JPH04116461A - The method and equipment for testing a paper - Google Patents

Abstract

PURPOSE: To measure the characteristics of a paper easily and quickly by applying a specified quantity of a liquid onto a film, moving a pallet at a constant pressure and speed on a sample while keeping a constant angle and then measuring the track of the liquid. CONSTITUTION: A plurality of liquid droplets are dripped onto a film 30. After the positions of the droplets are settled at 92, 94, 96, a dispenser 44 is shifted to the left and right. A motor 20 is then operated to drive chains 16, 18 and a spreading rod 60 is moved in the direction of an arrow 72. A pallet 74 is thereby moved to spread the droplets of ink 92, 94, 96 from the film 30 through an edge part 31 onto the surface of a sample 32. Consequently, liquid tracks 98, 100, 102 are formed and the operation is continued until the liquid tracks 98, 100, 102 disappear. Subsequently, the length of the ink track is measured using a measuring rod 84 and a similar test is performed for the opposite surface after turning down the sample 32. Information is obtained for the opposite sides and the characteristics of a paper, e.g. ink hold-out characteristics, opacity, opposite side characteristics, are measured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for testing paper. More specifically, the present invention provides a method for applying a preselected amount of test fluid 1 u.
id) on the paper surface.
down) test.

[Background of the Invention] As is well known, the color spreading test is a method in which an ink droplet or (J ink film) is stretched out on the paper surface and the area colored by the ink is examined to determine the properties of the paper.

These tests are often used by printing presses or ink manufacturers to formulate printing inks, but they are also used to examine the properties of paper.

As an advantage of this color development test, vapor mill (papel”
The advantages include that it can be carried out at the time of setting (m1ll), that it is low cost, and that the test time is short. However, since the evaluation is done visually,
There is a disadvantage of lack of reproducibility, and there is a problem in terms of test accuracy.

In TAPPI Journal, April 1989, pp. 81-83, T.C. and Panya published a document entitled "Predicting the printing quality of newsprint," which describes the printing suitability index (prjntabil) using a type of color spread test.
ity j, index) is described.

The test method described in this document involves adding an excess of ink with an average optical density of about 1 onto a piece or film of mylar (to avoid premature absorption of the ink into the paper). ), then a steel spatula (steel bl, ad
e) from the Mylar film onto the paper sample to be tested. After the ink-stretched paper sample has dried, image analysis is performed using a video camera and computer to determine the average optical density and print spot count.
The evaluation is made by determining the t mottle number).

As described above, the method of using a color development test to check printing suitability, that is, the current printing point, is a fairly complicated method.
It requires sophisticated and expensive equipment and requires a considerable amount of time for testing.

For this reason, there is a strong demand for a method that can quickly and reliably perform quality control at the vapor mill site regarding printing suitability.

As a commercially available small press for laboratory use, the trade name is IGT.

There are products sold by PRUFBAU, GFL, and many others, but these have practical disadvantages such as high cost, operator skill, and long testing time.

[Object of the invention] The present invention is aimed at improving the ink holdout characteristics of paper.
The purpose of the present invention is to provide a simple, quick, and easy-to-understand test method that is useful for predicting lcl-out characteristics.

SUMMARY OF THE INVENTION In its broadest sense, the present invention relates to a method for testing paper.
(uid droplet) A predetermined amount of liquid is applied onto the film, and a blade or spatula is moved at a substantially constant pressure and velocity while maintaining a constant angle to the film to arch the droplet from the film onto the sample. Stretch it out to form a liquid trail, continue moving the spatula until the droplet disappears and there is no more liquid trail, measure the length of the liquid trail, and use the measured length to determine the ink retention of the paper or This is defined as the ink holdout characteristic.

Preferably, when applying multiple portions of the liquid to the film, all approximately the same amount is applied to the film at regular intervals along a straight line approximately perpendicular to the direction of movement of the spatula, so that each droplet formed is It is desirable to measure the length of the liquid trail and average the measured lengths.

