Color mixing technology of colored rubber

Abstract

The invention provides a color mixing technology of colored rubber, which comprises the following steps: step S1, plasticizing natural rubber: plasticizing natural rubber raw materials in an internal mixer at 60-80 DEG C for 10-20 minutes, so that the Mooney viscosity of the natural rubber raw materials is reduced to 40-60; step S2, mixing and color mixing: quantitative color masterbatch is added into the plasticized natural rubber, the color masterbatch is selected from an organic pigment, an inorganic pigment or a mixture of the organic pigment and the inorganic pigment, and the adding amount of the color masterbatch is 0.3%-3% of the weight of the natural rubber; s3, composite foam molding: continuously compounding the natural rubber subjected to color mixing and a polyurethane coiled material in a double-screw extruder, and carrying out foam molding at 120-140 DEG C under the pressure of 8-12 MPa to form a double-sided different-color structure; s4, blanking and packaging: carrying out die cutting and blanking on the foamed and molded composite coiled material to prepare a yoga mat finished product with a specified size; according to the invention, a preset amount of color masterbatch can be added in a natural rubber mixing link, so that the natural rubber is colored rubber with a specified color after subsequent foaming molding.

Description

Technical Field

[0001] The present invention relates to the technical field of rubber product processing, in particular to a color mixing technology process for colored rubber. Background Art

[0002] Currently, the rubber colors of natural rubber yoga mats sold on the market are mainly black and gray, with relatively single colors. Although the products of natural rubber yoga mats can also enrich the design by mixing the colors of another material coil (such as PU) compounded with rubber and printing patterns, the single color of natural rubber itself still limits the diversification and personalization of product color design. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a color mixing technology process for colored rubber that can achieve adding a predetermined amount of color masterbatch in the natural rubber mixing process, and through precise calculation and mixing process, make the natural rubber present a specified color after subsequent foaming and molding.

[0004] The present invention is implemented by the following method: a color mixing technology process for colored rubber, the process comprising the following steps:

[0005] Step S1, natural rubber plasticization: Plasticize the natural rubber raw material in a mixer at 60 - 80 °C for 10 - 20 minutes to reduce its Mooney viscosity to 40 - 60;

[0006] Step S2, mixing and color mixing: Add a quantitative color masterbatch to the plasticized natural rubber, the color masterbatch is selected from organic pigments, inorganic pigments or a mixture thereof, and the addition amount is 0.3% - 3% of the weight of the natural rubber;

[0007] Step S3, composite foaming and molding: Continuously compound the color - mixed natural rubber with a polyurethane coil in a twin - screw extruder, and foam and mold at 120 - 140 °C and 8 - 12 MPa pressure to form a double - sided different - color structure;

[0008] Step S4, blanking and packaging: Die - cut the foamed and formed composite coil to make yoga mat finished products of specified sizes.

[0009] Further, the particle size of the color masterbatch is 1 - 10 μm, and a segmented temperature control is adopted during the mixing process: the first stage is 70 - 80 °C for mixing for 5 minutes, and the second stage is 90 - 100 °C for mixing for 10 minutes.

[0010] Further, in step S2, precision control of ±0.1% is also achieved through a mass flowmeter.

[0011] Further, in the double - sided different - color structure, the color difference between the two layers of natural rubber is ≤5%, and the physical property difference is ≤10%.

[0012] Further, in step S3, the rotation speed of the twin-screw extruder is 200 - 400 rpm, and the screw length-diameter ratio is 40:1.

[0013] The beneficial effects of the present invention are as follows: By quantitatively adding color masterbatch during the natural rubber mixing stage and combining precise control with the composite foaming process, the present invention realizes the customized production of the color of natural rubber; this process solves the problem of the single color of existing natural rubber products, supports double-color composite design, expands the product application scenarios; can produce natural rubber products of specified colors; customers can specify the color of natural rubber during the design of natural rubber products; two natural rubber coils with different colors, the same physical properties or different physical properties can be combined to realize the double-sided rubber production process. Description of the Drawings

[0014] Figure 1 It is the production process flow chart of the present invention. Detailed Embodiments

[0015] The present invention will be further described below with reference to the drawings.

