GB1600543A

GB1600543A - Method and apparatus for continuous manufacture of a coated material

Info

Publication number: GB1600543A
Application number: GB337578A
Authority: GB
Original assignee: GLYCO METALL WERKE; Glyco Metall Werke Daelen und Loos GmbH
Current assignee: GLYCO METALL WERKE; Glyco Metall Werke Daelen und Loos GmbH
Priority date: 1977-02-15
Filing date: 1978-01-27
Publication date: 1981-10-21
Also published as: IT1089322B; FR2380134B3; JPS53101071A; DE2706328A1; AR213018A1; FR2380134A1; PL203950A1; ES467014A1; BR7706919A

Description

(54) METHOD AND APPARATUS FOR CONTINUOUS MANUFACTURE OF A COATED MATERIAL (71) We, GLYCO-METALL-WERKE DAELEN & LOOS G.m.b.H., a German limited liability company, of 6200 Wiesbaden-Schierstein, Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particu larly described in and by the following state ment:- This invention relates to a method and apparatus for continuous manufacture of a coated material having a metallic or non-metallic carrier material and a coating of thermoplastics material. In particular, the invention relates to the provision of a coated material which is suitable for the production of thin-walled plain bearings or plain bearing elements which require high compression strength.

A metal-synthetic plastics coated material with a sliding bearing layer of polyamide 11 is known from German Specification No. 24 21 224. The connection between the carrier material and the sliding bearing layer is provided by a layer of epoxy resin.

The method of producing this coated material calls for a plurality of operations, a layer of epoxy resin in powder form first being applied to the carrier material after which the polyamide 11 is likewise sprinkled on in powder form. The epoxy resin is then maintained in an oven at a temperature of from 100" to 1200C until all the powder has melted. At this stage, the temperature is raised to 1 820C so that the polyamide 11 powder forms a closed layer over the molten epoxy resin. After cooling, the coated material which is so produced is compressed to a required thickness between a .pair of rollers. The intention at this stage is to apply to the epoxy resin layer a loading such as to produce a plastic deformation and to achieve an optimum thickness tolerance in the coated material.

However, this known method has disadvantages, particularly in that the production cycle is expensive in terms of cost and energy due to the relatively long holding times. Despite prolonged and expensive oven holding time, the duration is not sufficient necessarily to convert the epoxy resin to the C-stage, so that subsequent hardening is needed. Similarly, it is not possible, under control, to apply the layer of powdered epoxy resin sufficiently thinly. Experience has shown that a further disadvantage is that the epoxy resin does not provide over the entire width of the strip optimum adhesion to the polyamide 11. Experience has shown that additives such as MoS2 or graphite in the intermediate layer system likewise lead to further impairment of adhesion to the low friction material.It is also conventional for the known (see German Specification No 23 23 895) intermediate layers of epoxy resin, polyester resin, acrylic resin, and phenol resin to be spread onto the carrier material or for a further layer to be applied prior to final hardening of the intermediate layer. In this case, the additional time required for complete hardening of the intermediate layer is undesirably long and interferes with production flow.

Also known from German Specification No.

23 23 895 is a method of producing sliding bearing surfaces for machine parts. It relates particularly to a separately manufactured stripform sliding bearing coating consisting of a thermoplastics material, for example polytetrafluorethylene, polyamide, or a duroplastics material such as epoxy resin, polyester resin, or acrylic resin, with pockets of lubricant impressed into the surface and adhered onto a strip-like carrier material. Mentioned as a suitable adhesive is an unnamed rapidly hardening synthetic plastics adhesive. As a further alternative, it is known from German Specification No. 23 23 895 to apply to the strip-like carrier material a self-adhesive layer which is covered by a separating film requiring to be pulled off prior to adhesion to the sliding bearing coating.

This method does not provide a satisfactory solution to the economic manufacture of coating materials either, since several operations are in each case required to produce such a coating material.

It is also known (from German Specification No. 16 25 546) to build up a coated or plain bearing material from a supporting metal body and a sliding bearing layer of synthetic plastics such as a polyamide or polyacetylene, this layer having impressed lubricant pockets. Indicated as production methods in this connection are:spraying, dipping, vacuum application, roller application, brushing on, extrusion moulding, lamination and gluing. There is however no mention of intermediate layers to improve adhesion between the carrier material and the sliding bearing layer, so that physically occasioned disadvantages of inadequate adhesion between the carrier material and the sliding bearing layer must be expected with such known materials.Further, the uneconomic method of production is a disadvantage for large scale production, since these known methods only provide for manufacture in pieces.

