DK142854B - Method and apparatus for making plywood with adhesive plywood. - Google Patents

Description

(f) <ll) PUBLICATION WRITING 142854 D AND MARK (6i) in *, ci.3 d 04 h 11/00 (21) Application No. 5034/73 (22) Filed on 13 · Ββρ. 1973 [a ^ | (24> Lebedag 13 Sep 1973 (44) The application submitted and

the petition published on 9 f eb. 1 98I

DIRECTORATE OF

THE PATENT AND TRADEMARKET SYSTEM i30) P "0" 1 «1 ** den

Jan 5 1973, 676/73, GB

(71) BOND WORTH LIMITED * Severn Valley Mille * Stourport-on-Severn * Worce * = eterehlre * GB.

(72) · Inventor: William Colin Bourne, "Oak Ridge", 36 Areley Court, Areley

Kings * Stourport-on-Severn, Worceeterehlre, GB: Herbert Henry Cur = rell * "Hlllcrest", 32 Lickhill Road North, Stourport-on-Severn, Worce * eterehlre * GB.

(74) Plenipotentiary:

The engineering company Budde, Schou & Co.

(64) Method and apparatus for making pile fabric with adhesive pile.

0

The invention relates to a process for the production of peat fabric, as further specified in the preamble of claim 1.

In the manufacture of pile material by adhering studs to a base material, it is essential that the following conditions are met: 1. The adhesive must provide a reliable joint between the studs and the base material.

2. From the moment the mechanical control of the position or inclination of the studs relative to the base material provided by the stud attachment means is interrupted, the adhesive itself must be capable of providing sufficient control of the position or inclination of the studs that this position or inclination is not changed in any way. 2 142854 extent of importance.

3. Do not transfer the adhesive to any part of the studs that is visible when the putty material is in use.

In order to fulfill condition # 1, it is necessary for the adhesive to penetrate into the dot-forming yarn, and in order to achieve this, the viscosity must be kept at a low value for a period of time after the dot-forming yarn has been pressed into the adhesive. sublayer.

Condition # 2 is also difficult to meet, as it is generally necessary to push the newly inserted row of studs aside so as not to interfere with the insertion of the subsequent row of studs. This push-to-side is performed - necessarily - immediately after the stud forming yarn has been pressed into the adhesive, and there is a high probability that the angles of the studs with the base material will be changed when pushed aside as mentioned if the adhesive does not is stiff when this happens. It can be seen that there is a conflict here with condition # 1.

Also, there is a conflict between Condition # 3 and Condition # 1. The higher the viscosity of the adhesive, the less the risk that the adhesive will be transferred to parts of the studs visible when the putty material is in use. This is especially true in the case where the pile comprises rows of separate stud forming yarns which are pressed into the adhesive layer, the adhesive being able to rise between adjacent yarn pieces and coming into contact with the organs which press the yarn into the adhesive layer. When these members are then raised from the material, they can cause small amounts of adhesive which come into contact with parts of the studs which can be seen when the putty material is in use. If the adhesive is adhered to the said means, there is a great risk that it will be transferred to the studs in the subsequent row when the organs press it down into the adhesive layer.

The invention thus relates to a method in which these three contradictory conditions must be fulfilled, and it is therefore the object of the invention to overcome the contradictions between them and thus enable all conditions to be fulfilled.

