DE1427569B2 - WIDE SANDING BELT - Google Patents

Description

125 mm strip length and a breaking strength in the longitudinal direction of 21.4 to 21.8 kgf / cm width, one Transverse elongation of 20 mm / 125 mm strip length and a breaking strength in the transverse direction of 22.2 to 23.2 kg / cm width.

Five different rolls of such a fabric with essentially the same properties were found for the production of an abrasive belt with a phenolic resin filler containing 15 to 20 percent by weight of ethyl cellulose was modified, impregnated. During the impregnation, the tension in the warp direction was increased kept to a minimum in order to avoid overstretching in the warp direction (longitudinal direction of the web). Thereafter, the fabric was passed through a dryer to cure the filler, with the fabric in The warp direction has been subjected to the least amount of tension necessary to keep it at a specific Cure width. The fabric treated in this way had the properties listed in the following tables.

Table 1

role
No. Surfaces
weight
kp / m ² filler
g / m ² Weight
percent curse
term stock
share in Ge
weave Weight
percent not
watery curses
term stock
share in Ge
weave 1
2
3
4th
5 0.380
0.400
0.408
0.410
0.387 107
120
132
116
110 6.69
6.98
6.59
6.40
6.75 3.02
2.98
3.20
3.03
3.02

Tabel

To Eastern hour heat treatment at 121 ° C Along Longitudinal break Along Wet Along Without heat treatment Cross Transverse fracture Dry strain strength strain Longitudinal break strain Dry strain strength Role no. 7o kp / m width ° / o strength % Longitudinal break 7o kp / cm width 0.50 30.7 0.68 kp / m width 0.51 *) strength 0.59 *) 25.0 to 25.2 0.53 31.1 0.72 32.1 0.53 *) kp / m width 0.66 *) 23.9 to 29.2 1 0.48 31.1 0.63 32.7 0.48 *) 30.4 to 31.1 0.56 *) 22.0 to 22.5 2 0.48 31.3 0.66 32.5 0.47 *) 30.0 to 31.3 0.71 *) 26.3 to 26.5 3 0.50 30.9 0.67 ' 33.2 0.52 *) 30.4 to 31.2 0.59 *) 26.3 to 26.5 4th 32.2 30.4 to 30.7 5 30.0 to 30.9

*) Approximate values

For comparison, an underlay made of drill fabric (cotton fabric with twill weave) has become more common Art 107 cm wide, with a thread count of 30 x 19 (warp yarn No. 14, weft yarn No. 12) and a weight from 211 g / m dyed and dried, then, as described above, with the same fabrics, but also treated with the usual tension in the warp thread direction. The thickness of the drill fabric was before Treatment 0.30 mm, that of the cotton atlas fabric before treatment 0.32 to 0.35 mm. To the finishing - without heat treatment - the drill fabric had the following physical properties:

Table 3

Drill fabric underlay,
Treated with tension in the direction of the warp thread

Along
strain
% Longitudinal fracture
strength
kp / cm width Transverse expansion
7o Transverse fracture
strength
kp / cm width 0.35 37.5 1.4 8.93

50

55

60

As mentioned, the original width of the drill fabric was about 107 cm. During the treatment, tension was applied in the warp direction so that the fabric width after the second drying was 93 cm. A similar treatment of a 160 cm wide drill fabric resulted in a final width of 130 cm.
In contrast, the cotton atlas fabric had an original width of 135 cm and, after finishing, a width of the order of 127 cm. Since a certain longitudinal tension had to be applied to the cotton atlas fabric in order to pull it through the immersion trough, the squeegee rollers and the curing dryer, the cotton atlas fabric was stretched slightly in the direction of the warp thread. However, in contrast to the usual equipment, the stretching in both the transverse and the warp thread direction is canceled again. Although the width of the cotton atlas fabric is reduced in the finishing process, the application of practically the lowest possible tension in the warp direction actually causes the fabric to be pre-stretched in both the transverse direction and in the warp direction, so that the treated fabric has little residual stretch. Needling to a tenter frame during curing is often useful, but not necessary to achieve a certain width. If a tenter frame dryer is available, it can be used. Substantially the same results are obtained when working with practically the lowest possible warp thread elongation and using a tenter dryer to spread the fabric in the transverse direction during finishing.

As indicated in Table 2, the finished cotton atlas fabrics in the longitudinal and transverse directions approximately the same properties, d. H. the transverse stretch and the longitudinal stretch are just like the transverse and the longitudinal breaking strength in the same order of magnitude. With common sanding belt supports like that above-described twisted fabric, the transverse stretch is about 4 times as large as the longitudinal stretch and

the longitudinal breaking strength also about 4 times as high as the transverse breaking strength.

The finished cotton atlas fabric is then sprinkled with abrasive grain and separated into individual sections 10 (FIG. 1) which have the shape of parallelograms, the greater heights h of which are equal to the bandwidth. The longer sides of the individual sections 10 are then connected to one another by gluing with a synthetic resin adhesive, which is cured by heating under pressure between plates, so that an endless belt 14 is formed.