[0016] Example 1: Production of a monochromatic natural rubber yoga mat

[0017] Raw materials: 100 kg of natural rubber (Mooney viscosity 80), 1.5 kg of red organic pigment color masterbatch (particle size 5 μm);

[0018] Process parameters:

[0019] Plasticization: The temperature of the internal mixer is 70 °C, the time is 15 minutes, and the Mooney viscosity drops to 50;

[0020] Mixing: Segmented control (the first stage is 75 °C / 5 minutes, the second stage is 95 °C / 10 minutes);

[0021] Foaming: The temperature is 130 °C, the pressure is 10 MPa, and the foaming density is 0.6 g / cm 3 ;

[0022] Effect: The color of the finished product is uniform (color difference ΔE = 2.3), and the tensile strength ≥ 8 MPa, meeting the industry standards for yoga mats.

[0023] Example 2: Production of a double-color composite natural rubber yoga mat

[0024] Raw materials:

[0025] Upper layer: 100 kg of natural rubber, 1.2 kg of blue inorganic pigment color masterbatch (particle size 3 μm);

[0026] Lower layer: 100 kg of natural rubber, 1.8 kg of green organic pigment color masterbatch (particle size 8 μm);

[0027] Process parameters:

[0028] Compound foaming: The rotational speed of the twin-screw extruder is 300 rpm, the length-diameter ratio is 40:1, and the foaming temperature is 125 °C;

[0029] Laminated compounding: Achieve two-color synchronous compounding through a co-extrusion die head, and the interlayer adhesion strength ≥ 5 N / mm;

[0030] Effect: The double-sided color difference ΔE = 3.8, there is no peeling phenomenon between layers, and the resilience ≥ 85%.

[0031] Example 3: Verification of high-precision masterbatch quantitative control

[0032] Equipment: Adopt a Coriolis mass flowmeter (accuracy ±0.05%), and the addition amount of masterbatch is 0.5 kg (100 kg of natural rubber);

[0033] Result: Continuously produce 100 batches, the error of the actual addition amount of masterbatch ≤ 0.08%, and the compliance rate of the finished product color consistency reaches 99.6%.

[0034] Example 4: Application of alternative pigment system

[0035] Raw materials: 100 kg of natural rubber, 0.8 kg of liquid dye (phthalocyanine blue);

[0036] Process adjustment: The mixing temperature is reduced to 65 °C to avoid thermal decomposition of the dye;

[0037] Effect: The color saturation of the finished product is increased by 15%, and the light fastness reaches level 4 (ISO 105-B02 standard).

[0038] Segmented mixing process: Through two-stage temperature control, avoid thermal degradation of the masterbatch and ensure uniform dispersion at the same time;

[0039] Precision quantitative system: Adopt a Coriolis mass flowmeter, with an error ≤ ±0.1%, to ensure color consistency;

[0040] Two-color composite structure: Achieve double-sided different colors through the co-extrusion die head design, expanding the product design freedom.

[0041] The above are only the preferred embodiments of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope covered by the present invention.

Claims

1. A color - matching technical process for colored rubber, characterized in that, The process includes the following steps: Step S1, plasticization of natural rubber: Plasticize the natural rubber raw material in a mixer at 60 - 80 °C for 10 - 20 minutes to reduce its Mooney viscosity to 40 - 60; Step S2, mixing and color matching: Add a certain amount of masterbatch rubber to the plasticized natural rubber. The masterbatch rubber is selected from organic pigments, inorganic pigments or a mixture thereof, and the addition amount is 0.3% - 3% of the weight of the natural rubber; Step S3, composite foaming molding: Continuously compound the color-matched natural rubber with a polyurethane coil in a twin-screw extruder, and foam-mold at 120 - 140 °C and a pressure of 8 - 12 MPa to form a double-sided different-color structure; Step S4, blanking and packaging: Die-cut the foam-molded composite coil to produce finished yoga mats of specified sizes.

2. The color matching technical process of a colored rubber according to claim 1, characterized in that: The particle size of the masterbatch rubber is 1 - 10 μm, and segmented temperature control is adopted during the mixing process: The first stage is to mix at 70 - 80 °C for 5 minutes, and the second stage is to mix at 90 - 100 °C for 10 minutes.

3. The color matching technical process of a colored rubber according to claim 1, characterized in that: In step S2, precision control of ±0.1% is also achieved through a mass flowmeter.

4. A color rubber color mixing technology process according to claim 1, characterized in that: In the double-sided different-color structure, the color difference between the two layers of natural rubber is ≤5%, and the physical property difference is ≤10%.

5. The color matching technical process of a colored rubber according to claim 1, characterized in that: In step S3, the rotational speed of the twin-screw extruder is also 200 - 400 rpm, and the screw length-diameter ratio is 40:1.

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