Production process for special-shaped plastic frame of trolley case

Abstract

Disclosed in the present invention is a production process for a special-shaped plastic frame of a trolley case, belonging to the technical field of trolley cases. The production process comprises the following steps: S1, selecting a required plastic masterbatch, putting the plastic masterbatch into an extruder for performing extrusion, a special-shaped mold being mounted at a discharge opening of the extruder, and extruding same to obtain a plastic strip having a special-shaped cross section; S2, according to the size of a trolley case, cutting the plastic strip by a corresponding length, and mounting a zipper on one side of the plastic strip; S3, putting into a bending machine the plastic strip on which the zipper has been mounted, and bending same into a frame; and S4, dispensing an adhesive on the shaped plastic frame, and mounting same onto a trolley case body. According to process requirements, the present invention first extrudes the plastic frame conforming to the cross section shape and having a strip shape, and then processes the plastic frame to bend same into a frame. Thus, compared with traditional injection molding, the present invention has reduced process cost and improved production efficiency, and can manufacture thin-wall or special-shaped cross-section plastic frames.

Description

Production process of special-shaped plastic frames for trolley cases Technical Field

[0001] The invention relates to a production process of a special-shaped plastic frame for a trolley case, and belongs to the technical field of trolley cases. Background Art

[0002] A trolley case refers to a suitcase with a trolley and wheels. It is widely used because of its convenience. Among them, the plastic frame between the two halves of the trolley case plays an important role, which is used to connect the zipper and stabilize the case structure. The plastic frame, as a component, is produced separately and then installed on the case. In current technology, the plastic frame is all injection molded in one piece. The corresponding mold is designed according to the size of the trolley case, and then injection molded and cooled. However, there are the following problems: 1. The size of the mold cannot be changed after design, and different molds need to be designed for plastic frames of different sizes; 2. In order to be able to form after injection molding, a large amount of plastic is generally used during injection molding, so thin-walled plastic frames cannot be made, and only thick-walled ones can be made; 3. Injection molding cannot be done for certain special-shaped cross-sections, such as C-slots and T-slots on the plastic frame; 4. Since special-shaped cross-sections cannot be made, the produced plastic frames cannot be installed with zippers, and can only be made into trolley cases in the form of ordinary aluminum frames. Technical issues

[0003] The technical problem to be solved by the present invention is to provide a production process for a special-shaped plastic frame of a trolley case, which solves the problem that the production of the plastic frame of a traditional trolley case is complicated and limited. Technical Solutions

[0004] The technical problem to be solved by the present invention is to provide a production process for a special-shaped plastic frame of a trolley case, which solves the problem that the production of the plastic frame of a traditional trolley case is complicated and limited.

[0005] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions:

[0006] The production process of the special-shaped plastic frame of the trolley case includes the following steps:

[0007] S1. Select the required plastic masterbatch and put it into the extruder for extrusion. The discharge port of the extruder is equipped with a special-shaped die to extrude plastic strips with special-shaped cross-sections.

[0008] S2. Cut a plastic strip of the appropriate length according to the size of the suitcase and install a zipper on one side of the plastic strip;

[0009] S3. Place the plastic strip with the zipper installed into the bending machine and bend it into a frame;

[0010] S4. Install the prepared plastic frame on the drawbar box body by gluing.

[0011] As a preferred example, in step S1, two special-shaped dies are provided on the extruder, and the two special-shaped dies extrude the plastic strips simultaneously.

[0012] As a preferred embodiment, a male and female port is provided between the plastic strips extruded by the two special-shaped dies.

[0013] As a preferred example, the plastic strip in step S2 is provided with a notch along the length direction, and the zipper is engaged in the notch along the length direction of the plastic strip.

[0014] As a preferred example, the zipper is set in the slot manually or semi-automatically.

[0015] As a preferred example, in step S3, a heating device is provided at the corner of the bending machine.

[0016] As a preferred example, the heating temperature of the heating device is 120-150°C.

[0017] As a preferred example, the heating temperature of the extruder is 200-270°C. Beneficial effects

[0018] The beneficial effects of the present invention are as follows: according to the process requirements, the present invention first extrudes a plastic frame that conforms to the cross-sectional shape and is in the form of an elongated strip, and then bends the plastic frame into a frame. Compared with traditional injection molding, the present invention has the following advantages:

[0019] According to the different sizes of boxes, you only need to cut plastic frame strips of different lengths, without having to design molds of corresponding sizes one by one, which reduces process costs and improves production efficiency;

[0020] Extrusion molding does not need to consider the thickness of the wall and the mold opening and removal of the parts. Therefore, the plastic frame produced by this process can be made of any thickness and size. It can produce special cross-sectional shapes or thin-walled plastic frames to facilitate subsequent installation and improve strength. At the same time, it can extrude the corresponding notches for installing zippers. Modes for Carrying Out the Invention

[0021] In order to make the technical means, creative features, objectives and effects of the present invention easier to understand, the present invention is further explained below with reference to specific illustrations.

