BE553978A - - Google Patents

Description

       

   <Desc / Clms Page number 1>
 
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  The invention relates to a:? 1'Qcc and a device for 7pufre, r'c'es films in thGr :: '1o: lastic.:. U8 and Rl1 [loc: l "' .. c: ' :; and it concerns, more '' '' PI'ti Cl111 'Ó-n ", w, ..", J. + a process and a device that this penre for which a Î? ¯¯: 1 thel'i 'lo :: Jle.5: .tict'.e is oré-ciiauff and .1 ... t, in contact e 7? -ec a sur'Cpce 03,' Jrf'C!:. é ', lJ. IJ.C 'e. ,, :::; n81.11.e'7: -' lez en cone: c 2VOCl '..: -: 8 suru'ce c :)'.



  ] f, -) ortr-'e -, ier -ru bzz. >> ru] 1?: 1'tC '' 11y bzz.



  ::: p.1.1, fré '': e scope Y? 1 'a drum raufreiir por-sur. inside which one fRit reign a ('/.'",,..,<,:>,c'; 0 '"or a partial vice to attract the filra against the surface of 2.Ur8se.



  The invention 'has for t'ut to make co "") orter to?' ('i2} OSÍ tLfs of this kind ut P-7ibour 1 embosser cui' ōrçYt'hA a certain I1.O: '! bre t''ca.iT.r'1..1.1'ti3-'CS. . It: ') er'.1, and to emboss the wire- 2 at a 61evÓe speed and obtain crisp designs with well-defined embossings pure

 <Desc / Clms Page number 2>

 
 EMI2.1
 all parts of the fi lia. The tee: - 1. "I.lr describes c '- .. ¯.w constituted cry ne' '1anl" (., 1'C such eu * il ..: -., ..,,. , -1- ", -e (" "" 1, + ,, 'Ii., ... "," "r ¯".' Lj; .. L. Very perfected.



  The invention? for object a device for embossing a thread 't} 1'Jl "' 1'0, Ü8.sticye and é'.n2losus, this device CO" "ll'el; - .. t a tfibour, ': s 2 ,,:; c;: 081 a depression is irocuite and whose surface C e.:> u '-W.: e is porous for -W'! f 'r a thread: .i t'lcrlO')]. p E't1rIl '-'-' ï'a; oOl 7 that 1 * one makes pass around 6.u (it té ': ll: nur following an. arc the rroncfe [.': "1llit; .lôe, characterize en ce eu 'en Vele (p' (avoid the foundation of leakage paths of sequence! e length by which air can penetrate from the embosser, and c "e" '! ßêcl1er thus the formation of 'embossed designs, fs.ible7e; lt, defined on the film, of -e-io7-ens being) l' ^ V '(7S to avoid a Cī ".t1¯l.'¯h 7. Oi1 of 17 aspiration producing the embossing by the T7: 'tlr; r2.t.Of1 c "? Ir (l ;:

  Read the drum nearby. 'a limit of that part of the wire which is embossed by said drum.



  The d-isposiitif which is the subject of the invention makes it possible to produce a vacuum or aspiration? the inside of the embossing drum on the 360 degrees of its periphery, .-. when air can penetrate (i a: 1Rnière re7¯rtizTP:., e, Pis-Xe ') 21 the perforations made in the drum , the embossing can nevertheless be done by using differential pressures r ^ Gtter.īl1'e "")? "replaces in Cr8E'nt, Dar a depression (1,,:.: ie tp¯." l) or a n'2grf which depends on the degree to which the air:) 8U :; enter into the '7r ^ .. rabOhr CQ! 1111lC described later.



  The invention has as its object a near and an improved device Tour cooling and Jrov0er the hardening of the wire: .1 f '] rs fOl !.: é'l'1.fra7S, apns cuoi The 0 thread '', 1 is dried by making a suction to remove the cooled fluid 13.



  The above-mentioned ins '0 [trea + ;,? Title r'C :: "0T: l: JleE', several iodines for carrying out the invention. FIGS. 1 and 2 ¯Otl trE'i1'y sC} !: "'2.tic ::. NeY, slow and respectively in side view and in salivating section 2-2 fig. 1 ;, a f1Íf")' ) sitive

 <Desc / Clms Page number 3>

 
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 established according to the invention.



  Fig. 3 against, in end view, the t "-hour" "": nor de 1p fis.



  The fi1 ?. 1 against, on a larger scale and in section cl: 'lE'? how the embossing sleeve is fixed, in a way: 't2flC'¯'1; ¯ for the embossing drum.



  The. done. 5 shows, in axial section, a part of the embossing roll .¯ct2C10i1 and how the film '.11PI "' :: 101) lr" 'Q''i', '1' "is in contact with them as well an arrangement of the means è '1-1: "' n- chéité nou.r prevent the penetration of air into the t2." 1.1'f "Jur .U'f 'F; l".,.



  The fis. 6 against, .3. larger scale and in: axial section, com.în.ent cooperate the thermoplastic film the û'n1i011Y 'embosser and the sealing means- Figs. 7 '. And 8 show, respectively in ^ 7¯trti on (rough cut according to 7-7 fig. 1) and in side view, the adjustable support and guide organs for the means d5' t-aiichf, it ' .



  Fig. 9 shows, schpmaticue1Jl.ent, another embodiment of 1 -invention.



  Fig. 10! 'LOll, tre, on a larger scale and in section, following fig. 9, part of the latter embodiment.



  Fig. 11 shows, in cross-section (parts in elevation), "the embossing sleeve and the dobby film 12, as they initially come into contact with each other.



  Fig. 12 shows, in elevation (sections and parts broken away), a. another kind of ain-hpl'i ': E'n2 ":'. 0nr established according to the invention.



  Fig. 13 raoitre, en -, rlie de cot- "'S î,% ya -i ^. ^ Another embodiment of an embossing drum' .te). 'Li according to the invention.



  Fig. 1 /, Watch, S: ': y.llCt: 2E'; another embossing device which differs from that shown on the wire. 13, more

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 particularly in that the film is, temporarily, lightly bonded to the heating roller while, unlike what is shown in fig. 13, no backing strip surrounds the heating drum outside the film.



   Fig. 15 shows, in a schematic side view, part of an embossing device of another type comprising, more particularly, the use of several cooling bands.



   Figs. 16 and 17 show, respectively in cross section and in axial section according to 17-17 fig. 16, a kind of embossing drum which can be used when or, has recourse to fluid cooling in the embossing drum.



   Fig. 18 shows, in side view, part of an embossing device of another type for which a single cooling strip is used in combination with several drums. scholarship coolers
Fig. 19 shows, in side view, yet another device for embossing a thermoplastic film.



   Fig. 20 shows, in schematic side view, a preferred embodiment for cooling and drying the film as it passes through the machine of FIG. 19, most of this machine being deleted for the sake of clarity,
La'fig. 21 shows, in cross section, a stationary drying tube in which a vacuum or negative pressure acts to remove residues of coolant fluid, such as water or moisture from one side of the film.



   Fig. 22, shows, in end view (parts broken away and parts in section), a dryer roller acting by vacuum or by suction to remove residual rectifying fluid, such as water, or moisture vapors from water. other side of the film.



   Fig. 23 shows, similarly, another embodiment for the post-cooling.

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   Fig. 24 schematically shows a variant for obtaining the initial cooling.



   In the embodiment shown in fig. 1, the thermoplastic film 20 unwound from a supply reel 3 by means of a tensioning device which is angularly movable and may have two spaced rods 23 on and between them the film 20 slides and whose angular position with respect to the path followed by the film and determines at. Using the feed spool 21 and idle roller 24, adjust the film tension.



   The idle roller 24 as well as a tension roller 25 and a pressure roller 26 are mounted so as to be able to rotate between a pair of pivoting arms 27 of which only one is shown, these arms being able to rotate around a pivot 28.



   The tension roller 25 may include several elongated lamellae 29 movable longitudinally in a limited amplitude relative to each other. As a result, as the film passes around the tension roll 25, adjacent lamellae are moved alternately in opposite directions parallel to the surface of the film which is in contact with them, thus causing the yarn to move sideways and sideways. makes the folds disappear while stretching the material to a degree in a transverse direction.



  From the tension roll 25 the film 20 passes over the gripper roll 26, the surface of which may be covered with rubber or other suitable material having a high coefficient of friction. The film, after passing around the roll, presser
26, comes into contact with the surface of a first drum 30 which is relatively large and is driven by a transmission. ? regulating speed - to allow the variation of its speed for a purpose indicated later.

