CN115782045A - Improved forming processing method for plastic container products - Google Patents

Abstract

The invention discloses an improved molding and processing method for plastic container products. The steps are as follows: S1, adopting the method of injecting glue from the bottom to form the bottom of the container; The container walls are combined together; the side wall of the container wall cavity is provided with at least one side glue point. The invention not only reduces the requirement on the clamping force of the equipment, but also reduces the pressure on the injection mold and prolongs the life of the mold, and the reduction of the flow length ratio makes the mold volume smaller, saving the cost and space of the mold; the cooling water path of the mold is closer to the mold Inner wall to achieve the effect of saving cooling time and increasing production capacity per unit time. It can also reduce the material processing temperature. The lower the processing temperature, the faster the time to solidification and molding, which not only reduces energy consumption, but also reduces cooling time, shortens the molding cycle, and improves the waste of excessive thickness of the bottom caused by single-point glue feeding. Materials save materials and enhance the pressure bearing capacity of the product.

Description

A method for improving the molding and processing of plastic container products

technical field

The invention belongs to the technical field of container injection molding, and in particular relates to a method for improving the molding and processing of plastic container products.

Background technique

At present, most plastic packaging containers on the market are made of thin-walled materials with relatively large flow lengths for the purpose of saving costs. However, such materials with relatively large flow lengths have poor impact resistance and cannot meet the requirements of complex environments such as handling and moving. Moreover, in injection molding, the integral molding method of bottom center injection is usually used, which requires a large clamping force of the equipment, and the corresponding injection mold bears a large pressure. The life of the mold is relatively short and the production efficiency is low. The method also has the defect that the bottom is too thick to cause waste of material.

Contents of the invention

The invention provides a method for improving the molding and processing of plastic container products. The container injection molding adopts a two-step injection molding method, which reduces the flow length ratio and can use materials with good impact resistance for injection molding. The problem that the plastic mold cannot be exhausted.

The technical scheme adopted in the present invention is:

A method for improving the molding and processing of plastic container products, comprising the steps of:

S1, the bottom of the container is injected into the bottom of the container;

The bottom of the container is first injected, and the cavity of the bottom of the container used has at least one bottom glue point; according to the actual product, the number of bottom glue points can be designed, which can be one or more;

S2, the container wall is injected by side injection, and the bottom of the container is combined with the injected container wall as an insert;

Place the bottom of the container as an insert into the cavity of the container wall, and the side wall of the cavity of the container wall is provided with at least 3 side glue points.

The container wall is directly combined with the container bottom during the injection molding process. As the second step of split injection molding, the container is injection molded in two steps. Moreover, the bottom of the container exists as an insert, so the injection mold used for the container wall can fully realize exhaust.

As a preferred solution of the present invention, the side glue feed points are distributed on the inner wall or the outer wall of the cavity of the container wall. When the side glue points are distributed on the inner wall of the container wall cavity, the injection molding is equivalent to starting from the inner surface of the container wall; when the side glue points are distributed on the outer wall of the container wall cavity, the injection molding is equivalent to starting from the container wall. Injection molding begins on the outer side of the wall.

As a preferred solution of the present invention, there are at least 3 side glue-feed points, and the specific number is set according to the actual product. A suitable number of side glue-feed points can speed up the injection molding speed.

As a preferred solution of the present invention, the injection mold used for side feeding includes a container wall male mold and a container wall female mold, and the gap between the container wall male mold and the container wall female mold is the container wall cavity. , and the container wall cavity is at least one. Because the bottom of the container is injected separately and the side wall of the container is injected with multiple points of glue, the requirements on the clamping force of the equipment are greatly reduced, so that the original one mold and one cavity can be changed to one mold with two cavities or even more, which improves the production efficiency. , and the flow length ratio is greatly reduced, and materials with good impact resistance and low flow length ratio can be used to reduce production costs.

As a preferred solution of the present invention, a hot runner is preset in the male mold of the container wall, and the glue outlet point of the hot runner is located on the side wall of the male mold of the container wall, and the glue outlet point is the side glue inlet point of the cavity of the container wall. . The hot runner has a main channel and a branch channel. The glue outlet point of the branch channel is the side glue point, which communicates with the cavity of the container wall, and the hot-melt material is injected into the cavity of the container wall.

