Method for opening thermal shrinkage non-woven mask base material by using castor flat silk

Abstract

The invention belongs to the technical field of health-care skin-care materials, and particularly relates to a method for preparing a heat-shrinkable non-woven mask base material by using castor flat silk, which comprises the following steps: step 1, emulsifying and dispersing a core material in a wall material solution to prepare microcapsules, adding glutaraldehyde into the microcapsules for crosslinking, centrifugally washing, and freeze-drying to obtain a core material suspension; a temperature-sensitive color-changing microcapsule is formed; 2, castor bean flat silk is prepared and subjected to drafting orientation and cutting, and castor bean short fibers are formed; 3, preparing a spinning solution according to the temperature-sensitive color-changing microcapsule prepared in the step 1, and preparing the spinning solution into a heat-shrinkable fiber / microcapsule composite nanofiber membrane; and 4, compounding a non-woven base material, namely preparing the non-woven base material from castor silkworm short fibers, the heat-shrinkable fiber / microcapsule composite nanofiber membrane and the sericin coating. In the using process of the non-woven base material, the using state can be visually prompted through color changes, and the situation of excessive application is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of health-care and skin-care materials, and particularly relates to a method for developing a heat-shrinkable non-woven facial mask substrate by utilizing flat silk of ricinus silkworms. Background Art

[0002] In recent years, silk masks have become popular in the market due to their excellent skin-friendliness, breathability and natural moisturizing ingredients (such as sericin).

[0003] The ricinus silkworm, the world's third-largest silkworm species, produces silk fibers with unique mechanical properties and biocompatibility. However, the traditional cocoon-making method results in large variations in fineness and difficulty in unwinding, making it difficult to directly use in the development of high-value-added products. In recent years, flat-sheet silk technology (where ricinus silkworms spin silk on a flat surface to form "cocoon paper") has gradually emerged. This eliminates the tedious steps of peeling cocoons and removing pupae, and significantly improves the silk's orientation and crystallinity, providing new ideas for the efficient preparation of facial mask substrates.

[0004] However, existing flat yarn processing technology is mostly focused on the textile field, and how to combine it with non-woven technology is still a technical gap.

[0005] At the same time, the existing silk mask base material has a single function, lacks intelligent interactive design, and cannot intuitively indicate the usage status. Users often over-apply it because they cannot judge the optimal usage time, which may cause problems such as damaged skin barrier or overnutrition. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for developing a heat-shrinkable non-woven mask substrate using castor silk flat silk, which can intuitively indicate the usage status through color changes during the use of the non-woven substrate and reduce excessive application.

[0007] The technical solutions adopted by the present invention are as follows:

[0008] A method for developing a heat-shrinkable nonwoven facial mask substrate using castor silk flat silk, comprising the following steps:

[0009] Step 1: Preparation of thermochromic microcapsules: emulsifying and dispersing a core material comprising vitamin C, a thermochromic dye, and a carrier oil in a wall material solution to prepare microcapsules; adding glutaraldehyde to the microcapsules for cross-linking; washing by centrifugation; and freeze-drying to form thermochromic microcapsules;

[0010] Step 2: pre-treating the castor silk flat yarn to prepare the castor silk flat yarn and then drawing, orienting, and cutting the castor silk flat yarn to form castor silk staple fibers;

[0011] Step 3: Composite spinning of heat-shrinkable fiber and microcapsule, preparing a spinning solution based on the thermosensitive color-changing microcapsules prepared in step 1, and preparing the spinning solution into a heat-shrinkable fiber / microcapsule composite nanofiber membrane;

[0012] Step 4: non-woven substrate composite, the castor silkworm short fibers prepared in step 2, the heat-shrinkable fiber / microcapsule composite nanofiber membrane prepared in step 3 and the sericin coating are prepared into a non-woven substrate.

[0013] Furthermore, the step 1 includes the following steps:

[0014] Step 101: Mixing vitamin C, thermochromic dye, and carrier oil to form a core material;

[0015] Step 102: emulsifying and dispersing the core material prepared in step 101 in the wall material solution to form an O / W emulsion;

[0016] Step 103: Cooling the O / W emulsion to form microcapsules;

[0017] Step 104: Glutaraldehyde is added to the microcapsules for cross-linking, and the microcapsules are centrifuged, washed, and freeze-dried to form thermosensitive color-changing microcapsules.

