Abstract:
The method for producing a thread which includes a plurality of individual filaments individually supported at a distance from one another and coated with a flowable resin which includes a solvent and can be crosslinked under the effect of at least one physical variable and/or one chemical substance. The coated individual filaments are subsequently compacted so that a composite is formed which includes the individual filaments and the resin continuously surrounding them and which is free of gas pockets. The solvent included in the resin is expelled from the composite during a drying process. Subsequently, the composite, presently a monofilament thread, is wound up in a non-crosslinked state of the resin. All individual filaments are aligned unidirectionally during all steps of the method. The invention further relates to a device to perform the method and a monofilament thread produced with the device.

Description:
RELATED APPLICATIONS 
     This application is a continuation of International application PCT/EP2010/056038 filed on May 4, 2010 claiming priority from German application DE 10 2009 019 500.9 filed on May 4, 2009 and German application DE 10 2009 061 031.6 filed on Jul. 29, 2009. All the above applications are incorporated in their entirety by this reference. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to a method for producing a thread which includes a plurality of individual filaments. The invention furthermore relates to a method for producing a thread which includes a plurality of individual filaments. The invention also relates to a thread which includes a plurality of individual filaments and which is produced according to the method according to the invention or through a device according to the invention. 
     BACKGROUND OF THE INVENTION 
     Methods and devices for producing threads (yarns) including a plurality of individual filaments and threads of this type are well known in the art. In order to improve strength and cohesion of the individual filaments, which are monofilaments as defined in the instant application, in the finished thread, in particular when the individual filaments are staple fibers, this means filaments with relatively small length, the individual filaments are twisted with one another through a spinning method. As an alternative to twisting, individual filaments can also be glued together using curing or curable resins in order to achieve a composite with sufficient cohesion. Threads of this type with a resin component are designated as fiber composite materials. 
     It is a disadvantage of the known threads that textile fabrics produced therefrom through further processing (woven materials, knitted materials, laid tapes, fleeces or similar) or in turn semi-finished products (profiles, plates, bars or similar) made from these textile fabrics through further processing can only be computed with difficulty with respect to their static and dynamic properties. In particular, the finite element method (FEM) fails for structures made from threads, wherein the finite element method provides a rather precise numeric determination of loads in a component in wide fields of solid object statics with the large computing capacities available today. 
     Furthermore, a disadvantage of known composite materials including threads and resins providing cohesion for the threads is that the resin portion is rather high. This does not only reduce the strength of such composite materials but also increases cost since the resins are comparatively expensive. Furthermore, using large amounts of resins is also critical from an environment point of view or under the aspect of saving resources, since the resins are typically made from crude oil products. 
     BRIEF SUMMARY OF THE INVENTION 
     Thus it is an object of the invention to provide a method and a device for producing a filament through which threads (yarns) can be produced which are configured to be finished into textile fabrics which in turn are characterized by high strength, simple numerical computability of the mechanical loads and through low resin consumption. 
     The object is achieved by a method, wherein individual filaments are respectively supported endless and offset from one another and coated with a flowable resin including a solvent and crosslinkable under an impact of at least one physical variable and/or a chemical substance, wherein the coated individual filaments are subsequently compacted, so that a composite is formed which includes individual filaments and continuous resin enveloping the individual filaments, wherein the composite is free from any gas enclosures, wherein the solvent is subsequently expelled from the composite including resin during a drying process, wherein the composite provided as monofilament thread is wound up in a state where the resin is not crosslinked, wherein all individual filaments are supported in parallel orientation (this means unidirectionally) during all preceding process steps. 
     The invention is based on the finding that twisting the individual filaments of a thread as used as a standard in the art is very disadvantageous when the twisted thread shall be finished into a textile fabric in additional process steps to form a component of a subsequent resin-including composite material and additional semi-finished products shall be produced therefrom through adding resin. Twisting the individual filaments namely is very detrimental for a subsequent connection of a plurality of threads using a flowable resin to form a fiber composite material, since a penetration of the resin into the central portions about the longitudinal axis of the thread is almost excluded, since the twisted individual filaments close the inner portion quasi gas tight and shield it against a penetration of the resin. This causes a loss of strength loss for the thread, since the thread does not have sufficient cohesion in its interior due to the lacking resin. 
