CA1208896A - Method of manufacturing a friction article - Google Patents
Method of manufacturing a friction articleInfo
- Publication number
- CA1208896A CA1208896A CA000422417A CA422417A CA1208896A CA 1208896 A CA1208896 A CA 1208896A CA 000422417 A CA000422417 A CA 000422417A CA 422417 A CA422417 A CA 422417A CA 1208896 A CA1208896 A CA 1208896A
- Authority
- CA
- Canada
- Prior art keywords
- backing plate
- friction article
- friction
- zinc
- bath
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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- Braking Arrangements (AREA)
- Chemical Treatment Of Metals (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A method of manufacturing a friction article (42) wherein through a series of steps a chrome-zinc-phosphate coating applied to a ferrous based backing plate (10) enhances a resin bond through which a pad (36) of friction material is attached thereto. After the pad (36) of friction material is bonded to the ferrous based backing plate (10), the series of steps are repeated to create an additional chrome-zinc-phosphate coating on this structure to produce a water insoluble coating. Thereafter a lacquer is applied on the structure (42) to seal the coating from the atmosphere.
A method of manufacturing a friction article (42) wherein through a series of steps a chrome-zinc-phosphate coating applied to a ferrous based backing plate (10) enhances a resin bond through which a pad (36) of friction material is attached thereto. After the pad (36) of friction material is bonded to the ferrous based backing plate (10), the series of steps are repeated to create an additional chrome-zinc-phosphate coating on this structure to produce a water insoluble coating. Thereafter a lacquer is applied on the structure (42) to seal the coating from the atmosphere.
Description
12(~889~i A METHOD OF MANUFACTURING A FRICTION ARTICLE
This invention relates to a method of manufac-turing a friction article having a pad of friction material bonded to ferrous backing plate.
~ ~ . .
In manufacturing friction articles and in particular disc brakes for vehicles, it is common practice for the ferrous based backing plates to be stamped by a supplier and shipped to a friction material manufacture for final assembly with a pad of friction material. Due to the delay in time that often occurs from the time of manufac-ture of the backing plates to the attachment of the friction pad, the backing plates may rust or accumulate grime on the surface thereof. Both rust and grime can effect a resulting bond between the backing plate and pad of friction material. Therefore, the backing plates are uniformly cleaned by being passed through a shot peening or blast operation. While the shot peening operation adequately removes rust, grime, oil, grease and any other surface contaminants, the force associated with the shot peening operation may distort the ferrous or steel backing plate which may result in a subsequent rejection of the friction article. A resin binder is applied to a selected area of peened-cleaned backing plate and a pad of friction material is clamped onto the backing plate over the resin binder. The binder is cured to bond the pad of friction material to the backing plate. After checking the size of mls/~l~
~ 1 ~
12~3896 the friction article and removing any excess friciton material, the friction article is painted or resin dipped, to prevent the formation of ferrous oxides on the surface of the backing plate when exposed to normal operating conditions.
If the backing plate has been distorted, the bond between the pad of friciton material and the backing plate may not be uniform to withstand the shear forces experienced during a brake application. If the pad of friction material is sheared from the backing plate, an emergency condition exists in the braking system which could result in the destruction of property.
The completed backing plate could also be rejected by potential users for lack of dimensional integrity; such mls/ ~-~ ~a -" ~ ~
~Z~8B96 as backing plate flatness (T.I.R.). Normally, a grinding operation would have to be utilized to correct this defect.
According to the present invention there is pro-vided a method of manufacturing a friction article, the method including the steps of continually moving a ferrous based backing plate through a first bath containing first alkaline solution to clean the backing plate and removinq the backing plate from the first bath and thereafter con-tinually moving the backing plate through a first water bath to rinse the first alkaline solution from the clean backing plate. The backing plate is then removed from the first water bath and thereafter continually moved through a second bath containing a first solution of zinc-phosphate to coat the entire surface of the clean backing plate. The backing plate is then removed from the second bath and thereafter ccntinually moved through a second water bath to neutralize the reaction between the first 7inc-phosphate solution and the ferrous based backing plate. The backing plate is then removed from the second water bath and thereafter continu-ally moved through a third bath containing a first solution of chromic acid, the chromic acid having a Ph of about 6.9 in reacting with the zinc-phosphate coating to form a water insoluble chrome-zinc-phosphate coating on the backing plate. The backing plate is removed from the third bath and thereafter continually moved through a dryer to dry the chrome-zinc-phosphate coating. The backing plate is removed from the dryer and thereafter being tranported to a first work station, there is applied a phenolic resin binder to a selected area of the chrome-zinc-phosphate backing plate. A
pad of metallic based friction material is placed on the phenolic resin binder, and a compressive force is applied through a clamp to hold the pad on the selected area. The backing plate is continually moved through a second oven to cure the phenolic binder and establish a bond between the plate and backing plate to produce the friction article.
The friction article is then removed from the oven and a clamp released from the pad and backing plate. The friction article is cooled and continually moved through a fourth bath containing a second alkaline solution to clean any grime, lm/-~G -2-lZ~88~6 oil or grease deposited on the friction article during curing of the phenolic binder. The cleansed friction article is removed from the fourth bath and thereafter con-tinually moved through a third water bath to rinse the friction article and remove the second alkaline solution therefrom. The friction article is then removed from the third water bath and thereafter continually moved through a fifth bath containing a second solution of zinc-phosphate to completely coat the entire surface of the friction article.
The friction article is then removed from the fifth bath and thereafter continually moved through a fourth water bath to neutralize the reaction between the zinc-phosphate solution on the backing plate and the metallic elements of the fric-tion article. The friction article is removed from the fourth water bath and thereafter continually moved through a sixth bath containing a solution of chromic acid, the chromic acid having a Ph of about 6.9 and reacting with the zinc-phosphate coating to form a water soluable chrome-zinc-phosphate coated friction article. The friction article is removed from the sixth bath and thereafter continually moved through a heater to dry the chrome-zinc-phosphate coated friction article. After removing the article from the heater it is continually moved through a first chamber where a water soluable lacquer is applied to the dried f~-iction article to seal the surface thereof from the atmosphere and thereby reduce the formation of oxides with the metallic elements in the friction article. The friction article is removed from the first chamber and thereafter continually moved through a second chamber where the lacquer is dried.
The lacquer coated friction article is removed from the second chamber and transported to a second work station where the chrome-zinc-phosphate coating is removed from a work surface on the friction article as a ~ork surface is ground to a specific dimension. The friction article is then packed in a container for distribution to a customer.
According to a specific embodiment of the inven-tion, the ferrous based backing plate is cleaned through immersing in the first bath containing an alkaline solution consisting of phosphates, sodium carbonates and/or sodium lm/~ -2a-~ .
~Z~8~96 hydroxide whose temperature is between 65-75c for about 2 minutes wherein grime, oil, grease or any other surface contaminants are removed without effecting the physical characteristics of the backing plate. The use of a non-silicated cleaner is preferred. After removal from this first bath and neutralization of alkaline solution through a water bath, the backing plate is inspected for the presence of ferrous oxide. If ferrous oxide is present, the backing plate is immersed in a second bath containing approximately 50% by volume of Hydrochloric acid for about 30 seconds.
