PET preform

Abstract

The present invention relates to a PET preform, comprising: a preform body; the preform body is provided in a cylindrical shape, and the preform body includes a bottle mouth part, a bottle neck part and a bottle body part which are integrally injection-molded. The bottle mouth part, the bottle neck part and the bottle body part are connected in sequence, and a bottle bottom is provided at one end of the bottle body part away from the bottle neck part; a plurality of blocking blocks are convexly provided on the side wall of the inlet passage near one end of the bottle cavity part. Each blocking block is equidistantly arranged along the circumferential side wall of the inlet passage, and the cross-sectional shape of each blocking block is arc-shaped, and an air flow buffer groove is formed between two adjacent blocking blocks. When the connection between the bottle neck part and the bottle body part is stretched under the action of air pressure, the molten blocking block can effectively fill the depression at the connection between the bottle neck part and the bottle body part, so that the thickness distribution at the connection between the bottle neck part and the bottle body part is more uniform. By providing arc-shaped blocking blocks, it is beneficial to the bending of the connection between the bottle neck part and the bottle body part during the stretching process, which conforms to the bending amplitude of the bottle, and makes the blow molding effect of the bottle better.

Description

Technical Field

[0001] The present invention relates to the technical field of PET preforms, and particularly to a PET preform. Background Art

[0002] Plastic bottles are used to hold drinking water and beverages. Plastic bottles are characterized by being convenient to carry and having a long shelf life. A preform is a semi-finished product for making a bottle. When making a plastic bottle, first, a preform is injection-molded, and then the preform is heated and blown, so that the preform is deformed into a bottle. After the bottle is cooled and shaped, a plastic bottle can be formed.

[0003] Currently, during the blow molding process of the preform, hot air is blown into the preform from the mouth of the preform. During the blowing process, when the preform changes from cold to hot, the part near the mouth of the preform is first quickly heated and is in a softened and molten state. And because the connection between the bottleneck and the bottle body will be gradually stretched after blowing, the plastic at the mouth and the bottleneck is likely to sink towards the bottle body. Subsequently, even if air is continuously blown into the preform so that the outer surface of the bottle abuts against the inner surface of the mold cavity, and the bottle is expanded under the action of air pressure. However, due to the depression at the connection between the bottleneck and the bottle body, the stretching at the connection between the bottleneck and the bottle body may still be uneven. The thickness of the final product at the connection between the bottleneck and the bottle body is relatively thin, resulting in defective products of the bottle. Summary of the Invention

[0004] Based on this, it is necessary to provide a PET preform.

[0005] A PET preform includes: a preform body;

[0006] The preform body is set to be cylindrical. The preform body includes a mouth part, a neck part, and a body part that are integrally injection-molded. The mouth part, the neck part, and the body part are connected in sequence. A bottom is provided at one end of the body part away from the neck part. A mouth is opened in the mouth part. An inlet channel is opened in the neck part. A cavity is opened in the body part. The mouth is communicated with the cavity through the inlet channel;

[0007] A plurality of blocking blocks are convexly arranged on the side wall of the inlet channel near one end of the cavity part. Each of the blocking blocks is equidistantly arranged along the circumferential side wall of the inlet channel, and the cross-sectional shape of each of the blocking blocks is arc-shaped. An air flow buffer groove is formed between two adjacent blocking blocks.

[0008] In one embodiment, the average thickness of one end of the body part close to the neck part is less than the average thickness of one end of the body part away from the neck part.

[0009] In one embodiment, a plurality of smoothing grooves are provided at one end of the bottle body portion close to the bottle neck portion. Each of the smoothing grooves is correspondingly arranged with a blocking block, and the smoothing grooves and the blocking blocks are arranged adjacent to each other.

[0010] In one embodiment, the width of each of the smoothing grooves gradually increases from the end close to the blocking block to the end far from the blocking block.

[0011] In one embodiment, the depth of each of the smoothing grooves gradually decreases from the end close to the blocking block to the end far from the blocking block.

