TW202233492A - Manufacturing method and products of pet box lid - Google Patents

Abstract

The present invention provides a method for manufacturing a box cover made of PET. First, a plastic sheet is placed on a master mold, and the master mold has a mold cavity inside, and the bottom surface of the mold cavity has a convex ridge line. A male mold is used to press the plastic sheet to the cavity of the female mold, so that the plastic sheet contacts the convex ridge line of the mold cavity. During the process of pressing the plastic sheet into the cavity of the female mold by the male mold, the gas between the plastic sheet and the bottom surface of the female mold is discharged by the inclination angle between the convex ridge line and the peripheral surface. The plastic sheet is pressed to form a box cover, and one side surface of the box cover forms a wave-eliminating line by the convex ridge line, thereby reducing the generation of water ripples.

Description

Method for making box lids made of PET and products thereof

The invention relates to the technical field of a plastic product, in particular to a method for making a PET box cover and its product.

Generally speaking, a plastic processing (also rubber processing) method in which a plastic or rubber compound is formed into a product by heating and pressing in a closed mold cavity. Generally, powders, granules, granules, flakes, or even preforms with similar shapes to the products are placed in the cavity of the heated master mold, and then the mold is closed and pressurized to shape and solidify or vulcanize it. , and then demoulded to obtain the product.

However, when plastic is generally press-molded, excess gas is likely to remain between the plastic and the master mold, which in turn leads to water ripples in the plastic molding, which increases the defect rate of the product.

As shown in FIG. 7, it is revealed that the surface of a box cover 50 has water ripples, which makes the light reflected/transmitted on the surface of the box cover 50 in an uneven state, so consumers cannot clearly see where the box is located. content. Thus, it can be seen that the conventional manufacturing method still needs to be improved.

The purpose of the present invention is to provide a method for making a PET box cover and its product, which have the effect of reducing the generation of water ripples.

In order to achieve the above-mentioned purpose and effect, the present invention provides a box cover made of PET, which comprises a cover sheet, a peripheral portion surrounds the cover sheet, and an open lid is formed at one end of the range formed around the peripheral portion relative to the peripheral portion. A cover sheet, the cover sheet has a first surface, and a second surface opposite to the first surface, characterized in that the first surface includes a first beveled surface connected to a second beveled surface, a eliminating A wave line is formed at the junction of the first beveled surface and the second beveled surface.

In one embodiment, the first beveled surface has a first connecting side and a first peripheral side, the first connecting side is closer to the cover than the first peripheral side, and the second beveled surface is It has a second connection side and a second peripheral side, the second connection side is closer to the cover than the second peripheral side, and the first connection side is connected to the second connection side and forms the wave elimination line.

In one embodiment, the inclination angle of the first connecting side and the first peripheral side is between 0.5 degrees and 1.5 degrees.

A method for making a PET box cover, comprising the following steps: In a feeding step, a plastic sheet is placed in a female mold, wherein the female mold has a mold cavity inside, and the bottom surface of the mold cavity has a raised ridge; a pressing step, using a male mold to press the plastic sheet to the mold cavity of the female mold, so that the plastic sheet contacts the raised ridgeline of the mold cavity; In a venting step, in the process of pressing the plastic sheet to the cavity of the female mold by the male mold, the gas between the plastic sheet and the bottom surface of the female mold is discharged by the inclination angle between the raised ridgeline and the peripheral surface. discharge; In a molding step, the plastic sheet is pressed to form a box cover, and a wave-absorbing line is formed on one side surface of the box cover by the raised ridgeline.

In one embodiment, before the pressing step, a heating step of preheating the male mold to a predetermined temperature is further included.

Hereinafter, according to the purpose and effect of the present invention, preferred embodiments are given and described in detail with the accompanying drawings.