Thus the invention is based on the problem of producing a laminated material by an economic and continuous method, whereby, despite the use of an intermediate layer, the above-described disadvantages such as complicated application of the intermediate layer, long holding times and possibly additional heat treatment, can largely be avoided.

According to this invention there is provided a method of making a coated material which comprises a carrier material with a thermoplastics coating, the method comprising:- i) coating one or both faces of the carrier material with solventcontaining bonding agent;ii) drying the coated carrier material by completely evaporating the solvent of the bonding agent; iii) further coating at least one side of the coated carrier material with a thermoplastics material;iv) melting the thermoplastics material; and v) rolling the coated carrier material to cause it to become a laminated material.

Also according to this invention there is provided a method for continuous production of a coated material having a metallic or nonmetallic carrier material and a coating of thermoplastics material wherein, in a single passage, initially the carrier material, having been cleaned and if necessary degreased, has one or both its surfaces coated by spraying with a thin layer of solvent-containing bonding agent, which is then dried by complete evaporation of the solvent, whereupon the coated carrier material is, while still hot, coated at least on one side with a thermoplastics material which is thereafter melted under independently regulated top and bottom heat, and finally, while still warm, the multi-layer material produced is .converted to a laminated material suitable for further processing without additional preparation, by being rolled at a regulated temperature until it is of the necessary thickness, after which it is cooled.

The invention also includes apparatus for carrying out the method, in which apparatus there are disposed seriatim to form a single run: a) a cleaning and degreasing means for the carrier material; b) a first spray means for applying a thin layer of the solvent containing bonding agent on each side of the carrier maerial; c) a through-flow heavy duty dryer with means for circulating air and evaporating the solvent from the bonding agent layer; d) a second spray means for applying the thermoplastics material onto one surface of the still not coated carrier material; e) a through-flow oven with independently regulable top and bottom heat; f) a rolling device with regulated roll heating; and g) a through-flow cooling means.

The invention offers the advantage that it meets the problem posed in that an intermediate layer which is easily worked in a continuous process is applied to the carrier material and at the same time provides optimum adhesion with the thermoplastics coating, which may be a low friction material. In addition, the method can ensure a very thin and even application of the intermediate layer of bonding agent over the entire width of carrier material, preferably a strip, avoiding the disadvantages in respect of layer thickness and irregular adhesion which arise when a powdered material is sprinkled onto a backing.

In addition to resolving the technical problem posed, short processing time may be achieved while maintaining sufficient accuracy in application of the thermoplastics coating material, in order to meet the requirements of economical manufacture. The manner of applying the solvent-containing bonding agent and also the thermoplastics coating material, which preferably constitutes a low friction layer, is preferably of an electro-static nature.

As thermoplastics materials which can constitute a low friction layer, preferably polyamide, in particular polyamide 11, or polyoxymethylene or polypropylene can be used. In conjunction with these thermoplastics materials, solvent-containing bonding agents based on a butadiene-styrene-copolymer can be used for polyamide or solvent-containing bonding agents from the group of silanes, particularly silane with agents with polyacid formiate, or acid with polyazide formate, or a silane with azide formate functional groups for polypropylene or polyoxymethylene. Such bonding agents can be applied to the carrier material by electrostatic spraying in a liquid solvent-containing form.

The electrostatic spraying ensures continuous application of a thin layer of bonding agent extending easily over the entire width of the strip.

The preferred range of thicknesses is from 5pm to 20pom, and preferably between 7,um and 10pom.

The scope of the invention includes for example also the coating of a metallic carrier material with thermoplastics material which is based on polyethylene or polyethylene terephthalate or polybutylene terephthalate. In such a case bonding agents from the group of copolymers of ethylene, acrylic acid amide and acrylic acid ester or alklyl vinyl ethers obtained under high pressure by radical polymerisation, are suitable. Also, due to its solvent content, the bonding agent is present in a virtually liquid condition and is preferably electrostatically ap plied in the above-indicated regular layer thick ness.