[0022] The production process of the special-shaped plastic frame of the trolley case includes the following steps:

[0023] S1. Select the required plastic masterbatch, such as ABS, polyolefin, PP, and PVC. Put the plastic masterbatch into the extruder for extrusion. The extruder adopts a twin-screw extruder. The barrel of the extruder is divided into three zones. The temperature is 200-220℃, 220-240℃, and 240-270℃ according to the direction of material forward. The speed of the extruder is 240-300 rpm. The pressure of the molten material is 4MPa~10MPa. The discharge port of the extruder is equipped with a special-shaped mold. The molten material is extruded and cooled by the special-shaped mold to form a plastic strip with a special-shaped extrusion cross-section. The side wall of the plastic strip is provided with a notch along the length direction. The notch shape is C-shaped, T-shaped or dovetail-shaped, etc., which has a connecting function and is used to install a zipper.

[0024] S2. Cut plastic strips of corresponding length according to the size of the suitcase. The sizes of suitcases are generally 16 inches, 20 inches, 22 inches, 24 inches, etc. The length of the plastic frame is cut according to the length of the outer contour of the case. For example, the size of a 24-inch suitcase is 42cm*68cm*26cm. In this case, the length of the plastic strip to be cut is 210-230cm. Install a zipper on the cut plastic strip. The zipper has a connecting strip corresponding to the shape of the notch. The connecting strip is extended into the notch along the length direction of the plastic strip to complete the engagement of the zipper and the plastic strip. The zipper can be inserted manually or semi-automatically. Manually, a worker manually inserts the zipper into the plastic strip. Semi-automatically, a worker manually loads the material and a machine automatically inserts the zipper. Since inserting a zipper into a plastic strip is relatively simple, manual method is usually used.

[0025] S3. Put the plastic strip with the zipper installed into the bending machine. The bending machine uses a double-head bending machine and is equipped with a heating device at its bending point. The heating temperature is set to 120-150℃. Bending points are set on both sides of the bending machine. The plastic strip is placed at the two bending points and bent symmetrically and synchronously. Then the two bending points are close to each other. The distance between the two bending points is set according to the length and width of the plastic frame. The strip is bent symmetrically and synchronously again. The heating device is used to heat and soften the bending part of the plastic strip. Only two processes are required to bend it into a frame, completing the production of the plastic frame.

[0026] S4. Finally, the shaped plastic frame is glued and installed on the drawbar box body.

[0027] In one embodiment, two special-shaped molds are provided on the extruder in step S1, and the two special-shaped molds extrude plastic strips at the same time to improve production efficiency. At the same time, the two special-shaped molds are different: there is a male and female opening between the plastic strips extruded by the two special-shaped molds, that is, one of the plastic strips has a protrusion along the length direction, and the other plastic strip has a groove along the length direction. When the two groups of plastic strips are used to make a plastic frame, they are matched and installed on the two halves of the same trolley case. When the case is closed, the male and female openings engage with each other, further strengthening the supporting capacity of the plastic frame and reducing the degree of deformation of the trolley case caused by external force.

[0028] The above shows and describes 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. Various changes and improvements can be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements are within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents. Industrial Applicability

[0029] According to the process requirements, the present invention first extrudes a plastic frame that conforms to the cross-sectional shape and is in the form of an elongated strip, and then bends the plastic frame into a frame. Compared with traditional injection molding, the present invention has the following advantages:

[0030] According to the different sizes of boxes, you only need to cut plastic frame strips of different lengths, without having to design molds of corresponding sizes one by one, which reduces process costs and improves production efficiency;

[0031] Extrusion molding does not need to consider the thickness of the wall and the mold opening and removal of the parts. Therefore, the plastic frame produced by this process can be made of any thickness and size. It can produce special cross-sectional shapes or thin-walled plastic frames to facilitate subsequent installation and improve strength. At the same time, it can extrude the corresponding notches for installing zippers.

Claims

1. The production process of special-shaped plastic frame for trolley case is characterized by: The following steps are involved: S1. Select the required plastic masterbatch, put the plastic masterbatch into an extruder for extrusion, and install a special-shaped die at the discharge port of the extruder to extrude a plastic strip with a special-shaped cross section; S2. Cut a plastic strip of corresponding length according to the size of the suitcase, and install a zipper on one side of the plastic strip; S3, put the plastic strip with the zipper installed into the bending machine and bend it into a frame; S4. Install the prepared plastic frame on the drawbar box body by gluing.

2. The production process of the special-shaped plastic frame of a trolley case according to claim 1, characterized in that: In the step S1, two special-shaped dies are provided on the extruder, and the two special-shaped dies extrude plastic strips simultaneously.

3. The production process of the special-shaped plastic frame of a trolley case according to claim 2, characterized in that: A male and female port is arranged between the plastic strips extruded by the two special-shaped dies.

4. The production process of special-shaped plastic frame for a trolley case according to claim 1, characterized in that: The plastic strip in step S2 is provided with a notch along the length direction, and the zipper is engaged in the notch along the length direction of the plastic strip.

5. The production process of the special-shaped plastic frame of a trolley case according to claim 4, characterized in that: The zipper is arranged in the notch manually or semi-automatically.

6. The production process of special-shaped plastic frame for a trolley case according to claim 1, characterized in that: In step S3, a heating device is provided at the corner of the bending machine.

7. The production process of the special-shaped plastic frame of a trolley case according to claim 6, characterized in that: The heating temperature of the heating device is 120-150°C.

8. The production process of special-shaped plastic frame for a suitcase according to claim 1, characterized in that: The heating temperature of the extruder is 200-270°C.