[0012] In one embodiment, the slope of the side of the blocking block facing the bottle mouth portion is less than the slope of the side of the blocking block facing the smoothing groove.

[0013] In one embodiment, the ratio of the thickness of the blocking block protruding from the inlet passage to the thickness of the bottle neck portion is 1:(2.5 - 3.5).

[0014] In one embodiment, a bottle cap retaining ring is convexly provided on the outer surface at the connection of the bottle neck portion and the bottle body portion.

[0015] In one embodiment, the blocking block is arranged on the side of the bottle cap retaining ring close to the bottle bottom.

[0016] The beneficial effects of the present invention are as follows: By providing a blocking block with a circular arc convexity on the side wall of the inlet passage, the blocking block is first melted under the action of hot air. When the connection between the bottle neck portion and the bottle body portion is stretched under the action of air pressure, the melted blocking block can effectively fill the depression at the connection between the bottle neck portion and the bottle body portion, so that the thickness distribution at the connection between the bottle neck portion and the bottle body portion is more uniform. And by providing a circular arc-shaped blocking block, it is beneficial to the bending of the connection between the bottle neck portion and the bottle body portion during the stretching process, which conforms to the bending amplitude of the bottle, and makes the blow molding effect of the bottle better. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 It is a schematic cross-sectional structure diagram of a PET preform of an embodiment;

[0019] Figure 2 For Figure 1Schematic diagram of the partial enlarged structure at position A in Specific implementation mode

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0021] As Figures 1 to 2 shown, it is a PET preform 10 of an embodiment of the present invention, including a preform body 100; the preform body 100 is set to be cylindrical, and the preform body 100 includes a bottle mouth part 110, a bottle neck part 120 and a bottle body part 130 integrally injection-molded. The bottle mouth part 110, the bottle neck part 120 and the bottle body part 130 are connected in sequence. A bottle bottom 170 is provided at one end of the bottle body part 130 away from the bottle neck part 120. A bottle mouth 111 is opened in the bottle mouth part 110, an inlet channel 121 is opened in the bottle neck part 120, a bottle cavity 131 is opened in the bottle body part 130, and the bottle mouth 111 is communicated with the bottle cavity 131 through the inlet channel 121; a plurality of blocking blocks 200 are convexly arranged on the side wall of the inlet channel 121 at one end close to the bottle cavity 131 part. Each of the blocking blocks 200 is equidistantly arranged along the circumferential side wall of the inlet channel 121, and the cross-sectional shape of each of the blocking blocks 200 is arc-shaped. An air flow buffer groove is formed between two adjacent blocking blocks 200.

[0022] In this embodiment, the material of the preform is PET (polyethylene glycol terephthalate, polyethylene terephthalate). The preform body 100 is successively the bottle mouth part 110, the bottle neck part 120 and the bottle body part 130 from the bottle mouth 111 to the bottle bottom 170. Before blow molding, the diameters of the bottle mouth part 110, the bottle neck part 120 and the bottle body part 130 are the same, and before blow molding, the thicknesses of the bottle mouth part 110, the bottle neck part 120 and the bottle body part 130 are equal. However, at the connection between the bottle neck part 120 and the bottle body part 130, that is, on the side wall of the inlet channel 121 at the position close to the bottle cavity 131 part, arc-shaped blocking blocks 200 are convexly arranged. In this way, the local thickness at the connection between the bottle neck part 120 and the bottle body part 130 is relatively large due to the existence of the blocking blocks 200. The blocking blocks 200 are used to fill the depression where the thickness is reduced due to stretching at the connection between the bottle neck part 120 and the bottle body part 130.

[0023] It should be understood that the shape of the blocking block 200 is arc-shaped, which is beneficial to the flattening of the blocking block 200 after being heated and melted. Compared with square, trapezoidal or triangular protrusions, the arc-shaped blocking block 200 is easier to stretch and flatten in the molten state, so as to fill the depression caused by the reduced thickness at the connection between the bottle neck 120 and the bottle body 130 after stretching, and can better adapt to the bending extension at the connection between the bottle neck 120 and the bottle body 130, making the forming effect better.