The solvent in the bonding agent is evap orated off continuously in a downstream, re cycled air, heavy duty dryer at a temperature between 90 and 160 C and preferably between 90 and 110"C. A high rate of air circulation and a high temperature in the drying duct result in a short processing time for the strip material.

In any case, it is intended to ensure that the sol vent be completely removed from the bonding agent so that during subsequent application of a thermoplastics low-friction layer, no bonding faults occur.

In principle, the thermoplastics coating material can be applied by various known methods, for example sprinkling on in powder form or electrostatic powder coating, and appli cation of the thermoplastics material in powder form with an electrostatic applicator has been found to be most suitable, since it ensures a reliably even coating. However, if the thermoplastics powder material is applied in some manner other than electrostatically, it is essential to restrict the thickness of the layer of sprinkled on powdered material, for example by using a doctor blade.

Following application of the thermoplastics powder material, the coated strip material is passed through an oven having independently regulated top and bottom heat. Regulation of the temperature in the separate parts of the oven ensures that with short processing times, reliable and complete melting of the thermoplastics material occurs, with no decomposition. After melting of the thermoplastics material, the strip-form coated material is fedinthe warm state to a hot rolling assembly, for example having a shaped top roller which impresses lubricant pockets into the surface of the still plastically deformable low friction material, while at the same time producing a laminate of the necessary thickness.After the rolling stage there is a cooling stage which cools the coated strip material sufficiently that it can be wound into a roll and further processed, with no additional heat treatment.

An advantage of the invention is that a laminate can be economically produced in a single pass with no separate heat treatment.

By the method of the invention, it is preferable to produce a laminated coated material having a carrier material which is an acid-resistant non-rusting spring steel. However, other metallic carrier materials, for example steel of a standard specification, or bronze, brass, copper, aluminium and its alloys, and also metallic laminated materials, for example aluminiumplated steel, may be used.

In addition, also non-metallic carrier materials, for example "Bakelite" (Registered Trade Mark), or heat resistant film may be con sidere d.

The layer thickness of the carrier material may be as required and is preferably in the range of from 0.2 mm to 0.5 mm.

It is preferable to use polyamide 11 as the low friction thermoplastics coating material.

However, the method also includes other possibly heavier thermoplastics or duroplastics materials which have to be bonded to a smooth metallic carrier material. The low friction material may be blended with friction-enhancing additives for example MoS2, graphite, carbon, aluminium, or cadmium, as well as friction-reducing and temperature stabilising fillers. Such fillers may be chosen from the following or may be a mixture chosen from the following:- a metal oxide, metal carbide, metal boride, metal sulphide, lead, copper, bronze, tin, silver, indium, thalium, silicon, nickel, magnesium, antimony, plain bearing alloys in powder form, whisker form or as cermets.As is known, mixtures of powdered thermoplastics materials and powdered friction-reducing and temperature-stabilising fillers often tend to segregate when applied to the carrier and during melting of the thermoplastics material, particularly where low viscosity conditions arise. In order to avoid this segregation and in order further to enhance the physical properties, additional fine fibrous material, for example asbestos fibres, may be added to the mixture of materials constituting the low friction coating layer.

However, also other fibrous materials such as glass, boron nitride, graphite, carbon, molybdenum, silicon dioxide, copper, silver, aluminium and synthetic materials may be used. The fibre length should be restricted to 0.01 to 0.3 mm.

The low friction coating layer to be applied should be between 0.1 mm and 0.5 mm thick and preferably between 0.3 and 0.4 mm thick.

The slip-improving and temperature-stabilising as well as other additives which favourably influence the physical properties of the bearing material should amount to between 5% and 50% by volume and preferably between 10 and 30% by volume.

An embodiment of apparatus for carrying out the method will now be described, with reference to the drawing, the single figure of which is a diagrammatic side view.

Referring to the drawing, a spring steel strip 1,0.3 mm thick, is drawn continuously from a reel 2 and fed through a cleaning and scouring device 3, whence the strip 1, cleaned and degreased on both surfaces, passes into a first heatable spray box 4, in which it is coated on both surfaces with solvent-containing bonding agent by means of electrostatic spray devices 5.