   In practice, the weight of the arm 27 and of the organs which they support is sufficient to avoid the. sliding between the film 20 and the surface of the drum 30. The latter can rotate about its axis and preferably has an axial inlet and outlet to allow the introduction of a fluid

 <Desc / Clms Page number 6>

 
 EMI6.1
 heating in the cavity "of the drum. For this" "1-, ¯¯-;,; r, r, ¯ ;. ... n one against only the input 31 but it is /:"-!.r ' (-'0.t (, '. 11'1.1.-:' :; output r ^. ''. ROr7 .. e is rZ8.1ens: lt expected.

   Fluids of C1J.ffp?, E suitable for the drum 30 as well as the others +: :: 2 "b0Urf 6 e Chn" rT8.e described? ' further on include the value of water, hot oil or hot water.



   The drums 32 and 33 can be rotated to receive the film 20 one after the other, the drum 32 receiving the film
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 leaving the - drum 30 and the drum 33 taking up the fi 1 ': 1 spoke drum 32. The drum 3.4 can also rotate and constitutes the final heating drum and beyond this.
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 film passes over part of the grinding drum 35.

   In the case of thermoplastic polyvinyl chloride films, all of the drums 30, 32 to 34, with the inlet and outlet suitable for the girlfriend heating medium described above at the level of the drum 30, are heated to obtain appropriate heating of the drum. wire so that it is already at a temperature suitable for embossing when it comes into contact with the embossing drum.

     Each of the drums 32 to 34 is positively driven for example by suitable chassis and chain sprockets actuated by a drive which is that provided for the first drum 30 but with a forward offset housing to maintain the film 20 in the tensioned state. while
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 that it is heated to prevent wrinkling of the film out. cause of dilation.



   The embossing drum 35 is driven in a similar fashion.
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 Logue, at a peripheral speed cep 1 e the speed of the film which advances and its internal cavity is connected to a pump 8.:?:!ro)ri1e.



  (not shown) to suck in air during this ce.vi t6. The partial vacuum will create the interior of the embossing drum 35, passing through the embossing material described later, which will cause the film to emboss. The embossing drum 35 is not heated but it is heating up. so close to the final heating drum 34 that there is
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 only a minimum distance between the two ta-abours, this inter-

 <Desc / Clms Page number 7>

 
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 valle being overlapped by the fi In the r ?, oa1¯a.stirae heated 20.



  The S-shaped path, followed by the film as it: v: 2:> e around the drum 34 and the embossing drum 3, facilitates the passage or film between 'these drums with a?. "¯131J¯: 1U ?: 1 loss
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 heat. The embossing of the film 20 takes place during the first centimeters Cī ':' its passage around the embossing drum on which
 EMI7.3
 it cools on ^? c '., C2, iJSÇ'.Ll' ^ a sufficiently low temperature 7 "> so that it can be detached by the separator roller 36 hence the i.l''1. a'- 'ance on crazy rollers bzz to cooling rollers ??, 39. then passing over clean means remove the' ei :: 'O'.C¯¯à¯SSe, 1 liquid, designated in a way general pro} '/ -0j a.vent 0.: end at the winding reel fTs ^, cooled fluid s reur l¯;

   1 fsCJ you had the S '') '') can 2iI "2 #". # '#' '. Ilipé for. cool the film 20 after it has 2, - been embossed and while it is still on the drum gl? ". Î! ': - l1.J.r,'.



  1 'e.l? can be directed towards or projected onto the exposed surface of the film ™ 0, for example using perforated tubes 42.



  A z3 drip collector is provided, as shown to collect the li :: - J.1.iè.e that may fall from the. fil1 .. '.



  Eraser clearly visible in fig. 2, 3 and 4, the gasket drum 35 comprises an elongated tubular shaft /:.5 ironed at one end by a cap 46 and rr-1. by its other end, to a sucking stern. A pair of plates G 'F3' stop:; annulars 17 each comprising a hole C Otl 1, are fixed on 1-Ilc.-rbre 45 respectively h prxinit '"of the two e: vtrc-nits c this one. Several annular supports 41 ?, also comprising central holes:: r =, are y.,; .- 91 '- "le ln'" r. O '"1' 9 rbl'e z.5 and are wedged on it between the end plates s 47. The connection between the end plarues 47 and the shaft 45 is made airtight. using ring gaskets 49 tight between the plates? and
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 . the shoulders provided, this effect, on the shaft 45.
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  The peripheral portions of the end plates 47 and supports .48 support a cylindrical embossing sleeve.

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 50 in which are "': '17 .c ^ ,. VE? S a large number of holes 51 8cclt (S from each other. A positive contact as well as a seal 0tp.nch8 hl' 8ir, udder customer removable, are provided -between each of the plates (1'ex'tr '\ 1ité L' elle ronchon 50.

   This can advantageously be achieved by providing an annular groove 52 on the outer face of each of the end plates 47 An inflatable tubular member
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 53, ¯'¯1111 of a valve '54- protruding from this member, is housed in each of the grooves 50 which are open r8cialejr¯ent outwardly near the periphery of each end plate 47 When the organs 53 are inflated, they are clamped respectively against the ends of the sleeve 50 and the
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 corresponding end plates A7 to form an airtight seal between them. The stanchion 50 can be easily disengaged from the end plates 47 and the supports 48 when the tubular members 53 are deflated.



   The shaft 45, along the part which extends between the end plates 47, has several holes 55 through which the internal part of the shaft 45 communicates with the interior.
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 of the cylindrical uanchon 50. If desired, the supports! can also be perforated 'to reduce the possibility of irf': ulire pressure distribution in the axial direction to the interior of the sleeve 50.

   The outer surface of the sleeve 50 is coated or covered with a porous material 56 by which the active surface of the embossing drum is formed. As described in
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 detail further on the perforations 51 of r'lE'ch # 1 50 have a f'JF12 such and the i: '1Btiore 5 intended for 2 forcing the gstifr *: ./ 7? is c: 'inlrtln.ß in a manner it - ,. ē¯e such on the surface of the nenchon 50; ¯17 we avoid the formation of long paths c5..rcrJf-: rent: i, els for leaks .



   The nature of the material 56, used to force the embossing, depends on the kind of design desired along the thermoplastic film 20. These materials can vary between wide limits and include fabrics or knits as well as.
 EMI8.6
 other .. processed substances it is essential that they are ç7''c "1¯

 <Desc / Clms Page number 9>

 Nit porous to produce embossing of the film When a vacuum or suction acts through the material 56.

   In practice, the axial length of the perforated portion of the sleeve 50 and of the material 56 for forming the embossing should at least be equal to the width of the material to be embossed. Generally the width of the film 20 'is a little smaller than the axial length of the surface forming the embossing.

   Impermeable annular bands 57, which may be formed by permanently tacky tapes, are applied to the peripheral parts of the embossing sleeve so that air cannot penetrate the parts of the surface (the material 56 intended to form the embossing and thus covered while leaving an active surface for the formation of the boss, the axial length of this surface corresponding in substance to the width of the material to be embossed while being a little greater.

   The difference between the dimensions of the film 20 and the axial length of the embossing surface not covered by the impermeable strips 57 may vary to a certain degree but it is advantageous if it is less than the combined width of the means provided for. Check proximity to the end of the embossing drum to 'prevent' leakage of air along the side edges of the film 20 when it is in contact with the drum.



   For the embodiment shown in figs. 1 and 5 to 8, two pairs of endless belts 60 are supported, so as to pass partially around the ends of the embossing drum 35, in the immediate vicinity thereof. To facilitate the use of the belts 60 in combination with the various thermoplastic films the width of which varies between spread limits, the belts 60 are mounted in such a way that they can be brought closer or apart from each other by lateral displacement.

   On the face of each of the belts 60, which is on the side of the embossing drum 35 can be sewn or otherwise fixed an endless belt 61, ensuring the seal, in rubber or in

 <Desc / Clms Page number 10>

 
 EMI10.1
 another flexible material and i.'L'.JC '' rc: 7lC. ' a1) ::: '(Y) ir? 8.

   Couve clearly visible on the fis. 5 and 6, the belts 60 carrying the sealing strips 61 are so arranged that such bscriep 61 can ensure the protection of the exposed surface of the embossing machine 56, between the. neighboring edge ru filr-i 20 and the corresponding waterproof tape 57. It is obvious that before
 EMI10.2
 In operation in embossing drum 35, each of the sealing strips 61 is drawn against the exposed embossing material since the sealing strips are only attached to the ion. from their marginal parts to the belts 60, as visible at 62 and are free to be attracted, by
 EMI10.3
 suction, i-usr, u-1c 'be in tight contact with the exposed embossing material.

