Chemically-treated cleaning web

Abstract

A fuser debris inhibiting system and apparatus using an impregnated cleaning web. This web is impregnated with EDTA or its salts. The web can contact the fuser member directly or can contact external heat rolls which in turn contact the fuser roll. The delivery of EDTA to the surface of the fuser member substantially inhibits the formation of contaminants thereon.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a fuser system in an electrostatic marking apparatus using the impregnated fuser cleaning web of this invention.

FIG. 2 illustrates a test cleaning web to test the effectiveness of embodiments of the present invention.

FIG. 3 illustrates a cleaning system where the web directly contacts the fuser roll.

DETAILED DISCUSSION OF DRAWINGS AND preferred EMBODIMENTS

In FIG. 1, a fuser system 1 is illustrated having a fuser roll 2, a pressure roll 3 and a paper transport 4 which directs a paper-receiving medium 5 through a nip between rolls 2 and 3. The arrows on fuser roll 2 and pressure roll 3 indicate the rotational direction of each roll. A release agent reservoir 6 is shown in operative relationship to a meter roll 7 and a donor roll 8. In operative contact with the fuser roll 2 are two external heat rolls 9 (X-rolls), the X-rolls 9 are both in contact with a cleaning web 10 which is impregnated with the scavenging agent, EDTA (in the form of tetrasodium salt). Generally, a suitable impregnation is 8 milligrams of EDTA/square inch of web. This suitable measured amount of EDTA transfers from web 10 to existing X-rolls 9 and from X-rolls 9 to the surface of fuser roll 2. This inhibits formation of debris such as Zn fumarate and other contaminates from forming on the surface of fuser roll 2. The Zn fumarate (originating from Zn stearate in toner) contaminate causes print defects and premature development of offset. By using existing components of the fuser system 1 such as the web 10 and the X-rolls 9, an additional cleaning station as used in some prior art need not be installed in system 1. Since space is always a serious consideration in marking or electrophotographic systems, avoiding the necessity of a cleaning station is important. Also, using the cleaning web 10 and X-rolls 9 to inhibit contamination of the fuser roll 2 avoids the necessity of removing the fuser roll for external cleaning. This down time of the system 1 is important time-wise and monetarily. As earlier noted, the EDTA is impregnated into web 10 at a level of about 2 to 10 mg/in². Any suitable solution comprising EDTA may be used such as a solution containing EDTA from about 0.5%-30% by weight of the solution. In an embodiment, a suitable surfactant such as 1-methoxy-2 propanol may be added to the solution in order to improve wetting of the polyarylamide web material. Obviously, conditions will determine what amount of surfactant and of EDTA is needed to accomplish this inhibiting effect. The solution can have a pH of about from 7-11. In lieu of the cleaning web 10 contacting the X-rolls, it may be desirable in some embodiments to have the impregnated web 10 directly contact the fuser roll 2 to inhibit or minimize formation of Zn fumarate and other contaminates from the surface of fuser roll 2. In FIG. 1, boxes 17 located adjacent rollers 2, 3 and 9 are thermostats.

The impregnated web 10 is supplied from web supply roll 15 and the web moves to web take-up roll 14 for re-use or for replacement.

In FIG. 2, it is known, as above noted, that build-up of Zn fumarate on the surface of the fuser roll has been linked to shortened fuser roll life, print defects and, possibly, to premature offset. Thus, prevention or inhibiting this Zn fumarate build-up is more desirable than cleaning an already contaminated fuser roll and possibly damaging the fuser roll. As earlier mentioned, utilization of Zn sequestering agents as cleaners in and out of the system has long been proposed. These chemicals are typically ionic compounds that can chelate Zn (“wrap” themselves around Zn forming several coordination bonds to Zn²⁺ ion). Unfortunately, these ionic agents are not soluble in cold silicone oil and have only limited solubility in hot oil. It is therefore challenging to deliver them onto the fuser roll surface. This delivery problem can be overcome in the present invention by impregnating the X-roll cleaning web with a Zn sequestering agent such as EDTA. The chemicals are expected to be partially solubilized by the hot oil on the X-rolls as well as mechanically transferred to the fuser roll.