The present invention relates to a paper testing device comprising: a flat support surface supporting a substrate of a sample to be tested; an impermeable film disposed overlying a portion of the sample; dispenser means for dispensing a preselected amount of liquid onto the film; and a predetermined amount of droplets.
a metering pump means for supplying a controlled amount of liquid to the dispenser means, and a draw-down bar equipped with a spatula means, for making plets;
means for moving the drawing rod from the starting position; the spatula means is arranged on the side of the surface on which the droplets are to be applied onto the film, and the spatula means is arranged to stretch the droplets from the film along the sample surface and onto the sample. This makes it possible to create liquid trails from droplets.

Preferably, the test device includes means for measuring the length of the elongated liquid trail.

The dispenser means includes an outlet and mounting means for dispensing a plurality of liquids at regular intervals along a line perpendicular to the direction of movement of the drawing rod, the drawer being moved in a direction substantially perpendicular to the direction of movement of the drawing rod. It is desirable to be able to apply drops.

[Description of Preferred Embodiment] In FIG. 1, the main body (12) of the testing machine (10) has a sample mount or a flat sample support surface (14).
A pair of chains (16) and (18) are arranged parallel to the axis line A-A of the sample support surface (14) at a predetermined distance. The chain is connected to a suitable motor (20
) to drive as necessary.

The chains (16) (18) are inserted into the main body (12) in parallel grooves (22) (24) formed in the main body (12).
longitudinally disposed up to the forward end (26) of. In addition,
The sample support surface (27) of the front end (26) extends from the flat support surface (14) and extends from the main body (12).
) to the front end (15).

A suitable lamp (28) is provided at the end (15) to clamp the film strip (30) and sample (32) against the surface (27). The film piece extends a small distance in the longitudinal direction from the sample (32) and its edges (
31) is preferably perpendicular to the axis A-A. (The sample (32) preferably extends over substantially the entire length of the surface (14).) That is, it is measured in the direction of the axis A-A. The film piece (30) is exposed to droplet penetration and significant flow (f) until the droplet is stretched from the film onto the sample, as described below.
low).

Above the surface (27), a lateral movement guide member (39) is disposed on the struts (34, 36) in a direction substantially perpendicular to the axis A-A of the surface (14), and the guide member A guide groove (40) is formed in. Note that the axis A-A is parallel to the moving direction of the drawing rod (60), as will be described later.

A guide member (42) is disposed in the guide groove (40) corresponding to the shape of the groove, and a dispenser (44) is connected to the guide member. The dispenser (44) has an outlet end (46) for dispensing and a trigger valve (48).
have. The dispenser (44) has a line (5
0) to a precision metering pump (52) for supplying a preselected amount of liquid (preferably water-based ink for uncoated regular newsprint) to the dispenser (44). , by actuation of the trigger button (48), dispenses from the outlet (46) of the dispenser.

The metered supply pumps are manufactured by American Dito and American Hospital Group, and are manufactured by SMI UniPump and N
The one sold under 005326 has a dispersion amount of 0.
It is designed to be able to dispense amounts of 1 to 02%. In the case of the present invention, using a 1 milliliter (ml) syringe, approximately 3
Since it supplies ~15 microliters at a time,
This pump has been found suitable for the present invention.

Due to the cooperative action of the guide groove (40) and the guide member (42), the dispenser (44) moves in a direction transverse to the axis A-A of the surface (14), as shown by the arrow (54), and reaches the high position shown in the figure. The feed and dispensing opening (46) is pivoted from the raised position to the lowered position where it approaches the film (30) as indicated by the arrow (56).
t).

The removable expansion rod (60) includes a bridge stand (62) and is mounted on a pair of supports (64) and (66) provided on three sides of the chains (16 and 18), respectively. Each of the posts (64) (66) has a foot (68) (only one shown).

(see Figure 2) and chain (16) or (18).
to connect the enlarger rod (60) with the chain. When the chain moves in the direction indicated by arrow (70), the drawing rod (60) moves parallel to axis A-A in the direction indicated by arrow (72) (see Figure 1). Of course, when comparing test results, the speed of the draw rod in each test must be substantially the same.

It has been found that the speed should be selected in the range 10-30 cm/sec.

