Coating production process for improving rubbing-resistant color fastness and illumination color fastness of automobile punching leather

Abstract

The invention belongs to the technical field of production of automobile seat perforated leather, and discloses a coating production process for improving rubbing color fastness and illumination color fastness of automobile perforated leather. The technological process comprises the steps of bottom sealing, prime coating, embossing, punching, dust removal, protective coating bonding, floating coating and top coating. And a physical protection layer is provided, so that the problems of rubbing-resistant color fastness and illumination-resistant color fastness of the hole leather are fundamentally solved.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile seat perforated leather production, and relates to a coating production process for improving the friction resistance color fastness and light color fastness of automobile perforated leather. Background Art

[0002] In the field of car seat design and manufacturing, leather is widely popular for its unique texture, aesthetics and comfort. Especially in car seat leather, in order to improve the breathability and ventilation performance of the seat, the leather material will be punched during use. However, a major problem faced by perforated leather materials during use is insufficient friction color fastness, that is, color migration or fading is prone to occur when repeatedly rubbed or in contact with other substances, which not only affects the aesthetics of the seat, but may also cause pollution to the passengers' clothes. Under the current retanning and dyeing process, the brighter the color of the leather blank, the worse the friction color fastness after coating and punching. Moreover, after long-term use, the color of the leather blank will turn yellow due to aging such as light, which will produce an unsightly effect visually.

[0003] At present, the processing technology of leather perforation for automobile seats is generally to perform perforation after the coating process is completed and the coating is completely reacted and cured. The process flow of leather coating perforation is: back cover → base coating → embossing → middle coating → top coating → perforation.

[0004] The test method for the color fastness of perforated leather to friction resistance adopts the test method specified in QB / T 2537-2001. When wet friction is performed, the residual water in the felt will be absorbed by the cross-section of the leather blank inside the perforation, causing the leather blank to expand and deform after absorbing water, so that the felt will contact the cross-section of the coating and the cross-section of the leather blank when rubbing against the leather. Due to the limitations of current leather dyeing machines, the leather blank will fade during the friction process, and the leather coating will increase the risk of damage.

[0005] The principle of leather dyes combining with leather mainly involves the effects of two levels: chemistry and physics. At the chemical level, dye molecules react chemically with collagen in leather fibers to form stable chemical bonds; at the physical level, dye molecules enter the leather fibers through physical adsorption and penetration and are tightly combined with the leather fibers. The principle of leather dyes combining with leather involves the formation of chemical bonds and physical adsorption. Different types of dyes combine with leather fibers through different mechanisms to achieve dyeing effects. At present, the most commonly used dyes for automotive leather are the following two categories, acid dyes and metal complex dyes. The following are the principles of the combination of the two dyes with leather:

[0006] 1. Combination of acid dyes and leather

[0007] Acid dyes are a type of commonly used leather dyes. They usually contain acidic groups, such as sulfate or carboxyl groups. These acidic groups can form ionic bonds with amino groups in leather to form stable chemical bonds. In addition, the molecular structure of acid dyes is usually small, which can penetrate into the micropores of leather fibers and bind to leather fibers through physical adsorption.

[0008] 2. Combination of metal complex dyes and leather

[0009] Metal complex dyes contain metal ions, such as chromium and cobalt, which can form coordination bonds with functional groups such as carboxyl and hydroxyl groups in leather, thereby tightly binding to leather fibers. Metal complex dyes have strong binding force, and the dyed leather has good color fastness and weather resistance. Metal complex dyes can also penetrate into the micropores of leather fibers and bind to leather fibers through physical adsorption.

[0010] From the principle of dyeing, it can be found that dyes will be combined with leather fibers through physical adsorption. Therefore, it is inevitable that the leather blank will fade during the friction resistance color fastness test, and the dye will be transferred to the test felt, resulting in test failure.

[0011] The light aging test of perforated leather is carried out according to the provisions of GB / T 32088-2015, and the test time is 200h. The grayscale level of the sample is evaluated according to GB / T 250. Due to the dyeing mechanism of leather and the characteristics of the dye itself, it will turn yellow after long-term light exposure, so the cross section of the perforated leather will fade and turn yellow after light exposure.

