Forming process of edgeless powder puff and edgeless powder puff

Abstract

The invention discloses a forming process of an edgeless powder puff and the edgeless powder puff. The forming process comprises the following steps: preparing polyether polyol, isocyanate, water, silicone oil, PU leather and elastic sponge; the polyether polyol is subjected to vacuum dehydration at 120 DEG C until the water content is less than 0.05%, the polyether polyol and isocyanate are mixed according to the weight part ratio of (70-100): (20-50) to react to obtain a prepolymer, and the reaction temperature is greater than or equal to 80 DEG C; the preparation method comprises the following steps: mixing wollastonite powder and water to obtain a wollastonite powder mixed solution, mixing a prepolymer, the wollastonite powder mixed solution and silicone oil, and uniformly stirring at a high speed; pouring the uniformly mixed materials into a mold, and foaming at 25-70 DEG C for 12-15 minutes for molding; transferring to a drying tunnel for heating and curing after molding, and controlling the temperature in sections; slicing according to a set thickness to serve as a fabric; the fabric and the PU leather are compounded to the two opposite sides of the elastic sponge; carrying out fusion cutting molding on the compounded material on a hot press; the hot press adopts a micro-notch mold, the edge is concave inwards by 0.3 mm, and fusion hot cutting forming is conducted at the temperature of 80 DEG C through an ultrasonic technology, so that the edgeless powder puff is obtained.

Description

Technical Field

[0001] This invention relates to the field of cosmetic tool technology, and in particular to a molding process for a borderless powder puff and the borderless powder puff itself. Background Technology

[0002] Traditional powder puffs often use a hot-melt cutting process (170~190℃ high-temperature fusion cutting), which usually results in noticeable edges. During the molding process, protruding edges are left, leading to the following problems: makeup residue remains on the edges, affecting the neatness of the makeup; indentations are easily created during makeup application, resulting in patchy and powdery finishes; sharp edges can easily scratch sensitive areas such as the eye area and corners of the mouth; after frequent use or washing, the edges are prone to wear, cracking, or delamination, resulting in poor durability. Existing improved processes only reduce the edge size, failing to achieve true "edgeless" design, and still suffer from noticeable rough edges and a poor user experience, affecting both appearance and user experience. This invention addresses these shortcomings by optimizing raw material control and molding processes, proposing a molding process and resulting in an edgeless powder puff with smooth edges, no residue, and high durability. Summary of the Invention

[0003] To address the aforementioned issues, this invention provides a molding process and a borderless powder puff, achieving a powder puff with no protrusions or marks on the edges, thereby improving the evenness of makeup application and the user experience.

[0004] To address the problems mentioned in the background section and achieve the aforementioned technical objectives, the present invention provides the following technical solution: The first aspect of this invention provides a molding process for a borderless powder puff, comprising the following steps: preparing polyether polyol, isocyanate, water, silicone oil, PU leather, and elastic sponge; vacuum dehydrating the polyether polyol at 120°C to a water content of <0.05%; mixing the polyether polyol and isocyanate in a weight ratio of 70~100:20~50 to obtain a prepolymer, with a reaction temperature ≥80°C; mixing wollastonite powder and water to obtain a wollastonite powder mixture; mixing the prepolymer, the wollastonite powder mixture, and silicone oil, and stirring at high speed until homogeneous; and then... The uniformly mixed material is poured into a mold and foamed at 25~70℃ for 12~15 minutes to form. After forming, it is transferred to an oven for heating and curing, with temperature controlled in stages. After drying, it is sliced ​​into fabric according to the set thickness. The fabric and PU leather are laminated to the opposite sides of the elastic sponge. The laminated material is melted and cut into shape on a hot press. The hot press uses a zero-to-zero micro-concave mold with the mold edge concave by 0.3 mm. It is fused and hot-cut into shape at 80℃ using a 12Hz, 5200W ultrasonic process to obtain a borderless powder puff.