   This results in air leaks in the direction of the. arrow 63 (fig..6) parla, embossing material, [. side and under the peripheral parts of the film 20, are avoided.



   The means for supporting and guiding the belts 60, 61
 EMI10.4
 comprise an elongated guide member 6 supports between parts 65 of the frame (FIG. 7) and parallel to the embossing drum 35 while being spaced therefrom. Support members 66, 67 can each slide along the guide member 64 and bridge respectively connected by threaded portions to threaded rods 68, 69 which have respectively threads in directions.
 EMI10.5
 tions opposed to each other? with these rods ctant further interconnected by a sleeve 70 and are suryportfer, clans parts 65 of the eye pis of naniëre has -oarall-les the guide member 61.:- and had tanbour ',, - fr /. -1J:!: ': 5.

   The rotating cranks 71 '-0ntpes resgectivew''1t on l! 'U ::. Ef' fil3t'ior: i 6r and E-9 is used to rotate those # ci r's'is 1 '. i3 f0 {l ;, oc nui provokes the rE'9 "'rock' slow or parted it suoport skulls 66 and 7 follow the course. ij - oTilir" j? irioror¯ '! T "' r r'o ovines l'i - '"' "'c'F ro /' ti"! r '' ". 'T'is rur olifc11. rie rr"! v; os 3 r.ii'nor "'6 67. TT!'.", ri CC :: S! 1 (Jl.l1i es, by eye-nle that c! '¯Vi' "! Ve nar 72p., fonc fxraxitr- ceuFc Oii urc

 <Desc / Clms Page number 11>

 to be able to be moved vertically in an elongated opening 73 provided in the corresponding support member 66 or 67.

   When
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 '.., 1..1 :: "'. Greater effort than the weight of pulley 72:> ,. it alone is necessary) 'additional weights, such as those designated by 74, may be mounted on its The belts 60 are driven at a speed equal to the peripheral speed of the
 EMI11.2
 2¯-'¯J) '' 35 because of the contact of the sealing belts with it ..

   Likewise, UT3 drive shaft 'le :. can be journalled "." :: 1s' the part 65 of the frame, this shaft carrying a tangent wheel 76 driven by a worm 77 which:, in turn, is suitably reread to motor members provided to rotate the
 EMI11.3
 drums 30, 3z- and embossing drum 35.

   The drive shaft 75 can be connected to one of the pulleys 72 of each support member 66, 67 by chains 78 and chain sprockets 79. When it is desired to move the parts 66, 67 of the frame one begins with
 EMI11.4
 02 :: ': - "::

  Add side locking screws 80 which serve to secure each of the pinions 79 to the motor shaft 75 After the desired adjustment, parts 66, 67 of the frame have been made. Instead, the pinions 79 are slid in a corresponding manner, and the locking screws 80 are tightened again, Cornue said above,

     the thermoplastic film 20 is heated to the temperature suitable for the waffle before being
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 tight against, the embosser t8.:nbour 35. The film is tested after the embossing takes place and as it passes around the embossing drum, the film is cooled significantly below its embossing temperature so that it is cooled. can be detached from the saver drum.
 EMI11.6
 



  Consequently, the embossing tarabour 35 is "maintained at a temperature well wLLl-CieSS-0.115 of the embossing temperature of the film. Z:" Oroprenent embossing operation, by which is meant the de-embossing.
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 filn formation so that the surface of CeZLt7¯-s! corresponds to that of the embossing material 56, takes place during the first few centimeters that the film 20 moves around the embossing drum.

   So that the sealing belts 61

 <Desc / Clms Page number 12>

 
 EMI12.1
 can exert., an ur-l-Teri., the desired effect they must occupy a position in which they are clamped as closely as possible against the embossed drum at the places where the thermoplastic film 20 first comes into contact with it. the drum. As visible suris, fig. 1, rollers 81 are placed very close to drum 34 which is facilitated by the fact that. we use
 EMI12.2
 rollers having a relatively small diameter as shown, this allows each of the SI rolls (only one is shown in fig. 1) to be placed in the angle formed between the drum 34 and the embossing drum 35.



  Filiri 20 has a tendency towards embossing 56 due to intimate contact during embossing of the film.



  If the.rno "3lastic film accompanies the drum.:; <" Uf .l'èUr far enough. to reach the line along which the thermoplastic yarn joins the embossing drum after leaving the drum
 EMI12.3
 3., the uachine must be stopped and this defect must be remedied to prevent the film from being. To avoid this effect, the separator roll 36 is connected to the drive members per des.

   chains and sprockets appropriate? using a speed regulator 83 so that this roller can be driven at a speed greater than the peripheral speed of the embossing drum 35 so as to exert a positive tensile effect on the film
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 therr.2oplasticue, which prevents the filia from turning - # around the embossing drum beyond the separation line. In addition, the wall of the separator roll 36 can be perforated - and the interior
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 of this roller can be connected to a -io, -i -.-) e, The suction exerted on -le rope theI '"" 1O'1l2 .ti (: r: e oar 1 e r01J.lepu 8;

  arp te1u- 36 is notably less than that produced by the embossing drum 35.



  For example, a partial vacuum can be used in the separator roll 36, corresponding to about 100 or 125 mm of water while
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 that produced in the freight drum 33 may be about 335 to L. 10 ram of water.



  For the Yiontrt realization node on the end. 9 and

 <Desc / Clms Page number 13>

 10, the thermoplastic film 20 is heated to the embossing term as described with the aid of FIG. 1 and it passes from the heating drum 34 to the embossing drum 35.



  Thereon the film is cooled by a cooling belt 90 which is preferably a little wider than the film. A cooling drum 91, provided with an inlet connected by a conduit 92 to a source of a suitable coolant fluid such as water, and an outlet (not shown) for this fluid, is supportably rotatable. in the vicinity of the embossing drum 35. As the cooling belt 90 is driven at the peripheral speed of the. embossing drum 35, drum 91 should be of a sufficiently large diameter to achieve adequate cooling of belt 90.

   In practice, it has been found that a ratio (about 2: 1 between the diameters of the chill drum 91 and the embossing drum 35 is satisfactory. As described in connection with the rollers 81, the roll 98 has a relatively small diameter and is mounted in the immediate vicinity of the drum 34. After passing around the embossing drum 35, the cooling belt 90 passes over the roller 93 and then over the coating roller 94 which is supported so that it is partially immersed in the film. Cold water.

   This serves for the pre-cooling of the. belt 90 for removing some of the heat from the thermoplastic film 20 before it reaches the cooling drum 91. The roller 95 corresponds to the tension pulleys 72a, which can also be mounted so that they can move in a parallel fashion. limited vertical movement so that the cooling belt 90 is kept sufficiently tight.



   We. clearly seen in fig. 10 that recourse is had to two sealing belts 96 similar to the belts 61 referred to above, each of these belts being connected to one of the peripheral parts of the. belt 90. The width of the cooling belt 90 is chosen in such a way, relative to that of the thermoplastic film and relative to the length of the film.

 <Desc / Clms Page number 14>

 
 EMI14.1
 In this case, the GtRch6it straps 96 occupy a position in which they secure exposed surfaces of the embossing material 56 near each edge of the embossing material.
 EMI14.2
 thei-moplasticue film 20.



   The embossing drum 35 is suction over 3600 of its surface. There are some well-defined practical advantages of having the suction act on 360 of the surface of the embossing drum.
 EMI14.3
 In contrast, slow to what occurs with a drum, comprising an internal shoe on which the rotating drum slides to prevent entry of air through this area of the drum periphery.



   It is obvious that the manufacture of a drum of the type last mentioned is very expensive. because of the very precise contact that must be obtained between the shoe and the side wall of the drum. In addition, the. side wall must be perfectly circular because while the drum rotates it must rub against the internal shoe having a constant radius. In order to allow the embossing of films with different designs it is, in practice, necessary with a drum of the shoe and sector type to use, for each different design, a complete drum with its internal and external component parts. The use of another design cannot therefore be done in a rapid and economical manner.



     On the other hand, the use of a sulfur drum ;, established according to the invention, eliminates the intervention of an internal shoe and it has been observed that excellent embossings can be obtained without it being necessary for the envelope of the embossing drum has very precise dimensions. The end result is that, according to the invention, the only internal parts of the drum can be used when the design is changed and it suffices to substitute a new casing or structure bearing the desired design for the previous one.