[0018] Furthermore, the color change threshold of the thermochromic dye is 35°C.

[0019] Furthermore, the material of the thermochromic dye is cholesteric liquid crystal microcapsule or anthocyanin-metal complex, and the carrier oil is jojoba oil.

[0020] Furthermore, the step 2 of pre-treating the castor silk flat silk includes preparing the castor silk flat silk, removing impurities with low-temperature plasma, pre-treating by drawing, and short-fibering treatment;

[0021] The preparation of the castor silk flat silk comprises the following steps:

[0022] S1: Take silkworms that have just hatched from silkworm eggs and place them in a feeding plaque and feed them castor leaves, cassava leaves, or Ailanthus altissima leaves. When each group of silkworms reaches the fifth instar and 10%-15% are mature, add molting hormone. When more than 95% of the silkworms have become mature, allow them to fully defecate and urinate for more than 48 hours.

[0023] S2: After the mature silkworms have excreted their feces and urine, they are placed in a 200-300 5-year-old mature silkworm / m 2 The silkworms evenly spread the silk on the spinning plate, and the silkworms spin silk strands. After 40-50 hours, the spinning ends and a complete flat silk is formed.

[0024] The low-temperature plasma impurity removal comprises the following steps:

[0025] M1: Remove the castor silkworms from the flat silk surface after spinning, and remove solid impurities on the castor silk flat silk;

[0026] M2: The ricinus silk flat silk in M1 was treated for 6 minutes under an argon flow rate of 20 L / min and a power of 300 W;

[0027] The drafting pretreatment specifically comprises the following steps:

[0028] P1: The ricin silk flat silk that has been treated with impurities is clamped between the two clamps of the unidirectional stretching equipment and stretched. After reaching the set elongation, the stretching is stopped and kept at 60℃ for 10-20 minutes;

[0029] P2: Take the castor silk flat yarn in P1 out of the unidirectional stretching equipment;

[0030] The short-fiberization treatment is to use a mechanical cutter to cut the castor silk flat silk at equal distances according to a cutting distance of 40-50 mm to form short fibers.

[0031] Furthermore, the step 3 includes the following steps:

[0032] Step 301: dissolving a polylactic acid / polycaprolactone blend having a mass ratio of 7:3 in chloroform to a concentration of 12% to form a chloroform mixed solution;

[0033] Step 302: adding thermochromic microcapsules and dispersant, and ultrasonically homogenizing for 30 minutes to obtain a spinning solution;

[0034] Step 303: Processing the spinning solution into a nanofiber membrane through electrospinning.

[0035] Furthermore, the nonwoven substrate includes an outer layer, a middle layer and an inner layer, the outer layer is a heat-shrinkable fiber / microcapsule composite nanofiber membrane, the middle layer is ricin silkworm short fiber + PLA fiber, and the inner layer is a sericin coating.

[0036] Furthermore, the step 4 includes the following steps:

[0037] Step 401: Using a roller press, the outer layer, the middle layer, and the inner layer are compounded to form an integrated substrate;

[0038] Step 402 : placing the integrated substrate obtained in step 402 in a hot and humid environment at 50° C. and RH 80% for 20 minutes to obtain a nonwoven substrate.

[0039] The technical effects achieved by the present invention are:

[0040] (1) The present invention provides a method for developing a heat-shrinkable non-woven facial mask substrate using castor silk flat silk. The facial mask substrate is processed into a facial mask according to the processing method of the facial mask, and is fitted to the facial skin. The castor silk natural sericin on the facial mask nourishes the skin and has antibacterial and moisturizing effects. As the temperature of the facial mask material rises, the heat-shrinkable fibers shrink, causing the facial mask to shrink, thereby causing the facial skin to shrink, the pores to shrink, and the skin to tighten, achieving the effect of beautifying and maintaining the skin without any toxic side effects.