[0012] Patent number CN209794788U, a high-property perforated car seat leather, discloses a solution to improve friction resistance, but fails to solve the problem of color fastness to light of the perforated leather, and the hole diameter is limited to 1.0-1.2mm, and the alcohol friction resistance is poor. Patent number CN207435468U, a heat-shrinkable perforated leather dual-color effect instrument panel leather, discloses a instrument steering wheel leather that can form a visual dual-color effect, but does not consider the problem of color fastness to light of the perforated leather. Summary of the invention

[0013] In order to overcome the deficiencies of the prior art and to solve the above two stubborn problems, the present invention provides a coating production process for improving the color fastness to friction and color fastness to light of perforated leather for automobiles. The present invention develops a new production process and provides a physical protective layer to fundamentally solve the color fastness to friction and color fastness to light of perforated leather.

[0014] The above object of the present invention is achieved through the following technical solutions:

[0015] A coating production process for improving the color fastness of automobile perforated leather under friction and light; the process flow is: bottom sealing → primer → embossing → perforation → dust removal → followed by protective coating → intermediate coating → top coating.

[0016] The protective coating includes water-based small molecule acrylic resin, water-based aliphatic polyurethane resin, organic and inorganic pigment paste, sodium dodecylbenzene sulfonate, light stabilizer (HALS), isocyanate crosslinking agent and water.

[0017] The specific formula of the protective coating is as follows: 18-22wt% of water-based small molecule acrylic resin, 35-45wt% of water-based aliphatic polyurethane resin, 15-25wt% of water, 8-12wt% of organic and inorganic pigment paste, 0.4-0.6wt% of sodium dodecylbenzene sulfonate, 2-4wt% of light stabilizer (HALS), and 5.5-7.5wt% of isocyanate crosslinker.

[0018] The specific formula of the protective coating is preferably as follows: 20wt% of water-based small molecule acrylic resin, 40wt% of water-based aliphatic polyurethane resin, 20wt% of water, 10wt% of organic and inorganic pigment paste, 0.5wt% of sodium dodecylbenzene sulfonate, 3wt% of light stabilizer (HALS), and 6.5wt% of isocyanate crosslinker.

[0019] A coating production process for improving the color fastness to friction and light of automobile perforated leather, the specific steps are:

[0020] S1. Back cover: Car leather batch production, back cover operation, get the leather after back cover, make the back fiber fixed, convenient for subsequent punching operation;

[0021] S2. Primer: Use a reverse roller coater to roll the water-based pigment primer slurry onto the front of the leather after the back cover to form a coating film, and obtain the leather after primer coating. The roller coating amount is 100±20g / ㎡. After roller coating, it is dried in a drying channel at a drying temperature of 110-130℃. The primer slurry includes water, acrylic resin, pigment paste, crosslinking agent, and additives. The viscosity of the primer slurry is No. 6 Ford Cup 25-30 seconds;

[0022] S3. Embossing: Use a through-type embossing machine with the corresponding embossing roller to emboss the leather after primer coating; sandblast pattern, 100℃, 6m, 50bar. Obtain the embossed leather;

[0023] S4. Punching: Punching the embossed leather according to the hole type information required by the working conditions to obtain a semi-finished leather after punching;

[0024] S5. Dust removal: Use a negative pressure dust collector to remove dust from the semi-finished leather after punching, remove impurities such as fibers generated by the punching operation, and obtain the semi-finished leather after dust removal. The operating conditions are set to negative pressure 0.2-0.5 bar and speed 14-16m / min;

[0025] S6. Adhesive protective coating: The viscosity of the adhesive protective coating chemical is adjusted in the range of 22-26 seconds for No. 4 Ford Cup. The slurry of the adhesive protective coating is sprayed on the base coating of the semi-finished leather after dust removal by a sprayer, and adheres to the top of the base coating. Part of the chemical is sprayed into the hole and adheres to the inner wall of the perforated hole. Then it passes through a 120℃-130℃ drying channel at a speed of 10m / min, so that the slurry of the adhesive protective coating forms a film on the surface of the base coating and the inner wall of the hole, and forms a continuous adhesive protective coating on the inner wall of the perforated hole and the surface of the base coating, so as to obtain leather with a completed adhesive protective coating. The spraying amount is 20-30g / ㎡.