Please refer to Figures 1 and 2, the present invention provides a method for making a PET box cover, comprising the following steps:

In a feeding step, a pre-cut plastic sheet 10 is placed on a master mold 20. If mass production is required, the feeding action is usually a mechanically automated step. After the product is removed in a cycle, it will be automatically The next plastic sheet 10 is placed, thereby saving manufacturing time.

In a heating step, a male mold 30 is preheated to a predetermined temperature, and then the male mold 30 is used to perform a pressing action. In addition, the shape of the male mold 30 matches the shape of a mold cavity 22 of the female mold 20 , and a bottom surface 26 of the mold cavity 22 has a convex edge line 28 .

In a pressing step, the male mold 30 corresponds to the female mold 20 , the male mold 30 is pressed against the plastic sheet 10 , further, the male mold 30 approaches the direction of the female mold 20 , and then the plastic sheet 10 Press against the surface of the master mold 20 to make the plastic sheet 10 contact the raised ridgeline 28 of the mold cavity 22 .

In a venting step, the male mold 30 is used to press the plastic sheet 10 to the female mold 20 , so that the air between the plastic sheet 10 , the female mold 20 and the bottom surface 26 is discharged, thereby preventing the plastic sheet 10 from being damaged. Water ripples are formed on the surface.

In a molding step, the plastic sheet 10 is formed in the cavity 22 of the master mold 20 , and then the plastic sheet 10 is cooled, and then appropriately cut to form a box cover 40 .

Please refer to FIG. 3 , the cavity 22 is formed inside the female mold 20 , one end of the cavity 22 is an opening 24 and is open, and the other end of the cavity 22 is a bottom surface 26 and is closed , the bottom surface 26 has a raised ridgeline 28 . The opening 24 is opposite to the bottom surface 26 . The raised ridgeline 28 faces the opening 24 of the cavity 22 .

Please refer to FIG. 4 , the bottom surface 26 of the female mold 20 includes a first sloped surface 260 and a second sloped surface 262 , the first sloped surface 260 is connected to the second sloped surface 262 , and the first sloped surface 260 is connected to the second sloped surface 262 . The inclined plane 262 is symmetrical. The junction of the first inclined surface 260 and the second inclined surface 262 is the raised ridgeline 28 . Please refer to FIG. 1 , the male mold 30 presses the plastic sheet 10 to the bottom surface 26 of the female mold 20 . Further, the male mold 30 presses the plastic sheet 10 to the first inclined surface 260 of the female mold 20 and the second inclined surface 262, whereby the gas between the plastic sheet 10 and the master mold 20 is exhausted by the inclination angle between the raised ridgeline 28 and the peripheral surface, specifically, the plastic sheet 10 and the master mold The gas between 20 will be discharged through the first inclined surface 260 and the second inclined surface 262, thereby reducing the generation of water ripples.

Please refer to FIGS. 5 and 6 , the box cover 40 includes a cover piece 42 and a peripheral portion 44 . The peripheral portion 44 is connected to the cover sheet 42 , and the peripheral portion 44 surrounds the cover sheet 42 to form a space 46 . The inner wall surface of the space 46 has a stepped shape. An open cover 49 is formed at one end of the range surrounded by the peripheral portion 44 , and the cover 49 is opposite to the cover sheet 42 . The cover sheet 42 has a first surface 43 and a second surface 45 opposite to the first surface 43 .

The first surface 43 of the cover sheet 42 includes a first beveled surface 420 and a second beveled surface 422 , a wave absorbing line 48 is formed on the cover sheet 42 , specifically, the first beveled surface 420 is connected to the second beveled surface 422, and the first beveled surface 420 is symmetrical to the second beveled surface 422, and the junction of the first beveled surface 420 and the second beveled surface 422 is the wave elimination line 48.

The first beveled surface 420 has a first connecting side 424 and a first peripheral side 426 . The first connecting side 424 is connected to the wave-absorptive line 48 , and the first peripheral side 426 is close to the peripheral portion 44 . The first connecting side 424 is closer to the cover 49 than the first peripheral side 426 , and there is an angle between the first connecting side 424 and the first peripheral side 426 , and the angle is between 0.5 degrees and 1.5 degrees. between.

