JPH0717499Y2 - Ink ribbon for dot impact printer - Google Patents

Description

[Detailed Description of the Invention] (Industrial field of application) The present invention relates to an ink ribbon for a dot impact printer with less occurrence of "high spots", and more specifically, local printing printed on a recording paper by a dot impact printer. The present invention relates to a cloth ink ribbon in which the occurrence of spots or "high spots" is suppressed.

(Conventional technology and problems) Ink ribbons for dot impact printers used for printing on word processors, personal computers, etc.
Thin fabrics composed of fibers such as silk, polyester and polyamide are generally used, but polyamide-based strong fibers are mainly used as the material from the viewpoints of printing durability, printing clarity and ink impregnation. It is used.

However, when ink ribbons made from these conventional fabrics as base materials are stored in an ink ribbon cassette container and printed with a dot impact printer, there are some differences, but "high spots" occur. It is the current situation.

The phenomenon of "high spot" caused by this printing is a phenomenon that the ink adhesion density of the portion printed on the recording paper by the dot impact printer locally increases.
With the recent increase in supported character types used in word processors and personal computers or the addition of computer graphic functions, the object of printer display has been expanded from simple characters to figures, images, etc., which is becoming a problem.
The mechanism of occurrence of this "high spot" is considered as follows. That is, the cloth ink ribbon holds the ink inside the voids formed by the gaps between the filaments forming the warp and the weft of the fabric used as the base material, but the ink ribbon 1 is a dedicated cassette case. When it is housed in the inside of the No. 2, as shown in FIG. 1, it is in a state of being folded in multiple layers in the length direction. At this time, in the folded peaks and valleys, that is, in the bent portions 3 and 4 of the ink ribbon, a structural difference occurs between the inside and the outside of the folded warp. That is, on the inner side of the warp, the ink holding void is compressed and the outer side is expanded as described above.

Further, the weft yarns that are in contact with the folded inner side of the warp yarns are also clamped by the warp yarns, so that the ink holding gap is compressed. In the portion thus bent, the compression phenomenon of the ink holding gap occurs, so that the ink held inside is pushed out to the ribbon surface. The ink extruded on the surface has a weaker binding force with the ribbon as compared with when it is held inside, so that the ink is easily transferred from the ribbon to the recording paper during printing, so that the ink adhesion density of the recording paper is increased.

In order to solve these problems, the structure of the ink ribbon, the fluidity of the ink, the structure of the ribbon cassette case, the adjustment of the printing pressure of the printer, recording paper, etc. have been devised. No satisfactory solution has been found so far.

(Problems to be solved by the device) The object of the present invention is to use the printer, ink, ribbon cassette case, and recording paper that have been used in the past as they are, to reduce the occurrence of "high spots" as much as possible. The purpose of the present invention is to provide an ink ribbon. As a result of studies by the present inventors, it is extremely effective to control the elongation of the warp direction of the ink ribbon and the crimp angle of the warp under no stress so as to fall within a certain range. The inventors have found that the above problems can be solved, and arrived at the present invention.

(Means for Solving Problems) In the present invention, the elongation L (%) in the warp direction at room temperature is 12 ≦ L ≦ 25 under the load of 1 g / d (gram / denier) per warp in the same direction. , And a woven fabric having a crimp angle θ of 105 ° ≤ θ ≤ 115 ° in the woven fabric cross section parallel to the warp, and cut into a narrow tape shape so that the warp direction becomes the longitudinal direction. Ink ribbons for dot impact printers, which are obtained by impregnating ink.

The reason why the "high spot" can be remarkably suppressed by controlling the elongation of the ribbon in the warp direction and the crimp angle of the warp within the above ranges in the ink ribbon according to the present invention is considered to be as follows. . That is, the elongation in the warp direction is the filament yarn 1 which constitutes the warp
It is closely related to the ink-holding volume formed by the gaps between the individual threads, and a large elongation rate when the number of filaments per thread is constant indicates that the threads are well dispersed. Such threads also increase the ink retention voids.

As a warp dispersion state necessary to prevent “high spots”, the elongation rate L of the ink ribbon in the warp direction is the warp 1
At a load of 1 g / d per line, it is desirable to correspond to at least 12% or more, and preferably to 15% or more. However, if the elongation exceeds 25%, the durability as an ink ribbon is lost, which is not preferable.

The crimp angle of the warp is related to the degree of compression of the ink holding space when the ink ribbon is bent in the longitudinal direction, and when the curvature of bending is constant, the smaller the crimp angle of the warp, the more the bent portion is formed. Since the length of the warp yarn and the number of weft yarns increases, the bending stress is dispersed and the degree of compression of the ink holding void becomes small.

From this point of view, the crimp angle θ has a great influence in order to prevent the “high spot” and has a remarkable effect in the range of 105 ° ≦ θ ≦ 115 °. Further, even if the angle is less than this value, the "high spot" can be prevented, but in the case of θ <105 °, the density of the weft becomes high and the strength is improved, but the printing sharpness becomes poor, which is not preferable.

Thus, by controlling both the elongation in the warp direction and the crimp angle of the warp within the range of the present invention, an effect not seen in conventional products can be obtained.

Conventionally, there has been no study on the elongation of the ribbon in the warp direction and the crimp angle of the warp, but even if these are measured for conventionally known ink ribbons, they do not satisfy the scope of the present invention. Absent.