   As one only needs to prepare a new envelope and as greater tolerances are allowed for its physical dimensions, the arrangement described presents a

 <Desc / Clms Page number 15>

 
 EMI15.1
 great practical advantage in that it allows the rapid and nCOf10ai1C'176 use of new '-lodnies' 017.t E.'n' C r; ¯Wï f l1, to obtain very satisfactory aufrafes.



  We can see p. had when about 90 of the surface 4-ti Lri1îp17r yZ "ret'i 'r5tE11. discovered between the place one -fil tncr'" ml? stic leaves the te "ihour and the one where it comes in contact with this one. Ci, it is possible to maintain a sufficient vacuum in the 'i. ",'. J7? rr '' 7: Jtai 'obtain m suitable embossing. The directions and 1 distribution of the holes 51 de-ris the embossing sleeve 0
 EMI15.2
 are important 'because excessive dimensions and too great a concentration of these holes prevent or at least do not allow
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 not, of a '".8111.w-re CC? 110'1.1.C'.: ^ -. to maintain a sufficient vacuum
 EMI15.4
 in the embossing drum where the embossing of the
 EMI15.5
 thermoplastic films.

   Moreover1; the z- holes must be large enough and close enough for 1s. suction used produces a good embossing. '? 1 found that with materials
 EMI15.6
 most commonly used embossers, holes 51 may have-
 EMI15.7
 a diameter of between about 1 ima with a distance of 25 -rLYl from center to center and a diameter of about; 1.6 rr'1 with a cprt- ment of about 25 irtrn in the direction C7¯rcOnfI "'l'? T '! C' and of about 50 mm in the axial direction nar i-; --rt to the drum. With diensio; ". s and, a distribution of the holes, of the order s, JSīnC1!": Ll '. a stern c:' c; lt u,. '1 debit d' air C 'e? 1V? r0 "' 1 - ,? 5r) r" 3 f1 5.650 li'i3 per ninute allows to obtain a partial vacuum of approximately 125 and 380 runs of mercury.

   Afraid an example C'C1T? CL? the cylindrical '"a?' 1Ct"? ^ f1 50 has a diameter of 305 nm and an axiple length of 1525 1'2- '?.



  Holes having a la.?ltrE CipflTr¯r01? N rn.3 and a '-car holding 25? Y! from center to center are; ¯i2 in the, Sr C'rt, rnfl Puand or leaves an empty space of about 75 with a -) Oinc has an air flow of 1.250 Pi3 per gold - get ett V have a vida
 EMI15.8
 'suitable for embossing.
 EMI15.9
 



  For reasons yes are described below, holes 5l are distributed followed, lines rel 2t-1.T7Cr, lplt straight

 <Desc / Clms Page number 16>

 along the sleeve 50. The embossing dobby 56, which may be a piece of fabric which has a width equal to that of the perimeter of the outer face of the sleeve 50 and which has at least one complete reproduction of the embossing design as the it is desired to obtain, is fixed to said outer face of the embossing sleeve 50 using a thermosetting adhesive. The glue is applied to the outer face of the sleeve 50 along axial bands which each extend between each neighboring pair of holes 51. The embossing material 56 is then placed around the sleeve and the glue is cooked.

   As clearly visible on the pin 11, the glue not only connects the embossing material to the sleeve 50 but also fills the interstices of the material to form impermeable bands 97 which prevent the passage of air in the circumferential direction through the . embossing material thereby limiting the length of the paths along which leaks can occur in the circumferential direction to a value significantly less than the intervals existing between adjacent rows of holes 51.



   Another arrangement for obtaining uniform embossing of the thermoplastic film along each of the side edges of the film is shown in pin 12, the embossing drum 100 possibly being similar to that designated 35 in the preceding figures, but incorporating a sleeve. cylindrical 101 comprising, in addition to the holes 102 corresponding to the holes 51 of the sleeve 50, holes 103 arranged in two annular bands 104 adjacent to the opposite ends of the sleeve 101.

     As in the case above, the embossing material 56 is applied to a cylindrical sleeve 101 and its ends are sealed by the waterproof strips 57. The dimensions of the cylindrical sleeve 101, in comparison. The width of the thermoplastic film 20, are such that a small gap having a width of about 5 mm remains between each of the edges of the thermoplastic film and the corresponding strip 101 as indicated at 105.

   The holes 103 are arranged

 <Desc / Clms Page number 17>

 such that they are below the gap 105 as well as the marginal portions of the thermoplastic film 20 and are significantly closer to each other than the holes 102. When the interior of the embossing drum 100 is connected? A suction pump, a greater suction is exerted on the marginal parts of the thermoplastic film 20 which cover the rous 103 than on the remaining part of the film which covers the holes 102. The number of holes 103., households per unit area of the strips 104 are sufficient to continuously exert sufficient suction on the edges of the film to obtain a satisfactory embossing.

   While the uncovered portions of the bands along the arched portion of the drum, which is left free by the film, increase, to some degree, the rate with which air can enter the drum, this effect is however so small that the embossing does not have to suffer. This arrangement has a drawback in that the bands 104 must be relatively narrow so that, for films of which the widths vary considerably, one must have recourse to different embossing drums.



   Considering again FIG. 1, the cooling drums 38, 39 each have inlets 107 for a suitable coolant fluid, such as cold water, the outlets for this fluid not being shown!
The means 40 for removing the cooler comprise split tubes 108,109 which serve to remove water from the film 20, a bowl 110 occupying a location such that it can collect the water which falls therefrom.

   After passing over the slit tubes 108, 109, the film 20 advances on a crazy roll 111 to a perforated vacuum roll 112 'with an axial inlet 113 connected to a suction pump (not shown) which serves to hold roughly the vacuum. same partial vacuum in the roll 112 as in the separator roll 36,
Fig. 13 shows a large heating roller 210

 <Desc / Clms Page number 18>

 which can be made in the form of a metal drum.



  A hot fluid, such as hot oil, can flow through the drum by means of piping shown schematically at 211. A Thermplastic Film 212, para. example in vinyl material, is unwound from a spool 213 and bypasses the roll, heating 210 by being clamped against it by a belt 214.

   which is of a flexible heat resistant material, for example a wire mesh. It will be seen hereafter that this belt serves, then, to support the hot softened film and, therefore, it is designated as being a support belt 214. This belt is guided, along its path, by rollers. 215 to 220 and by the heating roller 210, the temperature of which may, for example, be of the order of 150 to 185. It should be noted that according to the. particular material of the film to be embossed, the temperature of the heating roller differs.

   The film, before plying the embossing roll, must be brought to a sufficiently high temperature so that it can be easily embossed. For example, it can be made hot enough and, therefore, elastic enough that it. can be embossed with a pressure of about 0.035 kg / cm2, In addition, it must not be hot enough that holes can be formed in the film when it passes around a porous embossing drum in which there is a vacuum of the kind described above.

   As an alternative, the film may be preheated by suitable means before passing around the heating drum.



     After leaving the heating roller 210, the support belt and the hot film, soften over the guide roller 219 which is heated by the circulation of a hot fluid which passes through it and which is supplied by the duct 211a, This duct may be connected in series to the duct 211 which supplies the hot fluid flowing through the heating roller 210. The path followed by the support belt 214 in the vicinity of the embossing roller 221 is determined by the relative positions of the guide rollers 219, 220 and by the

 <Desc / Clms Page number 19>

 
 EMI19.1
 roll ''. ^ 7īI; ¯ ['.- p, j; -1 ..

   S (rt1 :::: well vifihie f1-: r '...:,' # # pî '#. 1 .. 1 belt d?': '01 ... 1; ir :: ',:' l Jl: c # lt, Ol1l'1: l ': will roll it' -1 '.' Î: ': -':, ':,:' "1 r '". R rL arc J'2l2, tivG "slow short and 'nasse then (1¯'.t; r3',;, r fn hn: .¯¯-ça ce; ui6.t:; 3e 2O ç.) l: 'E' Mioi il rtO'Llr'- 1S at 1 '-: :) 1.1.18 <"), from -;" Ür: é:'. R; 0 ': 18.