The Hydrochloric acid reacts with ferrous oxide to produce a precipatate of ferrous chloride and water to further clean the ferrous based backing plate. Thereafter the cleaned backing plate is rinsed in a water bath to neutralize the Hydrochloric acid and immersed in a third bath containing a solution of zinc phosphate whose temperature is between 60-70C for about 10 minutes to produce a zinc-phosphate coat-ing on the ferrous based backing plate. The zinc-phosphate coated backing plate is neutralized in a water bath and thereafter immersed in a fourth bath containing a solution of chromic acid having a temperature of from 50-60C for about 30 seconds to creat a chrome-zinc-phosphate coating on the backing plate. Thereafter the chrome-zinc-phosphate backing plate is dried and a resin binder applied to a selected area thereof. A pad of a metallic based friction material is clamped to the backing plate over the resin binder. The binder is cured to establish a bond between the pad and backing plate and produce the friction article.
Depending on the curing process, some grime, oil, grease, or other surface contaminants may be present on the backing plate and/or pad of metallic based friction material.
lm/~C~ -2b-.,~
~d~
.~. ,~, lZ~8~96 Therefore, the friction article is returned to a fifth bath containing a second alkaline solution of phosphates, sodium carbonates and/or hydroxides, having a temperature of from 65-75 C for a period of 2 minutes to clean the friction article. After neutralizing the sodium hydroxide in a water bath, the cleaned friction article is immersed in a sixth bath containing a-solution of zinc-phosphate having a temperature of between 60-70C for about 10 minutes to add an additional zinc-phosphate coating to the backing plate lo and an initial coating to the pad of metallic based friction material. The zinc-phosphate coated friction article is rinsed in a water bath to terminate the deposition of zinc-phosphate on the friction article before being immersed in a seventh bath containing a solution of chromic acid having a temperature of between 50-600 C for about thirty seconds. The chromic acid reacting with the zinc-phosphate to create a water insoluble chrome-zinc-phosphate coating on the friction article. Thereafter, the friction article is dried and a water soluble lacquer sprayed thereon to seal the surface and thereby prevent the formation of oxides on the surface of the friction article.
The friction article is inspected and if needed, ground to a specific size before proceeding to a shipping container for distribution to a customer.
An advantage of this invention is that the chrome-zinc-phosphate coating in addition to enhancing the bond between the ferrous based backing plate and pad of mls/
~, .
12~896 metallic based friction material inhibits corrosion when the friction article is exposed to the atmosphere.
The invention will now be described with reference to the accompanying drawings wherein:
Figure l is a schematic illustration of the steps of chrome-zinc-phosphate coating a backing plate according to the principles of this invention; and Figure 2 is a schematic illustration of the steps of attaching a pad of metallic based friction material to the chrome-zinc-phosphate coated backing plate to produce a friction article which in turn is protected with a chromic-zinc-phosphate coating according to the principles of this invention.
The backing plate 10 shown in figure 1 is made from a ferrous based material. Usually backing plates 10 are stamped from a sheet of material having a uniform thickness. In order to aid in the stamping of the backing plates, a lubricant is applied to the sheet of material.
The backing plates are directly conveyed from the stamping machine to a tote box 12 for shipping to a user, normally a friction material manufacturer. By the time the backing plate reaches the friction material manufacturer, grime, oil, grease, rust and other materials may be found on the surface thereof. Necessitating the first steps of the invention disclosed herein in figure 1.
A backing plate lO is removed from tote box 12 and placed on a conveyor 15 for delivery to a first bath 14 mls/~ - 4 -12~896 containing an alkaline solution of phosphates, sodium carbonates and/or hydroxides having a Ph of between 11 and 13. To achieve this concentration between 37-53 gm of sodium hydroxide are added to a liter of solution (water).
The temperature of the solution is maintained between 65-75C. The size of the first bath 14 is selected to permit continuous movement of the backing plate 10 in the solution for between 1 and 3 minutes. This alkaline solution of phosphates, sodium hydroxides and carbonates (calcium hydroxide is also acceptable) removes grime, oil, grease, paint, dirt and other surface contaminants, but does not have an effect on ferrous oxide (rust) that may be present on the backing plate 10. Therefore, on removal from the first bath 14, the backing plate 10 is rinsed in a water bath 16 whose temperature is approximately 5-10C to neutralize or wash the alkaline solution from the backing plate 10.
The cleaned backing plate 10 is inspected for the presence of ferrous oxide. If ferrous oxide is found on the backing plate 10, the backing plate is immersed in a second bath 18 containing approximately 50% by volume of hydrochloric acid whose temperature is about 20C. The hydrochloric acid reacts with ferrous oxide on the surface of the backing plate 10 to produce as precipitate of ; ferrous chloride and water and thereby return the surface of the backing plate to its original ferrous based condition. The strength of the hydrochloric acid solution mls/~ _ 5 _ lzasss6 is such that backing plate 10 need not remain in the second bath for more than 30 seconds.
If the backing plate 10 does not have any ferrous oxide on its surface, the immersion in the second bath 18 can be omitted. However, in a continuous flow transmission line as shown in figure 1, it may be easier to clean all backing plates with hydrochloric acid rather than devise a means of selectively diverting backing plates 10 to the second bath 18 when ferrous oxide is observed on a surface thereof.
From the second tank 18, the backing plate 10 is rinsed in a water bath 20 to neutralize and remove any hydrochloric acid that may be retained on the surfaces thereof. By maintaining the temperature of the water bath between 5-10C, the speed of neutralization allows the backing plate 10 to continuous]y move through the water bath 20.
On exiting from water bath 20, backing plate 10 is conveyed to a third bath 22 containing a solution of zinc-phosphate solution which has been heated to a temperature of between 60-70C.
The concentration o~ zinc-phosphate solution is obtained by adding from 4-8% by volume of zinc-phosphate acid ZN H2 P4 to water until a desired Ph of between 2-4 is obtained. The size of this third bath has been selected such that it takes between 8-12 minutes for a backing plate 10 to pass through the tank. As the backing plate passes mlsj~
:~Z~889~
through tank 22, a coating of zinc-phosphate i9 deposited on the surface o~ backing plate 10. The thickness of the zinc-phosphate coating deposited on the surface of backing plate 10, is dependent on both the concentration of the zinc-phosphate acid and the time of reaction in this third bath 22.
Backing plate 10 is conveyed from the third bath 22 to a water bath 24 whose temperature is maintained between 5-10C. The relatively cold water neutralized the lQ zinc-phosphate acid and allows the coated backing plate 10 to be directly conveyed to a fourth bath 26.
Fourth bath 26 contains a solution of chromic acid which has been heated to a temperature of between 50-60C. The concentration of this solution is obtained by adding 1 liter of chromic acid to 400 liters of water.
This is a very weak solution and the Ph registers somewhere between 6.9-7Ø Even though this is a weak solution, when the zinc-phosphate coated backing plate 10 is immersed therein, a reaction takes place in a time period of between 20-40 seconds to create a chrome-zinc-phosphate coating on the backing plate 10. The chrome-zinc-phosphate coated backing plate 10 is conveyed from the fourth bath 26 into a dryer 28. The temperature in the dryer is maintained at approximately 45C. A higher temperature will obviously decrease drying time.
