KR810001068B1 - Apparatus for manufacturing rolling wheels made of synthetic resin - Google Patents

Abstract

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Description

Apparatus for manufacturing rolling wheels made of synthetic resin

1 is an illustration of the manufacturing apparatus of the present invention.

The present invention relates to an apparatus according to a method for producing bidirectionally stretched wheels from crystalline thermoplastic synthetic resins, in particular crystalline thermoplastic synthetic resins such as polyolepins.

The wheel of the polyolefin produced by the method and apparatus of the present invention is that the elongated state and strength should be greater in the longitudinal direction than in the lateral direction or approximately the same in both directions.

The method of first stretching in the longitudinal direction and then in the transverse direction has been known in the art, but in the case of a thermoplastic synthetic resin such as polyolefin, in particular, there is a risk of tearing after stretching in the longitudinal direction, and thus cannot be stretched in the transverse direction. Ideal stretching in the longitudinal direction was not possible.

In the case of polyolefin fins, they extend in both directions and have the same physical properties on both sides when the ratio is 1: 7. Until now, when the polypropylene wheel must be laterally stretched, the longitudinally stretched ratio cannot exceed 1: 5.6.

The other wheels extending in both directions are extended in the longitudinal and transverse directions at the same time, but in this case the wide wheel plates are pulled and guided transversely by a gripping device. If you continue to extend in the longitudinal direction, the gap between the attachments will be far apart, and if the apical membrane between the attachments has a recessed shape like a chock, the curved edges will have an unbalanced force distribution. It will be cut off. The result is a loss of up to 30% of the material in the area of the finished product.

The bidirectionally elongated wheels that are supplied as commodities on the market are continuously elongated in the longitudinal and transverse directions or simultaneously elongated in both directions, so that the elongation or tensile strength is smaller than the transverse direction in the longitudinal direction.

These wheels are required for applications where adhesive strength and smaller expansion are required in the longitudinal direction, for example for coating and printing of adhesives, such as those used for the manufacture of adhesive tapes or bag-shaped packaging. Almost no expansion should occur during repeated unwinding or rewinding with tensile force, which is difficult or in some cases not suitable for such applications.

BACKGROUND OF THE INVENTION A method of improving the mechanical properties of a wheel is known by stretching it to a temperature leading to the orientation of the wheel. For amorphous synthetic resin materials these temperatures are temperatures in the thermoplastic range and, in the case of crystalline materials, orientation is achieved by stretching near the crystalline melting point (temperature).

The present invention provides a device for improving the properties of a wheel made of thermoplastic material by stretching the wheel plate in both directions, the device adapting the wheel to the temperature at which the orientation occurs, and in the first step the wheel direction in the longitudinal direction. Partially stretched and then simultaneously stretched in both directions simultaneously under the same orientation temperature in the second step, whereby the remaining longitudinal stretch and the total transverse stretch are achieved, and the stretch is made to freeze the resulting stretch. It is supposed to cool the used wheels.

That is, 25% -50% of the total elongation length is suitable for the primary elongation applied in the longitudinal direction. In order to compensate for the difference in the processing conditions or the change in the material, the elongation in the first stage may be changed, while in the second stage, the elongation in both directions is constant.

By using the device of the invention the longitudinal elongation of the wheel in both stages can lead to the same total longitudinal orientation as the transverse orientation achieved in the second stage, in which the orientation in both directions in particular is at a maximum.

By changing the device of the invention the wheels are stretched in the overall longitudinal orientation in both stages, which is higher than the transverse orientation.

