WO2023135451A1

WO2023135451A1 - A method for testing micro- and nanocoatings on al and fe materials, in particular for moulds for moulding the finished products selected from the groups of the tyre, shoe sole, and mat.

Info

Publication number: WO2023135451A1
Application number: PCT/IB2022/051887
Authority: WO
Inventors: Stefan MICHNA; Jan Novotny; Jaroslava SVOBODOVA; Petr Horcica
Original assignee: Univerzita J. E. Purkyne V Usti Nad Labem
Priority date: 2022-01-15
Filing date: 2022-03-03
Publication date: 2023-07-20
Also published as: CZ202217A3

Abstract

The invention relates to the actual process and conditions of testing on a special testing mould for testing micro- and nanocoatings on Al and Fe materials during product moulding, in particular in a vulcanisation mould, the composition of the material used for testing, the equipment used as well as standardisation of the conditions of the testing process to achieve the quality parameters of the resulting rubber moulding pieces. The testing inserts with coatings are arranged and fixed in a uniform frame and correspond to moulds for moulding the finished products selected from the groups of tyres, shoe soles, and mats.

Description

A method for testing micro- and nanocoatings on Al and Fe materials, in particular for moulds for moulding the finished products selected from the groups of the tyre, shoe sole, and mat.

Field of the Invention

[0001 ] The invention relates to a method for testing micro- and nanocoatings on Al and Fe materials, in particular for moulds for moulding the finished products selected from the groups of the tyre, shoe sole, and mat. It is a methodical procedure on the test mould and a description of the compound used for the actual testing of micro- and nanocoatings on Al and Al-Fe materials when moulding products in a vulcanisation mould.

Background of the Invention

[0002] Currently, aluminium alloys and a combination of aluminium alloy and stainless steel plates are used to make metal moulds for tyre production, especially for summer tyre moulds and winter tyre moulds, respectively. The metal mould is composed of a certain number of segments, which is usually 8 to 36 depending on the size of the tyre being produced. The metal mould surface is not treated with any surface treatment technology. The moulds are used to produce tyres by vulcanising a mixture of organic substances at higher temperatures, i.e. from 150 to 170 °C. After a certain number of cycles, i.e. the number of tyres produced, the individual segments of the metal mould are necessary to clean. Similar moulds in terms of the material used are also used to manufacture of rubber soles for footwear, rubber mats, and the like.

[0003] In recent years, surface treatment operations of functional surfaces by micro- and nanocoating have been introduced into the technology of producing metal moulds from these types of alloys. These surface treatments are intended to extend the life of the moulds, reduce the frequency of necessary cleaning and improve the surface quality of the resulting products. Currently, testing of new micro- and nanocoatings is carried out directly on the manufactured mould; the individual mould segments are subjected to a coating process, and then the moulds and the coating are tested under operation conditions during this testing. However, this testing method has several disadvantages. It does not allow, for example, to test and compare an uncoated mould with a coated one at the same time under the same conditions. In addition, this method is economically demanding, as the price of the mould ranges from CZK 0.6 to 1.2 mil. Further, only one mould and one type of material, e.g. with or without Fe plates, are possible to be tested, making the whole process more expensive and timeconsuming. Virtually, there is no so-called testing mould on the market that would eliminate these disadvantages and allow testing and comparison of several surfaces and material types at the same time. For this reason and for these purposes, the mould was invented, described, tested in operation and patented in terms of drawing documentation and production itself.

[0004] Therefore, the design of the test mould and the method of the production thereof are already covered by a separate patent. The present patent addresses the testing procedure itself, the composition of the material to be tested as well as the standard conditions of the testing process. The test price for the testing mould for 2,400 pieces of mouldings is CZK 85,000; for testing directly on finished moulds, it is from CZK 510,000 for the summer compound to CZK 650,000 for the winter compound, which represents 6 times higher costs than for the testing mould. The differences in the price of the mould are even higher, wherein the price of one finished mould for tyre production ranges from CZK 0.7 to 1 .2 million, whereas the price of the testing mould is only CZK 292,000.