The bonding agent is continuously fed to the electrostatic spray devices 5 from storage containers 5', in which the bonding agent is adjusted by solvents to the viscosity required for electrostatic spraying. The rear wall of the spray box 4 is flushed with water so that any bonding agent which does not strike the strip 1 is picked up by the film ofwater. An appropriate bonding agent is butadiene-styrene copolymer.

The electrostatically applied layer of bonding agent is for example 8pm thick.

The spring steel strip 1' which, when it leaves the spray cubicle 4, is coated on both sides with bonding agent, runs into a throughflow heavy duty dryer 6 equipped with means 7 for air circulation and for example with infrared radiant heaters 8, the temperature therein generally being within the range of 90"C to 160"C. Effective evaporation of the bonding agent occurs at about 100 C in the heavy duty dryer 6.

The strip 1' coated on both sides with a layer of bonding agent then passes into a second heatable spray box 9 which has only one electrostatic spray device 10 so that a low friction layer of plastics material can be applied to one side of the strip 1'. The spray box 9 includes powder recovery means (not shown).

The electrostatic spray device 10 is fed by a mixing apparatus 11 with a mixture of thermoplastics material, friction-reducing and temperature-stabilising additives, and mechanically stabilising fine fibrous additives.

The thermoplastics material (in the present embodiment, polyamide 11) is supplied from a storage container 12, the friction-reducing and temperature-stabilising additives from a storage container 13, and the fine fibrous additive from astorage container 14,in each case in quantities dispensed according to the required ratio of mixture, into the mixing apparatus 11. If the electrostatic spraying apparatus 10 is constructed to spray dry, powdered or fine fibrous material, mixing and feeding to the spray apparatus 10 may occur in the dry state. (It is however also possible to form an intensively blended dispersion of solvent in the mixing apparatus 11 and to feed it to the electrostatic spraying apparatus 10, if the spray box 9 has a rear wall over which a film of water is flushed).

Now coated on one side with a layer of low friction plastics material, the strip 1" passes through a continuous or through-flow oven 15, the bottom heat 16 and the top heat 17 of which can be regulated independently, as shown. In this oven, the sprayedon mixture of thermoplastics material, friction-reducing and temperature-stabilising additives and fibrous additive is melted together to form one complete layer. The strip 1" from the oven 16 passes into a rolling assembly 18, of which the rollers 19 .and 20, as indicated, are regulable in temperature. In the rolling assembly 18, the low friction layer, not yet fully cooled, is reduced to the required final thickness. The upper roller 19 may be shaped to provide in the bearing coating, in the same rolling operation, depressions to accommodate initial lubricant.The strip 1 leaving the rolling assembly 18 then passes into a through-flow cooling device 21 in which the thermoplastics layer is completely cooled. The strip is then wound into a roll 22.

WHAT WE CLAIM IS: 1. A method of making a coated material which comprises a carrier material with a thermo-plastics coating, the method comprising: i) coating one or both faces of the carrier material with solvent-containing bonding agent; ii) drying the coated carrier material by completely evaporating the solvent of the bonding agent; iii) further coating at least one side of the coated carrier material with a thermoplastics material; iv) melting the thermoplastics material; and v) rolling the coated carrier material to cause it to become a laminated material.

2. A method for continuous production of a coated material having a metallic or non-metallic carrier material and a coating of thermoplastics material wherein, in a single passage, initially the carrier material, having been cleaned and if necessary degreased, has one or both its surfaces coated by spraying with a thin layer of solvent-containing bonding agent, which is then dried by complete evaporation of the solvent, whereupon the coated carrier material is, while still hot, coated at least on one side with a thermoplastics material which is thereafter melted under independently regulated top and bottom heat, and finally, while still warm, the multi-layer material produced is converted to a laminated material suitable for further processing without additional preparation, by being rolled at a regulated temperature until it is of the necessary thickness, after which it is cooled.

3. A method according to Claim 2 wherein the bonding agent is sprayed onto the carrier material electrostatically.

4. A method according to Claim 2 or Claim 3 wherein the bonding agent is of low viscosity.

5. A method according to Claim 2 or Claim 3 wherein the carrier material coated with bonding agent is electrostatically coated on one side with a thermoplastics material.

6. A method according to Claim 5 wherein electrostatic coating occurs with the thermoplastics material in powder form.

7. A method according to any preceding claim wherein the thermoplastics material is or contains polyamide, polyamide 11, polypropylene, polyoxymethylene, polyethyleneterephthalate, or polybutylenetherephthalate.