The sections 10 are expediently cut off from the base in such a way that the angle A is 75 to 80, preferably 78V2 ⁰ . The arrows in FIG. 1 indicate the direction of the warp threads in each individual section 10. If the connection 12 between two adjacent sections 10 is carried out carefully, a wide abrasive belt 14 of uniform thickness is obtained. In this regard, as already mentioned, the cotton atlas fabric underlays have the advantage over other fabric underlays that the connection points have the same thickness as the tape. This peculiarity of the cotton atlas fabric is difficult to explain, as the connections are only made after the cotton atlas fabric has been sprinkled with abrasive, when the backing has already been reinforced to a certain extent by the abrasive bond. It can be assumed that the high compressibility discussed above and the minimal number of cross-over humps on the tissue surface play a role in this.

After sprinkling, the finished sanding belt should have a Have a minimum breaking strength of 26.8 kg / cm width and a maximum elongation of about 7%.

Fabric underlays according to the invention are particularly suitable for the production of individual sections produced wide abrasive belts, but can also be used for abrasive belts of normal widths if the same strength and elongation in the longitudinal and transverse directions is desired.

1 sheet of drawings

Claims (15)

1 2 Connection points of the individual sections almost the Claim: same thickness as on the other parts of the grinding having strip web. Wide sanding belt with a fabric backing, according to the invention, this object is achieved in a released from interconnected individual sections 5 wide sanding belt of the type mentioned consists, whereby the warp threads in individual sections by using a fabric with a satin weave, at an angle to the direction of movement of the sanding belt The invention is explained in more detail using the drawing run, marked by a verb. It shows Twist of a fabric with a satin weave. F i g. 1 is a plan view of a single section ίο composite wide sanding belt and Fig. 2 is a section on an enlarged scale through the wide sanding belt along the 2-2 in Fig. 1 in the direction of the in F i g. 1 drawn arrows. 15 A fabric with a satin weave is preferred The invention relates to a wide sanding belt with a used, which in the direction of the warp threads and in Fabric backing that is essentially the same from the interconnected direction of the weft threads There are individual sections, the warp threads in the breaking strength and having the same elongation. A Individual sections at an angle to the direction of movement of such a fabric is obtained when weaving Sanding belt run. 20 kept warp tension to a minimum Such a wide sanding belt is made from, for example. In certain cases one can also know a tension in the production of the German utility model 1 702 614 and finishing of the fabric. This wide abrasive band is to be used from single-section weft thread direction; you then get a th made in the form of stretched parallelograms, the sanding belt backing from which individual sections on the longer edges with each other, z. B. can be connected well by KIe- 25 to a wide sanding belt,
Exercise, are connected and thus result in a sanding belt. As a fabric with a satin weave, a its seams or gluing points at an angle to the flexi- ble woven cotton fabric with a 4: 1 binding direction of the finished sanding belt. dung (cotton atlas) selected, but can also Although abrasive belts of this construction are used with much thicker woven fabrics. That Better sanding results than belts with cotton fabric parallel to the 30 th can be used as a warp or weft atlas ge direction of movement running connecting seams, but is in the production and finishing or glue points, you can make sure that the tissue in the direction of the practice not fully satisfied. Warp threads and in the direction of the weft threads essentially There are essentially two reasons for this: the same breaking strength and elongation are measured. Once a fabric 35 is used for the grinding belts. As a rule, you will prefer warp atlas because it is used with a twill weave, more rarely with a plain weave, the usual form of manufacture and therefore the cheapest one resulting from the processing of warp and weft threads. Typical thread counts per square centimeter of different breaking strengths and by which are: 40 x 28, 41 x 25, 38 x 24 and 38 x 22.
subsequent finishing in the direction of the warp threads The fabric with a satin weave offers the advantage of a higher elongation than in the direction of the weft threads 40 that its surface is much smoother than that of Has. Since the warp threads in the finished product are made from single-section fabrics with plain or twill weave. the th existing sanding belt at an angle to the number of crossings and thus the direction of surface movement of the sanding belt run, the hump is much smaller than with the twill and it when using the sanding belt because of the plain weave. This results in a higher degree of differentiation Elongation in warp and weft thread 45 wear resistance of the atlas fabric. Additionally, direction easily to an undesirable warping of that atlas fabric - if all other factors equal Band. are - theoretically a higher breaking strength and A second disadvantage of the known abrasive belts is lower elongation than woven fabrics of any other bond that in the case of the body or types used and that the thickness per unit weight Plain weave the fabric has a maximum number of 50 minimums. of crossings and that therefore a great Another advantage of the fabric with a satin weave Number of protrusions on the surface of the tissue. consists in the fact that it is considerably stronger together In these humps the tissue is more compressed than other tissue. This amalgamation subject to loss of strength and unpressibility, which affects the mobility of the desired Stretching leads. In addition, it is very likely to be related to 55 crossings difficult, when composed of individual sections with the minimum thickness per unit weight Wide sanding belts with fabric backing are mainly responsible for ensuring that the connection or plain weave on the seams or seams between the individual sections in the ferti connection points of the individual sections of the abrasive, abrasive coated abrasive tape the same thickness as the rest of the table, the same thickness as the rest of the sanding belt Adhere to the grinding belt path. Have differences in thickness. the seams of the sanding belt, however, lead to a typical sanding belt underlay, Use for rattling and for increased tape crumbling, five-strand woven cotton atlas with one wear, especially at the seams. Weight of 455 g / m and a nominal width of 135 cm The invention is based on the object of the 65 (thread count 38 · 24, single thread no. 17 for the The disadvantages of known wide chain and no. 9.5 for the weft described above) has after to remove sanding belts and to wash a wide sanding belt to remove dirt, sizing, create that does not tend to warp and the waxes and oils have a longitudinal stretch of 20 mm /