  C (r "¯7: 1 the T i 1? .1 is Cl1Y? Ort !: of q'é1.! Ir0?? # Be in contact with the 'Jlll:; :: 1-1'% '1ī I? '? UI'.? .31 in. :: - é: 'O: 1. C011] ri:!, Between J:' Ju2.eE: UY ce guidas s 219 and 220, COr. 'Le embossing roller y 7 "'r' 1 C; - :: a -: .. pr: lt l''ir! t- a E'l.lfcG ') ore1.1SC and CO'1: -'.- e a è .- ::: 'l :: r'siol anit:; Inside this' roll through conduit 2218., the softened hot wire is transferred from the backing belt 214 to the embossing roll 221.

   The film is supported around the embossing roll 221 in an upper arc 180. Since the film is hot and plastic when it first comes into contact with the embossing roll, very little pressure is sufficient to emboss its surface.

   The necessary pressure, with which the film is clamped against the embossing roller, is produced by the difference between the pressures acting respectively on the two faces, this difference resulting from the suction or even from the depression prevailing inside the. roll, embosser,

  A feature of the process and device described is that, after the hot plastic film is embossed, it is kept in contact with the embossing roll in an arc of great value and line, tending
 EMI19.2
 had 'it advances the Ions of this a.rc3 it is cooled directly and SUÎ''1.52?'! G'11-I, so that the film can r20¯t''¯ ''. C? and keep its waffle design. The C :: é '.. ufr'8ur "'21 roll with the'" '! 1 i that it supports is surrounded by a cooling belt '3 them Intervenes 0ffi- C2.C .¯, E''rt' ',. to cool relide1; le: 'l.t le fil.i ,,: p.1Jfrl.

   The cooling belt 222 is 2W) "901't {', -. R les roullepux rye = r17: 1 CC' - 'P z%' 3 and i7 and by a ¯rn1: ¯; at '67. cuidsge more ren '"1 22 $ c.'. 1Í is cooled: 98.1 'on. circulation of a, fluid l'2f1'0irli ::! '' C '' ... 1r, -, -; <, 1 '"u-"' ep. "... l of rolxaetj,; : 1n1'1t "± '1' a duct 226.



  The cooling belt; must be tr "F flc-, i '1-0 so nTa.'C: Z1C- Fit a large nOiilll! -2 of points r'O contact with the #"' # 'ir: 21xC'r,!, and -she must, ri :; .'r'f / r ':;! lC0, (' lv '): i.rl1.Y ",; t"' prl'1Y1C :)

 <Desc / Clms Page number 20>

 have a shape which substantially corresponds to that of the rear face of the film which has bosses conforming to those of the embossing roll. It must also be clean
 EMI20.1
 evacuate ra: Diè.81! slow heat 'o returning from the film.

   According to one embodiment, the cooling belt may comprise a very woolly fabric, such as flannel, of which the. face which comes into contact with the embossed film carries a. layer in
 EMI20.2
 vinyl material having a thickness of 0.05 ht # Cooling fluid 227, for example tap water, is contained
 EMI20.3
 rr, l cens a cup bzz and is applied with? 'a roller 229 on the face formed by the fabric of the cooling belt- slit, CO'1i11C' shown sch'-n8.tiueY1.0nt on the fi ' -. 13.

   It is: ... note, that the wetting of the reverse side of the cooling belt takes place at a location beyond where the belt has been cooled by the cold guide roller 225. The material layer vinyl coating, which covers the front face of the cooling belt, effectively prevents water, which wets the fabric side of this belt, moistens the waffle film but this layer is thin enough to allow rapid transfer
 EMI20.4
 of heat from the waffle fila) 11.to. f-a wet cloth layer.



   It has also been observed that when using the belt
 EMI20.5
 cooling with a vinylic reflective layer, described in pa-r with the embossing of a ther :: o) 18stiue (vinyl) film, the embossed film, in 'e'. 1e terms '".: 118 la' C01J.rroi refr0:! Fif3;: fIYlt: -, more easily detached from the roll Ga'L7f¯''ß''e, Jr.



  While the tisru cooling belts carry ther-noplastic layers i''1lerl: '' ': 91Jle? L'sen <'1.U J, 2urs f2C0S provide the aforementioned advantages, for other variants of the method and of the device, cooling belts in fabric ,. not carrying such layers on one of their faces, can be used in a satisfactory and advantageous manner with the device as described.

 <Desc / Clms Page number 21>

 



   For the device shown in fig. 13, the: @lm embossed. and the cooling belt 222 pulls together from the embossing roll 221 and then the film separates from the cooling belt and is wound up on a spool 230, which can be supported and rotated by the rollers 231. and 232.



   A screen or reflector is provided to prevent the embossing film from being heated again after it has left the embossing roll. For example, the screen or reflector 233 can separate the embossed film from the region where the hot roll 219 is located and, if possible, also from the region where the hot roll 210 is located.



   In some cases, due to the adhesion of the film to the embossing surface, which may be produced in part by the corrugations of the embossing surface, including some slightly recessed portions, the embossed film tends to stick to the embossing roll at the bottom. Instead of following the cooling belt 222 around the guide roller 224, To facilitate the separation a relatively small retaining or control roller 234 has been provided which, because of its position, the nature of its surface and the way it rotates, comes into contact with the film as the film falls away from the cooling belt 222 and the guide roller 224 and the retaining roller 234 returns the film to its desired position on the belt 222 of, it can easily be detached.

   The effect obtained by the retaining roller. 234 prevents the film from continuing its way around the roll, embosser 221. This roll 234 should have a surface which grips the film, for example made of sandpaper or the like. Likewise, it must rotate at a sufficiently high speed so that its surface of the film advances at a faster speed than that of the film, preferably several times greater.



   Consideration will be given to the region in which the hot film 12 first comes into contact with the cold embossing roll 221,
Under certain conditions, for example when the

 <Desc / Clms Page number 22>

 
 EMI22.1
 drawing of the embossed surface of the embossing roll has its ends, it may happen that the points Wl:.: ¯ l: 7 of the cold embossing roll have a tendency to cool and h harden the film too quickly, so than. the shape of the film does not sufficiently match that of the dented design
 EMI22.2
 ; .n1f:

  ! .qur and that the fila does not have the embossing of sir "if one does not involve means to remedy this drawback.
 EMI22.3
 



  For this purpose, heat can act on the wire ''! 2. 3 .- 'place where it comes into contact, take its place ,. with the embossing roller to keep it at a temperature suitable for embossing until the film is gar.fr ''. The heat can act in this place by the effect produced by a radiant heating element or
 EMI22.4
 by blowing air C11fl1 <. on the part of the rear face of the support belt which is opposite to that at which the film first comes into contact with the embossing roll. According to one variant, a very short oven can surround the film and the support belt at this location.



   Fig 14 shows a different embodiment of the embossing device. The main difference with that of fig. 13 is that that of FIG. 14 does not have a support strap to hold the film against the heated roller.
 EMI22.5
 fant corme does the belt 214- on the fis- 1? - On the other hand, on the freeze 14 a special provision is made to make adhere the "'l] ore.ire:' !. in t 1 th film to the roller of heating, cōïn.3 described below. On 12. '"i 14 the orZP8s, designated by the same reference numbers as those of fig. 13, are cōsi t "ç and function d.e la r = le..2n; è; e than those described above in detail with the aid of fig. 13.



  On the pin 1A, the film '7'lu is unwound r18 the reel 213 and then passes around the reel 235 while being clamped by the latter. against the roller or heating drum 237. The function of. roll 235 is to "iron" the film over the roll, heating 237 by temporarily connecting the fila. to this roll. Roll 235

 <Desc / Clms Page number 23>

 
 EMI23.1
 has, on its surface, a layer 236 of rubber or other elastic material.

   In some cases the roller 235 had been cooled, for example by passing tap water through this roller to prevent it from becoming too hot because it was too hot.
 EMI23.2
 very close to the roller, heating 210, which prevents the film from adhering to the roller 235. The heating roller 237 of the load. 14 is analogous to the heating roller 210 of FIG. 13 ,. except that the roller 237 is covered with a resin to prevent the film from sticking too strongly.

   The melting point or. the excessive softening point of this resin must be higher? the temperature of the drum. Resin ;? appropriate are
 EMI23.3
 nylon, silicones and resins of the genus of nol7; -t,: trp.- fluoroethylene. A suitable example of a resin of the kind last mentioned is that sold under the trademark "Teflon".
 EMI23.4
 by the E..I. du Pont de Nemours & Co., inc. A coating of a like resin can also be used on the roll.
210 of the device of FIG. 13.
 EMI23.5
 



  It has been found that a thermoplastic film, for example of the vinyl type, when "ironed" in this way on a hot roll such as 237, temporarily adheres to the surface of that roll. Roll 237 must be maintained? a temperature
 EMI23.6
 which the adjacent surface of the film '[; i'? er '; J'1l¯¯ ^ ¯.jīryor tends. soften having passed around the rolls had 227 the film
 EMI23.7
 leave this roll and advance on the roll of ¯vi <"" p¯e 219 warmed up and smaller and then on the vovJ.2? v. : ^, z¯, 'rrï2? d ''; '3cc; T¯on '21.



