CN115787309A - PU synthetic leather and embossing machine - Google Patents

Abstract

The invention discloses PU synthetic leather and an embossing machine, wherein the PU synthetic leather comprises a base cloth layer, a foaming layer, a surface layer and a surface treatment layer, one side of the foaming layer is attached to the base cloth layer, the other side of the foaming layer is attached to the surface layer, and the foaming layer is prepared from the following raw materials: a foamed layer of PU resin; the foaming layer PU resin is prepared by polymerizing castor oil modified polyol and aliphatic isocyanate; the thickness of the foaming layer is 450-550 mu m. The PU synthetic leather can realize the pressing of deeper patterns, and can keep good integrity under the embossing treatment at higher temperature.

Description

A kind of PU synthetic leather and embossing machine

technical field

The invention relates to the field of synthetic leather, in particular to a PU synthetic leather and an embossing machine.

Background technique

PU synthetic leather is widely used in high-end home decoration, automotive interior and other fields due to its soft feel, good physical properties and durability. The appearance of traditional PU synthetic leather is mainly realized through the change of pattern and single color. With the improvement of people's living standards, people not only satisfy the relatively simple appearance texture of leather products, but also put forward higher requirements for its external aesthetics. In order to meet people's more pursuit of leather appearance and quality, the existing PU synthetic leather surface is processed by 3D printing process.

The existing 3D printing process usually adopts the method of coating the liquid surface digital paste on the release paper with 3D patterns, drying the surface numerical paste and peeling off the release paper to obtain a 3D pattern. PU synthetic leather. However, due to the technical limitations of the release paper pattern, the existing PU synthetic leather printing depth is relatively shallow, and cannot reflect the 3D stereoscopic effect with strong stereoscopic effect. Moreover, the existing embossing settings cannot satisfy the production of deeper patterns.

Contents of the invention

Aiming at the deficiencies in the prior art, the present invention provides a kind of PU synthetic leather, which realizes the suppression of deep patterns after appropriate thickening of the foam layer of PU synthetic leather, adopts castor oil modified polyol and fat Polyurethane resin obtained by the polymerization of isocyanate is used as the PU resin of the foam layer to improve the heat resistance of PU synthetic leather. The PU synthetic leather can maintain good integrity at a higher embossing temperature, and the pattern after embossing is 3D The effect is better.

Meanwhile, an embossing machine for embossing the above-mentioned PU synthetic leather and an embossing method for embossing the above-mentioned PU synthetic leather are provided.

The present invention is realized through the following technical solutions:

A kind of PU synthetic leather, comprises base cloth layer, foam layer, surface layer and surface treatment layer, one side of described foam layer is bonded with base cloth layer, and the other side is bonded with face layer, and described foam layer The raw materials for preparing the layer include: PU resin for the foaming layer; the PU resin for the foaming layer is prepared by polymerizing polyalcohol modified with castor oil and aliphatic isocyanate; the thickness of the foaming layer is 450-550 μm.

Preferably, the coating amount of the foam layer is 250-300g/m2, and the drying temperature of the foam layer is 90-120°C, the drying time is 2-4 minutes, and the drying temperature is preferably 3 minute.

Preferably, the base fabric layer is a circular knitted fabric with a thickness of at least 0.8 mm.

An embossing machine is used for embossing the above-mentioned PU synthetic leather.

Preferably, the embossing machine includes a preheating zone, a heating zone, an embossing roll and a cooling roll connected in sequence; a plain roll is arranged below the embossing roll; the gap between the embossing roll and the plain roll is 0 to 1.2 mm; the pressure of the embossing roller during embossing is 2Mpa-10Mpa; the temperature of the heating zone is 140-200°C.

Preferably, the diameter of the embossing roller is 180-300 mm; the depth of the pattern of the embossing roller is 400-800 μm.

Preferably, the surface hardness of the embossing roll is at least 35HRC.

Preferably, the surface of the embossing roller is coated with a chromium layer after being sandblasted with 150 mesh; the thickness of the chromium layer is less than 10 μm.

Preferably, the embossing roller is made of S25C-S45C carbon steel.