To test an embodiment of the method, a cleaning web was prepared with five areas as shown in FIG. 2. The areas of the web were impregnated at 11 with tetrasodium EDTA at a level of 8 mg/in², some areas with sodium acetate at locations 12 at the same level of 8 mg/in². Part of the web was also left untreated as shown at sections or locations 13.

The same stress pattern (four stripes of different colors) was printed I each of the five areas using LX paper (stress test for the axial gelation lines). After 30K print severe print defect (axial differential gloss lines and irregular gloss patterns) were observed in all three areas not treated with EDTA. The printed patterns in the EDTA area did not show these defects. Additionally, the fuser roll appeared cleaner in the EDTA treated areas indicating lesser build-up of Zn fumarate. This showed clearly that the EDTA inhibited formation of the Zn fumarate in the EDTA treated areas. Similar results are expected using the other metal chelating agents disclosed and claimed herein since many of their properties are very similar to EDTA.

In FIG. 3, impregnated web 10 directly contacts fuser roll 2 (as opposed to contacting X-rolls 9) to inhibit formation on its surface of Zn fumarate debris and other contaminates. Otherwise all of the above discussion relating to FIG. 1 equally applies to FIG. 3. In one embodiment the fusing system comprises in an operative arrangement an impregnated cleaning web and a fuser member. The cleaning web is impregnated with a debris inhibiting amount of a metal chelating agent selected from the group consisting of ethylenediaminetetraacetic acid (EDTA), succinic acid, diethylenetriaminepentacetic acid (DPTA), N-(hydroxyethyl) ethylene-diaminetetraacetic acid (HEDTA), nitrilotriacetic acid (NTA), 2,3-dimercaptosuccinic acid (DMSA), their salts and mixtures thereof.

In another embodiment the fusing system herein is useful in inhibiting Zn containing contamination in an electrophotographic marking system. The system comprises in an operative arrangement, an impregnated movable cleaning web and a fuser roll. The web is impregnated with a composition of a surfactant and EDTA and adapted to directly or indirectly transfer at least a portion of said EDTA containing composition to said fuser roll surface. Thereby in this debris inhibiting step, it assists to prevent formation on said surface of at least some Zn fumarate. The web is enabled to continuously supply said EDTA directly or indirectly to said fuser roll and enabled to continuously inhibit formation of said Zn fumarate from said fuser roll. This system provides that said impregnated web is in contact with two X-rolls and enabled thereby to transfer at least a cleaning amount of EDTA to said X-rolls.

This system also provides in another embodiment where said web contacts at least one external heat roll (X-roll) and wherein said heat roll(s) are enabled to operatively contact said fuser roll.

The web is also available to contact said fuser roll directly.

To summarize, various embodiments of this invention provide a fusing system having in an operative arrangement a cleaning web and a fuser member. The web is impregnated with a debris inhibiting amount of a member selected from the group consisting of EDTA or other suitable chelating agent. The web can directly contact the surface of the fuser roll or it can contact the x-rolls which in turn will transfer the chelating agent to the fuser roll. The EDTA can be in solution prior to the impregnation into the web. In one embodiment it has a pH of about 7-11 and is present in the solution in an amount of from 0.5% to about 30% by weight of the solution. Obviously, any suitable amount of EDTA may be used.

A surfactant is used in one embodiment with the EDTA; the surfactant can be added in an amount of from 5%-15% by weight of the solution.

The preferred and optimally preferred embodiments of the present invention have been described herein and shown in the accompanying drawings to illustrate the underlying principles of the invention, but it is to be understood that numerous modifications and ramifications may be made without departing from the spirit and scope of this invention.

