JPS6112319A - Tenter - Google Patents

Abstract

PURPOSE:To enhance working efficiency by eliminating not only trouble such as rupture or cramp but also the mixing of a broken piece from a V-belt when the V-belt is used, by forming a member for grasping a film from a twisted yarn rope. CONSTITUTION:By using a rope excellent in heat resistance as a member for grasping a film, the plasticizer and low MW compound such as the oligomer of the film are eluted to be penetrated into the rope to a certain degree but the swelling of the rope is extremely small as compared with a V-belt and the low MW compound is held between twisted yarns to be acted on the friction part with the rope holding groove of a pulley as a lubricant. Because the rope has self-deformability, the change in the grasping force of the film is generated even by the slight swelling or thermal expansion of the rope and the rupture of the film at the grasping part is not generated. Because the rope having heat resistance is used, damage resistance is better than the V-belt and a problem, such that a broken piece is pressed to the film, is not generated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a tenter used for extending a thermoplastic resin film obtained by a calender. More specifically, the present invention relates to an improvement of the tenter by using a rope as the film holding member of the tenter.

[Conventional technology]

Conventionally, a thermoplastic resin film molded using a calendar was stretched out using a tenter and made into a product. By the way, a tenter pinches the film and spreads it laterally. That is,
It is a device for stretching the film, and its film holding part is usually a pin, chain, clip, or -belt. Pin-, chain-, and clip-type tenters partially clamp the film at its edges, so partial tensile stress is applied to the film, resulting in various problems such as film tearing and film twitching. Also,■
- In a tenter that uses a belt, the entire edge of the film is clamped, so the above problems are less likely to occur, but low molecular weight compounds such as plasticizers and oligomers contained in thermoplastic resins are eluted, and the work time is reduced. These low molecular weight compounds penetrate into the V-belt with the increase in ■-
There are problems in that the belt swells and protrudes from the belt holding groove of the pulley, and the gripping strength of the film changes, resulting in the gripping portion becoming thinner and tearing.

In addition, since the sandwiching film is a semi-molten resin, V-
The belt deteriorates due to the heat of the film and breaks at the end, resulting in the broken pieces being press-fitted into the film forming film, which significantly affects the quality of the product and also causes insufficient clamping force at the damaged part, resulting in production problems. There were also sexual problems.

[Problem that the invention seeks to solve]

An object of the present invention is to provide a tenter free from such problems.

[Means for solving problems]

In order to solve the above-mentioned problems, the inventors of the present invention conducted intensive research and completed the present invention.

That is, the tenter of the present invention is characterized in that the members that sandwich the film are twisted ropes.

The rope used in the present invention is made of twisted yarn having excellent heat resistance, such as vinylon, rayon, polyester, acetate, or the like.

Note that other ropes may be used as long as they have heat resistance and abrasion resistance.

By using a rope with excellent heat resistance as a member to sandwich the film, low molecular weight compounds such as plasticizers and oligomers from the film are eluted and penetrate the rope to some extent, but the swelling is incomparably smaller than that of a V-belt. , and a low-molecular compound is held between the twisted yarns and acts as a lubricant to the friction portion of the pulley with the rope holding groove.

Furthermore, since it is a rope and has self-deformability, even slight swelling or thermal expansion does not cause a change in the clamping force of the film, and the film does not tear at the clamping portion.

Furthermore, since a heat-resistant rope is used, it has better breakage resistance than a V-belt, so there is no problem of broken pieces being press-fitted into the film.

Note that the present invention can also be used with conventional tenters, except for using a rope for the film holding part. - [Example] The present invention will be explained below with reference to Examples.

Example 1 Using a nylon twisted rope in place of the belt in the tenter of an apparatus consisting of a calendar manufactured by Ishikawajima Harima ■, a belt-type tenter, and a group of take-up rolls, the following resin composition was heated to a width of 300C+I under the following conditions. It was made into a film with a thickness of 80 μm.

Dioctyl phthalate 50 parts by weight Epoxidized soybean oil 5 u Zinc stearate barium stabilizer 1.5 (2) Molding conditions Calendar Clearance 300 μm Temperature 180°C Roll speed 40 m/min Take-off 100 rrL/min Tenter
Input temperature 170℃ Output 1
50℃ Offer rate 1.5 times Take-up roll Take-up 100rrL/min Roll temperature 25℃ Observe the condition of the film over time and check for film tearing and foreign matter contamination at the tenter clamping part. 1 result was obtained.

* From the resin caught in the tenter clamp Comparative Example 1 A film was produced in the same manner as in Example 1 except that a commercially available V-belt (made by Ndo Kagaku ■ - Peltrend) was used. Observations similar to those in Example 1 were made.

The results are shown in Table-2. Note that the numbers in parentheses are the number of pieces caused by V-belt fragments.

Table 2 * Due to increased foreign matter contamination, the rope was returned to the pewter rope on the 21st day.

Example 2 A film was obtained in the same manner as in Example 1 except that a polyester rope was used as the rope.

When the same observation as in Example 1 was made, the same results as in Example 1 were obtained.

〔Effect of the invention〕

In the present invention, by simply using a rope as the holding member of the tenter, there are no problems such as tearing or twitching that were problems with conventional bottles, chains, and clips. It also prevents debris from entering the belt and greatly improves work efficiency.

Claims (1)

[Claims] A tenter characterized in that the member for sandwiching the film is a rope.