[0024] It should be understood that after blow molding, the bottle neck 120 and the bottle body 130 are expanded under pressure, so that the thicknesses of the bottle neck 120 and the bottle body 130 are uniform. And an external thread 161 is provided on the outer side of the bottle mouth 110 for screwing on the bottle cap. Therefore, the diameter of the bottle mouth 110 remains unchanged or slightly increases before and after blow molding, so that the thickness of the bottle mouth 110 is greater than the thicknesses of the bottle neck 120 and the bottle body 130, making the hardness and strength of the bottle mouth 110 higher.

[0025] In the above embodiment, by providing the blocking block 200 with an arc-shaped protrusion on the side wall of the inlet passage 121, the blocking block 200 is first melted under the action of hot air. When the connection between the bottle neck 120 and the bottle body 130 is stretched under the action of air pressure, the melted blocking block 200 can effectively fill the depression at the connection between the bottle neck 120 and the bottle body 130, so that the thickness distribution at the connection between the bottle neck 120 and the bottle body 130 is more uniform. And by providing the arc-shaped blocking block 200, it is beneficial to the bending of the connection between the bottle neck 120 and the bottle body 130 during the stretching process, which conforms to the bending amplitude of the bottle, making the blow molding effect of the bottle better.

[0026] In one embodiment, the average thickness of one end of the bottle body 130 close to the bottle neck 120 is less than the average thickness of one end of the bottle body 130 far from the bottle neck 120.

[0027] In this embodiment, one end of the bottle body 130 far from the bottle neck 120 is the end of the bottle body 130 close to the bottle bottom 170. Since the position of the bottle body 130 close to the bottle bottom 170 needs to support the whole bottle, the thickness at the position of the bottle body 130 close to the bottle bottom 170 is relatively large, which is beneficial to making the thickness of the bottle bottom 170 and the position of the bottle body 130 close to the bottle bottom 170 relatively large after blow molding, which is beneficial to supporting the bottle. And since the connection between the bottle body 130 and the bottle bottom 170 is curved, it can effectively improve the strength at the connection between the bottle bottom 170 and the bottle body 130.

[0028] In order to make the thickness at the connection between the bottle neck 120 and the bottle body 130 more uniform, in one embodiment, as Figure 1 and Figure 2As shown, several smoothing grooves 141 are provided at one end of the bottle body portion 130 close to the bottle neck portion 120. Each of the smoothing grooves 141 is correspondingly arranged with a blocking block 200, and the smoothing grooves 141 are arranged adjacent to the blocking blocks 200.

[0029] In this embodiment, smoothing grooves 141 are provided at the connection between the bottle neck portion 120 and the bottle body portion 130, and the smoothing grooves 141 are arranged on the side of the blocking block 200 facing the bottle body portion 130. Each smoothing groove 141 is aligned with a blocking block 200. In this way, after each blocking block 200 is melted by heat, it will drive the PET material to move towards the smoothing groove 141. It should be understood that the process of the movement of the blocking block 200 is to gradually flatten and sink into the bottle neck portion 120 and rush towards the smoothing groove 141, causing the smoothing groove 141 to gradually bulge, and then making the smoothing groove 141 flat. Subsequently, after the air pressure inside the preform is balanced, the bottle neck portion 120 and the bottle body portion 130 expand under the action of air pressure. At this time, the blocking block 200 further rushes towards the smoothing groove 141, making the thickness of the smoothing groove 141 gradually tend to be consistent with the connection between the bottle neck portion 120 and the bottle body portion 130. Under the action of air pressure, the connection between the bottle neck portion 120 and the bottle body portion 130 is fully expanded, making the thickness distribution at the connection between the bottle neck portion 120 and the bottle body portion 130 uniform.