This manufacturing apparatus is suitable for thermoplastic materials such as homopolymers and copolymers of olefins, for example, polyethylene, polypropylene, polybutylene, polyamide, polyester, that is, poly Homopolymers and copolymers of styrene terephthalate and halogenated olefins, such as polyvinyl chloride, polyvinylidene chloride, polystyrene, polycarbonate and the like. Thermoplastics may include common additives such as plasticizers, fillers, stabilizers, dyes, and the like. In a particular embodiment this device is used to shape the properties of a polypropylene wheel. These materials extend in the longitudinal direction at a temperature near the crystal melting point of polypropylene in the first stage to about 1: 2-1: 5, and at a temperature near the crystal melting point of polypropylene in the second stage simultaneously in the second stage. Within 5 to 1: 7, the total elongation in the longitudinal direction is increased from 1: 7 to almost 1:10 so that the total elongation of the wheel area is 1: 44-1: 50. The total area in which the polypropylene wheel is stretched depends on the raw materials and additives used and the temperature applied. In polypropylene, the ratio of 1:49 is considered to be the maximum value, which makes the thickness of the wheel uniform and gives the best physical properties.

In commonly used examples, the wheel length of polypropylene to enhance the longitudinal properties was extended in both stages to a total elongation of about 1: 8 in the longitudinal direction and about 1: 6 in the transverse direction.

If a wheel with equally balanced characteristics in both directions is required, the longitudinal elongation is 1: 3.5 in the first stage, 1: 2 in the second stage, and 1: 7 in the second stage.

The present invention also relates to a device for improving the physical properties of a wheel made of thermoplastic synthetic resin material by stretching the wheel in both directions, wherein the device accommodates the wheel while the wheel is stretched and adjusts the wheel to a temperature causing orientation. And a second extension device for longitudinal extension, a second extension device for extending in both directions, and a device for cooling the extension wheel in both directions, the wheel being in contact with the first extension device. The rollers are transported by rollers, each of which rotates at a faster speed than the previous one, and in the second extension unit, the wheels are stretched simultaneously in both directions by picking up the edges of the wheels of the attachment devices and spreading them apart. .

The attachment devices of the second stage extension device may be operated by a spindle with an increasing pitch, whereby the attachment device increases in the longitudinal direction at a speed of 1: 2 so that 1: 2 The transverse elongation is achieved while the transverse elongation is achieved by picking up the edge of the wheel and opening the gap as it moves along the path of the attachment devices. The angle between the paths of the two pairs of attachments can be changed if necessary, but the pitch and rotational speed of the spindles can be kept constant. Instead of being guided by the spindle, the attachments may be operated by linear motors with increasing speed.

In the first step, the roller speed of the first extension device can be changed indefinitely in order to correct the variation in the process by changing the longitudinal elongation.

The accompanying drawings are a device for use in the manufacturing process according to the present invention and the thermoplastic synthetic resin wheel according to the present invention, the contents of which are described in accordance with the accompanying drawings.

That is, it consists of a first extension device for extending in the longitudinal direction and a second extension device for pulling in both directions, in the second extension device adhesion device moving in opposite directions to extend simultaneously in the longitudinal and transverse direction The edge of the wheel is bitten and pulled, and then the cooling device extends in both directions.

The thermoplastic synthetic resin melted in the injection machine 1 is injected through the widely torn nozzle 2 and transferred to the cooling cylinder 3, in which several cylinders are connected in series. Although not shown in the figure, it is better to use the ironing device at the same time to straighten the wheels. After leaving the last cooling cylinder, the thermoplastic resin wheel 4 has a temperature much lower than the thermoplastic or crystalline melting temperature of the thermoplastic resin material required for stretching. After the wheel has passed through several conventional aids and preheating zones not shown in the figure, the wheel arrives at the longitudinal stretching device (5), which rotates at different speeds or changes the speed indefinitely. It consists of cylinders that can be made.

For example, the longitudinal stretching device 5 is composed of ten cylinders of unlimited speed change arranged in three zones. In the first zone, the wheels are heated by heating the cylinders. The cylinders of the second zone (original stretch zones) can be tempered while the third zone cylinders can cool.

The wheel continues to move forward and pass through the cooling section, followed by an appropriate auxiliary device as shown above (not shown), which, after leaving this longitudinal stretching device, is moved to the next device and simultaneously extended in both directions. The device consists of one preheat zone (6), one simultaneous stretch zone (7) and one tempering and fixation zone (8).