  L¯1 cïmuffaje 238 established in rcj: rrd from place Ci7 the film comes in (-'Fbori- in contact with the roller r.ufrcur, '1 i't2t7¯Cllt the film at a t2: lnratL'. re ¯ CO (1VB1'LC: 'lt u0111'. le; Fufre? G iust. '"that it is embossed, thus avoiding a premature rofrcirlir.c; er3nt.



  It should be noted that on. the end. 14 the film is tr-o.sf or- 'from the heat roll 237 to the emboss roll 221 without the intervention of a support belt such as the belt 2L4 of the belt.



  T-e vacuum embossing roller 221; and> j ---- 4 0

 <Desc / Clms Page number 24>

 cooling agent 222, the devices for cooling and rusting this belt, the retaining roller 234 and the devices
 EMI24.1
 separators of the fi-. 14 are the nones and the heart of the fis. 13.



  For another variant of the device, the:;: it can be "passed back" on the heating roller 237j co "-r'ie described using 1s made. 14 but a support belt, such as' glue marked 214- in Fig. 13, can also be used to transfer the film from the heat roller to the embossing roller, horn in Fig. 13.



   Fig. 15 shows a device comprising several
 EMI24.2
 cooling belts, three of these belts being no ::: ltr (es in this figure. To explain the usefulness of the intervention of several cooling belts it should be noted, that at a high degree, the speed, of operation. the speed with which the embossed film can be cooled depends on the device.
 EMI24.3
 



  For the device shown on fi. 13 and 1L: -, a given area of the embossed film, passing around the embossing roll 221, is kept in contact with the same area of the cooling belt.
 EMI24.4
 dissante 2-2: 2. On the end. 15, on the other hand, the rope, grufr is c1 'F,) orè brought into contact with a first cooling belt and, subsequently, as it passes through subsequent curvilinear parts of its path around the embossing roll it comes into contact with a first cooling belt. contact with different cooling belts, the object pursued by the use of several cooling belts acting
 EMI24.5
 on the eyelash gaufra film.

   successive points of its effect around the embossing roll being that the entire embossing operation can be done at a higher speed because sufficient cooling of the film is thus obtained which can thus retain its embossing
 EMI24.6
 after being detached from the embossing roll.



  For the neutral devices on fig 15, we can assume that the fila a. t'- heated and ranolli by a heating roller 210 similar to that shown in more detail in FIG. 13, while being held against, the roller 210 by the belt

 <Desc / Clms Page number 25>

 
 EMI25.1
 oc- support 1 -71 .'- ïr what it passes on the roll, guide heats? 1 and is tr: llS! r.'r 'from the sou'i belt - 1.sp 21 /. with the embossing roller 221. The f () Ï.1C.tlolliJ.e -, -, ..);, r 9 .. '10 --it,, -C1:. ¯. the ': 8'1e that the one describes 2. the help c: - the fie. 13.



  :. '1-iC' '' v '01, ""; ":; '7 ('> around the embossing roll ')') 1 1." "1'1 comes C¯ ': -": ¯J : 'cW1¯ story and # "'" # c .: 'I ::,' - ''! 'C ".. (7': - ,, l, .zr belt .¯ .." 7. ' O .. = ¯ ^. 'C''e "' * '1" "" "" -ir "1 -> # - #! ± 1; :: -. Belt 222 r'3 1 .... - l "t- 1 ':' The belt 2'2 .vC ', noise C't: iL in contact with the film and another belt =; î.Ç Y1 1;., 2, comes in contact with that here. C:) J.,. lC = 051¯, =. in rm.; anoint jbr 'c; -j.3nt the cooled belt feels 4.22 cesce ("1 l111" "' 1in. C;" ... 11> ;: c'J <: mt the cooled belt12sr: .1 : 'lte 422 ceases (', tre'.1 contpet with wire11 '[and another cooling belt 522 comes into contact l} with ce1l.Ü .... cL The devices for cooling and for tying the belts cooling units in Fig. 15 are similar to those in Fig. 13.

   It should be noted that for the device shown in 1 a fig. 15,. the water is supplied in ch8 - ("uG case to the face of the cooling belt which is not in contact with the embossed film. It is understood that the organs of the fie. 15., denote by ¯ ^ l = ' 1CS: 1 '^ Î; -' 'rnnCeS street those of fiT.13, make up 0'Q0 in an aue10ue way. The cooling belts and the members attached to them in fig. 15 are analogous to the l' ': Corresponding 1011tS- of the fis. 13. On f¯'7.,. 1.9 the sets with cooling belt are (éE'in6s by the: -1th figures of T ^ i'r,, 1C as on the fi3 13 except that in fig. 15 the figures, of the f "<: the aD.c'2 are ,,,: r, ç, pt ^ r. of zon, A00 on 500 All the different together, this 1J. '': n notes c. '? ¯'v? n:' it by looking at the drawings.



  Another variant is described here # d'-îsro'j.s C, '?'. Nn a r-odification Cl¯, r¯1 device 4, '; '- û =. described. Fig. 13 cohort only one belt: '2f1' ') ièis ::' n.i: e is a single chill roll 225 and a single station where water is supplied to the cooling belt by a roller 22Q. for 1 variant described ".-L1L1'.r. <r ''. 11c ^ '"? t is used; 1. only one cooling belt and - a #norte or 1 'rFl' is Înl7rlī 'belt' 2? there is O1 Ll. ' : '. llré

 <Desc / Clms Page number 26>

 cooling belts.

   After the cooling belt has passed around the embossing roll in an arc which is a fraction of the total curvilinear path it follows around the embossing roll, it may temporarily depart from that roll (e.g. in the area of the aforementioned station, fig. . 13), it can pass over another chill roll and return to the emboss roll in the same region where it left it.



  After returning to the embossing roller, the. cooling belt continues to pass around it and may, after having 'advanced in another' arc, leave the embossing roll again, for example at station B, to pass over another chill roll to then return to roll 21 at station B and continue its way around the embossing roller. Fig. 18 shows such a device in which a single cooling belt 622 'cooperates with cooling rolls 625, 725 and 825 and with the embossing roll 221.

   To explain the advantages of this device, it should be noted that the efficiency of the cooling belt, to facilitate high speed operation, is limited by the speed. here which it can evacuate the heat given off by the film. Addition of water to the cooling belt increases its heat capacity, but although the heat capacity of the wet belt can be very high, a factor limiting the operation of a device of the kind shown in Figs. 13 and 14 is the rate at which heat can be conducted through the water in the belt to its rear surface.

   For the device shown in Fig. 18, the limitation based on the rate of heat transfer from one particle of the wet belt to the next is, to some degree, eliminated. After the front side of the cooling belt, which comes into contact with the film, is heated a little by the film, it moves away from the film, is cooled directly by a chill roll such as

 <Desc / Clms Page number 27>

 
725 and then returns to the movie. A given surface of the outer face of the film, passing around the embossing roll, contacts more than one surface of the cooling belt.



   He is at. note that the last chill roll in the series (for example the one designated 825 in fig. 18) may advantageously be cooler than the other chill rolls need to be and, for this purpose, it may be refrigerated, for example, by passing cold brine through this roll while, the others can be cooled simply with tap water. Such an arrangement is very efficient and nonetheless economical. The embossing roll can be made as follows. Various arrangements can be made for the roller
221 and it is understood that any of these variants can be used with any of the devices described, in particular those of FIGS. 13, 14, 15 and '18.



   According to a first embodiment of the invention, the embossing roller comprises a perforated metal drum surrounded by a layer formed by a metal mesh which, in turn, is surrounded by a perforated sheet sleeve which bears on its face externally a layer of primed fabric with the edges of the fabric placed end to end and secured to the sheet sleeve. The outer face of the fabric has peaks and valleys with which to achieve the desired embossing. For example, the fabric may be lace, or may belong to various other genres. The air is sucked in from inside the roller or drum by a duct connected to one end of the latter along its axis.

   The vacuum 'acts on the entire 360 perimeter of the roll which provides the many advantages indicated above.