[0041] (2) The method of the present invention for developing a heat-shrinkable non-woven mask substrate using castor silk flat silk as the raw material for processing spunlace non-woven mask substrates eliminates the processes of peeling cocoons and treating silkworm pupa waste. Since there is no need for excessive impurity removal and cleaning processes in the later stage, and the flat silk is different from the cocoon, the silkworms can spin silk in a wide space instead of a limited space (cocoon). The orientation and crystallinity of the silk are good, and the strength and color of the silk are better than those of traditional processing methods. At the same time, the low-temperature heat-shrinkable material is mixed so that the mask has heat shrinkage during use, and the beauty effect is better.

[0042] (3) The present invention provides a method for developing a heat-shrinkable non-woven facial mask substrate using castor silk flat silk. The method comprises preparing a non-woven substrate composed of a heat-shrinkable fiber / microcapsule composite nanofiber membrane, castor silk short fibers, and a sericin coating. The method can utilize the temperature of the human face to change the color of the heat-shrinkable fiber / microcapsule composite nanofiber membrane when the non-woven substrate comes into contact with the human face. During the use of the non-woven substrate, when the heat-shrinkable fiber / microcapsule composite nanofiber membrane becomes transparent again, it indicates that the non-woven substrate has been used. The color change can intuitively indicate the use status and reduce excessive application. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a flow chart of the steps of the present invention. DETAILED DESCRIPTION

[0044] In order to make the purpose and advantages of the present invention more clearly understood, the present invention is described in detail below with reference to the following examples. It should be understood that the following text is only used to describe one or more specific embodiments of the present invention and does not strictly limit the scope of protection of the present invention.

[0045] like Figure 1 As shown, a method for developing a heat-shrinkable nonwoven mask substrate using castor silk flat silk comprises the following steps:

[0046] Step 1: Preparation of thermochromic microcapsules: emulsifying and dispersing a core material comprising vitamin C, a thermochromic dye, and a carrier oil in a wall material solution to prepare microcapsules. Glutaraldehyde is added to the microcapsules for cross-linking, followed by centrifugation and washing, and freeze-drying to form thermochromic microcapsules.

[0047] Specifically, step 1 includes the following steps:

[0048] Step 101: Vitamin C, thermochromic dye, and carrier oil are mixed in a ratio of 10:0.5:89.5 to form a core material;

[0049] Among them, the color change threshold of the thermochromic dye is preferably 35°C, its material can be cholesteric liquid crystal microcapsules or anthocyanin-metal complexes, and the carrier oil is preferably jojoba oil. The thermochromic dye provides reversible color change performance (35°C threshold), and jojoba oil serves as a phase change energy storage material (phase change enthalpy value 85-95J / g). Such a composite system enables the microcapsules to have temperature memory function.

[0050] Step 102: emulsifying and dispersing the core material prepared in step 101 in the wall material solution to form an O / W emulsion;

[0051] The wall material solution is preferably a gelatin-gum arabic complex, and the mass ratio of gelatin to gum arabic in the gelatin-gum arabic complex is 2.5:1.

[0052] Step 103: Cool the O / W emulsion to 10° C. to form microcapsules. The cooling rate is set at 2.5° C. / min (±0.5° C.).

[0053] Step 104: adding 0.1% glutaraldehyde to the microcapsules for cross-linking for 30 minutes, controlling the pH value of the cross-linking reaction at 4.8-5.2, washing by centrifugation, and freeze-drying to form thermosensitive color-changing microcapsules.

[0054] Step 2: pre-treating the castor silk flat yarn to prepare the castor silk flat yarn and then drawing, orienting, and cutting the castor silk flat yarn to form castor silk staple fibers;

[0055] Specifically, step 2 of pre-treating the castor silk flat silk includes the steps of preparing the castor silk flat silk, removing impurities with low-temperature plasma, pre-treating by drawing, and short-fibering treatment.