: The dried backing plate 10 is conveyed to a station 30 shown in figure 2 where a phenolic resin binder mls/ ~S _ 7 `:
lZC~896 is applied to a selected area 32 of the backing plate 10.
Pads 36 of a metallic based friction material such as disclosed in U. S. Patent 3,835,118 entitled "Sponge Iron Friction Material", which issued September 10, 1974 are located at a work station 34. A pad 36 is placed over the selected area 32 on the backing plate 10 and a clamp 38 attached thereto to provide a compressive force that holds the pad 36 to the backing plate 10.
The backing plate 10 with pad 36 clamped thereto is conveyed to an oven 40 whose temperature is about 148C.
The backing plate 10 and pad 36 remain in the oven for about 12 minutes during which time the resin binder cures to establish a bond between the backing plate 10 and pad 36 to produce a friction particle 42.
During the curing of the resin binder and the need to apply a lubricant to the clamp for ease in part removal, some type of contamination, i.e., oil, grease, grime, dirt, etc. may be deposited on the friction article 42. Although such contamination would not affect the operation of the friction article 42 for appearance purposes it has been decided to further process the friction article 42 in accordance with the teachings in this invention. The friction article 42 is conveyed from the curing oven 40 to a fifth bath 44. The fifth bath 44 contains an alkaline solution of phosphates, sodium hydroxide and/or carbonates, heated to a temperature of mls~ 8 -.. .
12~88~6 between 65-75 C. This alkaline solution is achieved by adding from 37-53 gm of sodium hydroxide to a liter of water to produce a Ph of between 11-13. The continuous moving conveyor moves the friction article 42 through the fifth bath 44 in a time period of between 1 to 3 minutes.
During this time the alkaline solution removes any contamination from the surface thereof.
The cleaned friction article 42 is rinsed in a water bath 46 whose temperature is maintained between 5-10C. The water bath 46 neutralizes the effect of the sodium hydroxide.
From water bath 46, the friction article 42 is conveyed to a sixth bath 48 containing a zinc-phosphate solution which has been heated to a temperature of between 60-70C. The concentration of zinc-phosphate solution is obtained by adding from 4-8% by volume of zinc-phosphate acid (ZN H2 P4) to water until a desired Ph of between 2-4 is obtained. The size of the sixth bath 48 is selected such that it takes between 8-12 minutes for the friction article 42 to be conveyed through tank 48. As the friction article 42 passes through tank 48, an additional coating of zinc-phosphate is deposited on the backing plate and an initial coating is deposited on the pad 36.
On removal from the sixth bath 48, friction article 42 is rinsed in a water bath 50 to neutralize the reaction coating effect of the zinc-phosphate solution.
The friction article 42 is conveyed from bath 50 mls/ ~ _ g _ ~2~889~
into a seventh bath 52 whîch contains a chromic acid solution which has been heated to a temperature of between 50-60C. The concentration of this solution is obtained by adding 1 liter of chromic acid to 400 liters of water.
Since this is a very weak acid solution thePh registers from 6.9-7Ø Even though this is a weak solution, when the zinc phosphate coated friction article 42 is immersed in tank 52, a reaction occurs in a time period of from 20-seconds to create a water insoluble chrome-zinc-phosphate coating on the entire friction article 42.
The friction article 42 is conveyed to a dryer 54where the chrome-zinc-phosphate coating is dried before being transferred to a spray chamber 56.
In the spray chamber 56, a water soluble lacquer is sprayed on the chrome-zinc-phosphate coating. The lacquer seals the coating and thus prevents the formation of oxides that may develop under some atmospheric conditions. For some application, a dip station may be utilized instead of a spray chamber 56 to accomplish this step.
From the spray chamber, the friction article proceeds to an inspection station 58 where the material is inspected in accordance to print specifications.
The friction article is then conveyed to a grinder station 60 where any excess material is removed from the operational wear surface 43 before being conveyed to a storage container 62 for shipping to a customer.
mls/~ - 10 -~Z~ 96 The quality control of the method of manufacture is checked in the following manner: Friction articles 42 are selectively removed from the production line 15 and transferred to a test station 64. At test station 64, the friction article 42 is subjected to a shear test to measure the strength of the bond between the backing plate lO and the pad of friction material 36.
In order to evaluate the method of manufacturing a friction article 42 according to this invention, the following specific method was performed.
A steel backing plate 10 was placed in the first bath 14 which contained an alkaline solution of sodium hydroxide whose temperature is approximately 71C. The concentration of sodium hydroxide in the solution was achieved by adding 45 gm of sodium hydroxide to l liter of water to produce a Ph of about 12. The backing plate 10 was immersed in the first bath 14 for 2 minutes during which time all grime, grease and oil were removed.
The backing plate after the neutralization of the sodium hydroxide solution in water bath 16 was conveyed to the second bath 18 since ferrous oxide was observed on a surface thereof.
The second bath 18 which contained a 50% by volume solution of hydrochloric acid at room temperature (20C), removed the ferrous oxide on the surface of backing plate 10 in about 30 seconds.
After neutralizing the hydrochloric acid in water mls/ ~
~Z(~8896 bath 20, the cleaned backing plate 10 was immersed in the third bath 22.
The third bath 22 which contained a solution of zinc-phosphate whose temperature was approximately 65C.
The concentration of zinc-phosphate in the solution was achieved by adding 6.5% by volume of zinc-phosphate acid to water until a Ph of 3 was obtained. Since the coating deposited on the backing plate is dependent on both the concentrations of the solution and the length of reaction time, backing plate 10 was retained in the third tank for 10 minutes.
After neutralizing the reaction of the zinc-phosphate on the ferrous based or steel backing plate 10 in water bath 24, backing plate 10 was immersed in the fourth bath 26.
The fourth bath contained a solution of chromic acid whose temperature was about 55C. The concentration of the chromic acid was obtained by adding 1 liter of chromic acid to 400 liters of water. Even with this weak solution 30 seconds were sufficient for a reaction to occur which created a chrome-zinc-phosphate coating on the ferrous or steel backing plate 10.
After drying the chrome-zinc-phosphate coated backing plate, a phenolic resin binder was applied to a selected surface and a pad of metallic friction material of the type disclosed in U. S. Patent 3,835,118 was clamped onto the backing plate lO over the resin binder.
mls/~, - 12 -12~889~i The clamped backing plate 10 and pad 36 were conveyed to oven 40 where the temperature was approximately 148C. The backing plate 10 and pad 36 were retained in the oven for approximately 12 minutes during which time the resin cured to create a bond between the backing plate 10 and pad 36 to create a friction article 42.
On removal from oven 40 and al lowed to cool to room temperature, 20C, friction article 42 was immersed in fifth bath 44.
The fifth bath 44 which contains an alkaline solution of sodium hydroxide identical to the first bath and maintained at a temperature of approximately 71 C. The friction article 42 was in bath 44 for approximately 2 minutes during which time all visible oil, grease and/or grime was removed.
After this sodium hydroxide solution was rinsed off of the friction article 42 in water bath 46, the friction article was conveyed to the sixth bath 48.