In the process of the characterizing part of claim 1, the contradictions between the above conditions are overcome by temporarily reducing the viscosity of the adhesive after the bottom material with the attaching row of non-forming yarn pieces has been removed from the application section. This temporary reduction in viscosity can go down to such a viscosity value and last for such a long time that the adhesive penetrates the yarn to the extent necessary to obtain a satisfactory attachment of the pile yarn to the base material. Furthermore, this can be achieved without increasing the risk of transferring adhesive to parts of the pile which are visible during use, and without the risk of disturbing the angular position of the individual studs relative to the base material. At some distance downstream from the attachment section, each of the studs on all sides is surrounded by additional studs, which therefore control the angle of the individual studs sufficiently to hold the hood upright in the correct manner, despite the low viscosity of the adhesive being low. value. Furthermore, there is no longer any need to move mechanical organs between adjacent studs, while the viscosity of the adhesive is low, so no distortion of the studs or adhesive layer will occur. Since condition # 1 is met by decreasing the viscosity of the adhesive after the bottom material has been removed from the adhesive section, the viscosity of the adhesive in the adhesion section can be selected taking into account conditions # 2 and 3. Although the adhesive in the adhesive section must necessarily be sufficiently thus, to adhere to the yarn pressed into the adhesive, it may thus still be sufficiently rigid that it alone can perform the function of controlling the angles of the individual studs with the base material.

The required heating of the adhesive may conveniently be performed as set forth in claim 2.

In the embodiment of the method according to the invention according to claim 3, the support provided by the adhesive to the applied studs is obtained as the studs are moved away from the application section. This reduces the risk of the pavement moving in an uncontrollable manner with respect to the base material. If the viscosity of the adhesive is not increased as set forth in claim 3, there is a certain risk that such movements may be caused by the movement of the base material across the guide rollers.

Claim 4 specifies specific temperature ranges which have proved suitable for obtaining a reliable application of the pile yarn in the application section without the problems referred to in claim 1, and a subsequent solid attachment of the pile yarn to the base material.

By the measure of claim 5, it is obtained that a temperature gradient is formed in the adhesive layer, with the lowest temperature 4 closest to the free surface of the layer and the highest at the bottom material. The viscosity of the adhesive varies in a similar manner to form a rather rigid "skin" at the free surface and a more liquid and sticky adhesive closest to the base material. Said "skin" reduces the risk of the adhesive being transferred to parts of the pile yarn visible in the finished material, e.g. a blanket. Thus, the individual studs will be pressed through the "skin" and adhered using the more tacky adhesive in the vicinity of the base material.

The invention also relates to an apparatus for carrying out the method according to the invention, which apparatus is of the kind specified in the preamble of claim 6. The apparatus according to the invention is peculiar to the design according to the characterizing part of claim 61.

The effect mentioned above in connection with the embodiment of the method according to claim 5 can be obtained according to the invention by the embodiment of the apparatus according to claim 7. In the embodiment of the apparatus set forth in claim 8, the heat transfer occurs to a great extent by heat conduction, which is an appropriate condition for the embodiment of the apparatus set forth in claim 9, by which it is possible to prevent overheating of the parts of the base material located outside the heating means and the adhesive applied thereto without plugs or plugs, respectively, in particular in the event that the feed is stopped.

The invention will be explained in more detail below with reference to the drawing, which shows an embodiment of the apparatus according to the invention and various stages during the manufacturing process, fig. Figure 1 is a side view of an apparatus from which side plates and certain other parts are removed for the sake of clarity; 2 is an enlarged part of the apparatus with certain details; FIG. 3 is a diagrammatic cross-sectional view of an adhesive-coated bottom material on which to create non-forming pile lengths; FIG. Fig. 4 shows the adhesive-coated bottom material shown in Fig. 3 and the pile-forming pile lengths immediately after their application, and Figs. 5 schematically shows the finished pile material.

The apparatus has a support 10 for a roller 11 with an adhesive-coated, pre-woven base material 12. The support 10 is arranged so that the roller 11 can rotate freely and the apparatus has 5

1A285A

furthermore, a driven rewind reel 13, which is normally operated at a predetermined speed to pull the base material 12 out of the reel 11 at an even rate. From the rewind roller 13, the base material passes around rollers in an accumulation zone 14 which serves to provide a substantially uniform tension in the base material after the rewind roller and to accommodate a variable length of the base material 12, so that minor changes in the speed at which the base material is unwound from the roller 11, relative to the speed at which the base material passes through the other part of the apparatus can be offset.

From the accumulation zone 14, the base material passes over the guide roller 15 and then along a feed path near a first heating means 16 to a stud attachment section where stud forming lengths of pile yarn are pressed into the adhesive layer of the base material 12.

