JPH0129265Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] The present invention relates to a felt needle used in a needle punch machine for mechanically entangling a web of fibers to form felt. It is used in many industries, including felt, melton and flannel fabric substitutes, and filters. [Prior Art] In recent years, the demand for needle-punched felt has increased more and more, and the production speed has become extremely high, and the need to increase the number of felts per unit area has also increased. For this, to increase the density of planting needles,
For example, a method of bundling and implanting a plurality of felt needles as in Japanese Patent Publication No. 49-48578 has been studied, and a method of shortening the barb spacing of felt needles is also known as a cross-barb needle. Furthermore, in order to avoid needle marks from punching and to obtain needle felts of uniform weight, different types of needles may be planted on one board, as known from Japanese Patent Publication No. 55-9106. It is also known to tilt the board itself. [Problems to be solved by the invention] The method of bundling felt needles described above is extremely useful because it increases the number of felt needles per unit area by several times at once, and as a result enables high-speed production. In order to achieve this, it is necessary to modify the needle board, bed plate, etc. of the needle punch machine, and since the driving resistance naturally increases, the torque is insufficient with a general-purpose needle punch machine. , a dedicated machine was required, making it difficult to apply to conventionally known needle punch machines. In addition, the cross barb designed to reduce the bar spacing and increase the entanglement efficiency at the same driving depth, which is designed to adapt to high-speed production, simply allows the driving depth to be shallower, and the expected entanglement is not achieved. It was not possible to obtain a matching rate. This means that by simply narrowing the barb spacing, it will not be possible to
This is thought to be due to the fact that the barbs after the th barb pass through without any effect and do not work effectively, and on the contrary, a normal felt needle with a wider bar spacing entangles a larger number of fibers. This tendency becomes more pronounced as the number of strokes increases. [Means and effects for solving the problems] The felt needle according to the present invention is a needle punch characterized in that the spacing between the barbs is uneven, and the spacing between the barbs becomes wider at a portion closer to the tip of the needle. It is a felt needle for machines, and is highly versatile as it can be adapted to any needle punch machine.Moreover, it has much better entanglement efficiency than the conventionally known crossbarb felt needles, making it suitable for high-speed production. As shown in FIGS. 1 to 3, this is a felt needle in which the barbs 2 are spaced unevenly. The felt needle of the present invention is a felt needle used in a needle punch machine for forming a web made of spread and spread fibers into felt by mechanical entanglement. This felt needle is characterized by uneven spacing of the barbs 2, which are protrusions provided on a plurality of ridge lines 3, and a wide spacing between the barbs near the needle tip. Unlike cross barbs, this needle has a wide spacing near the needle tip, which allows all barbs to work more effectively, resulting in a needle with high entanglement efficiency. To explain this in more detail, in a typical needle punch machine, the reciprocating motion for driving the needle is achieved by converting the motion of a rotary plate installed in the machine into reciprocating motion using a crank or the like. Therefore, the speed at which the needle moves up and down becomes 0 at the top dead center and the bottom dead center, and shows the highest speed value at the intermediate point. In recent years, high-speed needle punch machines have increased the number of reciprocations per minute (hereinafter referred to as "stroke number") by considering various factors such as the diameter of the rotating body and the crankshaft. There is no change in the fact that the reciprocating speed is non-uniform, and since the distance between reciprocating strokes (hereinafter referred to as "stroke") is tried to be as short as possible, the non-uniformity of the reciprocating speed tends to be expanded. The purpose of the present invention is to deal with such nonuniform reciprocating speeds so that each barb passes through a specific position, such as a bed plate or web, at equal time intervals as much as possible. The purpose is to determine the barb position accordingly. In the best case, the barb position is determined based on the crankshaft length and rotating body radius of each needle punch machine, but as a result of various studies, we found that this is not always necessary, and as shown in Figure 2, the barb position It has been found that by simply changing the spacing between the barbs in two stages, one near the tip and the other at the far end, there is a clear difference in entanglement efficiency from the conventional cross barb shown in FIG. Furthermore, by widening the distance between the barbs near the needle tip, which passes through the web at high speed, it is possible to move the entire barb closer to the needle tip, as shown in Figure 1, if necessary. Therefore, the needle depth during needling can be made shallower, which is advantageous for high-speed production. 1 to 3 show felt needles according to the invention, in which FIG. 1 shows a felt needle with two barbs in the same row.
This is a barbed needle, and FIG. 2 shows a felt needle with only two barb spacings, large and small, and FIG. 3 shows a nine-barb felt needle with all barb spacings unequal. [Example 1] Using a felt needle with the barb spacing shown in Figure 2, polypropylene (2 denier, 51 mm length) 80
Needle punching was performed on a 150 g/m ² web made of a blend of 20% rayon (1.5 denier, 38 mm length) and 20% rayon (1.5 denier, 38 mm length) by varying the needle density and needle depth. Tables 1 and 2 show the results of measuring the breaking strength of the punched felt using a constant-speed extension type tensile tester.This felt needle has high efficiency that conventional felt needles do not have. It was something to show. [Example 2] The same test as in Example 1 was conducted using the felt needles shown in Fig. 3 with all the barb spacings being unequal, and the results are shown in Tables 1 and 2. This needle was also more efficient than Example 1. [Comparative Examples 1 and 2] As Comparative Example 1, the conventional cross barb shown in FIG. 4 was used, and as Comparative Example 2, the conventional regular barb felt needle shown in FIG. 5 was used, and the same test as in the Example was conducted. Ivy. Both Examples 1 and 2 and Comparative Examples 1 and 2 had the same needle size (needle count, needle length, etc.) and the same barb shape (kickup height, throat shape, etc.), but Table 1 As shown in Table 2, the conventional felt needle used in the comparative example was clearly inferior in efficiency.

【table】

〔effect〕

When the needle of the present invention is applied to a well-known needle punch machine, it is not only possible to reduce the needle depth and needle density, making it ideal for high-speed production, but as a result, the felt also suffers from surface roughness due to punching. Moreover, it becomes a good felt with less drawbacks such as the web being expanded due to driving resistance and a reduction in area, and has high practical value.

[Brief explanation of the drawing]

1, 2 and 3 are views showing the barb positions of the felt needle according to the present invention, and FIGS. 4 and 5 are views of the conventional felt needle. 1...Felt needle, 2...Barb, 3...Ridge line.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A felt needle for a needle punch machine, characterized in that the spacing between the barbs is uneven, and the spacing between the barbs becomes wider closer to the tip of the needle. (2) The felt needle according to claim 1, which is a felt needle having at least three or more barbs arranged in the same row, the spacing between the barbs being unequal.