8. A method according to Claim 7 wherein the bonding agent comprises butadiene-styrene copolymer or contains such a copolymer if the thermoplastics material is polyamide.

9. A method according to Claim 8 wherein the bonding agent in the form of solvent-containing butadiene-styrene copolymer is applied in a layer 5 to 20pom thick, te the carrier material and is then exposed to circulating air at a temperature of between 90"C and 1 10"C.

10. A method according to Claim 9 wherein the layer is 7 to 10 elm thick.

11. A method according to Claim 8 wherein

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. bonding agent is butadiene-styrene copolymer. The electrostatically applied layer of bonding agent is for example 8pm thick. The spring steel strip 1' which, when it leaves the spray cubicle 4, is coated on both sides with bonding agent, runs into a throughflow heavy duty dryer 6 equipped with means 7 for air circulation and for example with infrared radiant heaters 8, the temperature therein generally being within the range of 90"C to 160"C. Effective evaporation of the bonding agent occurs at about 100 C in the heavy duty dryer 6. The strip 1' coated on both sides with a layer of bonding agent then passes into a second heatable spray box 9 which has only one electrostatic spray device 10 so that a low friction layer of plastics material can be applied to one side of the strip 1'. The spray box 9 includes powder recovery means (not shown). The electrostatic spray device 10 is fed by a mixing apparatus 11 with a mixture of thermoplastics material, friction-reducing and temperature-stabilising additives, and mechanically stabilising fine fibrous additives. The thermoplastics material (in the present embodiment, polyamide 11) is supplied from a storage container 12, the friction-reducing and temperature-stabilising additives from a storage container 13, and the fine fibrous additive from astorage container 14,in each case in quantities dispensed according to the required ratio of mixture, into the mixing apparatus 11. If the electrostatic spraying apparatus 10 is constructed to spray dry, powdered or fine fibrous material, mixing and feeding to the spray apparatus 10 may occur in the dry state. (It is however also possible to form an intensively blended dispersion of solvent in the mixing apparatus 11 and to feed it to the electrostatic spraying apparatus 10, if the spray box 9 has a rear wall over which a film of water is flushed). Now coated on one side with a layer of low friction plastics material, the strip 1" passes through a continuous or through-flow oven 15, the bottom heat 16 and the top heat 17 of which can be regulated independently, as shown. In this oven, the sprayedon mixture of thermoplastics material, friction-reducing and temperature-stabilising additives and fibrous additive is melted together to form one complete layer. The strip 1" from the oven 16 passes into a rolling assembly 18, of which the rollers 19 .and 20, as indicated, are regulable in temperature. In the rolling assembly 18, the low friction layer, not yet fully cooled, is reduced to the required final thickness. The upper roller 19 may be shaped to provide in the bearing coating, in the same rolling operation, depressions to accommodate initial lubricant.The strip 1 leaving the rolling assembly 18 then passes into a through-flow cooling device 21 in which the thermoplastics layer is completely cooled. The strip is then wound into a roll 22. WHAT WE CLAIM IS:

1. A method of making a coated material which comprises a carrier material with a thermo-plastics coating, the method comprising: i) coating one or both faces of the carrier material with solvent-containing bonding agent; ii) drying the coated carrier material by completely evaporating the solvent of the bonding agent; iii) further coating at least one side of the coated carrier material with a thermoplastics material; iv) melting the thermoplastics material; and v) rolling the coated carrier material to cause it to become a laminated material.

10. A method according to Claim 9 wherein the layer is 7 to 10 elm thick.

11. A method according to Claim 8 wherein

the bonding agent is a silane.

12. A method according to Claim 11 wherein the bonding agent is a silane with poly azide form ate, or is a silane with azide formate functional groups if the thermoplastics ma terial is or contains polypropylne or polyoxy methylene.

13. A method according to any of Claims 2 to 6 wherein the carrier material is metallic, the thermoplastics material is or contains polyethy lene or polyethyleneterephthalate or polybuty leneterephthalate and the bonding agent com prises copolymers of ethylene, acrylic acid amide and acrylic acid esters or alkyl vinyl ethers obtained by radical polymerisation under high pressure, or contains such copolymers.