[0030] In the above embodiment, through the cooperation of the smoothing groove 141 and the blocking block 200, at the initial stage of blow molding, the connection between the bottle neck portion 120 and the bottle body portion 130 can gradually transition towards a flat state, avoiding the situation of depression or relatively thin thickness at the connection between the bottle neck portion 120 and the bottle body portion 130 at the initial stage, making the thickness distribution at the connection between the bottle neck portion 120 and the bottle body portion 130 of the finally formed bottle more uniform, and making the finished product effect of the bottle better.

[0031] In one embodiment, the width of each of the smoothing grooves 141 gradually increases from the end close to the blocking block 200 to the end far from the blocking block 200.

[0032] In this embodiment, since the width of the smoothing groove 141 at the section close to the blocking block 200 is smaller and the width at the end far from the blocking block 200 is larger, this can well adapt to the diffusion direction of the PET material driven by the melting of the blocking block 200. It should be understood that after the blocking block 200 is melted by heat, under the action of air flow and air pressure, it will diffuse forward and outward. Therefore, the gradually increasing width of the smoothing groove 141 is beneficial to the flattening of the PET material of the blocking block 200, enabling the smoothing groove 141 to be better filled, so as to smooth the connection between the bottle neck portion 120 and the bottle body portion 130, and make the thickness distribution at the connection between the bottle neck portion 120 and the bottle body portion 130 uniform.

[0033] In one embodiment, please refer again to Figure 2 , the depth of each of the smoothing grooves 141 gradually decreases from the end close to the blocking block 200 to the end far from the blocking block 200.

[0034] In this embodiment, the depth of the smoothing groove 141 at the end close to the blocking block 200 is larger, and the depth at the end far from the blocking block 200 is smaller. In this way, during the process of gradually flattening the blocking block 200, first, the end of the smoothing groove 141 close to the blocking block 200 is filled, and then it gradually moves to the end of the smoothing groove 141 far from the blocking block 200 to fill the other end of the smoothing groove 141. Since the depth of the smoothing groove 141 at the end close to the blocking block 200 is larger, it is beneficial to fill the blocking block 200. And the depth of the smoothing groove 141 at the end far from the blocking block 200 is smaller. Even if less PET material moves here, it can still well fill the end smoothing groove 141 and effectively avoid the protrusion after filling.

[0035] In one embodiment, as Figure 2 shown, the slope of the blocking block 200 on the side facing the bottle mouth portion 110 is smaller than the slope of the blocking block 200 on the side facing the smoothing groove 141.

[0036] In this embodiment, the angle at which the blocking block 200 is inclined to the inner surface of the bottle neck portion 120 is the slope. The smaller the slope, the smaller the inclination and the flatter it is. The larger the slope, the larger the inclination and the steeper it is. In this embodiment, the slope on the side facing the bottle mouth 111 is smaller, which is beneficial for the PTE material of the blocking block 200 to flatten towards the smoothing groove 141. And the slope of the blocking block 200 on the side facing the smoothing groove 141 is larger, so that the PET material on this side can gradually flatten and expand, and can fully flatten the smoothing groove 141.

[0037] In one embodiment, the ratio of the thickness by which the blocking block 200 protrudes from the inlet passage 121 to the thickness of the bottle neck portion 120 is 1:(2.5 - 3.5).

[0038] In this embodiment, the thickness by which the blocking block 200 protrudes from the inlet channel 121 is the height by which the blocking block 200 protrudes from the inner surface of the bottle neck portion 120. The ratio of the height of the blocking block 200 to the thickness of the bottle neck portion 120 is 1:(2.5 - 3.5). It should be understood that if the thickness of the blocking block 200 is too high, the blocking block 200 is not easily flattened, resulting in local protrusions on the bottle neck portion 120 of the formed bottle. If the thickness of the blocking block 200 is too small, the flattening groove 141 cannot be fully flattened, resulting in depressions at the connection between the bottle neck portion 120 and the bottle body portion 130 of the formed bottle or a smaller thickness after stretching. Therefore, in this embodiment, the ratio of the thickness by which the blocking block 200 protrudes from the inlet channel 121 to the thickness of the bottle neck portion 120 is set to 1:(2.5 - 3.5). Preferably, the ratio of the thickness by which the blocking block 200 protrudes from the inlet channel 121 to the thickness of the bottle neck portion 120 is 1:3. In this way, the blocking block 200 can be fully flattened after melting, and the flattening groove 141 can be flattened. Moreover, it can effectively prevent the blocking block 200 from leaving protrusions after the bottle is formed, making the thickness distribution at the connection between the bottle neck portion 120 and the bottle body portion 130 of the bottle more uniform and the inner surface smoother.

