JPS6150771B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a roofing base sheet that can be marked with markings, in which a thermoplastic synthetic resin material 1 is formed into a sheet using a calender roll 2, and the final roll 5 portion of the calender roll 2 is used to form a sheet into a sheet. This relates to a method for manufacturing a roofing base sheet, which is characterized in that a light-colored paint 4 is applied to one side of the sheet 3, and after the paint 4 is applied, both ends of the sheet 3 are cut off using the final roll 5. be.

Roofing base sheets are generally colored black because they are molded by recycling scraps from electrical wire coatings. However, if the roof base sheet is black in this way, marking cannot be done, so one side of the roof base material is coated with a light colored paint such as white so that it can be marked. However, since the paint is usually applied using a roll coater, there is a problem in that unpainted areas occur at both ends of the roof base material in the width direction, and these areas remain black and cannot be marked. Furthermore, there is a difference in thickness between the areas where the paint is applied and the areas where it is not.
There was also a problem in that when the roofing base sheet was rolled up, it curled and could not be rolled accurately.

The present invention has been made in view of the above points, and an object of the present invention is to provide a method for manufacturing a roof base sheet that can obtain a roof base sheet coated with a bright color paint over the entire width. It is something to do.

The present invention will be explained in detail below with reference to Examples. 1a and b show an example in which an inverted L-shaped calender roll in which each roll 5 is arranged in an inverted L shape is used as the calender roll 2, and the molten thermoplastic synthetic resin material 1 supplied to the upper part of the calender roll 2 is The material is calender-molded using a calender roll 2 to form a sheet. On the last roll 5 (roll 4) of this calender roll 2, a pair of primary rotary cutters 6 are disposed on the side of the roll 4, and a pair of secondary rotary cutters 7 are disposed below the roll 4. There is. Further, on this final roll 5, a coating roll 8 is disposed between the primary rotary cutter 6 and the secondary rotary cutter 7. In FIG. 1, 10 is a paint tank filled with a clear paint 4 such as white, and 9 is a pick-up roll.

The sheet 3 calender-formed by the calender roll 2 is first trimmed (part a) by the primary rotary cutter 6 as shown in FIG. Paint 4 is applied. As shown in FIG. 3a, uncoated portions of the paint 4 occur at both ends of the sheet 3 in the direction perpendicular to the direction in which the sheet 3 is fed (ie, in the width direction). After the paint 4 has been applied, the sheet 3 is subjected to secondary trimming (part b) with a secondary rotary cutter 7, and the unpainted parts of the sheet 3 are removed from the sheet 3 as shown in Fig. 3b.
As shown in FIG. 3c, a roof base sheet can be obtained in which the paint 4 is applied over the entire width of the sheet 3. The cutting waste 11 generated during the primary and secondary trimming is wound around the final roll 5 as it is, and this cutting waste 11 is again fed to the upper part of the calender roll 2 to form a sheet 3.
reused for molding.

As described above, in the present invention, a clear paint is applied to one side of the sheet, and both side edges of the sheet are cut off after coating, so even if the paint is left uncoated at the side edge of the sheet, the unpainted portion will be removed. It is possible to obtain a roof base sheet coated with paint over its entire width by removing the roof sheet, which allows marking to be done without any problem, and there is a possibility that there will be a difference in thickness between the painted part and the unpainted part. Moreover, it is possible to prevent the sheet from deteriorating due to the entire surface being covered with paint. Moreover, since the cutting of both side edges of the sheet is done at the final roll of the calender roll, the cut part can be reused for molding with the calender roll, and there is no loss as would be the case if the sheet is cut off after it has been made into a product. There is no risk of it happening.

[Brief explanation of the drawing]

Figures 1 a and b are side and perspective views of an embodiment of the device used in the present invention, Figure 2 is a perspective view of the same sheet, and Figures 3 a, b, and c are top views showing the same sheet. , a top view, and a sectional view. 1 is a thermoplastic synthetic resin material, 2 is a calender roll, 3 is a sheet, 4 is a paint, and 5 is a roll.

Claims (1)

[Claims] 1 Thermoplastic synthetic resin material is made into a sheet using a calender roll, and the final roll part of the calender roll applies a light-colored paint to one side of the sheet, and after the paint is applied, this final roll part coats both sides of the sheet. A method for manufacturing a roofing base sheet, which comprises cutting it out.