14. A method according to any preceding claim wherein during rolling of the laminated material, the surface of the thermoplastics material is at the same time provided with depressions.

15. A method according to any preceding claim wherein the carrier material is of spring steel, or of bronze, brass, aluminium or alumin ium alloy or aluminium-plated steel.

16. A method according to any of Claims 2 to 14 wherein the carrier material is a non metallic heat-resistant film.

17. A method according to Claim 15 or 16 wherein the range of thicknesses of the carrier material is from 0.1 mum to 2 mm.

18. A method according to Claim 17 wherein the said thickness is from 0.2 to 0.5 mm.

19. A method according to any preceding claim wherein a low friction layer of a thickness of from 0.1 mm to 0.5 mm is formed by the thermoplastics material.

20. A method according to Claim 19 wherein the said thickness is from 0.3 to 0.4 mm.

21. A method according to Claim 19 or Claim 20 wherein, in mixture with the thermoplastics material, additives to improve friction and/or stabilise temperature and/or improve other physical properties are applied in powder, whisker or cermet form.

22. A method according to Claim 3 wherein the additives are chosen from MoS2, graphite carbon, aluminium, cadmium, metal oxide, metal carbide, metal boride, metal sulphide, lead, copper, bronze, tin, silver, indium, thalium, silicon, nickel, magnesium, antimony, .and metal alloys.

23. A method according to any of Claims 19 to 22 wherein the mixture with the thermoplastics material and if applicable friction diminishing and temperature-stabilising additives, mechanically-stabilising fibrous filler is applied.

24. A method according to Claim 23 wherein a mechanically stabilising fibrous filler is chosen from or is a mixture of the following materials: asbestos, glass, boron, nitride, graphite, carbon, molybdenum, silicon dioxide, copper, silver, and aluminium.

25. A method according to Claim 23 or Claim 24 wherein fibre length is from 0.01 to 0.3 mm.

26. A method according to any of Claims 21 to 25 wherein friction-reducing and temperature-stabilising additives and/or mechanically stabilising additives are admixed with the powdered thermoplastics material in powder form or in finely fibrous form, the mixture being electrostatically applied to form a low friction layer.

27. A method according to any of Claims 21 to 26 wherein the quantity of additives is from 5% to 50% by volume.

28. A method according to Claim 27 wherein the said quantity is from 10% to 30% by volume.

29. Apparatus for carrying out the method according to any preceding claim wherein, disposed seriatim to form a single run, are: a) a cleaning and degreasing means for the carrier material; b) a first spray means for applying a thin layer of the solvent-containing bonding agent on each side of the carrier material; c) a through-flow heavy duty dryer with means for circulating air and evaporating the solvent from the bonding agent layer; d) a second spray means for applying the thermoplastics material onto one surface of the still not coated carrier material; e) a through-flow oven with independently regulable top and bottom heat; f) a rolling device with regulated roll heating; and g) a through-flow cooling means.

30. Apparatus according to Claim 29 wherein the first spray means is heated.

31. Apparatus according to Claim 30 wherein the first spray means has a waterflushed rear wall.

32. Apparatus according to any of Claims 29 to 31 wherein the second spray means is heated.

33. Apparatus according to Claim 32 wherein the second spray means includes a powder recovery device.

34. Apparatus according to any of Claims 29 to 33 wherein, to apply the thermoplastics material, the second spray means includes an electrostatic spray device which is connected to a mixing device for the thermoplastics material, the friction-improving and temperature-stabilising additives, and, if applicable, the fine fibrous stabilising material.

35. Apparatus according to Claim 34 wherein the electrostatic spray apparatus for spraying powdered material and the mixing apparatus are constructed and arranged to produce a powdered mixture.

36. Apparatus according to Claim 34 wherein the spraying apparatus is constructed and arranged for electrostatic spraying of a dispersion of powdered or fine fibrous materials and the mixing apparatus is equipped with means of adjusting a dispersion to the viscosity suitable for electrostatic spraying.

37. Apparatus according to any of Claims 29 to 36 wherein the rolling device has a profiled roll for impressing depressions into the layer of thermoplastics material, to accommodate initial lubricant.

38. A method of making a coated strip material substantially as herein described with reference to the drawing.

39. Apparatus for making a coated strip material constructed and arranged substantially as herein described and shown in the accom panying drawing.