that is within an acceptable range in one particular folding device may be outside an acceptable range with another folding device. Therefore, it is preferable to determine the evaluation criteria for the sheet-like material individually.

  In addition, a plurality of specific types of sheet-like materials are prepared, the first step and the second step are performed for each sheet-like material, the rotational moment and the repulsion angle are measured, and the relational expression between the rotational moment and the repulsion angle from the obtained data. May be obtained in advance. As described above, if the relational expression between the rotational moment and the coefficient of restitution is obtained in advance for a specific type of sheet-like material, the first step is performed when it is necessary to evaluate the bendability of a new sheet-like material of the same type. There is an advantage that it can be evaluated only by measuring the rotational moment by. That is, if the value of the rotational moment obtained in the first step is used, the repulsion angle can be calculated from the relational expression obtained in advance, so that the bending aptitude can be easily evaluated by one measurement. it can.

  In another evaluation method of the present invention, the maximum bending moment and Taber stiffness of the sheet-like material are measured, and the ratio (maximum bending moment / Taber stiffness) is evaluated. Taber stiffness is performed according to JIS P-8125. The maximum bending moment is measured using a test piece having the same size as that used for the Taber stiffness. The maximum bending moment refers to the maximum value of the rotational moment required to bend the specimen to a specified angle. The bending is preferably performed at a constant speed, that is, an angular speed, that is, a tensioning / measuring mechanism.

  The evaluation standard for the ratio (maximum bending moment / Taber stiffness) is also produced by bending the mechanism and driving environment of the apparatus used for folding the sheet-like material, similarly to the evaluation standard in the third step. It differs depending on the usage mode, usage purpose, usage environment, inclusion, etc. of the finished product. For example, the ratio (maximum bending moment / Taber stiffness) is 0.3 for a packaging material (a contact ball) used to directly store an aggregate of sheet-like photosensitive materials such as heat-developable image recording materials and heat-sensitive recording materials. It is preferable to use a sheet-like material of ˜1.5. More preferably, it is 0.5-1.2, Most preferably, it is 0.7-0.9.

  Below, the apparatus which can be used when implementing the evaluation method of this invention is demonstrated. FIG. 1 is a perspective view showing an embodiment of the apparatus of the present invention, and FIG. 2 is a cross-sectional view seen from the direction A in FIG. In this apparatus, the sheet-like material 1 is placed on the bed 3 in a state before being folded. On the upper surface of the sheet-like material 1, a pressing plate 7 is installed so as to cover up to the vicinity of the bending position 5, and these are fixed by a clamp 9. As shown in FIG. 2, the end portion of the sheet material not covered with the pressing plate 7 is sandwiched between the fixing portions 13 of the bending arm 11. The bending arm 13 is fixed to a rotating shaft 15 that is rotatably supported and has a weight balance, and moves in the circumferential direction of the rotating shaft as the rotating shaft 15 rotates. The rotating shaft 15 passes through the cylindrical body 19 fixed to the pedestal 17 in a rotatable state. A transmission pulley 21 is installed at the end of the rotary shaft 15, and a weight A 23 and a weight B 25 are suspended from the transmission pulley 21 via a thread 27. Further, a tension / measuring mechanism 29 capable of giving a rotational moment and measuring can be connected to the tip of the weight A23 by a thread 27.

  In this apparatus, the weight A23 gives a rotation moment so as to rotate the bending arm 11 in the direction in which the sheet-like material 1 is bent at the bending position 5. Further, the weight B25 gives a rotational moment so as to rotate the sheet-like material 1 in the opposite direction (deployment direction). This device is provided with a mechanism (not shown) that can act and release a rotational moment in the deployment direction by the weight B25. For example, the weight B25 and the thread 27 may be detachable (for example, a hook), or a stand on which the weight B25 is placed and the weight B25 is placed on the stand as needed. The rotational moment in the direction may not be applied.

  The tension / measuring mechanism 29 can control the rotational moment and the movement of the bending arm by appropriately adjusting the tensile force applied to the thread 27 connecting the weight A23 and the weight B25. In order to facilitate the calibration described later, the weight B25 is preferably heavier than the weight A23. For example, the weight of the weight B25 can be 100 g, and the weight of the weight A23 can be 50 g.

  In order to perform measurement using such an apparatus, first, the sheet-like material 1 is fixed by the clamp 9 and the fixing portion 13 without being bent. Next, in a state in which the rotational moment in the unfolding direction by the weight B does not act, the tensile / measuring mechanism 29 applies the rotational moment at a constant speed and bends to a specified angle selected within the range of 90 ° to 180 °. The rotational moment is obtained from the tensile force of the tensile / measuring mechanism 29 at the time of bending to the specified angle. Next, the tensile force applied to the sheet-like material 1 is reduced by reducing the tensile force of the tension / measuring mechanism 29. The repulsion angle of the sheet-like material 1 at this time is measured. By the above operation, the rotational moment when bent to the specified angle and the repulsion angle when the rotational moment is reduced can be obtained. As described above, when the apparatus of the present invention is used, the rotational moment and the repulsion angle can be obtained continuously and easily using a single mechanism. Note that this measurement may be performed in a state where a rotational moment in the deploying direction by the weight B acts.

  The maximum bending moment can be measured in the same manner. That is, the sheet-like material 1 is fixed by the clamp 9 and the fixing portion 13 without being bent. Next, a rotation moment is applied at a constant speed by the tension / measuring mechanism 29 and the rotation is rotated until the rotation amount reaches a specified angle. The maximum rotational moment applied at this time is obtained from the tensile force of the tension / measuring mechanism 29.