The sixth bath 48 which contained a solution of zinc-phosphate acid identical to the third bath and maintained at a temperature of 65C. The zinc-phosphate reacted with the ferrous based or steel backing plate 10 and the ferrous elements in the pad of friction material to coat the friction article 42. Since time is an important element to the thickness of the coating deposited on the friction article 42, it was determined that 10 minutes were sufficient for this application.
mls/ \,~s - 13 i.,.
lZ~8~96 After neutralizing the zinc-phosphate acid on the friction article 42 in water bath 50, the friction article 42 was conveyed to the seventh bath 52.
The seventh bath 52 which contained a chromic acid solution identical to that in the fourth bath 26 and maintained at a temperature of 54 C. The chromic acid reacts with the zinc-phosphate coating on friction article 42 to produce a water insoluble coating of chrome-zinc-phosphate in about 30 seconds.
The chrome-zinc-phosphate coated friction article was dried in a hot air oven 54 and conveyed to a spray chamber 56.
A water soluble lacquer was sprayed on the friction article 42. The water soluble lacquer dried to provide a barrier that prevents the formation of oxide on the coating.
After inspection, the friction article was ground to the proper size in grinding chamber 60. The normal procedure would be to thereafter convey this finish product to container 62 for shipping to a customer.
For evaluation purposes, two sample friction articles A and B were manufactured in a manner recognized as prior art. In this method, the backing plate is cleaned by the shot peening method before a pad of friction material is attached thereto through the curing of the phenolic resin binder. The resulting friction articles were painted with an epoxy paint to provide corrosion mls/j~ - 14 -,,, . ~ ~ c ~
12C~8896 protection. When samples A and B were tested in shear machines 64, the friction pad separated from the backing plate when subjected to 2100 and 1925 Kg of force, respectively.
Thereafter 7 samples, C-l were manufactured in accordance with the specific method set forth above. When samples C-l were tested in shear machines 64, separation occurred under the following loads: 2800, 2450, 2300, 2460, 2580, 2190 and 2650 Kg.9 respectively. The above test clearly indicates that the chrome-zinc-phosphate coating enhances the phenolic resin bond that is produced between the backing plate and the pad of friction material. In addition to the chemical attraction between the coated backing plate, resin binder and pad of friction material, the relatively low temperatures at which the coating is applied does not distort the backing plate and which results in a more uniform surface area for the bond.
Further, it is felt that the chemical reaction between the chrome-zinc-phosphate coating and the ferrous based backing plate offers better corrosion protection than that achieved through conventional painting techniques.
mls/~ - 15 -
This invention relates to a method of manufac-turing a friction article having a pad of friction material bonded to ferrous backing plate.
~ ~ . .
In manufacturing friction articles and in particular disc brakes for vehicles, it is common practice for the ferrous based backing plates to be stamped by a supplier and shipped to a friction material manufacture for final assembly with a pad of friction material. Due to the delay in time that often occurs from the time of manufac-ture of the backing plates to the attachment of the friction pad, the backing plates may rust or accumulate grime on the surface thereof. Both rust and grime can effect a resulting bond between the backing plate and pad of friction material. Therefore, the backing plates are uniformly cleaned by being passed through a shot peening or blast operation. While the shot peening operation adequately removes rust, grime, oil, grease and any other surface contaminants, the force associated with the shot peening operation may distort the ferrous or steel backing plate which may result in a subsequent rejection of the friction article. A resin binder is applied to a selected area of peened-cleaned backing plate and a pad of friction material is clamped onto the backing plate over the resin binder. The binder is cured to bond the pad of friction material to the backing plate. After checking the size of mls/~l~
~ 1 ~
12~3896 the friction article and removing any excess friciton material, the friction article is painted or resin dipped, to prevent the formation of ferrous oxides on the surface of the backing plate when exposed to normal operating conditions.
If the backing plate has been distorted, the bond between the pad of friciton material and the backing plate may not be uniform to withstand the shear forces experienced during a brake application. If the pad of friction material is sheared from the backing plate, an emergency condition exists in the braking system which could result in the destruction of property.
The completed backing plate could also be rejected by potential users for lack of dimensional integrity; such mls/ ~-~ ~a -" ~ ~
~Z~8B96 as backing plate flatness (T.I.R.). Normally, a grinding operation would have to be utilized to correct this defect.
According to the present invention there is pro-vided a method of manufacturing a friction article, the method including the steps of continually moving a ferrous based backing plate through a first bath containing first alkaline solution to clean the backing plate and removinq the backing plate from the first bath and thereafter con-tinually moving the backing plate through a first water bath to rinse the first alkaline solution from the clean backing plate. The backing plate is then removed from the first water bath and thereafter continually moved through a second bath containing a first solution of zinc-phosphate to coat the entire surface of the clean backing plate. The backing plate is then removed from the second bath and thereafter ccntinually moved through a second water bath to neutralize the reaction between the first 7inc-phosphate solution and the ferrous based backing plate. The backing plate is then removed from the second water bath and thereafter continu-ally moved through a third bath containing a first solution of chromic acid, the chromic acid having a Ph of about 6.9 in reacting with the zinc-phosphate coating to form a water insoluble chrome-zinc-phosphate coating on the backing plate. The backing plate is removed from the third bath and thereafter continually moved through a dryer to dry the chrome-zinc-phosphate coating. The backing plate is removed from the dryer and thereafter being tranported to a first work station, there is applied a phenolic resin binder to a selected area of the chrome-zinc-phosphate backing plate. A
pad of metallic based friction material is placed on the phenolic resin binder, and a compressive force is applied through a clamp to hold the pad on the selected area. The backing plate is continually moved through a second oven to cure the phenolic binder and establish a bond between the plate and backing plate to produce the friction article.
The friction article is then removed from the oven and a clamp released from the pad and backing plate. The friction article is cooled and continually moved through a fourth bath containing a second alkaline solution to clean any grime, lm/-~G -2-lZ~88~6 oil or grease deposited on the friction article during curing of the phenolic binder. The cleansed friction article is removed from the fourth bath and thereafter con-tinually moved through a third water bath to rinse the friction article and remove the second alkaline solution therefrom. The friction article is then removed from the third water bath and thereafter continually moved through a fifth bath containing a second solution of zinc-phosphate to completely coat the entire surface of the friction article.
The friction article is then removed from the fifth bath and thereafter continually moved through a fourth water bath to neutralize the reaction between the zinc-phosphate solution on the backing plate and the metallic elements of the fric-tion article. The friction article is removed from the fourth water bath and thereafter continually moved through a sixth bath containing a solution of chromic acid, the chromic acid having a Ph of about 6.9 and reacting with the zinc-phosphate coating to form a water soluable chrome-zinc-phosphate coated friction article. The friction article is removed from the sixth bath and thereafter continually moved through a heater to dry the chrome-zinc-phosphate coated friction article. After removing the article from the heater it is continually moved through a first chamber where a water soluable lacquer is applied to the dried f~-iction article to seal the surface thereof from the atmosphere and thereby reduce the formation of oxides with the metallic elements in the friction article. The friction article is removed from the first chamber and thereafter continually moved through a second chamber where the lacquer is dried.