[0005] Preferably, the concentration of wollastonite powder in the wollastonite powder mixture is 27-29%.

[0006] Preferably, the mixing ratio of the prepolymer, wollastonite powder mixture and silicone oil is 47.8-48.3% prepolymer, 51.3-51.8% wollastonite powder mixture and 0.4-0.6% silicone oil.

[0007] Preferably, the stirring speed of the prepolymer, water and silicone oil is 3000~5000 rpm, and the stirring time is 4~8 seconds.

[0008] Preferably, the temperature segmented control process includes three segments: the first segment is baking at 75~85℃ for 5~6 hours, the second segment is baking at 45~55℃ for 2~3 hours, and the third segment is baking at 60~70℃ for 4~5 hours.

[0009] Preferably, the thickness of the fabric is 1.5~2mm.

[0010] Preferably, the molding process further includes a ribbon sewing step: sewing the ribbon onto the PU leather using a sewing machine.

[0011] Preferably, the molding process further includes a laser engraving step: laser engraving a pattern on the ribbon or PU leather.

[0012] Preferably, the molding process further includes a full inspection step: testing tensile and compressive properties, inspecting appearance, and randomly checking resilience and hardness.

[0013] A second aspect of the present invention provides a borderless powder puff, which is manufactured using the molding process described above.

[0014] The beneficial effects of this invention are as follows: By using ultrasonic low-temperature fusion hot cutting and zero-to-zero micro-concave mold design, this invention avoids the edge protrusion and residue of traditional high-temperature processes, resulting in smooth and flat edges with a borderless feel. It does not scratch the skin during use and reduces makeup lines and indentations. The optimized prepolymer synthesis process and raw material ratio improve the structural stability of the powder puff, making it less prone to edge breakage, cracking, or delamination, thus extending its service life. The composite structure of the fabric and elastic sponge improves the evenness of powder pickup, leaving no traces when applying makeup, resulting in a natural makeup look, reducing the phenomenon of "powder absorption," and reducing cosmetic waste. Attached Figure Description

[0015] Figure 1 This is a flowchart of the molding process for the edgeless powder puff of the present invention.

[0016] Figure 2 This is a comparison diagram of the edgeless powder puff of the present invention and a traditional powder puff. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0018] Example 1: A molding process for a borderless powder puff includes the following steps: Preparation of materials: Prepare the raw materials, including polyether polyol (molecular weight 3000), isocyanate (MDI), wollastonite powder (particle size 5μm), deionized water, silicone oil (viscosity 500mPa・s), PU leather (thickness 0.3mm), elastic sponge (density 25kg / m³), and ribbon (nylon material, width 5~8mm). Prepolymer synthesis: Polyether polyol was dehydrated to a water content of 0.04% under vacuum at 120°C; polyether polyol and isocyanate were mixed in a weight ratio of 70:50 and reacted at 85°C for 2 hours to obtain a prepolymer with an NCO% of 5% and a viscosity of 6000 mPa·s (25°C). Mixing: First, mix wollastonite powder and deionized water to prepare a wollastonite powder mixture with a concentration of 28%. Then, mix the prepolymer, wollastonite powder mixture and silicone oil in a weight ratio of 48:51.5:0.5 and stir at a high speed of 3000 rpm for 8 seconds to ensure uniform mixing. Foaming: Pour the uniformly mixed material into the mold and foam at 25°C for 15 minutes to form an open-cell structure with a pore size of 120~250μm. Curing: After molding, the product is moved to a 15-meter drying tunnel for heating and curing, with temperature controlled in stages: First section (0-5 meters): Bake at 80℃ for 6 hours to cure; Second section (5-10 meters): Bake at 50℃ for 3 hours to remove moisture, maintain for 50 minutes; The third section (10-15 meters): bake again at 65℃ for 5 hours. Cutting: After drying, cut into 1.5mm thick slices to be used as the base material for powder puffs. Lamination: Using hot melt adhesive (melting point 80~100℃), first laminate the PU leather to one side of the elastic sponge, and then laminate the fabric to the other side of the elastic sponge. The lamination pressure is 0.3~0.5MPa, and the holding time is 5~10 seconds.

