Patent ID: 12233610

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A plurality of preferred embodiments of the present invention are introduced below with reference to the description, in order to make the technical content thereof more clear and easier to understand. The present invention can be embodied in many different forms of embodiments, and the scope of protection of the present invention is not only limited to the embodiments mentioned herein.

In the drawings, structurally the same components are indicated by the same reference signs, and structurally or functionally similar constituent parts throughout are indicated by similar reference signs. The size and thickness of each constituent part as shown in the drawings are arbitrarily shown, and the present invention does not limit the size and thickness of each constituent part. In order to make the illustration clearer, the thickness of parts is appropriately exaggerated somewhere in the drawings.

As shown inFIGS.1and2, the device for radially strengthening a polylactic acid tube comprises a metal mold1, a rotating blade3, a distal blade4and a control rod5, wherein the metal mold1is tubular, and an inner wall thereof is used for accommodating a polylactic acid tube2to be strengthened. The rotating blade3, the distal blade4and the control rod5are all arranged inside the metal mold1. A rotating shaft31of the rotating blade3is arranged at an axial position of the tubular metal mold1, and the rotating blade3can rotate relative to the axial position of the metal mold1. One end of the rotating blade3is connected to the rotating shaft31, and the other end is movably connected to a first end41of the distal blade4so as to form a first movable joint32; in addition, a second end42of the distal blade4opposite to the first end41is movably connected to the control rod5. The control rod5can control the distal blade4to swing around the first movable joint32(i.e., taking the first movable joint32as a swing center), such that the included angle between the distal blade4and the metal mold1changes, wherein the direction in which the included angle increases is a direction in which the distal blade4opens. When the included angle between the distal blade4and the metal mold1reaches the maximum, the distal blade4is completely opened, wherein the value of the angle when the included angle between the distal blade4and the metal mold1reaches the maximum is determined according to actual requirements, and the specific numerical value thereof does not constitute a limitation to the present application. The direction in which the included angle decreases is a direction in which the distal blade4closes. The control rod5can control the distal blade4to swing, so as to control the opening and closing of the distal blade4.

FIGS.2and3show the working process of the strengthening device, wherein (a) represents an initial state, (b) represents the opening process of the distal blade4, (c) represents the state when the distal blade4is completely opened, (d) represents the closing process of the distal blade4, and (e) represents a state in which the distal blade4is completely closed.

The second end42of the distal blade4may be set to have a rounded corner.

The metal mold1may be made of a metal with a good thermal conductivity. The rotating blade3may be made of an antirust material, preferably an antirust metal.

The method for radially strengthening a polylactic acid tube using the above-mentioned device for radially strengthening a polylactic acid tube is described below by means of several embodiments.

Embodiment 1

As shown inFIGS.1,2and3, a polylactic acid tube2to be strengthened was put into a metal mold1, wherein the wall thickness of the polylactic acid tube2was 50-100 μm, the metal mold1was heated to a starting temperature T1 that exceeded the vitrification of the polylactic acid tube, and the temperature was maintained for 5 min; the rotating blade3was then rotated along the rotating shaft31in a rotation direction as indicated by an X direction inFIGS.2and3, so as to drive the distal blade4to rotate, wherein the X direction was a direction along the swing center of the distal blade4and away from the second end42of the distal blade4, and the rotating speed of the rotating blade3was controlled between 1 and 20 rpm, and at the same time, the distal blade4was opened at a speed of 0.1°/min using the control rod5and gradually approached the metal mold1; and when the opening of the distal blade4exceeded 2°, the opening of the distal blade4was suspended, and the temperature was raised to an end temperature T2 of the vitrification of the polylactic acid tube. After the end temperature T2 was reached, the rotating speed of the rotating blade3was controlled to 20-60 rpm, and the distal blade4continued to be opened until the distal blade4was completely opened; after squeezing and scraping for a period of time, the distal blade4was closed at a speed of 0.1°/min and restored to the initial state; and the metal mold1was cooled to room temperature, the strengthened polylactic acid tube2was took out, and redundant 2 mm tube sections at both ends of the processed tube were cut off. During the rotation process, the polylactic acid tube2was squeezed and scraped by the distal blade4, and molecular chains thereof were oriented along the rotation direction of the blade, thereby achieving a change from a disordered arrangement to a circumferential orientation as shown inFIG.4.