  In the apparatus of the present invention, since the weight A23, the weight B25, and the tension / measuring mechanism 29 are interlocked via the thread 27, the calibration can be easily performed. At the time of calibration of the measurement accuracy, a state in which a rotational moment by the weight B in the developing direction is applied. Then, the tensile force by the tension / measuring mechanism 29 is made zero, and the rotational moment by the weight B25 is made larger than the rotational moment by the weight A23. At this time, the tensile force due to the difference between the weight of the weight B25 and the weight of the weight A23 is applied to the tension / measurement mechanism 29. Calibration can be performed by checking the difference between the tensile force and the tensile force recognized by the tension / measuring mechanism 29.

  As described above, according to the apparatus of the present invention, necessary measurement and calibration can be performed very easily. In addition, since the mechanism is not complicated, the apparatus can be manufactured at low cost and maintenance is easy. Furthermore, it can be widely applied to various sheet-like materials and can also be automated.

  As mentioned above, although one Embodiment of the apparatus of this invention was described, this invention can take various embodiment besides this. For example, the rotational moment for bending may be applied only by the tension / measuring mechanism 29 without using the weight A23. Further, without using the weight A23 or the weight B25, a second tension mechanism may be installed at the tip of the thread 27 on the weight B25 side, and the rotational moment may be applied by the two tension mechanisms. Further, the fixing portion 13 of the bending arm 11 may fix most of the sheet-like member 1 to be bent. Other modifications and design changes apparent to those skilled in the art are also included in the scope of the present invention.

  The method and apparatus for evaluating the bendability of a sheet-like material according to the present invention can be used to widely evaluate various types of sheet-like materials. In particular, the method and apparatus for evaluating the bendability of a sheet-like material according to the present invention can be applied to the evaluation of a sheet-like material that has been subjected to ruled line processing, and therefore has high industrial applicability.

It is a perspective view which shows the one aspect | mode of the apparatus of this invention. It is sectional drawing seen from the A direction in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sheet-like material, 3 beds, 5 bending position, 7 holding plate, 9 clamp 11 bending arm, 13 fixed part, 15 rotating shaft, 17 base, 19 cylindrical body 21 transmission pulley, 23 weight A, 25 weight B 27 thread 29 tension / measuring mechanism

Claims (11)

  Measure the rotational moment when the sheet material is bent to the specified angle selected within the range of 90 ° to 180 ° at the bending position set in the plane of the sheet material, and bend to the specified angle. The sheet material is measured for the repulsion angle of the packaging material when a constant rotation moment smaller than the rotation moment when bent to the specified angle is applied, and the sheet is measured based on the measured rotation moment and the rebound angle. A method for evaluating the bendability of a sheet-like material, comprising evaluating the bendability of a sheet-like material.   The evaluation method according to claim 1, wherein the rotational moment applied to the sheet-like material when measuring the repulsion angle is selected so that the repulsion angle is within a range of 5 ° to 90 °.   A rotational moment and a repulsion angle when a specific type of sheet-like material is bent at a specified angle by the method according to claim 1 or 2 are measured, and a relational expression between the rotational moment and the repulsion angle is calculated in advance based on the measurement result. In addition to measuring the rotational moment when a new sheet-like material is bent at a specified angle, the repulsion angle is calculated from the above relational expression, and the repulsion angle is calculated based on the measured rotational moment and the calculated repulsion angle. A method for evaluating the bendability of a sheet-shaped recording material, comprising evaluating the bendability of a new sheet-shaped material.   Measure the maximum bending moment and Taber stiffness (JIS P-8125) of sheet-like material, and evaluate the ratio (maximum bending moment / Taber stiffness) of the sheet-like material. Method.   The evaluation method according to claim 4, wherein a sheet-like material having a ratio (maximum bending moment / Taber stiffness) within a range of 0.3 to 1.5 is evaluated as being appropriate.   The method for evaluating the bendability of a sheet-like material according to any one of claims 1 to 5, wherein the sheet-like material is a packaging material.   The method for evaluating the bendability of a sheet-like material according to any one of claims 1 to 5, wherein the sheet-like material is paperboard. Clamp for pressing and fixing near the folding line of sheet-like material,
An arm fixed to a rotatable rotating shaft; a fixture for fixing one end of a sheet-like material installed on the arm;
The measuring apparatus for performing evaluation according to any one of claims 1 to 3, further comprising a power mechanism that applies a rotational moment to the rotating shaft.   A transmission pulley fixed to the rotating shaft, a weight A that provides a moment for rotating the bending arm in the bending direction suspended from the transmission pulley, and a moment for rotating the bending arm that is suspended in the transmission pulley in the unfolding direction. The weight B, a mechanism capable of acting and releasing a rotational moment in the deploying direction by the weight B, and a tension / measuring mechanism capable of giving a moment for rotating the bending arm in the bending direction and measuring the moment. The measuring apparatus according to claim 8, wherein   The measuring apparatus according to claim 9, wherein the tension / measuring mechanism applies a rotational moment to the bending arm through the thread on which the weight A is suspended. The sheet-like material according to claim 8, further comprising a bed for placing the sheet-like material, wherein the clamp fixes the sheet-like material by pressing the sheet-like material toward the bed. The measuring apparatus according to item 1.

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