In the co-extension device, the thermoplastic synthetic resin wheel is stretched through the preheat zone 6 by bites at both edges by a guide device (not shown) called the attachment device where the wheel is heated to the desired end.

On the other hand, it is also possible to simultaneously stretch in both directions immediately in the second stage while maintaining the wheel at the temperature at which the orientation is achieved after stretching in the longitudinal direction in the first stage. This avoids recrystallization caused by the preheating zone 6 and tumblering, which adversely affects elongation.

In the simultaneous stretch zone 7, the attachment devices pull the thermoplastic synthetic resin wheels in the longitudinal and transverse directions simultaneously to achieve the desired longitudinal and transverse stretching. Guide and drive of the attachment devices are done by spindles rotating at a constant speed. The pitch of these spindles gradually increases.

It is also possible to operate these attachment devices by means of linear motors or other drives adjusted according to the desired longitudinal and lateral ratios.

The use of a linear motor is possible because the stretching force in the second stage is smaller after stretching in the longitudinal direction in the first stage. The co-extension zone 7 is located just in front of the tempering and fixation zone 8, which is important for a variety of thermoplastic synthetic resin materials. At the end of all units for co-extension, a cooling zone (not shown) is arranged to freeze the tension created in the thermoplastic resin wheel by cooling the thermoplastic resin wheel below the thermoplastic or crystalline melting temperature. After leaving the co-extension device, the thermoplastic synthetic resin wheel is wound around the roller of the take-up device 9.

Instead of an extruder consisting of cooling cylinders connected in series with the narrow slender nozzle described above, a heating device may be connected in front of the longitudinal stretching device, which is used to heat the pre-made thermoplastic wheel plate to the temperature required for stretching.

In special cases it may be advantageous to replace the extruder with a calender to produce the original wheel plates.

According to the method of the present invention, a thermoplastic synthetic resin wheel made of, for example, polyolefin, such as polypropylene, which has excellent mechanical properties in the longitudinal direction can be conveniently prepared and can be used for the base plate of adhesive tapes.

In the method of the present invention, the wheels are oriented in the simultaneous bilateral stretching step so that the mechanical properties of the wheels are balanced at least in both directions, but mainly in the longitudinal direction, while the longitudinal extension is preceded by most of the longitudinal orientations. It is done in stages.

In the case of a wheel made of polypropylene, a tension value of 2300-3300 Kpound / cm ² can be obtained depending on the longitudinal elongation.

In particular, tension values of 2500 KP / cm ² or more that have not been realized to date can be achieved by the device according to the method of the invention. The thermoplastic synthetic resin wheel exhibits excellent mechanical properties, in particular because of the higher strength required in the longitudinal direction for adhesive tape applications. However, simultaneous elongation also produces good results in the transverse direction, especially in terms of properties important to the actual use of the tape, such as crack resistance.

The adhesive tape according to the present invention consists of a base plate made of polypropylene wheel, which is stretched in the longitudinal direction at an elongation of 1: 2 to 1: 5 in the longitudinal direction at about the first melting point temperature and simultaneously in both directions in the second stage. In this case, the total elongation is 1: 7 to 1: 10 in the longitudinal direction, 1: 5 to 1: 7 in the lateral direction, the wheel area is approximately 1: 49, The wheel has a longitudinal tension of 2500 to 3300 KP / cm ² and gives a sensitive compressive adhesive coating.

The advantage of the method according to the invention is that the longitudinal elongation in the first stage can be easily changed while the longitudinal elongation in the simultaneous elongation stage is two stages of the wheel extending in both directions so that it can be kept constant. It is in subdividing the height of life. Since the spindles of the second extension device operating the anchorage have a very low and consistently validated pitch, the longitudinal velocity of the anchorage increases at a ratio of just 1: 2. By using the device having the first and second extension devices, not only a small change in the longitudinal extension is achieved, but also a longitudinal extension difference within the range of 1: 2 to approximately 1:11 as necessary every time the material is changed.伸張 差) can also be achieved.