Embodiment 2

As shown inFIGS.1,2and3, a polylactic acid tube2to be strengthened was put into a metal mold1, wherein the wall thickness of the polylactic acid tube2was 150-200 μm, the metal mold1was heated to a starting temperature T1 that exceeded the vitrification of the polylactic acid tube, and the temperature was maintained for 20 min; the rotating blade3was then rotated along the rotating shaft31in a rotation direction as indicated by an X direction inFIGS.2and3, so as to drive the distal blade4to rotate, wherein the X direction was a direction along the swing center of the distal blade4and away from the second end42of the distal blade4, and the rotating speed of the rotating blade3was controlled between 1 and 20 rpm, and at the same time, the distal blade4was opened at a speed of 0.1°/min using the control rod5and gradually approached the metal mold1; and when the opening of the distal blade4exceeded 2°, the opening of the distal blade4was suspended, and the temperature was raised to an end temperature T2 of the vitrification of the polylactic acid tube. After the end temperature T2 was reached, the rotating speed of the rotating blade3was controlled to 20-60 rpm, and the distal blade4continued to be opened until the distal blade4was completely opened; after squeezing and scraping for a period of time, the distal blade4was closed at a speed of 0.1°/min and restored to the initial state; and the metal mold1was cooled to room temperature, the strengthened polylactic acid tube2was took out, and redundant 2 mm tube sections at both ends of the processed tube were cut off. During the rotation process, the polylactic acid tube2was squeezed and scraped by the distal blade4, and molecular chains thereof were oriented along the rotation direction of the blade, thereby achieving a change from a disordered arrangement to a circumferential orientation as shown inFIG.4.

Embodiment 3

As shown inFIGS.1,2and3, a polylactic acid tube2to be strengthened was put into a metal mold1, wherein the wall thickness of the polylactic acid tube2was 300-500 μm, the metal mold1was heated to a starting temperature T1 that exceeded the vitrification of the polylactic acid tube, and the temperature was maintained for 30 min; the rotating blade3was then rotated along the rotating shaft31in a rotation direction as indicated by an X direction inFIGS.2and3, so as to drive the distal blade4to rotate, wherein the X direction was a direction along the swing center of the distal blade4and away from the second end42of the distal blade4, and the rotating speed of the rotating blade3was controlled between 1 and 20 rpm, and at the same time, the distal blade4was opened at a speed of 0.1°/min using the control rod5and gradually approached the metal mold1; and when the opening of the distal blade4exceeded 2°, the opening of the distal blade4was suspended, and the temperature was raised to an end temperature T2 of the vitrification of the polylactic acid tube. After the end temperature T2 was reached, the rotating speed of the rotating blade3was controlled to 20-60 rpm, and the distal blade4continued to be opened until the distal blade4was completely opened; after squeezing and scraping for a period of time, the distal blade4was closed at a speed of 0.1°/min and restored to the initial state; and the metal mold1was cooled to room temperature, the strengthened polylactic acid tube2was took out, and redundant 2 mm tube sections at both ends of the processed tube were cut off. During the rotation process, the polylactic acid tube2was squeezed and scraped by the distal blade4, and molecular chains thereof were oriented along the rotation direction of the blade, thereby achieving a change from a disordered arrangement to a circumferential orientation as shown inFIG.4.

The preferred embodiments of the present invention have been described in detail above. It should be understood that many modifications and changes can be made by a person of ordinary skill in the art according to the concept of the present invention without involving any inventive effort. Therefore, any technical solutions that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments on the basis of the prior art according to the concept of the present invention should be within the scope of protection as defined by the claims.