[0026] S7. Middle coating: Use a sprayer to spray the middle coating slurry on the leather that has been coated with the protective coating. Part of the chemical is sprayed on the top of the protective coating, and part of the chemical is sprayed into the hole and adheres to the inner wall of the hole. Then it passes through a 120℃-130℃ drying channel to form a film of the middle coating slurry on the surface of the protective coating and the inner wall of the hole, and form a continuous middle coating on the inner wall of the hole and the surface of the protective coating to obtain leather with a finished middle coating. The spraying amount of the middle coating is 30-40g / ㎡.

[0027] S8. Top coating: Use a sprayer to spray the top coating slurry on the leather that has been finished with the mid-coat coating, and then pass through a 120℃-130℃ drying channel at a speed of 10m / min to form a top coating layer with a top coating spraying amount of 25-30g / ㎡. The perforated finished leather is finally finished.

[0028] The beneficial effects of the present invention compared with the prior art are:

[0029] The present invention provides a coating production process for improving the color fastness to friction and light of automobile perforated leather. The specially defined adhesive protective layer has the characteristic of penetrating adhesion, and its composition includes water, sodium dodecylbenzene sulfonate, small molecule acrylic acid, aliphatic polyurethane resin, light stabilizer (HALS), and crosslinking agent. When the coating is sprayed onto the leather semi-finished product after perforation treatment, the adhesive protective layer coating not only forms a film on the unperforated part of the leather, but also sprays or flows from a part to the perforated cross section of the leather, so that the adhesive protective layer coating forms a very thin adhesive protective layer coating on the perforated cross section to form a protective layer. The sodium dodecylbenzene sulfonate in the protective layer has the effect of assisting penetration, which can help the chemical material to penetrate into the perforated cross section. The film-forming resin bonding has the effect of hydrolysis resistance, plays the role of bonding the primer coating and the middle coating in the coating process, and at the same time protects the leather blank from water absorption and deformation during the wet rubbing color fastness test, so that the leather blank cross section fades less during the friction color fastness test. Generally speaking, the light resistance of pigment paste is better than that of dye. The chemical stability and insensitivity to light of inorganic pigments result in less color change when exposed to light for a long time.

[0030] Before spraying, the color of the protective layer coating needs to be adjusted according to the color of the leather blank, so that the color of the protective layer coating is close to the color of the leather blank. In this way, the influence of the coating on the color of the leather blank in the hole will be minimized, and the film thickness of the protective layer coating and subsequent coatings is only about 5μm, so it will not affect the color of the leather blank in the hole.

[0031] The unique light stabilizer (HALS) in the coating will capture the free radicals generated during light aging of the coating, blocking the further oxidative damage of these active groups, thereby reducing the risk of yellowing of the dye. It is equivalent to adding a layer of "armor" to the perforated cross-section of the perforated leather, so that it can isolate the penetration of water and enhance the yellowing resistance to light. Then the protective layer coating and the subsequent sprayed middle coating and top coating will no longer only form a coating on the front of the leather, but also form a protective layer of about 2-8μm on the inner wall of the perforation. This protective layer prevents the felt from directly contacting the fibers of the leather blank during the color friction fastness test, thereby forming a protective layer for the color of the leather blank, reducing the risk of fading due to friction. Similarly, when the sun is directly shining, the sun will no longer directly irradiate the leather blank fibers. The isolation effect of the protective layer and the light stabilizer (HALS) contained therein will reduce the damage of the sun to the leather blank fibers, reducing the risk of discoloration of the perforated leather blank fibers. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Schematic diagrams of perforated leather finishing layers of the prior art and the present invention, FIG. (a) is a schematic diagram of a perforated leather finishing layer of the prior art process; FIG. (b) is a schematic diagram of a perforated leather finishing layer of the present invention process.

[0033] Figure 2 The actual pictures of the pore leather prepared in Example 1 of the present invention after the abrasion resistance color fastness test are shown in Figure 1. (a) is dry friction, (b) is wet friction, (c) is alkaline sweat, and (d) is alcohol.

[0034] Figure 3 The actual pictures of the pore leather prepared in Example 1 of the present invention after the abrasion resistance color fastness test are shown in Figure 1. (a) is dry friction, (b) is wet friction, (c) is alkaline sweat, and (d) is alcohol.

