Embossment of thin film articles

Abstract

To provide an embossment (100) on a film sheet, and a glove made of an embossed film sheet.SOLUTION: An embossment (100) includes a base surface (103), a protrusion surface (102) in an opposite side of the base surface (103), and at least one concave area (104) being formed in the protrusion surface (102) and extending from the protrusion surface (102) to the base surface (103). A depth (Dr) of the concave area (104) is 50-99% of a height (He) of the embossment (100) between the base surface (103) and the protrusion surface (102).SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to the embossment of thin film articles, and in particular to the embossment of thermoplastic elastomer (TPE) gloves to improve glove durability and grip performance. [Background technology]

[0002] Gloves are known as personal protective equipment (PPE) and ensure the protection of human hands when coming into contact with certain objects, chemicals, or living organisms. Many types of gloves have been invented to suit different applications. Food handling is one of the common sectors that requires the use of gloves, where gloves are introduced to prevent cross-contamination of human hands and food.

[0003] Four common types of gloves in the food industry are acrylonitrile-butadiene rubber (NBR) gloves, polyvinyl chloride (PVC) gloves, thermoplastic elastomer (TPE) gloves, and polyethylene (PE) gloves. Each of these four glove types has advantages and disadvantages in terms of cost, durability, ergonomics, and chemical hazards.

[0004] Compared with NBR gloves and PVC gloves, TPE gloves have the lowest chemical hazard, but are slightly inferior in durability and grip performance. The two main drawbacks of TPE gloves are durability and grip performance. In the prior art, several attempts have been made to overcome the poor durability and grip performance associated with the shortcomings of TPE gloves. Traditionally, these gloves have been embossed with overlapping textures or patterns to overcome the above-mentioned drawbacks. However, overlapping textures or embossed patterns cannot achieve a balance between durability and grip performance.

[0005] Therefore, there is a need for embossments that allow thin film articles, such as TPE gloves, to have improved durability and grip performance without increasing manufacturing and overhead costs. Summary of the Invention

[0006] An embossment in a film sheet is disclosed. The embossment comprises a base surface, a raised surface opposite the base surface, and at least one recessed area formed therein and extending from the raised surface to the base surface. The depth of the recessed area is 50% to 99% of the height of the embossment between the base surface and the raised surface.

[0007] According to the present invention, the size of the embossment is 0.10 mm to 10.00 mm, and the size of the recessed area is 0.05 mm to 5.00 mm.

[0008] Typically, the design of the embossments and recessed areas is selected from the group consisting of at least one pattern, at least one shape, or a combination thereof.

[0009] Preferably, the pattern is selected from the group consisting of flowers, waves, water drops, fish scales or abstract designs, patterns imitating the appearance of animate or inanimate objects, while the shape is selected from the group consisting of circles, squares, rectangles, diamonds, hexagons, octagons, or combinations thereof.

[0010] Alternatively, the depth of the recessed area is 80% to 90% of the height of the embossment. Additionally, the recessed area may be stepped.

[0011] Furthermore, the thickness of the film sheet before embossing is 25 μm to 60 μm.

[0012] According to another aspect of the present invention, a glove made from a film sheet having at least one embossment is disclosed.

[0013] Further aspects, features, and advantages of the present invention will become apparent to those skilled in the art upon review of the following detailed description of preferred embodiments of the invention in conjunction with the drawings listed below. [Brief explanation of the drawings]

[0014] The present invention will be more fully understood from the detailed description given below and the accompanying drawings, which are given by way of example only and do not limit the invention.

[0015] [Figure 1] FIG. 1 is a top view of an exemplary embossment (with hexagonal and intermediate circular recessed areas) according to the present invention. [Figure 2a] FIG. 2 is a cross-sectional view of an embossment of a film sheet showing 100% depth of the recessed areas in accordance with the present invention. [Figure 2b] FIG. 2 is a cross-sectional view of an embossment of a film sheet showing an 80% depth of the recessed area, in accordance with the present invention. [Figure 3] 1 is a cross-sectional view of an embossment of a film sheet showing a recessed area with multiple steps in accordance with the present invention. [Figure 4] 1A-1C illustrate exemplary embossments made in a thermoplastic elastomer (TPE) glove in accordance with the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] Detailed descriptions of preferred embodiments of the present invention are disclosed herein. However, it should be understood that these embodiments are merely examples of the present invention, which may be embodied in various forms. Therefore, the details disclosed herein should not be interpreted as limiting, but merely as a basis for the claims and for teaching those skilled in the art of the present invention. Numerical data or ranges used herein should not be interpreted as limiting.

[0017] The present invention relates to embossment in film sheets. Specifically, the present invention proposes a new embossment to address poor durability and grip performance in thin articles, such as gloves, made from film sheets. Although the present invention describes the application of embossment to gloves, the teachings of the present invention can be applied to any article made from film sheets using an extrusion casting process.

[0018] The embossment as proposed by the present invention is a three-dimensional design with a combination of patterns and / or shapes of various sizes.