The lacquer coated friction article is removed from the second chamber and transported to a second work station where the chrome-zinc-phosphate coating is removed from a work surface on the friction article as a ~ork surface is ground to a specific dimension. The friction article is then packed in a container for distribution to a customer.
According to a specific embodiment of the inven-tion, the ferrous based backing plate is cleaned through immersing in the first bath containing an alkaline solution consisting of phosphates, sodium carbonates and/or sodium lm/~ -2a-~ .
~Z~8~96 hydroxide whose temperature is between 65-75c for about 2 minutes wherein grime, oil, grease or any other surface contaminants are removed without effecting the physical characteristics of the backing plate. The use of a non-silicated cleaner is preferred. After removal from this first bath and neutralization of alkaline solution through a water bath, the backing plate is inspected for the presence of ferrous oxide. If ferrous oxide is present, the backing plate is immersed in a second bath containing approximately 50% by volume of Hydrochloric acid for about 30 seconds.
The Hydrochloric acid reacts with ferrous oxide to produce a precipatate of ferrous chloride and water to further clean the ferrous based backing plate. Thereafter the cleaned backing plate is rinsed in a water bath to neutralize the Hydrochloric acid and immersed in a third bath containing a solution of zinc phosphate whose temperature is between 60-70C for about 10 minutes to produce a zinc-phosphate coat-ing on the ferrous based backing plate. The zinc-phosphate coated backing plate is neutralized in a water bath and thereafter immersed in a fourth bath containing a solution of chromic acid having a temperature of from 50-60C for about 30 seconds to creat a chrome-zinc-phosphate coating on the backing plate. Thereafter the chrome-zinc-phosphate backing plate is dried and a resin binder applied to a selected area thereof. A pad of a metallic based friction material is clamped to the backing plate over the resin binder. The binder is cured to establish a bond between the pad and backing plate and produce the friction article.
Depending on the curing process, some grime, oil, grease, or other surface contaminants may be present on the backing plate and/or pad of metallic based friction material.
lm/~C~ -2b-.,~
~d~
.~. ,~, lZ~8~96 Therefore, the friction article is returned to a fifth bath containing a second alkaline solution of phosphates, sodium carbonates and/or hydroxides, having a temperature of from 65-75 C for a period of 2 minutes to clean the friction article. After neutralizing the sodium hydroxide in a water bath, the cleaned friction article is immersed in a sixth bath containing a-solution of zinc-phosphate having a temperature of between 60-70C for about 10 minutes to add an additional zinc-phosphate coating to the backing plate lo and an initial coating to the pad of metallic based friction material. The zinc-phosphate coated friction article is rinsed in a water bath to terminate the deposition of zinc-phosphate on the friction article before being immersed in a seventh bath containing a solution of chromic acid having a temperature of between 50-600 C for about thirty seconds. The chromic acid reacting with the zinc-phosphate to create a water insoluble chrome-zinc-phosphate coating on the friction article. Thereafter, the friction article is dried and a water soluble lacquer sprayed thereon to seal the surface and thereby prevent the formation of oxides on the surface of the friction article.
The friction article is inspected and if needed, ground to a specific size before proceeding to a shipping container for distribution to a customer.
An advantage of this invention is that the chrome-zinc-phosphate coating in addition to enhancing the bond between the ferrous based backing plate and pad of mls/
~, .
12~896 metallic based friction material inhibits corrosion when the friction article is exposed to the atmosphere.
The invention will now be described with reference to the accompanying drawings wherein:
Figure l is a schematic illustration of the steps of chrome-zinc-phosphate coating a backing plate according to the principles of this invention; and Figure 2 is a schematic illustration of the steps of attaching a pad of metallic based friction material to the chrome-zinc-phosphate coated backing plate to produce a friction article which in turn is protected with a chromic-zinc-phosphate coating according to the principles of this invention.
The backing plate 10 shown in figure 1 is made from a ferrous based material. Usually backing plates 10 are stamped from a sheet of material having a uniform thickness. In order to aid in the stamping of the backing plates, a lubricant is applied to the sheet of material.
The backing plates are directly conveyed from the stamping machine to a tote box 12 for shipping to a user, normally a friction material manufacturer. By the time the backing plate reaches the friction material manufacturer, grime, oil, grease, rust and other materials may be found on the surface thereof. Necessitating the first steps of the invention disclosed herein in figure 1.
A backing plate lO is removed from tote box 12 and placed on a conveyor 15 for delivery to a first bath 14 mls/~ - 4 -12~896 containing an alkaline solution of phosphates, sodium carbonates and/or hydroxides having a Ph of between 11 and 13. To achieve this concentration between 37-53 gm of sodium hydroxide are added to a liter of solution (water).
The temperature of the solution is maintained between 65-75C. The size of the first bath 14 is selected to permit continuous movement of the backing plate 10 in the solution for between 1 and 3 minutes. This alkaline solution of phosphates, sodium hydroxides and carbonates (calcium hydroxide is also acceptable) removes grime, oil, grease, paint, dirt and other surface contaminants, but does not have an effect on ferrous oxide (rust) that may be present on the backing plate 10. Therefore, on removal from the first bath 14, the backing plate 10 is rinsed in a water bath 16 whose temperature is approximately 5-10C to neutralize or wash the alkaline solution from the backing plate 10.
The cleaned backing plate 10 is inspected for the presence of ferrous oxide. If ferrous oxide is found on the backing plate 10, the backing plate is immersed in a second bath 18 containing approximately 50% by volume of hydrochloric acid whose temperature is about 20C. The hydrochloric acid reacts with ferrous oxide on the surface of the backing plate 10 to produce as precipitate of ; ferrous chloride and water and thereby return the surface of the backing plate to its original ferrous based condition. The strength of the hydrochloric acid solution mls/~ _ 5 _ lzasss6 is such that backing plate 10 need not remain in the second bath for more than 30 seconds.
If the backing plate 10 does not have any ferrous oxide on its surface, the immersion in the second bath 18 can be omitted. However, in a continuous flow transmission line as shown in figure 1, it may be easier to clean all backing plates with hydrochloric acid rather than devise a means of selectively diverting backing plates 10 to the second bath 18 when ferrous oxide is observed on a surface thereof.
From the second tank 18, the backing plate 10 is rinsed in a water bath 20 to neutralize and remove any hydrochloric acid that may be retained on the surfaces thereof. By maintaining the temperature of the water bath between 5-10C, the speed of neutralization allows the backing plate 10 to continuous]y move through the water bath 20.
On exiting from water bath 20, backing plate 10 is conveyed to a third bath 22 containing a solution of zinc-phosphate solution which has been heated to a temperature of between 60-70C.
The concentration o~ zinc-phosphate solution is obtained by adding from 4-8% by volume of zinc-phosphate acid ZN H2 P4 to water until a desired Ph of between 2-4 is obtained. The size of this third bath has been selected such that it takes between 8-12 minutes for a backing plate 10 to pass through the tank. As the backing plate passes mlsj~
:~Z~889~
through tank 22, a coating of zinc-phosphate i9 deposited on the surface o~ backing plate 10. The thickness of the zinc-phosphate coating deposited on the surface of backing plate 10, is dependent on both the concentration of the zinc-phosphate acid and the time of reaction in this third bath 22.