A kind of embossing method of PU synthetic leather, described embossing method is used for embossing above-mentioned PU synthetic leather, and described embossing method comprises the steps:

Preheating: Preheat the PU synthetic leather at a temperature of 60°C;

Heating: heat the preheated PU synthetic leather at a temperature of 140-200°C;

Embossing: emboss the heated PU synthetic leather, the pressure during embossing is 2Mpa ~ 10Mpa;

Cooling: Use cooling rollers to water-cool the embossed PU synthetic leather.

Compared with the prior art, the present invention has the advantages of:

1. By increasing the thickness of the foam layer to 450-550 μm, the maximum embossing depth of PU synthetic leather is increased, and the embossed PU synthetic leather pattern can also have a three-dimensional effect; at the same time, castor oil modified polyol is used And aliphatic isocyanate polymerization to obtain a high temperature resistant polyurethane foam layer, and the final prepared PU synthetic leather has high heat resistance and wear resistance, so that the PU synthetic leather can also be embossed at a higher temperature It has excellent physical properties.

2. By controlling the drying temperature of the foam layer to be 90-120°C and the drying time to be 2-4 minutes, the foam layer can be fully dried.

3. By using a circular knitted fabric with a thickness of at least 0.8mm as the base fabric layer, the embossed product will be flat and not deformed as a whole.

Description of drawings

Fig. 1 is the structural representation of a kind of embossing machine for embossing above-mentioned PU synthetic leather of the present invention

Fig. 2 is a schematic structural view of a PU synthetic leather of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail in conjunction with the following examples, so that those skilled in the art can fully understand the technical content of the present invention. It should be understood that the following examples are used to further illustrate the present invention, and should not be interpreted as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art according to the above contents of the present invention all belong to the protection of the present invention scope. The specific process parameters and the like in the following examples are only examples of suitable ranges, that is, those skilled in the art can make a selection within a suitable range through the description herein, and are not limited to the specific values exemplified below.

As shown in Fig. 2, the present invention provides a PU synthetic leather, including a base fabric layer, a foam layer, a surface layer and a surface treatment layer. The base fabric layer, the foam layer, the surface layer and the surface treatment layer are laminated sequentially.

The foam layer includes the following preparation materials: foam layer PU resin, and other additives. Among them, the PU resin of the foaming layer is prepared by polymerization of polyols modified by aliphatic isocyanate and castor oil, and the PU resin of the foaming layer prepared by the polymerization of polyols modified by aliphatic isocyanate and castor oil has excellent properties. High temperature resistance, so that the final prepared PU synthetic leather has high heat resistance. Other additives include flame retardants, solvents and catalysts. The foaming layer includes the following preparation raw materials in parts by weight: 61 parts of foaming layer PU resin, 35 parts of flame retardant, 3 parts of solvent and 1 part of catalyst. When preparing the foamed layer, increase the gap value of the scraper for preparing the foamed layer, so that the amount of resin scraped by the foamed layer will increase. Specifically, the blade gap value of the foam layer is controlled so that the thickness of the foam layer is controlled at 450-550 μm. After scraping and coating, adjust the oven temperature for drying the foaming layer to 90-120°C, increase the air supply volume, and dry for 2-4 minutes to fully dry the foaming layer; prevent foaming After the layer resin coating amount increases, the original drying conditions cannot fully dry the foaming layer. Preferably, the coating amount of the foam layer is 250-300 g/m2.

The base fabric layer adopts a circular knitted fabric with a thickness of more than 0.8mm, so that the embossed product is flat and does not deform as a whole.

As shown in Fig. 1, the present invention also provides an embossing machine for embossing the above-mentioned PU synthetic leather, including sequentially connecting a feeding zone, a preheating zone, a heating zone, an embossing roller, a cooling roller and a receiving zone, and embossing Plain weave rollers are also arranged below the rollers.

What are the advantages of embossing equipment using the sequence of preheating, heating, embossing, and cooling compared to single embossing;

Among them, whether there are any advantages in the setting of the parameters of each part of the equipment and the setting of the embossing roller material and parameters compared with the existing embossing equipment parameters.