From the stud attachment section 17, the base material to which the studs are affixed moves about additional guide rollers 18 and then along a path near another heating member 19 and around a bottom guide roll 20 to a coil 21 upon which the pile material is wound. The coil 21 is supported by two support rollers 22, one or both of which are driven to pull the base material 12 through the apparatus from the reel roll 13.

Studs of any suitable shape may be provided for bringing a plurality of stud-forming pile lengths from a source of supply to the stud-fitting section and for pressing a portion of each of these stud-forming lengths into the adhesive layer disposed on the base material 12.

The supply source for pile yarn can be any known arrangement which presents a number of yarn ends which can be of one color when desiring to produce a patterned pile material, or which may be different in color to produce a patterned pile material. The pile yarn source can e.g. be a coil among several, each of which carries a series of side by side arranged coils of pile yarn in the desired color order. In each case, the coils will be provided with a comb between whose tens of yarn ends protrude toward the attachment section, or with a series of tubes through which the yarn ends project toward the attachment section.

Alternatively, the pile yarn supply source may be a rack with a plurality of coils sufficiently large to provide in each position along the row a group of yarn ends of different colors and with support means for each group of yarn ends, the supporting means being movable by means of selection means. according to Jacquard or other principles for the purpose of presenting a yarn of selected color to the dressing section.

The preferred form of yarn handling agents is shown in FIG. 2, and includes grippers 23 adapted to move back and forth toward and away from the pile yarn source 40 along a horizontal path, the grippers being suitably slidable along the upper side of a housing 24.

The housing 24 has an end surface extending across the conveying path along which the base material 12 is conveyed to the attachment section 17, and this surface defines one side of a slot 25, the opposite boundary of which is formed by a vertical end surface of a chest plate 26 which is located between the housing 24 and the pile yarn source 40.

The grippers 23 are normally closed by springs 27 but can be opened by rollers 28 which cooperate with cam grooves 29 provided on the upper elements of the grippers.

The yarn handling means further comprise a pressing means 30 which can be moved up and down a vertical path extending through the slot 25, as well as a knife 31 which can be raised and lowered at a location near the pile yarn source 40 and which can also be moved back and forth along a web extending along the series of yarn ducks provided by the pile yarn source to cut the yarn.

In FIG. 2, yarn handling agents are shown at the beginning of a duty cycle. The grippers 23 are initially closed and occupy a position above the housing 24 at the slot 25 · The grippers are advanced toward the pile source 40 and simultaneously opened by the rollers 28 which rotate about fixed positions during this portion of the operation. When the grippers are advanced far enough for the series of yarn ducks provided by the pile yarn source to be accommodated in their jaws, the rollers 28 are raised thereby allowing the grippers to be closed by the gripper springs 27.

The grippers 23, with the yarn ends retained therein, are now retracted to their original position, thereby pulling the yarn out of the source 40. When the required length of yarn has been pulled out, the knife 31 is brought down to contact the yarn and then moving back and forth to cut this in such a place that a yarn continues to protrude from the comb or other support which is a component of the yarn source.

The series of stud-forming pile yarns now held by the grippers 23 is pulled into a position in which they lie over the slot 25.

7

14285A

The rollers 28 then move downwardly to open the grippers, and at the same time the pressing member 30 moves downwardly to engage a central portion of each stud forming yarn and to push this middle portion through the slot 25 into the adhesive layer supported by the base material 12. Opposite end portions of each stud forming length project upwardly from the adhesive layer and into the slot 25 to form raised studs.

The pressing means 30 is now retracted in one direction upwardly from the slot 25, and a pushing member 32 mounted in the housing 24 is advanced over the lower portion of the slot 25 to contact the upright studs and displace them away from the slot and substantially in the direction of the pile yarn source 40. Simultaneously with the operation of the pushing member 32, the base material 12 is advanced to an extent corresponding to the distance desired to be between the successive rows of U-shaped studs in the finished product.