Backing plate 10 is conveyed from the third bath 22 to a water bath 24 whose temperature is maintained between 5-10C. The relatively cold water neutralized the lQ zinc-phosphate acid and allows the coated backing plate 10 to be directly conveyed to a fourth bath 26.
Fourth bath 26 contains a solution of chromic acid which has been heated to a temperature of between 50-60C. The concentration of this solution is obtained by adding 1 liter of chromic acid to 400 liters of water.
This is a very weak solution and the Ph registers somewhere between 6.9-7Ø Even though this is a weak solution, when the zinc-phosphate coated backing plate 10 is immersed therein, a reaction takes place in a time period of between 20-40 seconds to create a chrome-zinc-phosphate coating on the backing plate 10. The chrome-zinc-phosphate coated backing plate 10 is conveyed from the fourth bath 26 into a dryer 28. The temperature in the dryer is maintained at approximately 45C. A higher temperature will obviously decrease drying time.
: The dried backing plate 10 is conveyed to a station 30 shown in figure 2 where a phenolic resin binder mls/ ~S _ 7 `:
lZC~896 is applied to a selected area 32 of the backing plate 10.
Pads 36 of a metallic based friction material such as disclosed in U. S. Patent 3,835,118 entitled "Sponge Iron Friction Material", which issued September 10, 1974 are located at a work station 34. A pad 36 is placed over the selected area 32 on the backing plate 10 and a clamp 38 attached thereto to provide a compressive force that holds the pad 36 to the backing plate 10.
The backing plate 10 with pad 36 clamped thereto is conveyed to an oven 40 whose temperature is about 148C.
The backing plate 10 and pad 36 remain in the oven for about 12 minutes during which time the resin binder cures to establish a bond between the backing plate 10 and pad 36 to produce a friction particle 42.
During the curing of the resin binder and the need to apply a lubricant to the clamp for ease in part removal, some type of contamination, i.e., oil, grease, grime, dirt, etc. may be deposited on the friction article 42. Although such contamination would not affect the operation of the friction article 42 for appearance purposes it has been decided to further process the friction article 42 in accordance with the teachings in this invention. The friction article 42 is conveyed from the curing oven 40 to a fifth bath 44. The fifth bath 44 contains an alkaline solution of phosphates, sodium hydroxide and/or carbonates, heated to a temperature of mls~ 8 -.. .
12~88~6 between 65-75 C. This alkaline solution is achieved by adding from 37-53 gm of sodium hydroxide to a liter of water to produce a Ph of between 11-13. The continuous moving conveyor moves the friction article 42 through the fifth bath 44 in a time period of between 1 to 3 minutes.
During this time the alkaline solution removes any contamination from the surface thereof.
The cleaned friction article 42 is rinsed in a water bath 46 whose temperature is maintained between 5-10C. The water bath 46 neutralizes the effect of the sodium hydroxide.
From water bath 46, the friction article 42 is conveyed to a sixth bath 48 containing a zinc-phosphate solution which has been heated to a temperature of between 60-70C. The concentration of zinc-phosphate solution is obtained by adding from 4-8% by volume of zinc-phosphate acid (ZN H2 P4) to water until a desired Ph of between 2-4 is obtained. The size of the sixth bath 48 is selected such that it takes between 8-12 minutes for the friction article 42 to be conveyed through tank 48. As the friction article 42 passes through tank 48, an additional coating of zinc-phosphate is deposited on the backing plate and an initial coating is deposited on the pad 36.
On removal from the sixth bath 48, friction article 42 is rinsed in a water bath 50 to neutralize the reaction coating effect of the zinc-phosphate solution.
The friction article 42 is conveyed from bath 50 mls/ ~ _ g _ ~2~889~
into a seventh bath 52 whîch contains a chromic acid solution which has been heated to a temperature of between 50-60C. The concentration of this solution is obtained by adding 1 liter of chromic acid to 400 liters of water.
Since this is a very weak acid solution thePh registers from 6.9-7Ø Even though this is a weak solution, when the zinc phosphate coated friction article 42 is immersed in tank 52, a reaction occurs in a time period of from 20-seconds to create a water insoluble chrome-zinc-phosphate coating on the entire friction article 42.
The friction article 42 is conveyed to a dryer 54where the chrome-zinc-phosphate coating is dried before being transferred to a spray chamber 56.
In the spray chamber 56, a water soluble lacquer is sprayed on the chrome-zinc-phosphate coating. The lacquer seals the coating and thus prevents the formation of oxides that may develop under some atmospheric conditions. For some application, a dip station may be utilized instead of a spray chamber 56 to accomplish this step.
From the spray chamber, the friction article proceeds to an inspection station 58 where the material is inspected in accordance to print specifications.
The friction article is then conveyed to a grinder station 60 where any excess material is removed from the operational wear surface 43 before being conveyed to a storage container 62 for shipping to a customer.
mls/~ - 10 -~Z~ 96 The quality control of the method of manufacture is checked in the following manner: Friction articles 42 are selectively removed from the production line 15 and transferred to a test station 64. At test station 64, the friction article 42 is subjected to a shear test to measure the strength of the bond between the backing plate lO and the pad of friction material 36.
In order to evaluate the method of manufacturing a friction article 42 according to this invention, the following specific method was performed.
A steel backing plate 10 was placed in the first bath 14 which contained an alkaline solution of sodium hydroxide whose temperature is approximately 71C. The concentration of sodium hydroxide in the solution was achieved by adding 45 gm of sodium hydroxide to l liter of water to produce a Ph of about 12. The backing plate 10 was immersed in the first bath 14 for 2 minutes during which time all grime, grease and oil were removed.
The backing plate after the neutralization of the sodium hydroxide solution in water bath 16 was conveyed to the second bath 18 since ferrous oxide was observed on a surface thereof.
The second bath 18 which contained a 50% by volume solution of hydrochloric acid at room temperature (20C), removed the ferrous oxide on the surface of backing plate 10 in about 30 seconds.
After neutralizing the hydrochloric acid in water mls/ ~
~Z(~8896 bath 20, the cleaned backing plate 10 was immersed in the third bath 22.
The third bath 22 which contained a solution of zinc-phosphate whose temperature was approximately 65C.
The concentration of zinc-phosphate in the solution was achieved by adding 6.5% by volume of zinc-phosphate acid to water until a Ph of 3 was obtained. Since the coating deposited on the backing plate is dependent on both the concentrations of the solution and the length of reaction time, backing plate 10 was retained in the third tank for 10 minutes.
After neutralizing the reaction of the zinc-phosphate on the ferrous based or steel backing plate 10 in water bath 24, backing plate 10 was immersed in the fourth bath 26.
The fourth bath contained a solution of chromic acid whose temperature was about 55C. The concentration of the chromic acid was obtained by adding 1 liter of chromic acid to 400 liters of water. Even with this weak solution 30 seconds were sufficient for a reaction to occur which created a chrome-zinc-phosphate coating on the ferrous or steel backing plate 10.