   It follows from the above that the temperature of the various parts of the device is of great importance for the latter to be able to operate successfully. Since the film is hot by the time it reaches the embossing roll, it has a tendency to heat the latter. If the device was not arranged so as to

 <Desc / Clms Page number 28>

 To be able to prevent the embossing roll from becoming too hot, high speed operation could not be obtained because the @iln could not cool sufficiently during its passage around the street roll the embossed pattern remains.

   For the embossing roll as described, the temperature thereof is kept sufficiently low by two factors, the first and most important being that the cooling belt continuously removes heat from the embossed film which tends to prevent heat from it being transmitted to the embossing roll and, secondly, the suction over the entire 3600 perimeter of the embossing roll, including the region in which this roll is exposed by not being in contact with the film in this region tends to draw a certain amount of air, at room temperature, through the wall of the embossing roll in the above-mentioned region. This air circulation in and through the roll provides additional cooling.



   Another embodiment of the embossing roll is generally analogous to the above but differs from it in that the interior of the embossing roll is subdivided by partitions into several chambers so that the suction is only. produced approximately in the part of the embossing roll in which it is in contact with the film. Since there is a chamber in such an embossing roll which is isolated from the vacuum chamber, a jet of cold air can air the interior of this roll in the isolated region.



   To achieve additional cooling, for any of the embodiments of the embossing rollers described, an air flow may be projected onto the exterior of the embossing roll where the film is not in contact with that. -this.



   Yet another embodiment of the embossing roll is shown in Figs. 16 and 17. Its construction is more complicated, but it has the advantage that liquid cooling can be obtained inside the embossing roll all around. The embossing roll, as shown includes a

 <Desc / Clms Page number 29>

 
 EMI29.1
 drum with double prey the inner wall '/: #: it forced pru-n cylinder 240 and the outer wall by uu cyliiure 24.1. Lo: cylinders are supported one by the other by supports) 42Y and 0 r, e of spacers, provided for each extracted from these cylinders. The cylinders 2.40 and 241 have aligned holes 243. interconnected by conduits or tubes 244.

   The suction is exerted by the ii-¯ / ## '¯ ". -; -; r"; i cyliiidj-c inside 240 to the ± .ide 1- 245 connected to one end of this cylinder. Known the cylinder 240 is closed at its other end, we realize that the air is sucked into the inner cylinder only by the tubes 244 which terminate outside the outer cylinder 241, so we can see that the suction zone 247 in the inner cylinder 240 is isolated from the area 243 between the inner and outer cylinders.

   Cooling fluid, such as tap water, circulates in this zone 248 by being introduced by a. led
249 opening into one end of this gap and being discharged through a duct 250 starting from the other end. The resulting cooling effect serves to prevent overheating of the embossing roll.



   It should be noted that the orifices 243 are quite apart from each other. On the outer face of the outer cylinder
241 is applied a layer 251 formed by a metal mesh.



   This layer is, in turn, surrounded by a sleeve 252 of perforated sheet metal, the perforations of this sleeve being closer than the orifices of the cylinders 240 and 241 On the sleeve 252 is tightly clamped and glued a surface layer 253 of finished fabric or the like which forms the actual embossing surface, the surface pattern of which has the shape desired for the embossing. The film 212 and the cooling belt 222 then appear, in that order, on the outside of the layer of this fabric in FIGS. 16 and 17.

   When it is desired to modify the design, the perforated sheet metal sleeve 252 can be removed together with the fabric surface layer 253. Another sleeve, portart 1a. surface layer of fabric having a different pattern

 <Desc / Clms Page number 30>

 can then be placed on the embossing roll,
To prime the fabric surface layers of all embossing roll embodiments, or! may use a heat-resistant thermosetting resin.



   Yarns which can be advantageously embossed by adopting the principles of the invention are films of vinyl, nylon (polyamide), cellulose acetate, rubber hydrochloride, polyethylene and Sara.n (polyvinylidene chloride). .



   While the cooling belt device described above in combination with the other component parts of the device provide remarkable, unexpected and important advantages, it should be noted that the invention, in its broadest sense, does not is not necessarily limited to combinations including cooling belts. For example, instead of using cooling belts, the device can be modified by causing another cold medium to act on the embossed film while the latter is still in contact with the embossing surface. Thus, jets of cold air or water can be directed towards the outer face of the film as it passes around the embossing roll.

   While this modified device can provide some of the important advantages of the invention which result from the use of the new sub-combinations of the device and of the method, it is understood that this modified device does not make it possible to obtain the particular advantages resulting from the use of cooling belts in combination with the other elements of the device.



   It should also be noted that various features described above used in conjunction with one of the general embodiments of the device in question may be adopted for a device constituted in a different manner. For example, the arrangements with cooling belt of FIGS. 15 and 18 can be used with a device comprising heating means for the film, as shown in FIG. 13 or in fig. 18 ie with or without support strap.

 <Desc / Clms Page number 31>

 



   Considering fig. 19-24 only those parts and their operation which have been described above and which are necessary for an understanding of the invention are described in detail in detail. Fn regarding the. machine shown in fig.19 it suffices to say that all the members shown on the pins 21 to 24, for example, are suitably journaled in bearings,. bearings or the like, when necessary, or are established between them between standard uprights or side frames S.

   All the movable members are interconnected so that they can cooperate with each other and they are actuated by a motor M connected directly to these members or. indirectly by appropriate transmissions P.



   Before describing the machine and its operation in more detail, it will be observed that the term "thermoplastic film" is understood to mean, for example, a film made from any of the vinyl plastic machines such as polyvinyl chloride or polyethylene compounds. Likewise, the embossing roll may be similar to those described above.



   More particularly in fig. 20 is shown an idle roll 910 on which passes a thermoplastic film 911 which then advances around a roll 912 suitable for removing the folds of the film. Such a roller can, for example, consist of wooden slats which can move relative to each other by being actuated by suitable means, so that they are moved alternately in a backward motion. -and back and forth in the longitudinal direction of the roller.



   The film then passes around the pressure roller 913,. preferably rubber or covered with rubber yes clamps the film against the first of a series of rollers to heat the film in steps, these rolls being heated (one way more and more intense and being denoted by 914. 915 , 916 and 917.



   At this time, the thermoplastic film has. gradually reaches its softening temperature and is in a state of being embossed by being contacted, for example, with a roller

 <Desc / Clms Page number 32>

 porous or cloth-covered embosser or with a suction drum 918. The vacuum, which is produced in this drum, produces very immediately the necessary embossing effect on the softened film and, while this surrounds this roll or embossing drum at a large angle the film is cooled. The cooling takes place preferably by running or spraying water on the film. This can be done by circulating the water in several sections of pipes or tubes 918 'which are drilled with small holes, having a diameter of about 0.1 mm, these holes being spaced from each other by 25 mm.

   It should be noted that the water, or any other cooling fluid, is ejected directly on or against the film since one has. in this case removed the support strap.



  The first pipe occupies a position such that the water hits the film shortly after the embossing has taken place. These pipes are mounted in such a way that their position is adjustable as regards their spacing with respect to the roller 918 and to the film 11.



   The reason that the first jets of water may initially act on the hot film, as shown in the drawings, is that complete shaping or embossing of the hot film has already taken place by the time the film reaches this location.



   The excess water is collected in a suitable drip pan, as it flows 1n = of the film but there is still some residual water or moisture which adheres to the film and which should be removed before the film is wound on a reel to be ready for use. This can be achieved by suitable vacuum-operated drying means which are described below.

   The film 911, after it has been embossed and cured by cooling, may contain an excess of the coolant or water which is first removed by the separator roll 919, acting by the vacuum or by vacuum, this roller extending along the roller or drum 918 while being placed near the latter. This prevents this excess

 <Desc / Clms Page number 33>

 of fluid or water, the thigh will flow, drop by drop, along the part of the film (or over the heated roll 917) which is about to pass over the roll 918.



   The film then advances around idle rolls 920 and 921 and passes over aftercooler rolls 922 and 923 which can be cooled in a suitable manner, for example by passing tap water through these rolls.



   The operations for the final drying are carried out by then passing the film 911 over one or more fixed slotted tubes 924- in which a vacuum or a depression is created. These tubes may have a diameter of about 7.5 mm and may each comprise a slit which has a width of about 6.25mm and which extends along the upper part of the tube shown in 925 on 1 a fig. 21. The slits are covered with a wire mesh made of 925 'stainless steel, the mesh size and weight of which roughly correspond to those of the perforated screens used against flies. The openings in the wire mesh allow air to pass at high speed along the wet side of the 911 film and through. slot.