In order to provide adhesion of the snap-forming pile yarns in relation to the base material 12 in the application section 17, it is necessary that the adhesive layer provided with the base material is in a tacky state as this adhesive is advanced to and into the application section. The adhesive layer is therefore heated by the first heating means 16 to such a first temperature that the zone of the adhesive layer located in the application section will be tacky, but will have a relatively high viscosity. As the adhesive from the application section is passed on / cooled and solidified.

FIG. 3 shows the bottom material 12 with the adhesive 33 applied thereon before arriving at the application section. In FIG. 4, the bottom material and the adhesive are shown in the application section together with a U-shaped stud 34, a middle part of which is pressed into the adhesive layer. It will be seen that upon the displacement of the adhesive of the stud 34, an adhesive ridge 35 is formed between the stud 34 and a pre-mounted neighboring stud 34a. In addition, a somewhat smaller adhesive violence 36 has been formed at the side of the flap facing away from the flap 35 · Since the adhesive is in a fairly rigid state, as the flap 34 is transported further from the attachment section, these vaults help prevent the flotation of the flap 34T legs are bent apart and away from the correct upright position relative to the base material 12.

As the stud 34 leaves the attachment section, it is retained mainly by the adhesive of the adhesive 33 to fibers found at the substantially downward side of the middle portion of the stud. As shown at 37, some of the adhesive may rise upward along the center portion of the stud, but due to its relatively high viscosity, the adhesive will generally not flow over the center portion of the stud to completely enclose it. It will be appreciated that, leaving the application section, the stud is not retained sufficiently securely to form a durable padding material. The adhesive layer 33 is therefore heated in a subsequent operation by means of the heating element 19 to a temperature higher than the first temperature, with the aim of temporarily reducing the viscosity of the adhesive to a relatively low value. As shown in FIG. 5, the adhesive, when its viscosity is thus reduced, will penetrate the middle portion of each stud 3½ and, through the action of hair tubes, penetrate to some extent in the upright legs of each U-shaped stud. In addition, the adhesive flows in over the individual stud. The adhesive is then allowed to cool to ambient temperature, at which temperature the adhesive does not stick and is relatively rigid so that the studs are securely anchored to the base material 12.

Conveniently, the second heating means 19 is adapted to transfer heat to the adhesive 33 through the base material 12. The second heating means is therefore preferably formed as a plate having a flat, continuous surface for abutment with the base material, heating elements to keep its temperature at the desired value. Preferably, the sheet has a width equal to the width of the portion of the base material covered by the adhesive layer, and such that a temperature equilibrium condition is achieved in the individual zone of the adhesive layer prior to the portion of the base material which carrying this zone, moving out of contact with the heating means.

Also, the first heating means 16 is preferably arranged to transfer heat to the adhesive layer 33 through the base material 12. This provides a temperature gradient in the adhesive layer so that the adhesive closest to the bottom material is somewhat warmer and therefore less viscous than the adhesive which is present. settle at the exposed surface of the adhesive layer. The preferred embodiment of the first heating means 16 comprises a plate provided with a flat, continuous surface for abutment against the base material at that of its sides which faces away from the side carrying the adhesive layer.

In connection with this plate there are electric heating elements for keeping the plate at a predetermined temperature.

142854 9

As shown in FIG. 1, in conjunction with the second heating means 19, the apparatus may have two rollers 38 disposed at each end of the heating means and movable towards and away from the base material 12, so that in the event that the feed of the base material is interrupted, the rollers 38 can be interrupted. engagement with the base material to lift it out of its abutment against the heating means, thereby preventing overheating of the base material. If desired, a similar movable roller 39 may be attached to the first heating means 16.

It will be appreciated that the distance between the consecutive U-shaped studs is exaggerated in FIG. 5 for the sake of clarity. Normally, the studs would be positioned sufficiently close together to support each other, thereby preventing the upright legs of the individual U-shaped studs from substantially departing from a correct upright position relative to the base material 12 when the adhesive 33 has a relatively low viscosity.