As a preferred solution of the present invention, a hot runner is preset in the master mold of the container wall, and the glue outlet point of the hot runner is located on the side wall of the master mold of the container wall, and the glue outlet point is the side glue inlet point of the cavity of the container wall . The hot runner has a main channel and a branch channel. The glue outlet point of the branch channel is the side glue point, which communicates with the cavity of the container wall, and the hot-melt material is injected into the cavity of the container wall.

As a preferred solution of the present invention, the injection molded container wall is a structure with two ends open and a large top and a small bottom. The container wall has a cavity structure, and the cross section can be circular or polygonal; it is especially suitable for wide-mouth containers. , such as injection molding of barrels and square boxes.

As a preferred solution of the present invention, the plastic materials used for injection molding include but are not limited to PP, PE, and PC. Such materials have good toughness and strong impact resistance, thereby improving the overall impact resistance of the injection molded product.

As a preferred solution of the present invention, the male container wall mold and/or the female container wall mold is provided with a cooling structure near the cavity of the container wall. Changing the flow length ratio can make the cooling water channel closer to the inner wall of the mold, saving cooling time and increasing the production capacity per unit time.

As a preferred solution of the present invention, the side glue injection points are distributed in the middle of the cavity of the container wall, because conventional containers do not have high requirements for the load-bearing and pressure bearing of the bottom, but have high requirements for the pressure-bearing strength of the container wall. Among them, the containers are all stacked, and the side of the container is a weak place, especially in the middle of the side wall. Therefore, in order to improve the overall pressure bearing capacity, the side multi-point glue point can be set in the middle of the side wall. The principle of injection molding shows that the thickness of the glue point is thicker than other positions, which increases the median thickness of the side wall.

Compared with the traditional bottom single gate glue injection in the prior art, the present invention has the following beneficial effects:

1. Greatly reduce the requirements on the clamping force of the equipment, saving equipment investment.

Due to the reduction of the projected area, the requirements for the clamping force of the equipment are greatly reduced. At the same time, due to the liberation of the clamping force of the equipment, the original one mold and one cavity can be changed to one mold with two cavities or even more, which further improves the production efficiency.

2. It greatly reduces the pressure on the injection mold, prolongs the life of the mold, and creates more value for the enterprise.

The reduction of the flow length ratio can make the mold volume smaller, saving mold cost and space; at the same time, the mold cooling water circuit can be designed closer to the inner wall of the mold, so as to save cooling time and increase the production capacity per unit time.

3. It can reduce the material processing temperature and save energy consumption.

Because the thermal conductivity of injection molding materials is constant, under the premise of ensuring product quality, the lower the processing temperature, the faster the time to solidification and molding, which not only reduces energy consumption, but also reduces cooling time and shortens the molding cycle.

4. Solve the problem of flow length ratio, so that the product has a major change in terms of raw materials, and materials with good toughness and strong impact resistance can be used.

5. Improve the waste of material caused by single-point glue feeding, and improve the thickness of the side wall to increase the pressure bearing capacity, which greatly improves the overall mechanical properties of the product and saves materials (about 3% to 8% reduction in materials).

Because the general packaging container does not have high requirements for the load-bearing and pressure-bearing of the bottom, but has high requirements for the pressure-bearing strength of the side of the container. The original single-point injection at the bottom caused the bottom to be too thick due to the influence of the filling process, and the pressure on the side was due to the reinforced support ring and surface support on the top and bottom of the container, so the weakest point was the middle of the side. The multi-point glue on the side of the invention is thickened just at the glue-feed position, thereby increasing the median thickness of the side wall, conforming to the principle of injection molding and mechanics, saving materials and enhancing the pressure-bearing capacity of the product.

Description of drawings

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 that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is the front view of the injection mold of the bottom surface of the present invention, which is injected with glue.

Fig. 2 is a top view of the injection mold of the bottom surface of the present invention, which is injected with glue into the bottom of the barrel.

Fig. 3 is a front view of the injection mold for side-feeding the barrel wall of the present invention.