After drying the chrome-zinc-phosphate coated backing plate, a phenolic resin binder was applied to a selected surface and a pad of metallic friction material of the type disclosed in U. S. Patent 3,835,118 was clamped onto the backing plate lO over the resin binder.
mls/~, - 12 -12~889~i The clamped backing plate 10 and pad 36 were conveyed to oven 40 where the temperature was approximately 148C. The backing plate 10 and pad 36 were retained in the oven for approximately 12 minutes during which time the resin cured to create a bond between the backing plate 10 and pad 36 to create a friction article 42.
On removal from oven 40 and al lowed to cool to room temperature, 20C, friction article 42 was immersed in fifth bath 44.
The fifth bath 44 which contains an alkaline solution of sodium hydroxide identical to the first bath and maintained at a temperature of approximately 71 C. The friction article 42 was in bath 44 for approximately 2 minutes during which time all visible oil, grease and/or grime was removed.
After this sodium hydroxide solution was rinsed off of the friction article 42 in water bath 46, the friction article was conveyed to the sixth bath 48.
The sixth bath 48 which contained a solution of zinc-phosphate acid identical to the third bath and maintained at a temperature of 65C. The zinc-phosphate reacted with the ferrous based or steel backing plate 10 and the ferrous elements in the pad of friction material to coat the friction article 42. Since time is an important element to the thickness of the coating deposited on the friction article 42, it was determined that 10 minutes were sufficient for this application.
mls/ \,~s - 13 i.,.
lZ~8~96 After neutralizing the zinc-phosphate acid on the friction article 42 in water bath 50, the friction article 42 was conveyed to the seventh bath 52.
The seventh bath 52 which contained a chromic acid solution identical to that in the fourth bath 26 and maintained at a temperature of 54 C. The chromic acid reacts with the zinc-phosphate coating on friction article 42 to produce a water insoluble coating of chrome-zinc-phosphate in about 30 seconds.
The chrome-zinc-phosphate coated friction article was dried in a hot air oven 54 and conveyed to a spray chamber 56.
A water soluble lacquer was sprayed on the friction article 42. The water soluble lacquer dried to provide a barrier that prevents the formation of oxide on the coating.
After inspection, the friction article was ground to the proper size in grinding chamber 60. The normal procedure would be to thereafter convey this finish product to container 62 for shipping to a customer.
For evaluation purposes, two sample friction articles A and B were manufactured in a manner recognized as prior art. In this method, the backing plate is cleaned by the shot peening method before a pad of friction material is attached thereto through the curing of the phenolic resin binder. The resulting friction articles were painted with an epoxy paint to provide corrosion mls/j~ - 14 -,,, . ~ ~ c ~
12C~8896 protection. When samples A and B were tested in shear machines 64, the friction pad separated from the backing plate when subjected to 2100 and 1925 Kg of force, respectively.
Thereafter 7 samples, C-l were manufactured in accordance with the specific method set forth above. When samples C-l were tested in shear machines 64, separation occurred under the following loads: 2800, 2450, 2300, 2460, 2580, 2190 and 2650 Kg.9 respectively. The above test clearly indicates that the chrome-zinc-phosphate coating enhances the phenolic resin bond that is produced between the backing plate and the pad of friction material. In addition to the chemical attraction between the coated backing plate, resin binder and pad of friction material, the relatively low temperatures at which the coating is applied does not distort the backing plate and which results in a more uniform surface area for the bond.
Further, it is felt that the chemical reaction between the chrome-zinc-phosphate coating and the ferrous based backing plate offers better corrosion protection than that achieved through conventional painting techniques.
mls/~ - 15 -
Claims (9)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of manufacturing a friction article comprising the steps of:
continually moving a ferrous based backing plate through a first bath containing first alkaline solution to clean said backing plate;
removing said backing plate from said first bath and thereafter continually moving said backing plate through a first water bath to rinse the first alkaline solution from said cleaned backing plate;
removing said backing plate from said first water bath and thereafter continually moving said backing plate through a second bath containing a first solution of zinc-phosphate to coat the entire surface of said cleaned backing plate;
removing said backing plate from said second bath and thereafter continually moving said backing plate through a second water bath to neutralize the reaction between the first zinc-phosphate solution and the ferrous based backing plate;
removing said backing plate from said second water bath and thereafter continually moving said backing plate through a third bath containing a first solution of chromic acid, said chromic acid having a pH of about 6.9 and reacting with zinc-phosphate coating to form a water insoluble chrome-zinc-phosphate coating on said backing plate;
removing said backing plate from said third bath and thereafter continually moving said backing plate through a dryer to dry said chrome-zinc-phosphate coating;
removing said backing plate from said dryer and transporting said backing plate to a first work station;
applying a phenolic resin binder to a selected area of said chrome-zinc-phosphate backing plate;
placing a pad of metallic based friction material on said phenolic resin binder;
applying a compressive force through a clamp to hold said pad on said selected area;
continually moving said backing plate through a second oven to cure said phenolic binder and establish a bond between said pad and backing plate to produce said friction article;
removing said friction article from said oven;
releasing said clamp from said pad and backing plate;
cooling said friction article;
continually moving said friction article through a fourth bath containing a second alkaline solution to clean any grime, oil, or grease deposited on said friction article during curing of the phenolic binder;
removing said cleaned friction article from said fourth bath and thereafter continually moving said friction article through a third water bath to rinse the friction article and remove the second alkaline solution therefrom;
removing said friction article from said third water bath and thereafter continually moving said friction article through a fifth bath containing a second solution of zinc-phosphate to completely coat the entire surface of said friction article;
removing said friction article from said fifth bath and thereafter continually moving said friction article through a fourth water bath to neutralize the reaction be-tween the zinc-phosphate solution on said backing plate and the metallic elements in the friction article;
removing said friction article from said fourth water bath and thereafter continually moving said friction article through a sixth bath containing a solution of chromic acid, said chromic acid having a pH of about 6.9 and reacting with said zinc-phosphate coating to form a water insoluble chrome-zinc-phosphate coated friction article;
removing said friction article from said sixth bath and thereafter continually moving said friction article through a heater to dry said chrome-zinc-phosphate coated friction article;
removing said friction article from said heater and thereafter continually moving said friction article through a first chamber where a water soluble lacquer is applied to the dried friction article to seal the surfaces thereof from the atmosphere and thereby reduce the formation of oxides with the metallic elements in the friction article;
removing said friction article from said first chamber and thereafter continually moving said friction article through a second chamber where said lacquer is dried;
removing said lacquer coated friction article from said second chamber;
transporting said friction article to a second work station where said chrome-zinc-phosphate coating is removed from a work surface on said friction article as a work surface is ground to a specific dimension; and packing said friction article in a container for distribution to a customer.