[0056] The preparation of castor silk flat silk comprises the following steps:

[0057] S1: Silkworms that have just hatched from eggs are placed in a feeding plaque and fed with castor leaves, cassava leaves, or Ailanthus altissima leaves. When the silkworms in each group reach 5th instar and 10%-15% are mature, molting hormone is added to the diet using a gradient concentration method (0.5 mg / L → 1.0 mg / L). Molting hormone can shorten the 5th instar stage of castor silkworms by 2-3 days, making the cocooning time of castor silkworms uniform. When more than 95% of the silkworms have become mature silkworms, they are allowed to fully defecate and urinate, and the defecation and urination period is more than 48 hours;

[0058] S2: After the mature silkworms have excreted their feces and urine, they are placed in a 200-300 5-year-old mature silkworm / m2 The silkworms will evenly spread the silk on the spinning board, and the silkworms will slowly spin out silk strands. After 40-50 hours, the spinning is finished and a complete flat silk is formed.

[0059] Among them, low-temperature plasma impurity removal includes the following steps:

[0060] M1: Remove the castor silkworms from the flat silk surface after spinning, and remove solid impurities on the castor silk flat silk;

[0061] M2: The castor silk flat silk in M1 was treated for 6 minutes at an argon flow rate of 20 L / min and a power of 300 W to remove impurities on the silk surface and activate the fiber surface;

[0062] The drafting pretreatment specifically includes the following steps:

[0063] P1: The castor silk flat yarn that has been treated with impurities is clamped between the two clamps of the unidirectional stretching equipment and stretched. After reaching the set elongation, the stretching is stopped and kept at 60℃ for 10-20 minutes to stabilize the size of the castor silk flat yarn and ensure that the fiber orientation degree is ≥75%;

[0064] P2: Take the castor silk flat yarn in P1 out of the unidirectional stretching equipment;

[0065] The tensile force range of the unidirectional stretching equipment is 5N-10N, preferably 8N; the unidirectional tensile elongation is 20%-30%, preferably 25%; the stretching rate is 50-100mm / min;

[0066] Because the orientation of silk cannot be controlled when castor silkworms produce flat silk, and the silk fibers cross each other, the length difference is large during the short-fiberization process, and short fibers are easily generated. Therefore, before the short-fiberization process, the flat silk is first pulled in one direction to make it tend to the same direction. After the short-fiberization process, the fiber length difference is not large, which is conducive to the subsequent processing and forming of spunlace non-woven fabrics.

[0067] The short fiberization process is to use a mechanical cutter to cut the castor silk flat silk at equal distances according to a cutting distance of 40-50 mm to form short fibers;

[0068] Since some silk threads cross each other in the flat silk, the length of single fibers in each segment is generally between 35-55 after cutting to ensure dimensional stability.

[0069] Step 3: Composite spinning of heat-shrinkable fiber and microcapsule: preparing a spinning solution based on the thermosensitive color-changing microcapsules prepared in step 1, and preparing the spinning solution into a heat-shrinkable fiber / microcapsule composite nanofiber membrane, so that the thermosensitive color-changing microcapsules are evenly embedded in the fiber;

[0070] Specifically, step 3 includes the following steps:

[0071] Step 301: dissolving a polylactic acid (PLA) / polycaprolactone (PCL) blend with a mass ratio of 7:3 in chloroform (concentration 12%) to form a chloroform mixed solution;

[0072] Step 302: Add thermochromic microcapsules (5% w / w) and a dispersant (Tween 80, 0.5%), and homogenize by ultrasonication for 30 minutes to prepare a spinning solution;

[0073] The dispersant is a mixture of Span80 and Tween80 (mass ratio 1:1);

[0074] Step 303: Processing the spinning solution into a nanofiber membrane by electrospinning. The obtained nanofiber membrane (fiber diameter 200-500 nm, porosity 80%) has thermosensitive color-changing microcapsules uniformly embedded in the fibers;

[0075] Here, the parameters of electrospinning are voltage 20kV, receiving distance 15cm, spinning liquid flow rate 1.2mL / h, and ambient humidity ≤40%. That is, in an environment with ambient humidity ≤40% and voltage 20kV, the spinning liquid is ejected at a flow rate of 1.2mL / h. The polymer of the spinning liquid solidifies during the flight to form a heat-shrinkable fiber / microcapsule composite nanofiber membrane.