[0035] Figure 4 The following are actual comparison diagrams of the color fastness of the holes of the perforated leather prepared in Example 1 of the present invention and the prior art after the light exposure test. (a) is the prior art, and (b) is Example 1. DETAILED DESCRIPTION

[0036] The present invention is described in detail below by specific examples, but the protection scope of the present invention is not limited. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can be obtained from commercial channels.

[0037] The coating formula for improving the color fastness to friction and light of automobile perforated leather of the present invention is:

[0038]

[0039]

[0040] Example 1

[0041] A coating production process for improving the color fastness to friction and light of perforated leather for automobiles; the specific steps are:

[0042] S1. Back cover: Car leather batch production, back cover operation, get the leather after back cover, make the back fiber fixed, convenient for subsequent punching operation;

[0043] S2. Primer: Use a reverse roller coater to roll the water-based pigment primer slurry onto the front of the leather after primer coating to form a coating film, and obtain the leather after primer coating. The roller coating amount is 100±20g / ㎡. After roller coating, it is dried in a drying channel at a drying temperature of 110-130℃. The primer slurry includes water, acrylic resin, pigment paste, crosslinking agent, etc. The viscosity of the primer slurry is No. 6 Ford Cup 25-30 seconds;

[0044] S3. Embossing: The leather after the primer coating is embossed with a through-type embossing machine using the corresponding embossing roller; the sandblast pattern is embossed with a sandblast plate, the embossing roller temperature is 100°C, the pressure is set to 50 bar, the conveyor speed is 6 m / min, and the embossed leather is obtained after the embossing operation is completed;

[0045] S4. Punching: Punching the embossed leather according to the hole type information required by the working conditions, the punching parameters are a hole diameter of 1.2 mm and a diagonal hole spacing of 5 mm. After the punching operation is completed, the semi-finished leather after the punching is obtained;

[0046] S5. Dust removal: Use a negative pressure dust collector to remove dust from the semi-finished leather after punching, remove impurities such as fibers generated by the punching operation, and obtain the semi-finished leather after dust removal. The operating conditions are set to negative pressure 0.2-0.5 bar and speed 14-16m / min;

[0047] S6. Adhesive protective coating: The viscosity of the adhesive protective coating chemical is adjusted in the range of 22-26 seconds for No. 4 Ford Cup. The slurry of the adhesive protective coating is sprayed on the semi-finished leather coating after dust removal by a sprayer, and adhered to the top of the primer coating. Part of the chemical is sprayed into the hole and adhered to the inner wall of the perforated hole. Then it passes through a 120℃-130℃ drying channel at a speed of 10m / min to form a film of the adhesive protective coating slurry on the coating surface and the inner wall of the hole, and a continuous adhesive protective coating is formed on the inner wall of the perforated hole and the surface of the primer coating to obtain leather with a completed adhesive protective coating. The spraying amount is 20-30g / ㎡.

[0048] S7. Middle coating: Use a sprayer to spray the slurry of the middle coating on the leather that has been coated with the protective coating. Part of the chemical is sprayed on the top of the protective coating, and part of the chemical is sprayed into the hole and adheres to the inner wall of the hole. Then it passes through a 120℃-130℃ drying channel to form a film of the middle coating slurry on the surface of the protective coating and the inner wall of the hole, and form a continuous middle coating on the inner wall of the hole and the surface of the protective coating to obtain leather with a finished middle coating. The spraying amount of the middle coating is 30-40g / ㎡.

[0049] S8. Top coating: Use a sprayer to spray the top coating slurry on the leather that has been finished with the mid-coat coating, and then pass through a 120℃-130℃ drying channel at a speed of 10m / min to form a top coating layer with a top coating spraying amount of 25-30g / ㎡. The perforated finished leather is finally finished.

[0050] Furthermore, the formula of each coating in the above examples is:

[0051]

[0052]

[0053]

[0054] The coating formula of embodiment 2 is:

[0055]

[0056]

[0057]

[0058] Others are the same as in Example 1

[0059] Comparative Example 1

[0060] The existing production process is: back cover → primer → embossing → mid-coat → top-coat → punching.