continually moving a ferrous based backing plate through a first bath containing first alkaline solution to clean said backing plate;
removing said backing plate from said first bath and thereafter continually moving said backing plate through a first water bath to rinse the first alkaline solution from said cleaned backing plate;
removing said backing plate from said first water bath and thereafter continually moving said backing plate through a second bath containing a first solution of zinc-phosphate to coat the entire surface of said cleaned backing plate;
removing said backing plate from said second bath and thereafter continually moving said backing plate through a second water bath to neutralize the reaction between the first zinc-phosphate solution and the ferrous based backing plate;
removing said backing plate from said second water bath and thereafter continually moving said backing plate through a third bath containing a first solution of chromic acid, said chromic acid having a pH of about 6.9 and reacting with zinc-phosphate coating to form a water insoluble chrome-zinc-phosphate coating on said backing plate;
removing said backing plate from said third bath and thereafter continually moving said backing plate through a dryer to dry said chrome-zinc-phosphate coating;
removing said backing plate from said dryer and transporting said backing plate to a first work station;
applying a phenolic resin binder to a selected area of said chrome-zinc-phosphate backing plate;
placing a pad of metallic based friction material on said phenolic resin binder;
applying a compressive force through a clamp to hold said pad on said selected area;
continually moving said backing plate through a second oven to cure said phenolic binder and establish a bond between said pad and backing plate to produce said friction article;
removing said friction article from said oven;
releasing said clamp from said pad and backing plate;
cooling said friction article;
continually moving said friction article through a fourth bath containing a second alkaline solution to clean any grime, oil, or grease deposited on said friction article during curing of the phenolic binder;
removing said cleaned friction article from said fourth bath and thereafter continually moving said friction article through a third water bath to rinse the friction article and remove the second alkaline solution therefrom;
removing said friction article from said third water bath and thereafter continually moving said friction article through a fifth bath containing a second solution of zinc-phosphate to completely coat the entire surface of said friction article;
removing said friction article from said fifth bath and thereafter continually moving said friction article through a fourth water bath to neutralize the reaction be-tween the zinc-phosphate solution on said backing plate and the metallic elements in the friction article;
removing said friction article from said fourth water bath and thereafter continually moving said friction article through a sixth bath containing a solution of chromic acid, said chromic acid having a pH of about 6.9 and reacting with said zinc-phosphate coating to form a water insoluble chrome-zinc-phosphate coated friction article;
removing said friction article from said sixth bath and thereafter continually moving said friction article through a heater to dry said chrome-zinc-phosphate coated friction article;
removing said friction article from said heater and thereafter continually moving said friction article through a first chamber where a water soluble lacquer is applied to the dried friction article to seal the surfaces thereof from the atmosphere and thereby reduce the formation of oxides with the metallic elements in the friction article;
removing said friction article from said first chamber and thereafter continually moving said friction article through a second chamber where said lacquer is dried;
removing said lacquer coated friction article from said second chamber;
transporting said friction article to a second work station where said chrome-zinc-phosphate coating is removed from a work surface on said friction article as a work surface is ground to a specific dimension; and packing said friction article in a container for distribution to a customer.
2. The method of manufacturing as recited in claim 1 wherein said first alkaline solution contains from: 37 - 53 gm/1 of a material selected from a group consisting of phosphates, sodium hydroxides and carbonates, resulting in a pH of between 11 and 13, said first alkaline solution being heated to between 65-75°C, said ferrous based backing plate being immersed in said first alkaline solution for a time period of between 1-3 minutes.
3. The method of manufacture as recited in claim 1 wherein said first alkaline solution contains from 37-53 gm/1 of sodium hydroxide resulting in a Ph of between 11 and 13, said alkaline solution being heated to between 65-75°C, said ferrous based backing plate being immersed in said first solution for a time period of between 1-3 minutes.
4. The method of manufacturing as recited in claim 1 wherein said first alkaline solution contains from 37-53 gm/1 of calcium hydroxide resulting in a Ph of between 11 and 13, said alkaline solution being heated to between 65-75°C, said ferrous based backing plate being immersed in said first solution for a time period of between 1-3 minutes.
5. The method of manufacture as recited in claim 4 wherein said first solution of zinc-phosphate has a Ph of between 2 and 4 and is heated to a temperature of 60-70°C for coating the cleaned backing plate, said zinc-phosphate coating being deposited on said cleaned backing plate in a time period of from 8-12 minutes.
6. The method of manufacture as recited in claim 5 wherein said first solution of chromic acid contains 1 ? chromic acid/400 ? of water and is heated to between 50-60°C, said chrome-zinc-phosphate coating being deposited on said backing plate in a time period of from 20-40 seconds.
7. The method of manufacture as recited in claim 1 further including the steps of:
checking said lacquered friction article to measure the bond that has been developed between backing plate and pad of friction material.
checking said lacquered friction article to measure the bond that has been developed between backing plate and pad of friction material.
8. The method as recited in claim 1 wherein said applying of a water soluble lacquer is achieved through spraying the friction article.
9. The method as recited in claim 1 wherein said applying of a water soluble lacquer is achieved through dipping the friction article.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US35353682A | 1982-03-01 | 1982-03-01 | |
| US353,536 | 1982-03-01 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1208896A true CA1208896A (en) | 1986-08-05 |
Family
ID=23389543
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000422417A Expired CA1208896A (en) | 1982-03-01 | 1983-02-25 | Method of manufacturing a friction article |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPS58160638A (en) |
| AR (1) | AR231338A1 (en) |
| AU (1) | AU556370B2 (en) |
| CA (1) | CA1208896A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2683380A4 (en) * | 2011-03-10 | 2016-01-20 | Hendrickson Usa Llc | Heavy-duty vehicle brake assembly with sealing interface |
| EP3070139A4 (en) * | 2013-11-12 | 2017-06-21 | Akebono Brake Industry Co., Ltd. | Friction material |
| CN112119237A (en) * | 2018-07-31 | 2020-12-22 | 泰明顿服务责任有限公司 | Method for producing a brake lining, method for shortening the drying time of an adhesive layer applied to a lining carrier for a brake lining |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04362325A (en) * | 1991-06-07 | 1992-12-15 | Nissin Kogyo Kk | Cleaning of frictional element base plate |
| JP2002048174A (en) * | 2000-08-01 | 2002-02-15 | Nisshinbo Ind Inc | Friction member and method for manufacturing thereof |
-
1983
- 1983-02-25 CA CA000422417A patent/CA1208896A/en not_active Expired
- 1983-02-25 AR AR29223583A patent/AR231338A1/en active
- 1983-03-01 JP JP3189683A patent/JPS58160638A/en active Pending
- 1983-03-01 AU AU11923/83A patent/AU556370B2/en not_active Ceased
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2683380A4 (en) * | 2011-03-10 | 2016-01-20 | Hendrickson Usa Llc | Heavy-duty vehicle brake assembly with sealing interface |
| EP3070139A4 (en) * | 2013-11-12 | 2017-06-21 | Akebono Brake Industry Co., Ltd. | Friction material |
| US10190649B2 (en) | 2013-11-12 | 2019-01-29 | Akebono Brake Industry Co., Ltd. | Friction material |
| CN112119237A (en) * | 2018-07-31 | 2020-12-22 | 泰明顿服务责任有限公司 | Method for producing a brake lining, method for shortening the drying time of an adhesive layer applied to a lining carrier for a brake lining |
| CN112119237B (en) * | 2018-07-31 | 2022-04-08 | 泰明顿服务责任有限公司 | Method for producing a brake lining, method for shortening the drying time of an adhesive layer on a lining carrier |
Also Published As
| Publication number | Publication date |
|---|---|
| AU1192383A (en) | 1983-09-08 |
| AR231338A1 (en) | 1984-10-31 |
| JPS58160638A (en) | 1983-09-24 |
| AU556370B2 (en) | 1986-10-30 |
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