   The bent portions of the fabric threads also exert a sweeping effect on the film while physically loosening and breaking up the water droplets *. The film 911 then passes over an idle roll 9-6 and then around a perforated drying roll 927, in which the vacuum acts. This roller is made of stainless steel sheet and is drilled with holes having a diameter of between 1 and 1.2 mm, these holes being spaced 25 mm from center 2 center.

   The roller is covered with a similar wire mesh 927 '(fig. 22)? that designated by 925 'on. Fig, 24. The water on the back side of the film is removed by the air stream which passes through the annular gap formed by the wire mesh and then passes through the perforations of the roll.



   Preferably, a second group of drying wires is provided in the form of tubes 929 and 930 acting by vacuum or by vacuum, which are similar to tubes 924.

 <Desc / Clms Page number 34>

 



  The wet side of the film passes over these tubes after leaving the idle roll 928, the film then passing around the idle roll 931 and around another roll 932, acting by vacuum or vacuum, before bypassing the idle roll 933 and be wound on a spool to be ready for use.



   It should be noted that the separator roll 919 can be perforated in any suitable manner, analogous to that of the pinning roll 927, acting by vacuum. These rollers as well as the slotted tubes, are all connected to the suction side of a fan which delivers a large amount of air creating a relatively low vacuum (about 15 mm of water). . thread;

  '! can get ugly wet when it comes in contact with the post-cooling rollers 922 and 923, these rolls often being wet by condensation but this moisture is usually removed completely along with any other residual moisture after the film has passed around the first roll vacuum 927 and on the split tubes 924 into which the vacuum has been evacuated. The second set of vacuum tubes 929 and 930 as well as the second vacuum roller 932 are used simply to ensure complete drying when the film sets. moves at a high speed.



   The 927 and 932 vacuum drying rollers perform two functions, i.e. tools serve not only to remove residual water but also as a pull roller. 1 The peripheral speed of these rollers is slightly more larger than that of the post-cooling rollers 922 and 923 and the film cannot slide on these rollers because the vice squeezes the film against the wire mesh, which pulls the film over the split drying tubes 924, 929 and 930.



   For the implementation of this invention, provision is made mainly for the use of water as a cooling fluid. This water can be at room temperature, but it is preferred that it be refrigerated for obvious reasons.



   For the variant shown in fig. 23, the film 911 passes through a roller 934 which rotates in a cooling fluid.

 <Desc / Clms Page number 35>

 disseur or in a. water bath 935 contained in a bowl 936.



  The film then passes around the split tubes 924 and 924 '. acting by suction, placed on either side of said film. This arrangement is intended to be used in place of the cooling drums 922 and 923, more especially when several of these drums are too bulky or too massive or when their use is not particularly important in the machine.



   For the variant shown in fig. 24, the film 911 passes over the heat roll 917, comes into contact with the embossing or finishing roll 918, immediately passes through the cooling medium or water bath 937 contained in the bowl 938 and then bypasses the separator roll 919. This arrangement is intended to replace the pipes with cooling jets 918 '.



   The advantages obtained with the arrangements described above are numerous. One can, for example, adopt higher running speeds for the film and one can obtain a completely dry film. The cooling water may be at a higher temperature when it is in direct contact with the film than when it is used to cool an organ, such as a backing strip or belt or a roll which is in contact with the film. contact with the film. All of this results in more Economical manufacture and operation in that convenient operating speeds can be achieved by using tap water.
 EMI35.1
 



  Understand it goes without saying, and CO 'L'.te it results from already going from what proceeds, the invention is not readable!' Slow 8, those of his wedding Ce.J? Z1C''10I1 not 's117SL1 those of the aodes of' realization of its various parts, fycnt # '** more particularly considered; 'it embraces, on the contrary, all the vP3'i = iv \ - tes.


    

Claims (1)

CLAIMS. 1.- Method for embossing a thermoplastic film which advances, is heated during its advancement to an embossing temperature, and passes around a rotating porous roll having an embossing surface, characterized in that it is applied to the rotating roll which is maintained cold, suction on all 360 of its perimeter constantly at a rate commensurate with the porosity of its surface in order to maintain inside the roller a pressure lower than atmospheric pressure and sufficiently low to apply the film ,. which is cooled simultaneously, firmly against the embossing surface of the roll, thereby producing a clean embossing of the film, the embossed film then being moved away from this surface. 2. A method according to claim 1, characterized in that the film is held against the porous roll in an arc by suction, and it is cooled directly during its contact with the roll by applying a cooling liquid on its outer surface on the greater part of said arc. 3. - Method according to claim 2, characterized in that the cooling liquid is water which is applied to the film by spraying water onto the latter. 4. A method according to any one of the preceding claims, characterized in that after being removed from the roll, the. film is further cooled by passing it around another roll containing a cooling agent. 5. - Apparatus for carrying out the method according to any one of the preceding claims and comprising a device for advancing a thermoplastic film to be embossed, a device for heating the film to an embossing temperature, and a rotating porous embossing roller. having an embossing surface for embossing the film as it passes around the roll, characterized in that suction is constantly exerted by a <Desc / Clms Page number 37> suitable device over all 360s of the circumference of the roll, at a rate commensurate with the porosity of its surface to maintain a pressure inside the roll below atmospheric pressure and sufficiently low to apply the film firmly against the surface of the roll. embossing, thereby producing a clean embossing of the film. 6.- Apparatus following claim 5, characterized in that it comprises a device for cooling and hardening the film and for this purpose applying a cooling liquid 'on the film as it advances around the roll. 7. Apparatus according to claim 5 or 6, characterized in that it comprises a device for removing the embossed film from the roll and comprising a separator and dryer roll which is porous. 8. Apparatus according to claim 7, characterized in that the separator and dryer roll is rotatably supported near the embossing roll, a device being provided for selectively rotating the separator roll at a higher linear speed. larger than that of the embossing roller. 9.- Apparatus according to any one of claims 5 to 8, characterized in that the embossing roller comprises a perforated central shaft, a perforated sleeve and several annular parts carried by the shaft to support the sleeve, the suction being exerted at through 1-the shaft inside the sleeve all around. 10.- Apparatus according to claim 9, characterized'en that a fabric sheath is threaded over the perforated sleeve. 11.- Apparatus according to claim 9, characterized in that there are provided end plates between which are placed the annular parts, a device being mounted on each of the end plates and comprising near the periphery thereof. ci an inflatable annular tube to form a removable seal ensuring airtightness between these plates and the <Desc / Clms Page number 38> adjacent opposite ends of the sleeve when the tubes are inflated. 12.- Apparatus according to claim 11, characterized in that it comprises a device for applying cold water to the inside of the embossing roll, including at the point where the film first comes into contact. with the roller. 13.- Apparatus for embossing a thermoplastic film or the like, in which suction is produced within a roll having a porous embossing surface for embossing a softened thermoplastic film which passes around the roll on an extended arc , characterized in that in order to avoid re-entry of air into the embossing roll by diverted paths, which would have the effect of producing ill-defined embossing patterns on the film, a device is provided to prevent a decrease in embossing suction by reentering air into the roll near the boundary of the portion of the film which is embossed by the roll. 14.- Apparatus according to claim 13, characterized in that the device for. preventing re-entry of air reducing the embossing suction comprises a belt device which is in contact with the film as it passes around the embossing roll, portions of this belt covering the film and the roll, to prevent re-entry of the film. air along the edges of the film. 15.- Apparatus according to claim 14, characterized in that the belt device comprises a pair of flexible waterproof sealing belts which respectively cover the longitudinal edges of the film and part of the roll over at least part of the film. 'arc which film travels on the roll and near the start of this arc, to prevent re-entry of air under the edges of the film., so as to have a design clearly embossed at these edges. 16. - Apparatus according to claims 14 and 15, characterized in that the belt device can be used not only <Desc / Clms Page number 39> to ensure the sealing of the film but also to cool it. 17.- Apparatus according to claim 13, characterized in that to prevent a decrease in the embossing suction, there are provided on the roller annular regions having a relatively greater porosity at the ends of the roller, than in the region of the roller included. between these annular regions. 18.- Apparatus according to any one of claims 13 to 16, characterized in that spaced strips of impermeable material are provided, extending longitudinally through the porous material in a direction parallel to the axis of the roll. . 19.- Apparatus according to any one of the preceding claims, characterized in that the air can enter the roll through a sector not covered by the film but, thanks to the device for preventing air re-entry, no re-entry. air is only possible in the region of the edges of the film.