[0076] Step 4: non-woven substrate composite, the castor silkworm short fibers prepared in step 2, the heat-shrinkable fiber / microcapsule composite nanofiber membrane prepared in step 3 and the sericin coating are prepared into a non-woven substrate;

[0077] Here, the nonwoven substrate includes an outer layer, a middle layer, and an inner layer;

[0078] Outer layer: heat shrinkable fiber / microcapsule composite nanofiber membrane (weight 15g / m2);

[0079] Middle layer: 60% castor silkworm staple fiber + 40% PLA fiber, hydroentangled (water pressure 80-150 Bar, 3 times each on both sides);

[0080] Inner layer: sericin coating (5% concentration, spraying amount 10g / m2) to improve skin-friendliness.

[0081] Specifically, step 4 includes the following steps:

[0082] Step 401: Using a roller press at a temperature of 45° C. and a pressure of 0.5 MPa, the outer layer, the middle layer, and the inner layer are laminated to form an integrated substrate;

[0083] Step 402 : placing the integrated substrate prepared in step 402 in a hot and humid environment (50° C., RH 80%) for 20 minutes, pre-shrinking by 3%-5% to ensure dimensional stability, and preparing a non-woven substrate.

[0084] In summary, this technical solution processes the facial mask base material into a facial mask according to the facial mask processing method, which fits the facial skin. The natural sericin of the ricin silkworm on the facial mask nourishes the skin and has antibacterial and moisturizing effects. As the temperature of the facial mask material rises, the heat-shrinkable fibers shrink, causing the facial mask to shrink, thereby causing the facial skin to shrink, reducing pores and tightening the skin, achieving the effect of beauty and skin care without any toxic side effects.

[0085] When producing flat silk as the raw material for processing the base material of spunlace non-woven fabric mask, the processes of peeling cocoons and handling silkworm pupa waste are eliminated. Since there is no need for excessive impurity removal and cleaning processes in the later stage, flat silk is different from cocoons, allowing silkworms to spin silk in a wide space instead of a limited space (cocoon). The orientation and crystallinity of the silk are good, and the strength and color of the silk are better than those of traditional processing methods. At the same time, the low-temperature heat shrinkage material is mixed, so that the mask has heat shrinkage during use, and the beauty effect is better;

[0086] By preparing a non-woven substrate composed of a heat-shrinkable fiber / microcapsule composite nanofiber membrane, castor silkworm short fibers, and a sericin coating, the heat-shrinkable fiber / microcapsule composite nanofiber membrane can be discolored by utilizing the temperature of the human face when the non-woven substrate comes into contact with the human face. During the use of the non-woven substrate, when the heat-shrinkable fiber / microcapsule composite nanofiber membrane becomes transparent again, it indicates that the non-woven substrate has been used. The color change can intuitively indicate the usage status and reduce excessive application.

[0087] The foregoing is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art may make various improvements and modifications without departing from the principles of the present invention, and such improvements and modifications are also within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described or explained herein shall, unless otherwise specified or limited, be implemented in accordance with conventional means in the art.

Claims

1. A method for developing a heat-shrinkable nonwoven facial mask substrate using castor silk flat silk, characterized in that: The following steps are involved: Step 1: Preparation of thermochromic microcapsules: emulsifying and dispersing a core material comprising vitamin C, a thermochromic dye, and a carrier oil in a wall material solution to prepare microcapsules; adding glutaraldehyde to the microcapsules for cross-linking; washing by centrifugation; and freeze-drying to form thermochromic microcapsules; Step 2: pre-treating the castor silk flat yarn to prepare the castor silk flat yarn and then drawing, orienting, and cutting the castor silk flat yarn to form castor silk staple fibers; Step 3: Composite spinning of heat-shrinkable fiber and microcapsule, preparing a spinning solution based on the thermosensitive color-changing microcapsules prepared in step 1, and preparing the spinning solution into a heat-shrinkable fiber / microcapsule composite nanofiber membrane; Step 4: non-woven substrate composite, the castor silkworm short fibers prepared in step 2, the heat-shrinkable fiber / microcapsule composite nanofiber membrane prepared in step 3 and the sericin coating are prepared into a non-woven substrate.