The bridge platform (62) is bent downward and is provided with a flexible spatula or blade (74) near its free end.

When the drawing rod (60) is in engagement with the chains (1,6) (18), the action of the weight (76) causes the spatula (74) to move the surface of the film (30) and sample (32). (Which surface it abuts depends on the position of the enlarger rod (60)). Weight (76
) can be adjusted as required, with a preferred weight of approximately I kg. The direction of the spatula (74) is
It is desirable to arrange the drawing rod (60) substantially perpendicular to the direction of the axis ΔA of 4), that is, the direction of movement of the drawing rod (60).

If desired, a measuring rod (80) can also be provided on one side of the body (12) via a suitable projection (82). The measuring rod (84) is movable along the measuring rod (80) and can be pivoted downward as shown by the arrow (86) to access the upper surface of the sample (32).

Measure the liquid traces (98) (100) (1) using the measuring rod (84).
When calculating the length of 02), as described later, the edge part (31) of the film (30) is
It is important that it is aligned with the reference line shown by (90).

In order to carry out the present invention, first, an appropriate drop amount (drop
volume). Since this dripping amount can be a standard amount for all papers, a reasonable length of liquid trace (98) (100) (10
2) should be selected so as to obtain. Dripping amount is about 5
When it comes to microliters, most newsprint (news
It was found that the ink mark (print) was about 7-26 cm. In addition, in the case of paperboard (linerboard), it is desirable to increase the amount of dripping. If you want to get a long liquid trail, just increase the amount of dripping.

For example, for paperboard, the desired drop volume is 35-40 microliters. In addition, in the case of newsprint, the desired dropping amount is 4 to 10 microliters, and the more preferable dropping amount is 5 to 6 microliters.

The fluid in the form of droplets must have such fluidity, ie, viscosity, that it withstands the test and that a liquid trail is formed along its length. For this reason, it is desirable to use one selected ink when conducting the test. Note that different inks will give different results.

When trigger valve (48) is actuated, ink is pumped from metering pump (52) through line (50) to dispenser (44). As a result, a quantity of liquid (ink) is discharged through the end outlet (46) of the dispenser (44). Normally, the trigger valve (48)
triggers when the dispenser (44) is in position in the direction of the lateral force of the surface (14) and in a lowered position near the surface of the film (30).

l.riga (48) operates to drive the pump (52) iij.

The edge of the sample (32) must be under the film (30). The simplest method is to place a piece of mylar (2 mil for film element (30) (mils thick Mylar film is preferred) and clamped at one end using a clamp (28).

In FIG. 1, several drops are applied onto the Mylar piece (30), as shown at (92), (94), and (96).

When the position of the droplet is determined as (92), (94), and (96),
Move the dispenser (44) as shown. Second
In the figure, the enlarger rod is on the side of the droplet (92) (94) (96) closest to the clamp (28) and the foot (68)
are engaged with chains (16) and (18). The motor (20) is then actuated to drive the chains (16) (18) to move the enlarger rod (60) and the spatula (74) to move the ink droplets (92) (94) ( 96) from the small piece (30) through the edge (31) and onto the surface of the sumburu, (98) (100) (102
) Create a liquid trail as shown in ).

The enlarging rod (60) is moved in the direction of the arrow (72) (axis A-A), and its movement is caused by the liquid traces (98) (100).
This continues until (102) is exhausted.

The length of these ink marks can be determined using a measuring stick (8
4) Or measure using a ruler.

Flip the sample (32) over and perform a similar test on the opposite side of the sample.

The test results are shown in Figures 3 and 4.
FIG. 4 shows typical test results when a droplet is applied to one side of the same sample and the other side of the same sample is applied with a droplet. L1, L1, and L3 in FIG. 3 indicate the holdout characteristics of one side of the paper sample. Ll, Ll
It is desirable that the length L is the average of L3 and L3.

In the same way, measure the length of the liquid trace formed on the opposite side of the paper sample, average these measurements, and calculate the length of the liquid track formed on the opposite side of the paper sample.
It is desirable to set the value 1 as the holdout characteristic on the side.