The adhesive with which the bottom material 12 is coated on one side may preferably be a so-called hot melt adhesive, the composition of which is not substantially altered by the heating the adhesive undergoes during the fabrication of the pile material. A suitable adhesive is supplied by the company Evode Limited, Stafford, England under the term Thermoflow 750 ^.

The adhesive preferably contains from 20 to 50% by weight of an ethylene vinyl acetate copolymer, from 15 to 40% by weight of an adhesive resin, and 25 to 60% by weight of a filler. The adhesive may additionally contain waxes, a stabilizer and plasticizers. The melt adhesive flow index of the preferred adhesive is in the range 1-200, as defined in ASTN 1239 65E. The copolymer preferably has a vinyl acetate content which is between 20 and 35% by weight. An adhesive in which the copolymer is 30 to 40 # is particularly satisfactory. The tackifying resin may be wood resin, a hydrocarbon resin, a terpene resin, a modified wood resin or any combination thereof. The filler may be a mineral filler, e.g. kaolin or talc.

The plate of the first heating element l6 can preferably have a temperature between 75 and 110 ° C. Typically, the length of this sheet in the feed direction of the base material is approx. 400 mm. The temperature of the second heating element 19 plate is preferably in the range of 200 ° C. This plate may be slightly longer than the plate of the first heater.

In one embodiment of the method which is also encompassed by the invention, the adhesive may be applied to the base material while advancing to the application section. Thus, the adhesive can be applied in a tacky state immediately in front of the adhesive section so that the adhesive can be brought into the adhesive section with the base material while still in the tacky state. In this case, the first heating means may be of an embodiment adapted to heat the adhesive, being supplied from a source of supply, but prior to application of the adhesive to the base material. If desired, the adhesive may contain a volatile solvent or diluent to reduce the viscosity of the adhesive when applied to the base material. Such a volatile solvent or diluent would evaporate from the adhesive layer formed on the base material, so that the adhesive layer after the heating process which takes place after the bottom material is removed from the application section would be cooled to form a non-sticky, solid layer.

It has further been envisaged that the heating process which follows the removal of the base material from the application section may be performed on apparatus separate from that in which the studs are placed on the base material. Thus, the bottom material with adhered studs can be transported from the application section to a roll, whereupon the material is stored until it undergoes the subsequent heating process. This subsequent heating can take place after the material studs have been cut so that they exhibit a flat peat surface.

Claims (6)

142854 11 A method of fabricating pile fabric, in which a bottom material having an adhesive layer, whose viscosity decreases upon heating, is fed to a stud attachment section extending across the feed material direction, and to which a plurality of putty pile lengths are applied to such in that a portion of each stud forming length is pressed into the adhesive layer and thereby adhered to the base material, after which the base material with the number of stud forming lengths adhered thereto is removed from the attachment section, characterized in that is removed from the application section, the temperature of the adhesive is temporarily increased so that its viscosity is temporarily reduced. The method according to claim 1, characterized in that the adhesive in the application section has a temperature which is higher than the ambient temperature and after passing through the application section is heated to a temperature which substantially exceeds its temperature in the application section. 3. A process according to claim 1 or 2, characterized in that the viscosity of the adhesive is increased while the adhesive is moved away from the application section and prior to the temporary reduction of the viscosity. Method according to claim 2 or 3, characterized in that the temperature of the adhesive in the application section is between 75 and 110 ° C and that the adhesive, after passing the application section, is heated to a temperature above 170 ° C. Process according to claim 2, characterized in that the elevated temperature of the adhesive in the application section is obtained by passing heat through the base material into the adhesive layer. Apparatus for carrying out the method according to claims 1-5, which apparatus has means (13,15,18,20) for conveying a woven base material (12) and a temperature-sensitive adhesive along a conveying path through an air-applying section (17) and means (23-31) for adding a plurality of dot-forming pile-length yarn lengths from a source to the application section and to press a portion of each dot-forming length into the adhesive in the application section, as well as first heating means (16) which