[0039] In one of the embodiments, as Figure 1 shown, a bottle cap retaining ring 150 is convexly provided on the outer surface at the connection between the bottle neck portion 120 and the bottle body portion 130.

[0040] In this embodiment, the shape of the bottle cap retaining ring 150 remains the same before and after blow molding. The bottle cap retaining ring 150 is used to block the bottle cap or support the bottle cap ring on the bottle cap at the bottle neck portion 120 of the bottle. By providing the bottle cap retaining ring 150, not only can the bottle cap or the bottle cap ring be effectively blocked, but also support can be provided for the bottle neck portion 120, making the bottle neck portion 120 stronger.

[0041] In one of the embodiments, the blocking block 200 is provided on one side of the bottle cap retaining ring 150 close to the bottle bottom 170.

[0042] In this embodiment, the blocking block 200 is provided below the bottle cap retaining ring 150. In this way, the blocking block 200 is closer to the bottle body portion 130, which is beneficial for better stretching under the action of air pressure, and further makes the connection between the bottle neck portion 120 and the bottle body portion 130 better extended and stretched, and is beneficial for making the thickness at the connection between the bottle neck portion 120 and the bottle body portion 130 more uniform.

[0043] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0044] The embodiments described above merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A PET preform, characterized in that, Comprising: Preform body; The preform body is set to be cylindrical. The preform body includes a bottle mouth part, a bottle neck part and a bottle body part which are integrally injection molded. The bottle mouth part, the bottle neck part and the bottle body part are connected in sequence. A bottle bottom is provided at one end of the bottle body part far from the bottle neck part. A bottle mouth is provided on the bottle mouth part. An inlet channel is provided on the bottle neck part. A bottle cavity is provided on the bottle body part. The bottle mouth is communicated with the bottle cavity through the inlet channel; A plurality of blocking blocks are convexly arranged on the side wall of the inlet channel at one end close to the bottle cavity part. Each of the blocking blocks is equidistantly arranged along the circumferential side wall of the inlet channel, and the cross-sectional shape of each of the blocking blocks is arc-shaped. An air flow buffer groove is formed between two adjacent blocking blocks; Wherein, the average thickness of one end of the bottle body part close to the bottle neck part is smaller than the average thickness of one end of the bottle body part far from the bottle neck part. A plurality of smoothing grooves are provided at one end of the bottle body part close to the bottle neck part. Each of the smoothing grooves is correspondingly arranged with one of the blocking blocks, and the smoothing grooves and the blocking blocks are adjacently arranged.

2. The PET preform according to claim 1, characterized in that, The width of each of the smoothing grooves gradually increases from the end close to the blocking block to the end far from the blocking block.

3. The PET preform according to claim 1, characterized in that, The depth of each of the smoothing grooves gradually decreases from the end close to the blocking block to the end far from the blocking block.

4. The PET preform according to claim 1, characterized in that, The slope of one side of the blocking block facing the bottle mouth part is smaller than the slope of one side of the blocking block facing the smoothing groove.

5. The PET preform according to claim 1, characterized in that, The ratio of the thickness of the blocking block protruding from the inlet channel to the thickness of the bottle neck part is 1:(2.5 - 3.5).

6. The PET preform according to claim 1, characterized in that, A bottle cap retaining ring is convexly arranged on the outer surface at the connection between the bottle neck part and the bottle body part.

7. The PET preform according to claim 6, characterized in that, The blocking block is arranged on the side of the bottle cap retaining ring close to the bottle bottom.

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