2. A method for developing a heat-shrinkable nonwoven facial mask substrate using castor silk flat silk according to claim 1, characterized in that: The step 1 comprises the following steps: Step 101: Mixing vitamin C, thermochromic dye, and carrier oil to form a core material; Step 102: emulsifying and dispersing the core material prepared in step 101 in the wall material solution to form an O / W emulsion; Step 103: Cooling the O / W emulsion to form microcapsules; Step 104: Glutaraldehyde is added to the microcapsules for cross-linking, and the microcapsules are centrifuged, washed, and freeze-dried to form thermosensitive color-changing microcapsules.

3. A method for developing a heat-shrinkable nonwoven facial mask substrate using castor silk flat silk according to claim 1, characterized in that: The color change threshold of the thermochromic dye is 35°C.

4. A method for developing a heat-shrinkable nonwoven facial mask substrate using castor silk flat silk according to claim 3, characterized in that: The material of the thermochromic dye is cholesteric liquid crystal microcapsule or anthocyanin-metal complex, and the carrier oil is jojoba oil.

5. A method for developing a heat-shrinkable nonwoven facial mask substrate using castor silk flat silk according to claim 2, characterized in that: The step 2 of pre-treating the castor silk flat silk includes preparing the castor silk flat silk, removing impurities with low-temperature plasma, pre-treating by drawing, and short-fibering treatment; The preparation of the castor silk flat silk comprises the following steps: S1: Take silkworms that have just hatched from silkworm eggs and place them in a feeding plaque and feed them castor leaves, cassava leaves, or Ailanthus altissima leaves. When each group of silkworms reaches the fifth instar and 10%-15% are mature, add molting hormone. When more than 95% of the silkworms have become mature, allow them to fully defecate and urinate for more than 48 hours. S2: After the mature silkworms have excreted all their feces and urine, they are placed in a 200-300 5-year-old mature silkworm / m 2 The silkworms evenly spread the silk on the spinning plate, and the silkworms spin silk strands. After 40-50 hours, the spinning ends and a complete flat silk is formed. The low-temperature plasma impurity removal comprises the following steps: M1: Remove the castor silkworms from the flat silk surface after spinning, and remove solid impurities on the castor silk flat silk; M2: The ricinus silk flat silk in M1 was treated for 6 minutes under an argon flow rate of 20 L / min and a power of 300 W; The drafting pretreatment specifically comprises the following steps: P1: The ricin silk flat silk that has been treated with impurities is clamped between the two clamps of the unidirectional stretching equipment and stretched. After reaching the set elongation, the stretching is stopped and kept at 60℃ for 10-20 minutes; P2: Take the castor silk flat yarn in P1 out of the unidirectional stretching equipment; The short-fiberization treatment is to use a mechanical cutter to cut the castor silk flat silk at equal distances according to a cutting distance of 40-50 mm to form short fibers.

6. A method for developing a heat-shrinkable nonwoven facial mask substrate using castor silk flat silk according to claim 5, characterized in that: The step 3 comprises the following steps: Step 301: dissolving a polylactic acid / polycaprolactone blend having a mass ratio of 7:3 in chloroform to a concentration of 12% to form a chloroform mixed solution; Step 302: adding thermochromic microcapsules and dispersant, and ultrasonically homogenizing for 30 minutes to obtain a spinning solution; Step 303: Processing the spinning solution into a nanofiber membrane through electrospinning.

7. A method for developing a heat-shrinkable nonwoven facial mask substrate using castor silk flat silk according to claim 1, characterized in that: The nonwoven substrate comprises an outer layer, a middle layer and an inner layer, the outer layer is a heat-shrinkable fiber / microcapsule composite nanofiber membrane, the middle layer is castor silkworm short fiber+PLA fiber, and the inner layer is a sericin coating.

8. A method for developing a heat-shrinkable nonwoven facial mask substrate using castor silk flat silk according to claim 7, characterized in that: The step 4 comprises the following steps: Step 401: Using a roller press, the outer layer, the middle layer, and the inner layer are compounded to form an integrated substrate; Step 402 : placing the integrated substrate obtained in step 402 in a hot and humid environment at 50° C. and RH 80% for 20 minutes to obtain a nonwoven substrate.

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