JPH07104603A - Felt for roll cleaning - Google Patents

Abstract

PURPOSE:To compatibly improve the coating capacity by an increase in the holding quantity of an offset preventive liquid in the felt for roll cleaning and improve cleanability of paper dust and toner scrap. CONSTITUTION:The fiber layer 3 on the side which comes into contact with a roll and cleans the roll of a non-woven fabric which consists of the single fiber layer obtd. by adding an improvement to the structure of non-woven fabric felt 1 is raised to a brush form by needle punching, by which the apparent density thereof is adjusted to a relatively coarse range from 0.02 to 0.1g/cc. On the other hand, the fiber layer 2 on the other side is made into the structure which has an apparent density of 0.1 to 0.9g/cc and is deuser than the fiber layer described above. The modulus of elasticity in compression of the non- woven fabric felt 1 including both fiber layers is specified to >=5%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention uses a roll for copying.
The present invention relates to an improvement in felt of a material for cleaning the roll of an apparatus that performs various processing such as printing.

[0002]

2. Description of the Related Art Conventionally, of so-called blade type and roll type, among materials which are applied to an anti-offset liquid by contact with a heating and fixing roll in an antistatic copying machine or an antistatic printer, and are cleaned. Have used various non-woven fabric materials, and needle punched non-woven fabrics made of heat-resistant fibers such as aromatic polyamide have been used for some time. Also, for example, the actual fair 3-48602
In the publication, a pulp layer is arranged on the offset prevention liquid side, a rough fiber nonwoven fabric layer is provided on the fixing roll side, and the offset prevention liquid is held by the pulp layer, and the nonwoven fabric layer exhibits coating and cleaning properties of the prevention liquid. Such an offset prevention liquid supply coating roller has been proposed.

[0003]

However, in the case where the needle-punched nonwoven fabric made of the above heat-resistant fiber is used,
The non-woven fabric has a small difference in density in the cross-sectional direction, and although the holding amount of the preventive liquid can be secured, the cleaning property is not sufficient and the coating ability is deteriorated due to paper dust or toner residue.

On the other hand, in the roller proposed in the latter, there is no description about the improvement of the rigidity due to the improvement of the fiber arrangement in the cross-sectional direction in the non-woven fabric layer to be used, and it is expected that the effect of incorporating the accumulated substance can be expected by roughening. Also, there is concern about fatigue due to use, and as a measure against fatigue, a pile-woven brush-like structure is partly used, but this type of structure does not allow the pile base fabric part to be thick due to its manufacturing method, preventing offset. There was a problem that the amount of liquid retained was poor and that the pile weave was missing.

The present invention addresses the above-mentioned situation, and in particular, by finding the difference in density in the cross section direction of the nonwoven fabric and the effective compression elastic modulus, the coating ability is improved in the roll cleaning felt by increasing the holding amount of the anti-offset liquid,
The purpose of the invention is to achieve both improvement of cleaning property of paper dust and toner residue.

[0006]

In order to achieve the above object, the present invention improves the nonwoven fabric felt structure, and in a nonwoven fabric consisting of a single fiber layer, the fiber layer on the side to be contacted with the roll for cleaning is needle punched. Brushed up by processing to give an apparent density of 0.02 g / cc to 0.1 g
/ Cc is a relatively coarse range, while the fiber layer on the other side has an apparent density of 0.1 g / cc to 0.9 g / cc, and has a structure denser than the fiber layer, and includes both fiber layers. The compression elastic modulus of the non-woven felt is set to 5% or more. The invention according to claim 2 is characterized in that a thermoplastic or thermosetting resin is applied to the surface of the dense fiber layer in order to prevent hair loss of the non-woven felt layer.

[0007]

When the felt of the present invention is used for roll cleaning of, for example, an antistatic copying machine, the anti-offset liquid is retained by the dense fiber layer and the coarse fiber layer is entirely a single fiber layer. Since the fibers are connected to the fibers of the dense fiber layer, the coating amount can be increased regardless of the coarseness of the coarse density fiber layer.

Further, since the coarse density fiber layer has many fiber gaps,
The paper dust and toner residue are taken in, and the life of the fiber layer surface can be prevented from shortening due to its accumulation. Furthermore, the high compression modulus of the high-density fiber layer prevents the life from decreasing due to sag. The peelability of the toner dust from the fixing roll is also good.

It is possible to eliminate the fear of hair loss by applying resin to the high-density layer surface.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 (a) and 1 (b) are views showing a cross section of a felt according to the present invention. In FIG. 1, 1 is a felt according to the present invention, which is composed of a single fiber layer and is needle punched from the lower side. When applied, relatively long naps are produced in a brush shape on the upper surface to form a coarse fiber layer 3 by the naps, and the lower part is a dense high-density fiber layer 2.