Claims

1. A fusing system comprising in an operative arrangement an impregnated cleaning web and a fuser member, said cleaning web impregnated with a debris inhibiting amount of a metal chelating agent selected from the group consisting of ethylenediaminetetraacetic acid (EDTA), succinic acid, diethylenetriaminepentacetic acid (DPTA), N-(hydroxyethyl) ethylene-diaminetetraacetic acid (HEDTA), nitrilotriacetic acid (NTA), 2,3-dimercaptosuccinic acid (DMSA), their salts and mixtures thereof.

2. The system of claim 1 wherein said web contacts the fuser member directly.

3. The system of claim 1 wherein said web contacts at least one external heat roll, and wherein said heat roll is in contact with said fuser member.

4. The system of claim 1 wherein said web is impregnated with a material comprising said metal chelating agent of claim 1.

5. The system of claim 1 wherein said web is impregnated with a solution comprising said metal chelating agent of claim 1, said solution having a pH of about 7 to 11.

6. The system of claim 1 wherein said web is impregnated with a solution comprising said chelating agent of claim 1 in an amount of from about 0.5% to about 30% by weight of the solution.

7. A fusing system comprising in an operative arrangement an impregnated cleaning web and a fuser roll, said web impregnated with a surfactant and a chelating agent of claim 1 and adapted to directly or indirectly transfer said surfactant and said chelating agent to said fuser roll, said surfactant and said chelating agent enabled to inhibit zinc by-products and contamination from forming on said fuser roll.

8. The system of claim 7 wherein said web contacts at least one external heat roll (X-roll) and wherein said heat roll(s) are adapted to be in contact with said fuser member.

9. The system of claim 7 wherein said web contacts said fuser roll directly.

10. The system of claim 7 wherein at least a portion of said EDTA is transferred from said web to at least one X-roll, and wherein said EDTA is subsequently contacted by said X-roll with a surface of said fuser roll.

11. The system of claim 7 wherein said impregnated web is in contact with two X-rolls and enabled thereby to transfer at least a cleaning amount of EDTA to said X-rolls.

12. A fusing system useful in inhibiting Zn containing contamination in an electrophotographic marking system, said system comprising in an operative arrangement, an impregnated movable cleaning web and a fuser roll, said web impregnated with a composition of a surfactant and EDTA, and adapted to directly or indirectly transfer at least a portion of said EDTA containing composition to said fuser roll surface to thereby in a debris inhibiting step to prevent formation on said surface of at least some Zn fumarate, said web enabled to continuously supply said EDTA directly or indirectly to said fuser roll and enabled to continuously inhibit formation of said Zn fumarate from said fuser roll.

13. The system of claim 12 wherein said web contacts at least one external heat roll (X-roll) and wherein said heat roll(s) are enabled to operatively contact said fuser roll.

14. The system of claim 12 wherein said web contacts said fuser roll directly.

15. The system of claim 12 wherein said web is impregnated with an EDTA composition or material having a pH of about 7-11 and wherein said web is impregnated with EDTA at a level of about 8-10 mg/in2.

16. The system of claim 12 wherein said web is impregnated with a material or solution comprising EDTA in an amount of from about 0.5% to abut 30% by weight of said solution, and whereby a surfactant is present in an amount of from about 5%-15% by weight of said solution.

17. The system of claim 12 using a method of inhibiting the formation of contaminants such as Zn Fu on said fuser roll, which comprises contacting said fuser roll with a composition comprising EDTA.

18. The system of claim 12 wherein said web is in operative continuous contact with two X-rolls and enabled to thereby transfer at least a cleaning amount of said material containing said EDTA to said X-rolls, said X-rolls enabled to contact said fuser roll and adapted to transfer at least a portion of said EDTA containing material to a surface of said fuser roll.

19. The system of claim 12 wherein said fuser roll is enabled to continuously contact a marked receiving member such as paper and wherein said EDTA treated fuser roll is enabled to minimize transfer of toner decomposition products to said fuser roll and said receiving member.

20. The system of claim 12 wherein said fuser roll is enabled after said debris inhibiting step, to minimize transfer of Zn fumarate from said fuser roll to a marked receiving member such as paper.