Fig. 4 is a top sectional view of the injection mold for side-feeding the barrel wall of the present invention.

Fig. 5 is a diagram showing the relationship between the glue feed point on the upper side of the male mold of the container wall and the cavity of the container wall in the present invention.

Fig. 6 is a diagram showing the relationship between the glue feed points on the upper side of the master mold of the container wall and the cavity of the container wall in the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Example:

Taking the injection molding of barrel containers as an example to illustrate a method for improving the molding and processing of plastic container products, it includes the following steps:

S1, the bottom of the container is injected into the bottom of the container;

The bottom of the container is first injected, and the cavity of the bottom of the container used has at least one bottom glue point; according to the actual product, the number of bottom glue points can be designed, which can be one or more;

The injection mold used for the injection molding of the bottom of the container includes a male bottom mold 1 and a female mold 2 at the bottom of the container. A cavity 10 is formed between the male mold 1 and the female mold 2 at the bottom of the container. There are multiple bottom injection molding hot runners 3, and the glue outlet point of the bottom injection hot runner is the bottom glue inlet point 11 of the bottom cavity of the container. The hot-melt material enters from the bottom injection molding hot runner 3 and is injected into the container from the bottom glue inlet point In the bottom cavity, it is cooled to form the bottom of the barrel. In this embodiment, four bottom glue inlet points are used, as shown in Figures 1 and 2.

S2, the container wall is injected by side injection, and the bottom of the container is combined with the injected container wall as an insert;

The container bottom 12 is placed in the cavity of the container wall as an insert, and the side wall of the cavity of the container wall is provided with at least three side glue injection points.

The container wall is directly combined with the container bottom during the injection molding process. As the second step of split injection molding, the container is injection molded in two steps. Moreover, the bottom of the container exists as an insert, so the injection mold used for the container wall can fully realize exhaust.

As shown in Figures 3 and 4, the injection mold used for side injection includes a container wall male mold 4 and a container wall female mold 5, and the gap between the matching parts of the container wall male mold 4 and the container wall female mold 5 is the container wall. Wall cavity, container wall cavity is one in the present embodiment, certainly also can be a plurality of forms, set according to actual situation.

The bottom of the barrel is placed as an insert into the cavity of the container wall, and the cavity of the container wall is injected with side glue.

As for the distribution position of the side glue point, it can be on the inner wall or the outer wall of the cavity of the container wall. When the side glue points are distributed on the inner wall of the container wall cavity, the injection molding is equivalent to starting from the inner surface of the container wall; when the side glue points are distributed on the outer wall of the container wall cavity, the injection molding is equivalent to starting from the container wall. Injection molding begins on the outer side of the wall.

Specifically, the outer wall or the inner wall of the container wall cavity is related to the container wall male mold and the container wall female mold, that is, the side glue point can be set on the container wall male mold or the container wall female mold. Specifically according to the actual design.

And the used side glue points are at least 3, the specific number is set according to the actual product, the appropriate number of side glue points can speed up the injection molding speed, this embodiment uses 4 side glue points.

Moreover, the container wall male mold used is a protrusion, the container wall female mold is a groove, the protrusion is inserted into the groove and forms a container wall cavity with the groove, and a hot runner is preset in the container wall male mold, and the heat flow The glue outlet point of the channel is located on the side wall of the male mold of the container wall, and this glue outlet point is the side glue inlet point 8 of the cavity of the container wall. The hot runner has a main flow channel 6 and four branch flow channels 7. The glue outlet point of the branch flow channel 7 is the side glue entry point, which communicates with the container wall cavity 9. The distribution relationship between the side glue entry point and the container wall cavity is shown in As shown in Figure 5, the hot-melt material is injected into the container wall cavity.

Of course, a hot runner can also be preset in the master mold of the container wall. The glue outlet point of the hot runner is located on the side wall of the master mold of the container wall, and the glue outlet point is the side glue inlet point of the cavity of the container wall. The hot runner has a main channel and a branch channel. The glue outlet point of the branch channel is the side glue point, which communicates with the cavity of the container wall. The hot melt material is injected into the cavity of the container wall. The side glue point is connected with the container wall. The distribution diagram of the cavity is shown in Fig. 6 .