[0019] Referring to the accompanying figures, Figure 1 presents a top view of an exemplary embossment designed in accordance with the present invention. Figures 2a and 2b present a cross-section of an embossment in a film sheet showing recessed areas. Figure 3 presents a cross-section of an embossment in a film sheet showing recessed areas with multiple steps. Figure 4 presents an exemplary embossment made in a thermoplastic elastomer (TPE) glove.

[0020] Each of the features of the embossment is described in detail below. The first feature of the present invention, presented in FIG. 1, considers the design of the embossment (100) including at least one pattern and / or at least one shape. The pattern may be, but is not limited to, a flower, wave, water droplet, fish scale, or any pattern imitating an abstract design, animate, or inanimate object, while the shape may be, but is not limited to, a circle, square, rectangle, diamond, hexagon, octagon, or combinations thereof. The size of the embossment (100) having the above-mentioned pattern and / or shape is 0.10 mm to 10.00 mm, more preferably 0.30 mm to 2.00 mm. For example, as presented in FIG. 1, the embossment (100) in the film sheet is represented as a hexagon.

[0021] The at least one pattern and / or at least one shape in the embossment (100) provides a plow effect and prevents movement of an object when gripping using a TPE glove having one or more embossments according to the present invention. The plow effect is achieved by the uneven surface of the embossment (100). The plow effect also helps improve gripping performance when handling objects.

[0022] 2a and 2b, the embossment (100) in the film sheet comprises a base surface (103), a raised surface (102) opposite the base surface (103), and at least one recessed area (104) formed therein and extending from the raised surface (102) to the base surface (103). When the embossment in the film sheet is used to manufacture a TPE glove, the dark dotted lines in FIGS. 2a and 2b indicate the base surface (103) of the embossment (100) that will come into contact with an object, and the raised surface (102) will come into contact with the user's hand.

[0023] According to a second aspect of the present invention, recessed areas (104) are present for each pattern and / or shape of the embossment (100). When the embossment (100) in the film sheet is viewed from above, the recessed areas (104) appear formed within the embossment (100).

[0024] The recessed areas (104) serve to provide additional contact area for the object. The design of the recessed areas (104) includes at least one pattern and / or at least one shape, including, but not limited to, flowers, waves, water droplets, fish scales, or any pattern imitating an abstract design, animate, or inanimate object, while the shape includes, but is not limited to, circles, squares, rectangles, diamonds, hexagons, octagons, or combinations thereof. The size of the recessed areas (104) is smaller than the size of the embossment (100), ranging from 0.05 mm to 5.00 mm, and more preferably from 0.07 mm to 1.00 mm. For example, as shown in FIG. 1, the recessed areas (104) in the embossment (100) are depicted as circles.

[0025] A third feature of the present invention discloses that the recessed area (104) is stepped. The steps of the recessed area (104) generally correspond to the height (H e The depth (D r ) and the embossment height (H e) is the distance between the base surface (103) and the raised surface (102) of the embossment (100). Preferably, the depth (D) of the recessed region (104) is adjusted to provide flexibility in controlling the durability and grip performance of the thin film article. r ) is the height (H e ) is 80% to 90% of the total surface area. Alternatively, two or more steps may be introduced into the recessed area (104), as shown in Figure 3. Thus, each recessed area (104) can have multiple steps (300) by controlling the step height.

[0026] FIG. 2a shows the depth (D r ) is the embossment height (H e ) in which the depth (D r ) is the height (H) of the embossment (100) e ) which is not desirable for the present invention. On the other hand, FIG. 2b shows that the depth (D r ) is the embossment height (H e ) is 80%.

[0027] The depth (D r ) plays an important role in providing flexibility in controlling the durability and grip performance of thin film articles.

[0028] Figure 4 shows a TPE glove manufactured from a film sheet having an embossment (100) prepared according to the present invention. Two or more embossments (100) on the glove are separated by non-embossed areas (101), as shown in Figures 1-4. The non-embossed areas (101) contribute to increasing the surface area that comes into contact with an object.

[0029] The combination of these three features introduces a three-dimensional design of the embossment, which further expands the possibilities for incorporating various new features into thin film articles, especially TPE gloves, resulting in improved durability and grip performance. TPE film sheets are embossed with the above features using, but not limited to, an extrusion casting process followed by a heat-sealing process. The heat-sealing process refers to the method used to manufacture hand-shaped gloves by sealing two layers of film sheets together.

[0030] The following examples are intended to illustrate the invention in a non-limiting manner.

[0031] Thermoplastic elastomer (TPE) film construction Table 1 summarizes the composition of the film sheets used to manufacture the TPE films.

[0032] [Table 1]

[0033] As shown in Table 1, the composition of the film sheet used to manufacture the TPE film is 10.00 wt% to 40.00 wt% LDPE, 20.00 wt% to 80.00 wt% m-LLDPE, 10.00 wt% to 40.00 wt% TPO, and 0.01 wt% to 2.00 wt% amide. LDPE is the primary component of the TPE film. m-LLDPE provides strength and sealing capabilities to the TPE film used to manufacture gloves. m-LLDPE may be substituted for Ziegler-Natta LLDPE. TPO provides elasticity to the TPE film, and the TPO used is an ethylene-α-olefin copolymer. Finally, the amide provides donning efficiency when the TPE film is used in thin-film articles such as gloves. The amide may be substituted for erucamide.