The feeding area is used to place PU synthetic leather, and send the PU synthetic leather to the preheating area for preheating; the preheating temperature is 60°C. Then send the PU synthetic leather to the heating zone for heating; the temperature of the heating zone is 140-200°C. The heated synthetic leather is sent to embossing rollers for embossing. The gap between the embossing roller and the flat grain roller is 0-1.2mm, and the adjustment accuracy is 0.01mm. The embossing depth of PU synthetic leather can be adjusted by adjusting the gap between the embossing roller and the flat grain roller. The embossed PU synthetic leather is sent to cooling rollers for cooling. The cooled PU synthetic leather is sent to the receiving area for collection.

Among them, the embossing roller adopts an electrically heated embossing roller, and the temperature range of the embossing roller during embossing is 150-200°C, so as to meet the temperature requirements when embossing PU synthetic leather. The diameter of the embossing roller is 180-300 mm in diameter. The pattern depth on the surface of the embossing roll is 400-800 μm. The material of the embossing roller is S25C～S45C carbon steel. After the surface of the embossing roller is treated with 150-mesh sandblasting, a chromium layer is plated on the surface of the embossing roller, and the thickness of the chromium layer is less than 10 μm. The processing speed of the embossing machine is 1-10m/min.

The present invention also provides an embossing method for embossing the above-mentioned PU synthetic leather, which includes the following steps: preheating: preheating the PU synthetic leather at a temperature of 60°C;

Heating: heat the preheated PU synthetic leather at a temperature of 140-200°C;

Embossing: emboss the heated PU synthetic leather, the pressure during embossing is 2Mpa ~ 10Mpa;

Cooling: Use cooling rollers to water-cool the embossed PU synthetic leather.

Example 1

PU synthetic leather with a thickness of 1.1mm is used as the raw material for embossing; the thickness of the base fabric of the PU synthetic leather is 0.9mm, and the thickness of the foam layer is 0.2mm. The raw materials for the preparation of the foaming layer include by weight: 61 parts of PU resin for the foaming layer, 35 parts of flame retardant, 3 parts of solvent and 1 part of catalyst. Send the PU synthetic leather to the preheating zone for preheating at a temperature of 60°C; then send the PU synthetic leather to the heating zone for heating at a temperature of 190°C. Adjust the gap between the embossing roller and the flat grain roller to 0.6mm, and the embossing pressure of the embossing roller to 3Mpa. The embossing roller used in the embossing equipment has a roller diameter of 200 mm, a pattern depth of 600 μm, a roller body made of S35C carbon steel, and a surface hardness of 8 μm. The processing speed of the embossing machine is set to 3m/min. The embossing depth of the PU synthetic leather obtained by final processing is 1 mm.

Example 2

The PU synthetic leather with a thickness of 1.0mm is used as the raw material for the printing process. The base cloth layer thickness of the PU synthetic leather is 0.8mm, and the thickness of the foam layer is 0.2mm; wherein, the foam layer includes the following preparation materials by weight: 61 parts Foam layer PU resin, 35 parts of flame retardant, 3 parts of solvent and 1 part of catalyst. The PU synthetic leather is sent to a preheating zone for preheating at a temperature of 60°C; then the PU synthetic leather is sent to a heating zone for heating at a temperature of 180°C. Adjust the gap between the embossing roller and the flat grain roller to 0.7mm. The embossing pressure of the embossing roller is 5Mpa. The embossing roller used in the embossing equipment has a roller diameter of 200 mm, a pattern depth of 500 μm, a roller body made of S25C carbon steel, and a surface hardness of 8 μm. The processing speed of the embossing machine is set to 5m/min. The embossing depth of the PU synthetic leather obtained by final processing is 1mm.

Example 3

Adopt the PU synthetic leather that thickness is 1.1mm as the raw material of printing process, the base cloth layer thickness of PU synthetic leather is 0.9mm, and the thickness of foam layer is 0.2mm; Wherein, foam layer comprises following preparation raw materials by weight: 61 parts Foam layer PU resin, 35 parts of flame retardant, 3 parts of solvent and 1 part of catalyst. The PU synthetic leather is sent to a preheating zone for preheating at a temperature of 60° C.; then the PU synthetic leather is sent to a heating zone for heating at a temperature of 190° C. Adjust the gap between the embossing roller and the flat grain roller to 0.5mm. The embossing pressure of the embossing roller is 3Mpa. The embossing roller used in the embossing equipment has a roller diameter of 200 mm, a pattern depth of 600 μm, a roller body made of S35C carbon steel, and a surface hardness of 8 μm. The processing speed of the embossing machine is set to 3m/min. The embossing depth of the PU synthetic leather obtained by final processing is 1 mm.