The second beveled surface 422 has a second connection side 428 and a second peripheral side 430 . The second connection side 428 is connected to the wave-absorptive line 48 , and the second peripheral side 430 is adjacent to the peripheral portion 44 . The second connection side 424 is closer to the lid 49 than the second peripheral side 430 . Please refer to FIG. 1 again, one side surface of the box cover 40 forms the wave elimination line 48 by the convex ridge line 28 of the master mold 20 .

According to the above, the present invention uses the first inclined surface 260 and the second inclined surface 262 of the master mold 20 to discharge excess gas, thereby avoiding the formation of water ripples on the surface of the plastic sheet 10 .

The above-mentioned embodiments are only used to illustrate the technology of the present invention and its effects, but are not intended to limit the present invention. Anyone skilled in the art can modify and change the above embodiments without violating the technical principle and spirit of the present invention. Therefore, the scope of protection of the present invention should be listed in the scope of the patent application described later. .

10: Plastic sheet 20: master mold 22: Mold cavity 24: Open mouth 26: Underside 260: First Bevel 262: Second Bevel 28: Raised ridges 30: male model 40: box cover 42: Coverslip 43: First Facial 420: First bevel face 422: Second bevel face 424: First connection side 426: 1st perimeter side 428: Second connection side 430: Second peripheral side 44: Zhou Department 45: Second Facial 46: Space 48: Wave elimination line 49: Cover 50: box cover

Fig. 1 is a schematic diagram of the manufacturing flow of the present invention. Fig. 2 is a block flow diagram of the present invention. Fig. 3 is an external view of the master mold of the present invention. Fig. 4 is a cross-sectional view of a master mold of the present invention. Fig. 5 is an external view of the box cover of the present invention. Fig. 6 is a sectional view of the cover of the present invention. FIG. 7 is a schematic diagram of a conventional box cover with water ripples.

10: Plastic sheet

20: master mold

22: Mold cavity

26: Underside

28: Raised ridges

30: male model

40: box cover

Claims (5)

A box cover made of PET, which comprises a cover sheet, a circumference surrounding the cover sheet, and an open cover formed at one end of a range formed around the circumference relative to the cover sheet, the cover sheet having a first A face, and a second face relative to the first face, is characterized in that: The first surface includes a first beveled surface connected to a second beveled surface, and a wave absorbing line is formed at the junction of the first beveled surface and the second beveled surface. The PET box cover of claim 1, wherein the first beveled surface has a first connection side and a first peripheral side, and the first connection side is closer to the lid than the first peripheral side , the second beveled surface has a second connection side and a second peripheral side, the second connection side is closer to the cover than the second peripheral side, and the first connection side is connected to the second connection side and form the wave clipping line. The PET box cover according to claim 2, wherein the inclination angle of the first connecting side and a first peripheral side is between 0.5 degrees and 1.5 degrees. A method for making a PET box cover, comprising the following steps: In a feeding step, a plastic sheet is placed in a female mold, wherein the female mold has a mold cavity inside, and the bottom surface of the mold cavity has a raised ridge; a pressing step, using a male mold to press the plastic sheet to the mold cavity of the female mold, so that the plastic sheet contacts the raised ridgeline of the mold cavity; In a venting step, in the process of pressing the plastic sheet to the cavity of the female mold by the male mold, the gas between the plastic sheet and the bottom surface of the female mold is discharged by the inclination angle between the raised ridgeline and the peripheral surface. discharge; In a molding step, the plastic sheet is pressed to form a box cover, and a wave-absorbing line is formed on one side surface of the box cover by the raised ridgeline. The method for producing a PET box cover according to claim 4, wherein before the pressing step, a heating step of preheating the male mold to a predetermined temperature is further included.

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