[0034] How to prepare embossed TPE gloves Embossed TPE gloves are manufactured by transferring the embossment to a film sheet using a series of rollers during a conventional extrusion-casting process. The embossed film is then sealed into the TPE glove using a heat-sealing process.

[0035] This method is not limited to extrusion casting using a single screw extruder. The extrusion temperature is in the range of 150°C to 280°C, preferably 170°C to 260°C. Meanwhile, the heat-sealing temperature is in the range of 280°C to 380°C, preferably 330°C to 350°C. The heat-sealing speed is in the range of 110 seals / min to 160 seals / min, preferably 125 seals / min to 140 seals / min.

[0036] The TPE gloves with the embossment of the present invention were tested at different depths (D r The recessed area (104) of the adhesive sheet was used to test for durability and grip performance. The results are summarized in Table 2. Mechanical properties were tested according to ASTM D412-16, including but not limited to tensile strength and elongation. Grip performance was tested for static coefficient of friction (COF) and tack according to ASTM D1894. Finally, durability was tested using a finger rub test.

[0037] [Table 2]

[0038] Measurements of static COF, adhesion, and durability were performed on the outside of the glove, i.e., the contact surface between the glove and the object. A higher static COF indicates better adhesion and gripping performance. A higher adhesion angle also indicates better gripping performance. Meanwhile, durability shown in Table 2 refers to the number of rubs between the thumb and index finger. A higher value for durability is considered preferable because it withstands frictional movements and resists tearing during processing. Regarding the durability of TPE gloves in practical applications, the gloves were subjected to continuous rubbing between the object and the TPE glove.

[0039] Based on Table 2, the present invention provides a wide range of depths (D r It can be seen that it is possible to fabricate a wide range of depths (D r ) produces different results in terms of durability of TPE gloves in terms of grip performance as measured by static coefficient of friction (COF) and tack. r It can also be seen that by controlling the tensile strength, the mechanical properties of the TPE gloves were not affected, but the durability and grip performance changed significantly.

[0040] Furthermore, the test in Table 2 was carried out to measure the depth (D r ) shows optimal results. Therefore, embossments with 80% and 90% recesses provide a balance between the durability and grip performance of TPE gloves.

[0041] Furthermore, the thickness of the film sheet before embossing is controlled within the range of 25 μm to 60 μm, preferably 32 μm to 38 μm, and most preferably 35 μm. Controlling the thickness of the film sheet before embossing is important because a thickness less than 25 μm results in poor durability, while a thickness greater than 60 μm results in defects in the glove due to the presence of crack lines on the film. Alternatively, the overlay embossing on the film is not critical. Therefore, the produced texture may not provide the durability and grip performance intended by the present invention.

[0042] In summary, embossment features designed in accordance with the present invention can overcome the imbalance between durability and grip performance in thermoplastic elastomer (TPE) gloves.

[0043] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a," "an," and "the" may be intended to include the plural forms as well, unless clearly indicated otherwise. The terms "comprise," "comprising," "including," and "having" are inclusive and thus specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0044] The method steps, processes, and operations described herein should not be construed as requiring performance in the particular order described or illustrated unless the method of performance is expressly specified. It should also be understood that additional or alternative steps may be utilized. The use of the phrase "at least" or "at least one" suggests the use of one or more elements, as may be in one of the embodiments to achieve one or more desired purposes or results.

Claims

1. An embossment (100) in a film sheet, comprising: (i) a base surface (103); (ii) a raised surface (102) opposite said base surface (103); (iii) at least one recessed area (104) formed therein and extending from said raised surface (102) to said base surface (103); Equipped with The depth (D) of the recessed region (104) is defined as the height difference between the raised surface (102) and the depth position of the recessed region (104) furthest from the raised surface (102). ｒ ) is the height (H) of the embossment (100) between the base surface (103) and the raised surface (102). ｅ ) and the thickness of the film sheet before embossing is 25 to 60 μm.

2. The embossment (100) of claim 1, wherein the size of the embossment (100) is between 0.10 mm and 10.00 mm.

3. The embossment (100) of claim 1, wherein the recessed area (104) has a size of 0.05 mm to 5.00 mm.

4. 10. The embossment (100) of claim 1, wherein the design of the embossment (100) and the recessed area (104) is selected from the group consisting of at least one pattern, at least one shape, or a combination thereof.

5. 5. The embossment (100) of claim 4, wherein the pattern is selected from the group consisting of flowers, waves, water droplets, fish scales, or patterns that mimic abstract designs, animate or inanimate appearances.

6. 5. The embossment (100) of claim 4, wherein the shape is selected from the group consisting of a circle, a square, a rectangle, a diamond, a hexagon, an octagon, or a combination thereof.

7. The embossment (100) of claim 1, wherein the recessed area (104) is stepped.

8. The embossment (100) of claim 1, wherein the thickness of the film sheet before embossing is between 32 and 38 μm.

9. A glove manufactured from a film sheet having at least one embossment (100) according to any one of claims 1 to 8.

Images