[0061] S1. Back cover: Car leather batch production, back cover operation, get the leather after back cover, make the back fiber fixed, convenient for subsequent punching operation;

[0062] S2. Primer: Use a reverse roller coater to roll the water-based pigment primer slurry onto the front of the leather after primer coating to form a coating film, and obtain the leather after primer coating. The roller coating amount is 100±20g / ㎡. After roller coating, it is dried in a drying channel at a drying temperature of 110-130℃. The primer slurry includes water, acrylic resin, pigment paste, crosslinking agent, etc. The viscosity of the primer slurry is No. 6 Ford Cup 25-30 seconds;

[0063] S3. Embossing: The leather after the primer coating is embossed with a through-type embossing machine using the corresponding embossing roller; the sandblast pattern is embossed with a sandblast plate, the embossing roller temperature is 100°C, the pressure is set to 50 bar, the conveyor speed is 6 m / min, and the embossed leather is obtained after the embossing operation is completed;

[0064] S4. Middle coating: Use a sprayer to spray the slurry of the middle coating on the leather after embossing, and then pass it through a 120℃-130℃ drying channel to form a film on the surface of the base coating of the middle coating slurry, and obtain the leather with the middle coating. The spraying amount of the middle coating is 30-40g / ㎡.

[0065] S5. Top coating: Use a sprayer to spray the top coating slurry on the leather that has been finished with the mid-coat coating, and then pass through a 120℃-130℃ drying channel at 10m / min to form a top coating layer with a top coating spraying amount of 25-30g / ㎡. The leather is finally finished.

[0066] S6. Punching: Punching the finished leather according to the hole type information required by the working condition, the punching parameters are hole diameter 1.2mm, diagonal hole spacing 5mm, and after the punching operation is completed, the semi-finished leather after punching is obtained;

[0067] Furthermore, the formula of each coating in the above examples is:

[0068]

[0069]

[0070] The perforated finished leather prepared in Example 1 and the perforated finished leather prepared in the prior art were tested for color fastness to friction and color fastness to light, and the results were as follows:

[0071] 1. Abrasion resistance and color fastness of perforated leather:

[0072] The test was carried out according to the method specified in QB / T 2537-2001, with the test head mass being 1000g.

[0073] a) Alkaline sweat: C 6 H 9 O 2 N 3 HCl·H 2 O(L-histidine monohydrochloride) 0.5g + NaCl 5g + Na 2 HPO 4 12H 2 O5g (or Na 2 HPO 4 ·2H 2 O 2.5g) was prepared into 1L aqueous solution, and the pH was adjusted to 8.0 with NaOH solution (0.1mol / L).

[0074] b) Alcohol: concentration ≥ 95%

[0075] The grade is assessed according to GB / T 251-2008.

[0076] Color fastness to rubbing Standard requirements Prior art Example 1 Dry friction (2000 times) ≥3-4 3 4-5 Wet friction (500 times) ≥3-4 2 4-5 Alkaline sweat (200 times) ≥3-4 2-3 4-5 Alcohol (10 times) ≥3-4 2-3 4-5

[0077] 2. Color fastness test of perforated leather hole edge under light:

[0078] Carry out light fastness test according to GB / T 32088-2015 for 200h. Evaluate the grayscale of the sample according to GB / T 250.

[0079]

[0080] The automobile perforated leather material can be produced by the coating process of the present invention without changing the current retanning and dyeing process, so that the product can fully meet the requirements of friction color fastness during reuse, and the light color fastness of the hole edge of the perforated leather can meet the requirements. After the perforated automobile leather has been used for a long time, the color of the leather blank will not turn yellow after light aging, and the appearance of the perforated leather is maintained. The coating production process for the friction color fastness and light color fastness of the perforated leather has a simple process and good test effect, and can completely solve the problems of the friction color fastness and light color fastness of the automobile perforated leather.

[0081] The above-described embodiments are only preferred embodiments of the present invention, but not all feasible embodiments of the present invention. For those skilled in the art, any obvious changes made thereto without departing from the principles and spirit of the present invention should be considered to be included in the scope of protection of the claims of the present invention.

Claims

1. A coating production process for improving the color fastness to friction and light of perforated leather for automobiles, characterized in that: The process flow is: back cover → primer → embossing → punching → dust removal → protective coating → mid-coating → top coating; The protective coating includes water-based small molecule acrylic resin, water-based aliphatic polyurethane resin, organic and inorganic pigment paste, sodium dodecylbenzene sulfonate, light stabilizer, isocyanate crosslinking agent and water.