In Figures 3 and 4, the liquid traces are from one test, but five liquid traces were formed on each side of each sample sheet, the test was conducted on two sample sheets, and these were used to form one test. It is preferable to use the test results for the first time.

It is of course possible to increase or decrease the liquid trace, and it is also possible to create a value of L or 1 by averaging the liquid trace.

Although testing both sides of the sample sheet is not essential to the invention, if double-sided printing is performed,
It is particularly desirable to test both sides. By forming a liquid trail on one side of the sample sheet and then forming a liquid trail on the other side of the sample sheet, information from both sides of the sample sheet is included in one sample. Similarly, by looking through a sample from one side, one can determine the liquid trace on the other side of the sample.

As mentioned above, ink holdout characteristics, opacity (
show-through), double-sided properties (two 5i
It provides a relatively simple and fairly accurate test for dedness, which can be easily carried out at the mill or print shop, and which
ed 1nk) and droplets can be used to determine the suitability of paper.

If the drop rate is accurately controlled, the length of the ink trail will be significant.

Although the invention has been described in detail, modifications can be made by those skilled in the art without departing from the scope of the invention as defined by the claims.

[Brief explanation of drawings]

Fig. 1 is a perspective view of the color spreading tester of the present invention, Fig. 2 is a partially cutaway side view showing the state when the enlarger bar is at the starting position, and Fig. 3 is a side view showing the state in which the enlarger bar is at the starting position. Figure 4 shows typical test results when applying 3 drops of ink and conducting a color spreading test. Figure 4 shows the same paper sample, applying 3 drops of ink to the other side and conducting the color spreading test again. It is a figure which shows the test result when doing. (10) Testing machine (14) (27) , , Sample support surface (16
) (18) , Chain (30) Film (39) Guide member (44) Dispenser (60) , , Stretching rod (SO) , , Measuring rod (92) (94) (96) , , Droplet (98
) (100) (102) , , , liquid trace (52
), . (84). Sample guide groove metering supply pump spatula measuring rod

Claims (8)

[Claims] (1) Place a film impermeable to liquid over the paper sample to be tested, apply at least one predetermined amount of liquid onto the film, and transfer the drop from the film onto the sample. To form a liquid trail on the sample surface by stretching it, the spatula is moved at a constant pressure and speed while maintaining a constant angle to the film until the droplet on the sample surface disappears and there is no liquid trail. A method for testing paper in which the length of the liquid trail is measured by continuing to move the spatula until the ink holdout characteristic of the paper sample is defined as the measured length. (2) When applying multiple droplets to the film, all droplets of approximately the same amount are applied onto the film at regular intervals along a straight line approximately perpendicular to the direction of movement of the spatula, and each droplet is 2. The method of claim 1, wherein the length of each liquid trail formed is measured. (3) The method according to claim 1, wherein the amount of droplets is 4 to 10 microliters in the case of newsprint. (4) The method according to claim 2, wherein the amount of droplets is 4 to 6 microliters in the case of newsprint. (5) a flat support surface for supporting a substrate of the sample to be tested; a film impermeable to liquids arranged to overlap one end of the sample placed on the support surface; dispenser means for dispensing a preselected volume of at least one drop of liquid onto the film; and metering pump means for supplying a controlled volume of liquid to the dispenser means to produce a predetermined volume of droplets; and means for moving the enlarging rod from a starting position along a substantially straight line substantially perpendicular to the spatula means, the spatula means being a means for applying droplets onto the film. paper testing device, which by its movement is able to stretch the droplet from the film along the sample surface and create a liquid trail on the sample. (6) The dispenser means includes an outlet and a mounting means for the dispenser means, and is movable in a direction substantially perpendicular to the direction of movement of the enlarger rod to move at regular intervals along a straight line substantially perpendicular to the direction of movement of the enlarger rod. 6. Apparatus according to claim 5, characterized in that it is possible to apply a plurality of droplets in one droplet. 7. The device of claim 5, wherein the spatula is flexible. 8. The apparatus of claim 5, further comprising means for measuring the length of the elongated liquid trail.