[0019] Fusion Hot Cutting: The composite material is placed in a hot press using a zero-to-zero micro-notch mold. The mold edge is recessed inward by 0.3 mm to prevent leakage at the sealing point after powder puff forming, reducing the contact area and achieving a zero-edge sealing effect. Fusion hot cutting is then performed at 80℃ using a 12Hz, 5200W ultrasonic process with a cutting pressure of 0.2~0.4MPa and a processing time of 1~3 seconds, resulting in an edgeless structure. Sewing ribbon: Use a sewing machine to sew a 1cm wide ribbon onto the PU leather surface with a stitch length of 2-3mm and a thread tension of 5-8N to ensure the ribbon is flat and does not fall off. Laser engraving: Laser engraving patterns on ribbons or PU leather surfaces. Laser engraving power is 5~10W, speed is 100~200mm / s, and depth is 0.01~0.03mm. Full inspection: Tensile properties were tested using a tensile tester: tensile strength ≥ 1.5 MPa, elongation at break ≥ 100%; Compression performance was tested using a pressure gauge: compression deformation rate ≤5% (25℃, 50% compression, held for 24 hours); Appearance inspection: No stains or burrs, shape tolerance ≤ 0.1mm; Spot checks: resilience (recovery time ≤ 3 seconds after 50% compression), softness / hardness (Shore A 20~30 degrees).

[0020] Example 2: Preparation of materials: Same as in Example 1; Prepolymer synthesis: Polyether polyol was dehydrated to a water content of 0.03%; polyether polyol and isocyanate were mixed in a weight ratio of 100:20 and reacted at 80°C for 2.5 hours to obtain the prepolymer (NCO%=10%, viscosity 7500mPa・s (25°C)). Mixing: The concentration of the wollastonite powder mixture is 29%; it is mixed at a weight ratio of prepolymer:wollastonite powder mixture:silicone oil = 47.8:51.8:0.4 and stirred at 5000 rpm for 4 seconds. Foaming: Foam at 35℃ for 12 minutes, pore size 180~250μm; Curing: 30-meter drying tunnel, 80℃ for 5 hours (10 meters) → 50℃ for 2 hours (10 meters) → 65℃ for 4 hours (10 meters); Cutting: 2.0mm thick fabric; Combination and subsequent steps: Same as in Example 1. Example 3: Prepolymer synthesis: Polyether polyol and isocyanate were mixed in a weight ratio of 85:35 and reacted at 90°C for 1.5 hours. The prepolymer had an NCO% of 8% and a viscosity of 7000 mPa·s (25°C). Mixing: The concentration of the wollastonite powder mixture is 28%; it is mixed at a weight ratio of prepolymer:wollastonite powder mixture:silicone oil = 48.1:51.3:0.6, and stirred at 4000 rpm for 6 seconds. Foaming: Foam at 70℃ for 13 minutes, pore size 150~220μm; Other steps: Same as in Example 1 (cutting thickness 1.8mm). Comparative experiment: The edgeless powder puffs prepared in Examples 1, 2, and 3 (experimental group) were compared with powder puffs produced using a traditional hot-melt cutting process (control group, hot-melt cutting at 180℃, with an edge protrusion of 0.8mm) for performance evaluation. The control group used a conventional high-temperature hot-melt cutting process (referring to the recommended high-temperature cutting parameters of 170~190℃ in the "General Technical Requirements for Cosmetic Puffs" (QB / T 4256-2011), with the actual test using a cutting temperature of 180℃ and an edge protrusion of 0.8mm). The comparison results are shown in Table 1 and appendix. Figure 2 As shown: The results of the above comparative experiments show that the edgeless powder puff of the present invention is significantly superior to the traditional powder puff in terms of edge smoothness, durability, makeup effect and economy.