Summary of the Invention

[0005] The above drawbacks are largely eliminated by the method for testing micro- and nanocoatings on Al and Fe materials, in particular for moulds for moulding the finished products selected from the groups of the tyre, shoe sole, and mat, according to the present invention. Summary of the invention is that within the testing mould containing at least three Al-alloy testing inserts and three Al-alloy testing inserts with Fe plates having the same composition as the finished-product moulds themselves, at least two A-alloy testing inserts and at least two Al-alloy testing inserts with Fe plates are provided with coatings to be tested. A semi-finished product measuring 25 to 35 x 25 to 35 x 65 to 75 mm and weighing 85 to 95 g, containing 36 to 39% wt. of rubber, 28 to 32% wt. of filler, 9 to 11 % wt. of plasticiser, 3 to 5% wt. of vulcanising agents, 15 to 17% wt. of reinforcing materials, 0.8 to 1 .2% wt. of chemicals increasing the durability and service life of the tyre and/or improve the environmental performance thereof, and 0.8 to 1 .2% wt. of other substances is placed in the testing inserts provided with coatings, after which the testing mould is placed between the upper and lower plates electrically heated at a temperature of 155 to 165 °C, and the semifinished product is moulded for 540 to 660 s under the pushing pressure of 17 to 19 MPa. The moulding pieces are then manually removed from the mould, and the individual moulding pieces are compared with each other, and further qualitative examination thereof is carried out.

[0006] The testing inserts are preferably coated by technological processes selected from the group of chemical deposition, laser sputtering and magnetron sputtering.

[0007] The patent summary consists in the testing procedure itself on a special testing mould, the composition of the material used for testing, the equipment used, as well as the standardisation of the conditions of the testing process to achieve quality parameters of the resulting rubber moulding pieces. The testing inserts with coatings are arranged and fixed in a uniform frame and correspond to moulds for moulding the finished products selected from the groups of the tyre, shoe sole, and mat.

[0008] The composition of the material used for testing is as follows.

[0009] Rubber is the most important and most represented component. Whether it is natural rubber from the tropical Brazilian rubber tree or the increasingly used synthetic rubber produced artificially from polymers contained in crude oil. However, natural rubber still outperforms synthetic rubber in some features; in particular, it remains more flexible than synthetics even at lower temperatures. The natural rubber disadvantage consists in the high price and transport costs thereof, so synthetic rubbers are widely used today. In cases where synthetic rubbers will be used in the final products, the use thereof in the material examination and testing process is not a problem. [0010] Another significant component of tyres are fillers, especially furnace black or silica. These substances add strength and hardness to the rubber and increase the resistance thereof to wear and heating. The furnace black produced from crude oil gives tyres their typical black colour.

[001 1 ] In addition, plasticisers are used. These substances are most often in the form of various mineral oils or resins and increase plasticity, thus facilitating the mechanical processing of the rubber.

[0012] Winter tyres have a significantly softer compound, which is due to the fact that they contain more oil and silica, 12 to 15% by weight overall.

[0013] Another component is vulcanising agents. It is mainly powdered sulphur affecting the rubber processing process, so-called vulcanisation. The more sulphur, the harder the resulting rubber, wherein the summer tyres contains more sulphur.

[0014] Metal or fabric fibres, such as rayon, nylon, etc., are used as reinforcing materials to give the rubber greater strength and cohesion. For the tests, the reinforcing materials of the same composition and shape as for the final products will be chosen.

[0015] In addition, special chemicals are used to increase the tyres’ resistance and durability or improve the environmental performances thereof, and the rest are other substances such as dyes, metal powders, etc.

[0016] Therefore, the mould allows up to 6 different combinations of materials and coatings to be tested in a single process, effectively reducing the financial costs of testing and examination of several micro- and nanocoatings at once, comparing them with each other, testing them under the same conditions, and shortening the overall process time. The possibility to test and compare up to 6 variants at the same time under exactly the same technical and technological conditions is a great benefit.

Brief Explanation of Drawings [0017] The method of testing micro- and nanocoatings on Al and Fe materials according to the present invention will be described in more detail in a particular example embodiment referring to the accompanying figures. Fig. 1 shows the axonometric view of the semi-finished product to be moulded. Fig. 2 shows the top view of the mould placed in a machine before moulding. Fig. 3 shows the top view of the mould placed in a machine and ready for moulding with a semifinished product. Fig. 4 shows the axonometric view of the moulding process. Fig. 5 shows the top view of the open mould after moulding with a moulding piece. Fig. 6 is a description of the individual parts of the moulding machine, and Fig. 7 shows the top view of the finished moulding piece after removal from the mould.