Here, the fibers constituting the non-woven felt 1 are preferably heat resistant fibers, and aromatic polyamide, heat resistant polyester fibers or the like can be used.
Among them, the former fiber known as Nomex (trade name) is very suitable.

The coarse fiber layer 3 formed by producing long naps of the felt 1 structure in a brush shape has an apparent density of 0.02 g / cc to 0.1 g / cc, and the thickness ( The nap height) is 1.5 to 3.0 mm, preferably around 2 mm.

On the other hand, the fiber layer 2 on the other side is the coarse fiber layer 3 described above.
Is a denser fiber layer, and its apparent density is usually 0.
It is 1 g / cc to 0.9 g / cc and the thickness is about 1 to 2 mm.

The two fiber layers 2 and 3 are needle-punched from the lower side of a single fiber layer composed of the above-mentioned fibers, and in particular, the bed plate is in the shape of a brush and the one-layer structure is as if the brush-like naps are the upper layer. It can be constructed by performing a Deiroa process that is configured as if it has a two-layer structure.

Thus, the felt 1 composed of both fiber layers 2 and 3 obtained by the above needle punching process is required to have a compressive elastic modulus higher than that of the conventional needle punched nonwoven fabric and not less than 5%. If it is less than 5% or less, the service life will be shortened due to settling, and the removal of paper dust and toner residue from the fixing roll will be hindered.

The felt of the present invention constructed as described above is used on the side where the napped coarse fiber layer 3 comes into contact with the roll to be cleaned, while the high-density layer 2 side is arranged on the opposite side. It is used as a roll-cleaning felt for rolls used for offset printing and various types of processing such as heat-fixing rolls for antistatic copying machines and printers.

The results of comparing the performance of each of the embodiments shown in FIGS. 1 (a) and 1 (b) with the conventional nonwoven fabric 1 '(comparative example) by the upper and lower needle punching processes shown in FIG. 2 will be described below.
In the table, NP is an abbreviation for needle punch. Margin below

[0019]

[Table 1]

In the above table, the offset preventive liquid retention amount and the cleaning effect original evaluation were based on the following methods. (A) Amount of offset prevention liquid retained The amount of silicone oil impregnated and retained per unit volume of felt is shown. Silicone oil is 10,000cps,
Volatile content is 0.1% or less. (B) Original evaluation of cleaning effect 40 copies were made without a cleaning device to contaminate the fixing roll, and then a cleaning device that processed the felt according to the examples and comparative examples into a roll shape was installed, and the copy was made 20 times to make the surface of the fixing roll. The stains were visually compared and evaluated on a 5-point scale. The larger the number, the better the cleaning effect.

From the above results, it can be seen that the felt according to the present invention has a slight improvement in protection of the offset preventing liquid but a remarkable improvement in the cleaning effect as compared with the conventional nonwoven fabric.

[0022]

As described above, according to the present invention, the non-woven fabric composed of a single layer has a brush-like napped coarse fiber layer having a predetermined apparent density on the side in contact with the roll and a high density fiber layer on the other side.
It is a felt with a compression elastic modulus of 5% or more, and when it is used for roll cleaning in processing using rolls, the offset preventing liquid is sufficiently retained in the dense fiber layer, and the fibers in the coarse fiber layer are Since it is connected to the fibers of a dense fiber layer, it has an advantage that the coating amount can be increased regardless of the coarse density.

Further, since the coarse density fiber layer has many fiber gaps, it is possible to prevent paper powder or toner dust from being taken into the gaps and prevent the life of the fiber layer surface from being shortened due to its accumulation.

Further, since the felt of the present invention has a higher compressive elastic modulus than that of the conventional non-woven fabric, the life of the felt is prevented from being shortened and the above-mentioned paper powder and toner residue are effectively removed from the fixing roll. is there.

When the thermoplastic or thermosetting resin according to the second aspect is applied to the dense fiber layer surface, it is effective in preventing fluffing.

[Brief description of drawings]

1 (a) and 1 (b) are partial cross-sectional schematic views showing each embodiment of the felt according to the present invention.

FIG. 2 is a partial cross-sectional view of a conventional non-woven felt.

[Explanation of symbols]

 1 felt 2 high density fiber layer 3 coarse fiber layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B08B 1/00 2119-3B

Claims (2)

[Claims] 1. A non-woven fabric comprising a single fiber layer, wherein the fiber layer on the side to be cleaned that comes into contact with a roll is napped into a brush shape by needle punching, and its apparent density is 0.02 g / cc to 0.1 g / cc is in a relatively coarse range, while the fiber layer on the other side has an apparent density of 0.1 g / cc
A roll cleaning felt, wherein the nonwoven fabric felt having a structure that is denser than that of the above-mentioned fiber layer is about 0.9 g / cc and the compression elastic modulus of the nonwoven fabric felt made of both fiber layers is 5% or more. 2. The roll cleaning felt according to claim 1, wherein a thermoplastic or thermosetting resin is applied to the surface of the dense fiber layer.