The following diagram shows several different types of wheels that can be stretched with a balanced wheel, ie, bilateral stretching can be made to approximately the same maximum. This chart shows what corresponds to life.

TABLE 1

At laterally low elongation, longitudinal total elongation can be readily achieved for all materials by increasing the first stage elongation.

For comparison with the above table, the tension values for six polypropylenes on the market from several manufacturers in Germany are shown in the following table. The thickness of the test wheel is 20 μm.

TABLE 2

From the diagram above, it can be seen that the transverse elongation and tension carried out by continuous elongation, first in the longitudinal direction and then in the transverse direction, for the wheels manufactured for goods, are higher in the longitudinal direction. Therefore, these wheels are not suitable for various purposes.

Example 1

Polypropylene particles (from Hostalen® PPN 1060® Fardwerke Hoechst AG) with a melt index of Mg 230/5 (according to DIN 53,735) of 10 g per 10 minutes were melted in a 200 mm diameter injection molding machine Injection was carried out through a wide nozzle to a chiller (70 ° C.).

The cooled wheel had a thickness of 900μ, a width of 650mm and a surface temperature of 72 ° C. After reheating to about 150 ° C., the wheels elongated at a ratio of 1: 3.5 in the longitudinal direction between the cylinders rotating at different surface velocities and cooled until the surface temperature reached approximately 80 ° C. The wheel, having a width of about 600 mm and a thickness of 260 μ, was driven into the attachment device and elongated at the same time in a ratio of 1: 7 in the longitudinal direction of 1: 2 in the longitudinal direction after passing through the preheating zone. The wheels are bitten and moved by the spindles which are spread out in the stretch zone.

After undergoing thermofixing and cooling, 18μm thick wheels were obtained, and the bilateral tensions of these wheels ranged from 2000KP / cm ² to 2400KP / cm ² .

Example 2

The polypropylene wheel was elongated at a ratio of 1: 3.5 to 1: 5 in the longitudinal direction in the first stage, and elongated at a ratio of 1: 2 in the longitudinal direction again in the second stage. In the second step, the transverse stretch was adjusted such that the surface stretch of the wheels was about 1:49.

For comparison, the wheels of the same material were first elongated in the longitudinal direction to an elongation of 1: 4 to 1: 5.5, and then laterally elongated so that the elongation of the surface was also about 1:49. As a result, the same values as in the following table were obtained.

TABLE 3

It was no longer possible to achieve high elongation in the longitudinal direction in the conventional method where continuous elongation in the longitudinal and transverse directions is achieved. The relatively high elongation in the longitudinal direction resulted in splitting of the wheel the next time in the transverse direction. Since there was no device for stretching the wheel surface to 1:49, it was impossible to compare the wheel surface in both directions at the same time.

Embodiments of the present invention are as follows.

1. Apparatus according to the claims wherein the speed of the stretching rollers moving inside the longitudinal stretching device is unlimited or variable.

2. The apparatus of item 1 above, wherein the attachment device, in which the wheel pulls the two edges in the longitudinal direction, is operated by a linear motor.

Claims (1)

Apparatus for simultaneously stretching the wheels made of thermoplastic resin in both directions, ie in the transverse direction of the wheels perpendicular to the longitudinal direction and the longitudinal direction, the device for receiving the wheels while the wheels are being stretched and for adjusting and maintaining the wheels at high temperatures And each roller is driven by the first extension device for the longitudinal extension of the wheels and the linear motors with increasing speed so that the rear rollers are driven faster than the front rollers and the speed of each rollers can be changed indefinitely. Adherent devices driven by spindles that are driven or rotated at a constant speed, if desired, gradually increase in pitch and increase the speed of the sedentary device in such a way as to pick up both edges of the wheel. The attachments are located on the opposite wheel while moving along the path (guide groove). Thermoplastic synthetic resin, characterized in that it comprises a second extension device for extending in both directions at the same time is made to extend in the lateral direction as a long distance between each other and the device for cooling the wheel extending to both sides The manufacturing apparatus of the rolling wheel which uses a raw material.

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