Examples of the Invention Embodiments

[0018] The exemplary method of testing micro- and nanocoatings on Al and Fe materials for tyre moulds comprises testing mould containing three Al-alloy testing inserts 5 and three Al-alloy testing inserts with Fe plates having the same composition as the finished-product moulds themselves, two A-alloy testing inserts and two Al-alloy testing inserts with Fe plates are provided with coatings to be tested. A semi-finished product, measuring 30 x 30 x 70 mm and weighing 90 g, is introduced into the testing inserts provided with the coatings. The semifinished product contains 38% wt. of rubber, 30% wt. of fillers, 10% wt. of plasticisers, 4% wt. of vulcanizing agents, 16% wt. of reinforcing materials, 1 .0% wt. of chemicals increasing the resistance and durability of the tyre and/or improving the environmental performance thereof, and 1.0% wt. of other substances. The testing mould is placed between the upper and lower plates 3, 6 electrically heated at a temperature of 160 °C, and the semi-finished product is moulded for 600 s with a pushing pressure of 18 MPa. After finishing the moulding, the mouldings are manually removed from the mould, the individual mouldings are compared with each other, and further qualitative examination thereof is carried out.

[0019] The testing inserts 5 are coated by technological processes selected from the group of chemical deposition, laser sputtering and magnetron sputtering. [0020] The testing mould, assembled in this way, was successfully tested with the described material and the specified test procedure methodology by moulding to produce specific semi-finished rubber compound products for the individual moulds’ needs. The resulting product, i.e. the moulding piece, is shown in Fig. 7. Products produced in this way can be compared with each other and subjected to further qualitative examination.

[0021 ] Description of the moulding in a deck-moulding machine 1 and moulding conditions on the platform of tread pattern inserts 5 with coatings:

1 . The size of the semi-finished product is approximately 30 mm x 30 mm x 70 mm as shown in FIG. 1 , wherein the weight of 90 g corresponds to the weight of the finished moulding piece with a 10% excess; the semi-finished product is at room temperature, and the composition thereof is as described above.

2. The mould and the testing inserts 5 with coatings are introduced into the testing machine according to Fig. 2, the material to be tested is added in the form of loaves, one piece per moulding, Fig. 3.

3. The temperature of the upper and lower plates electrically heated 3, 6, on which the mould is arranged, is set at 160 °C.

4. The lower plate 6 carries the compression mould 2, and the upper plate 3 has a pushing plate 4 clamped underneath - for the description of the whole equipment, see Fig. 6.

5. The moulding cycle time is 600 s (10 min), and the pushing pressure is 180 bar (18 MPa) - Fig. 4.

6. Separation with a water-based agent, frequency of separation is once every 15 offsets.

7. Manual removal of the moulding pieces from the mould - Fig. 5 and 7.

Industrial Applicability

[0022] The testing mould, along with the above process and material for testing micro- and nanocoatings on Al and Fe materials during product moulding, in particular in a vulcanisation mould, according to the present invention, finds the application thereof mainly in the automotive and textile industry for testing coated moulds intended for the manufacture of products of a vulcanisation compound, such as tyres, shoe soles, mats, etc. Reference Signs List

[0023]

1. deck-moulding machine;

2. compression mould

3. upper plate electrically heated 4. pushing plate

5. tread pattern inserts

6. lower plate electrically heated

Claims

8 CLAIMS

1 . A method for testing micro- and nanocoatings on Al and Fe materials, in particular for moulds intended for moulding finished products selected from the groups of tyre, shoe sole, and mat, characterised in that the testing mould comprising at least three Al alloy testing inserts and three Al alloy testing inserts with Fe plates, having the same composition as the moulds intended for moulding the finished products themselves, wherein at least two Al alloy testing inserts and at least two Al alloy testing inserts with Fe plates are provided with testing coatings, and the semi-finished product measuring 25 to 35 x 25 to 35 x 65 to 75mm, weighing 85 to 95g, and containing 36 to 39% wt. of rubber, 28 to 32% wt. of fillers, 9 to 1 1 % wt. of plasticisers, 3 to 5% wt. of vulcanising agents, 15 to 17% wt. of reinforcing materials, 0.8 to 1 .2% wt. of chemicals increasing the durability and life of the tyre and/or improving the environmental performance thereof, and 0.8 to 1 .2% wt. of other substances is introduced into the testing inserts provided with coatings, whereupon the testing mould is placed between upper and lower plates (3, 6) electrically heated at a temperature of 150 to 170 °C, and the semi-finished product is moulded for 540 to 660 seconds at a pushing pressure of 17 to 19 MPa, after which the moulding pieces are manually removed form the mould and the moulding pieces are compared with each other and further qualitatively examined.

2. The testing method according to claim 1 , characterised in that the testing inserts are coated by technological processes selected from the group consisting of chemical deposition, laser sputtering, and magnetron sputtering.