[0021] As can be seen from the above embodiments, compared with the traditional hot-melt cutting process for powder puffs, the advantages of the molding process of the present invention and the resulting edgeless powder puff are as follows: By using ultrasonic low-temperature (80℃) fusion hot cutting and zero-to-zero micro-concave mold design, the edge protrusion and residue of traditional high-temperature processes are avoided, resulting in smooth and flat edges, a borderless feel, no scratches on the skin during use, and reduced makeup lines and indentations; the optimized prepolymer synthesis process and raw material ratio improve the structural stability of the powder puff, making it less prone to edge breakage, cracking, or delamination, and extending its service life; the composite structure of fabric and elastic sponge improves the evenness of powder pickup, leaving no traces when applying makeup, resulting in a natural makeup look, reducing the phenomenon of "powder absorption", and reducing cosmetic waste.

[0022] Regarding the embodiments of the present invention, it should also be noted that, without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other to obtain new embodiments.

[0023] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A molding process for a borderless powder puff, characterized in that, Includes the following steps: Materials preparation: Prepare polyether polyol, isocyanate, wollastonite powder, water, silicone oil, PU leather and elastic sponge; Prepolymer synthesis: Polyether polyol is dehydrated under vacuum at 120°C until the water content is <0.05%. The polyether polyol and isocyanate are mixed and reacted in a weight ratio of 70~100:20~50 to obtain the prepolymer. The reaction temperature is ≥80°C. Mixing: First, mix wollastonite powder and water to obtain a wollastonite powder mixture. Then, mix the prepolymer, the wollastonite powder mixture, and the silicone oil, and stir at high speed until homogeneous. Foaming: Pour the well-mixed material into the mold and foam at 25~70℃ for 12~15 minutes to form; Curing: After molding, the product is moved to an oven for heating and curing, with temperature controlled in stages; Cutting: After drying, cut into slices according to the set thickness to use as fabric; Composite: The fabric and PU leather are bonded to opposite sides of the elastic sponge; Fusion hot cutting: The composite material is melted and cut into shape on a hot press. The hot press uses a zero-to-zero micro-concave mold with the mold edge concave inward by 0.3 mm. The fusion hot cutting is carried out at 80℃ using a 12Hz, 5200W ultrasonic process to obtain a borderless powder puff.

2. The molding process of the edgeless powder puff according to claim 1, characterized in that, The concentration of wollastonite powder in the wollastonite powder mixture is 27-29%.

3. The molding process of the edgeless powder puff according to claim 1, characterized in that, The mixing ratio of the prepolymer, wollastonite powder mixture and silicone oil is 47.8-48.3% prepolymer, 51.3-51.8% wollastonite powder mixture and 0.4-0.6% silicone oil.

4. The molding process of the edgeless powder puff according to claim 1, characterized in that, The prepolymer, water, and silicone oil are stirred at a speed of 3000-5000 rpm for 4-8 seconds.

5. The molding process of the edgeless powder puff according to claim 1, characterized in that, The temperature segmented control process includes three stages: the first stage is baking at 75~85℃ for 5~6 hours, the second stage is baking at 45~55℃ for 2~3 hours, and the third stage is baking at 60~70℃ for 4~5 hours.

6. The molding process of the edgeless powder puff according to claim 1, characterized in that, The thickness of the fabric is 1.5~2mm.

7. The molding process of the edgeless powder puff according to claim 1, characterized in that, The molding process also includes a ribbon sewing step: using a sewing machine to sew the ribbon onto the PU leather.

8. The molding process of the edgeless powder puff according to claim 7, characterized in that, The molding process also includes a laser engraving step: laser engraving patterns on ribbons or PU leather.

9. The molding process of the edgeless powder puff according to claim 8, characterized in that, The molding process also includes a full inspection step: testing tensile and compressive properties, inspecting appearance, and randomly checking resilience and hardness.

10. A borderless powder puff, characterized in that, The borderless powder puff is manufactured using the molding process described in any one of claims 1 to 9.

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