In summary, the embossed thickness of the PU synthetic leather prepared by the present invention can reach more than 1.0 mm after the embossing treatment by the embossing equipment. Compared with the traditional processing method of making patterns on release paper, the maximum depth can only reach 0.7-0.8mm; the present invention effectively improves the maximum embossing depth of PU synthetic leather and enhances the three-dimensional effect of PU synthetic leather patterns. And, adopt castor oil modified polyalcohol and the foaming layer PU resin that aliphatic isocyanate polymerization prepares to make foaming layer, make PU synthetic leather of the present invention can bear the temperature of about 140 degrees Celsius, this PU synthetic leather has better High temperature resistance, and can maintain good integrity under higher temperature embossing treatment. At the same time, a circular knitted cloth with a thickness of at least 0.8 mm is used as the base cloth layer, so that the embossed product is flat and not deformed as a whole.

It should be pointed out that the above-mentioned preferred embodiments are only to illustrate the technical conception and characteristics of the present invention, the purpose of which is to enable those familiar with this technology to understand the content of the present invention and implement it accordingly, and cannot limit the scope of the present invention. protected range. All equivalent changes or modifications made according to the spirit of the present invention shall fall within the protection scope of the present invention.

Claims (10)

1. The utility model provides a PU synthetic leather, includes base cloth layer (1), foaming layer (2), surface course (3) and surface treatment layer (4), one side and the base cloth layer (1) laminating of foaming layer (2), the opposite side laminates with surface course (3), its characterized in that, the preparation raw materials of foaming layer (2) include: a foamed layer of PU resin; the foaming layer PU resin is prepared by polymerizing castor oil modified polyol and aliphatic isocyanate; the thickness of the foaming layer (2) is 450-550 mu m.

2. The PU synthetic leather according to claim 1, wherein the amount of the foamed layer (2) is 250-300 g/m2, and the drying temperature of the foamed layer (2) is 90-120 ℃, and the drying time is 2-4 minutes.

3. PU synthetic leather according to claim 1, wherein the base layer (1) is a circular knit having a thickness of at least 0.8 mm.

4. An embossing machine, characterized in that it is used for embossing the PU synthetic leather according to any one of claims 1 to 3.

5. The embossing machine according to claim 4, characterized in that it comprises a preheating zone (5), a heating zone (6), an embossing roller (7) and a cooling roller (9) connected in succession; a plain grain roller (8) is arranged below the embossing roller (7); the clearance between the embossing roller (7) and the plain weave roller (8) is 0-1.2 mm; the pressure of the embossing roller (7) during embossing is 2-10 Mpa; the temperature of the heating zone (6) is 140-200 ℃.

6. The embossing machine according to claim 5, characterized in that the diameter of the embossing roller (7) is between 180 and 300mm; the pattern depth of the embossing roller (7) is 400-800 mu m.

7. The embossing machine according to claim 5, characterized in that the surface hardness of the embossing roller (7) is at least 35HRC.

8. The embossing machine according to claim 7, characterized in that the surface of the embossing roller (7) is coated with a chromium layer after 150 mesh blasting; the thickness of the chromium layer is less than 10 μm.

9. The embossing machine according to any one of claims 4 to 8, characterized in that the material of the embossing roller (7) is carbon steel from S25C to S45C.

10. An embossing method of PU synthetic leather, characterized in that it uses the PU synthetic leather of any one of claims 1 to 3 as a raw material for embossing treatment, the embossing method comprising the steps of:

preheating: preheating the PU synthetic leather at the temperature of 60 ℃;

heating: heating the preheated PU synthetic leather at the temperature of 140-200 ℃;

embossing: embossing the heated PU synthetic leather, wherein the pressure during embossing is 2-10 Mpa;

and (3) cooling: and (3) carrying out water cooling treatment on the embossed PU synthetic leather by using a cooling roller.

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