2. A coating production process for improving the color fastness to friction and light of automobile perforated leather as claimed in claim 1, characterized in that: The specific formula of the protective coating is as follows: 18-22wt% of water-based small molecule acrylic resin, 35-45wt% of water-based aliphatic polyurethane resin, 15-25wt% of water, 8-12wt% of organic and inorganic pigment paste, 0.4-0.6wt% of sodium dodecylbenzene sulfonate, 2-4wt% of light stabilizer (HALS), and 5.5-7.5wt% of isocyanate crosslinker.

3. A coating production process for improving the color fastness to friction and light of automobile perforated leather as claimed in claim 1, characterized in that: The formula of the subsequent protective coating is as follows: 20wt% water-based small molecule acrylic resin, 40wt% water-based aliphatic polyurethane resin, 20wt% water, 10wt% organic and inorganic pigment paste, 0.5wt% sodium dodecylbenzene sulfonate, 3wt% light stabilizer (HALS), and 6.5wt% isocyanate crosslinker.

4. A coating production process for improving the color fastness to friction and light of automobile perforated leather as claimed in claim 1, characterized in that: Primer: Use a reverse roller coater to roll the water-based pigment primer slurry onto the front of the leather after the back cover to form a coating film, and obtain the leather after primer coating. The roller coating amount is 100±20g / ㎡. After roller coating, it is dried in a drying channel at a drying temperature of 110-130℃; the primer slurry includes water, acrylic resin, pigment paste, crosslinking agent, and additives. The viscosity of the primer slurry is No. 6 Ford Cup 25-30 seconds.

5. A coating production process for improving the color fastness to friction and light of automobile perforated leather as claimed in claim 1, characterized in that: Embossing: Use a through-type embossing machine with a corresponding embossing roller to emboss the leather after primer coating; sandblast pattern, 100℃, 6m, 50bar. Obtain embossed leather.

6. A coating production process for improving the color fastness to friction and light of automobile perforated leather as claimed in claim 1, characterized in that: Dust removal: Use a negative pressure dust collector to remove dust from the semi-finished leather after punching, remove the fibers and other impurities generated by the punching operation, and obtain the semi-finished leather after dust removal. The operating conditions are set to negative pressure 0.2-0.5bar and speed 14-16m / min.

7. A coating production process for improving the color fastness to friction and light of perforated leather for automobiles as claimed in claim 1, characterized in that: Protective coating: The viscosity of the protective coating chemical is adjusted in the range of 22-26 seconds for No. 4 Ford Cup. The slurry of the protective coating is sprayed on the base coating of the semi-finished leather after dust removal by a sprayer, and adhered to the top of the base coating. Part of the chemical is sprayed into the hole and adhered to the inner wall of the hole. Then it passes through a 120℃-130℃ drying channel at a speed of 10m / min, so that the protective coating slurry forms a film on the surface of the base coating and the inner wall of the hole, and forms a continuous protective coating on the inner wall of the hole and the surface of the base coating, so as to obtain leather with a finished protective coating. The spraying amount is 20-30g / ㎡.

8. A coating production process for improving the color fastness to friction and light of automobile perforated leather as claimed in claim 1, characterized in that: Middle coating: Use a sprayer to spray the middle coating slurry on the leather that has been coated with the protective coating. Part of the chemical is sprayed on the top of the protective coating, and part of the chemical is sprayed into the hole and adheres to the inner wall of the hole. After passing through a 120℃-130℃ drying channel, the middle coating slurry forms a film on the surface of the protective coating and the inner wall of the hole, and forms a continuous middle coating on the inner wall of the hole and the surface of the protective coating to obtain leather with a finished middle coating. The spraying amount of the middle coating is 30-40g / ㎡.

9. A coating production process for improving the color fastness to friction and light of automobile perforated leather as claimed in claim 1, The method is characterized in that: top coating: the top coating slurry is sprayed on the leather with the intermediate coating by a spraying machine, and then passed through a 120℃-130℃ drying channel at a speed of 10m / min to form a top coating layer with the top coating slurry, and the spraying amount of the top coating is 25-30g / ㎡; The perforated finished leather is then given a final finish.

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