The processing conditions for satisfying the elongation in the warp direction and the crimp angle of the warp within the scope of the present invention to obtain the ink ribbon with less generation of high spots are the scouring and heat setting methods which are usually carried out on fabrics. Even if it is applied, no good result is obtained, and it is necessary to take measures to disperse the yarns constituting the fabric positively while preventing tension from being exerted in the longitudinal direction as much as possible during the scouring treatment. Examples include a method using a flow treatment machine, a treatment using a relaxer, and a dry heat relaxation treatment.

Further, during heat setting, it is necessary to perform treatment while applying overfeed in the longitudinal direction of the fabric, which is higher than the conditions used for normal heat treatment.
% Is preferred.

In any case, in order to obtain an ink ribbon satisfying the scope of the present invention, it is necessary to select various processing conditions so as to meet them. Those individual conditions vary depending on the type of material, the processing means, the processing apparatus, etc., but it is easy for a person skilled in the art to select the processing conditions suitable for the given range of the present invention.

As the thread material, conventionally used polyester, polyamide and the like can be appropriately used, but polyamide-based strong fiber is particularly preferable.

Hereinafter, the present invention will be described in detail based on embodiments, but the present invention is not limited to the following embodiments without departing from the gist thereof.

Example 1 Using warp and weft single filament 34 filaments, total fineness 40 denier, cutting strength 8g / d strong nylon 66 filament yarn, warp density 210 yarns / inch, weft yarn density 113 yarns / inch, weaving width 128cm Weaving into a plain woven fabric, spreading and giving a sufficient kneading effect, relax scouring and desizing at 70 ° C, and heat setting at 180 ° C with an overfeed rate of 10%, warp density 209 yarns / inch, weft yarn Finished to a density of 125 pieces / inch and a width of 127 cm. Next, using this woven fabric as a base fabric, the length of the warp direction was set to 13 mm, and the fabric was cut into a width of 13 mm and impregnated with a normal ribbon ink to prepare an ink ribbon.

The warp elongation L of this ink ribbon is per warp
At a load of 1 g / d (8.36 kg / inch), L = 14.7%, and the crimp angle θ of the warp was 110 °. The crimp angle θ of the warp is 10 pieces of the cross section of the ribbon before being impregnated with ink, which is clathrated and solidified with a transparent resin and cut by a microtome in a direction parallel to the warp of the ribbon to form a thin-layer cross section. Was taken with an optical microscope, measured by photographic analysis, and arithmetically averaged.

Comparative Example 1 Using the nylon 66 filament yarn used in Example 1 above, a plain weave fabric having a warp density of 197 yarns / inch, a weft density of 120 yarns / inch, and a weaving width of 145 cm was woven and subjected to normal relaxing scouring and desizing. , Heat set, warp density 206 yarns /
Inch, weft density: 124 threads / inch, 140 cm width finished. Using this woven fabric as a base fabric, the fabric was cut in the same manner as in Example 1 and impregnated with ink to prepare an ink ribbon.

The warp elongation L of this ink ribbon is per warp
At a load of 1 g / d, L = 8.6, and the crimp angle θ of the warp was 120 ° C. The structure of the obtained ribbon was almost the same as that of a commercially available ink ribbon.

Comparative Example 2 The ink ribbons stored in the commercially available printer ribbon cassette GRN-01 (manufactured by Mitsubishi Pencil) for NEC personal computers were compared with those obtained in Example 1 and Comparative Example 1.

The commercially available ink ribbon was composed of warp and weft yarns each having 34 filaments and a total fineness of 40 denier, a strong nylon 66 filament yarn, and a warp density of 211 yarns / inch,
A plain weave with a weft density of 125 threads / inch.

The rate of impregnation with the ribbon was 25%, and the elongation L of the warp and the warp crimp angle θ were L = 13.3% and θ = 11, respectively.
It was 5 °.

The ink ribbons obtained in the above Example 1 and Comparative Example 1 were adjusted so that the ink impregnation rates with respect to the ribbon ink were 20%, 25%, and 30%, respectively, and the commercial sample obtained in Comparative Example 2 was also added to the personal computer. Print evaluation was performed using a printer of ^# N5200-05 (NEC). The evaluation results are shown in Table 1. The ink ribbon according to the present invention has a remarkable effect of preventing high spots as compared with the ink ribbon prepared in the comparative example and the commercially available products.

The numerical values in Table 1 are density ratios calculated by the following equation using whiteness (L value) obtained by spectrally measuring the printed portion.

[Brief description of drawings]

FIG. 1 is a schematic view showing a state where the ink ribbon is stored in a cassette case, and FIG. 2 is a schematic view showing a cross section parallel to the warp of the ink ribbon. 1 ... Cassette case, 2 ... Ink ribbon, 3 ... Ink ribbon upper bent portion, 4 ... Ink ribbon lower bent portion, .theta .... Crimp angle.

Claims (1)

[Scope of utility model registration request] 1. An elongation L (%) in the warp direction at room temperature is 12 ≦ L ≦ 25 at a load of 1 g / d per warp in the same direction.
And in the cross section of the woven fabric parallel to the warp, the crimp angle θ of the warp is 105 ° ≤ θ ≤ 115 °, and the tape has a narrow width so that the warp direction is the longitudinal direction. An ink ribbon for a dot impact printer, which is cut into pieces and impregnated with ink.