The hot-melt material enters from the main flow channel 6 and distributes to the side of the container wall cavity from the branch flow channel 7 respectively, injects into the cavity of the container wall from the side glue point, and is directly integrally formed with the bottom of the barrel after cooling.

After injection molding, the wall of the barrel is a cavity structure with openings at both ends and a large top and a small bottom, and the cross section is circular. Of course, other wide-mouth containers can also be injection molded. The cross section of the container wall is polygonal, such as a square box.

Because of the change of flow length ratio, materials with good toughness and strong impact resistance can be used in injection molding, such as PP, PE, PC, etc., to improve the overall impact resistance of injection molding products, and to make the cooling water channel closer to the inner wall of the mold. Save cooling time and increase productivity per unit time.

The two-step split injection molding can effectively solve the exhaust problem of the side-feeding mold, and reduce the clamping force of the equipment and the pressure on the mold.

The invention changes the flow length ratio, divides the container into two parts, side wall and bottom, and performs injection molding in two steps, because the problem of mold exhaust cannot be solved by adding glue at multiple points on the side wall, and the exhaust point of this type of mold can only be on the side The bottom is exhausted, so the process of one-step side wall multi-point glue injection cannot be realized, so the product is divided into side wall + bottom two-step molding.

The bottom is processed first, and then the bottom is used as an insert for secondary molding together with the container wall. It is divided into two parts for processing. In the side wall processing and molding, multiple points of glue can be injected through the middle part of the side wall. On the one hand, the flow length ratio is greatly reduced. On the other hand, multiple glue injection points can be designed according to product requirements, thus greatly Shorten the molding cycle.

Similarly, in the processing and molding of the bottom, one or more glue inlet points can also be designed according to the size of the bottom. This method can save the clamping force of the equipment, and it is easier to arrange the cooling water circuit of the mold to improve the cooling effect, shorten the molding cycle, shorten the injection time, etc.

In the description of this specification, descriptions referring to the terms "one embodiment", "example", "specific example" and the like mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one of the present invention. Examples or examples. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto, any person familiar with the technical field within the technical scope disclosed in the present invention, according to the technical solution of the present invention Any equivalent replacement or change of the inventive concepts thereof shall fall within the protection scope of the present invention.

Claims (9)

1. The improved forming and processing method of the plastic container product is characterized by comprising the following steps:

s1, performing injection molding to form a container bottom in a bottom glue feeding mode;

the container bottom cavity is provided with at least 1 bottom glue inlet point;

s2, the container wall is molded in a mode of glue feeding from the side surface, and the container bottom is placed in the cavity of the container wall as an insert and combined with the molded container wall.

2. The improved plastic container product molding process of claim 1, wherein: the side glue inlet points are distributed on the inner side wall or the outer side wall of the container wall cavity.

3. The improved plastic container product molding process of claim 2, wherein: the lateral wall of the container wall cavity is provided with at least 3 side glue feeding points.

4. The improved plastic container product molding process of claim 1, 2 or 3, wherein: the injection mold used for side glue feeding comprises a container wall male mold and a container wall female mold, a gap between the matching parts of the container wall male mold and the container wall female mold is a container wall cavity, and the number of the container wall cavities is at least one.

5. The improved plastic container product molding process of claim 4, wherein: the hot runner is preset in the container wall male die, the glue outlet point of the hot runner is positioned on the side wall of the container wall male die, and the glue outlet point is the side glue inlet point of the container wall cavity.

6. The improved plastic container product molding process of claim 4, wherein: the hot runner is preset in the container wall female die, a glue outlet point of the hot runner is positioned on the side wall of the container wall female die, and the glue outlet point is a side glue inlet point of a container wall cavity.

7. The improved plastic container product molding process of claim 4, wherein: the wall of the container which is injected is a structure with two open ends and big top and small bottom.

8. The improved plastic container product molding process of claim 4, wherein: the plastic material used for injection molding includes but is not limited to PP, PE, PC.

9. The improved plastic container product molding process of claim 4, wherein: and a cooling structure is arranged on the container wall male die and/or the container wall female die at a part close to the container wall cavity.

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