     This problem is solved through the method according to the invention through coating the individual filaments already and subsequently compacting them which provides a composite which only includes the individual filaments and the resin enveloping them over the entire cross-section. Through a suitable compacting method, gas enclosures are excluded in the cross-section of the composite. In threads which are produced according to the method according to the invention, thus excellent cohesion is provided after crosslinking the resin also in the interior of the thread, since the gluing effect is also provided there to its full extent. Thus, strength is significantly increased and the capability to numerically determine loads is improved. 
     The invention however is based on the additional finding that using threads with cured resin as well as using twisted threads which do not include resin is not helpful for further processing threads into textile fabrics or semi finished products fabricated there from through adding resin, but an excellent connection of the individual filaments in the textile fabric or semi finished products produced there form is obtained when the linking of the resin is only performed when the threads have been brought into the shape which they shall have in the finished product. Since the threads in the non-crosslinked resin condition according to the invention still have individual filaments which are moveable relative to one another and extend parallel to one another this provides very good contact between the adjacent threads of a structure to be produced there from with the greatest possible contact surfaces. Thus a very far reaching flattening of the threads can be achieved under pressure towards a rectangular cross section which yields flat contact surfaces, for example, between threads crossing over one another. This in turn leads to a particular strength of the manufactured product after crosslinking the resin and substantially reduces resin consumption due to a high portion of individual filaments in the finished product, since the free spaces that are not filled by single filaments are being drastically reduced. 
     Thus the invention teaches to wait with crosslinking the resin until after one or plural process steps, which are all performed after thread production, the desired final shape of the structure to be produced is reached in order to use the bonding potential of the resin only when an interconnection between a plurality of threads of the individual filaments included therein can be provided in the finished product. Thus, the invention provides a new semi finished product “multi-filament thread with non-crosslinked resin” with a unidirectional orientation of the individual filaments in which the resin after drying performs the essential intermediary task to join the interconnection of individual filaments to form a monofilament thread that can be handled and to maintain this shape during subsequent processing steps. This applies, for example, for subsequent transporting, unwinding, weaving, knitting or fleece production etc. of threads into finished products or semi finished products for producing finished products. From a handling point of view a monofilament thread is provided which however due to the non-crosslinked resin before the subsequent crosslinking process, in particular under pressure loading can be handled, wherein the individual filaments move relative to one another and wherein the compacted form after crosslinking is maintained as final shape of the finished product or semi finished product. The drying of the resin, this means removing the solvent has to be performed at least so that the viscosity of the resin on the one hand side provides cohesion for the individual filaments and on the other hand side prevents that the wound up thread sticks on a spool between adjacent windings or threads and then cannot be correctly spooled off any more for further use. 
     A particularly simple way of resin coating is to coat the individual filaments through submersion in a resin bath, wherein the individual filaments are preferably pulled through the bath continuously. This provides very even resin application and almost no resin loss occurs through material which may not reach the filaments in alternative coating methods. Also the volumes of such baths can be kept very small which is advantageous for changing the resin material or in case of a stoppage. 
     It is further proposed according to the invention to use at least one nozzle for compacting the individual filaments, wherein the plurality of the coated individual filaments is pulled through the nozzle. Thus, an inner cavity of the nozzle should be frustum shaped so that superfluous resin is retained in the interior of the nozzle when the compacted single filaments exit from an opening cross section of the nozzle. The nozzle cross section that tapers towards the outlet opening generates dynamic pressure when the individual filaments are moved, wherein the dynamic pressure facilitates good filling of the subsequent cross section with resin, in particular also of the central portion and thus almost completely removes possible gas portions in the subsequent yarn cross section. Preferably the nozzles are in a resin bath. 
     In a particularly advantageous manner the method according to the invention can be performed with the subsequent filament types:
         a) filaments made from synthetic polymers, in particular made from aramide, preferably made from para-aramide;   b) filaments made from carbon;   c) filaments made from glass;   d) filaments made from minerals, in particular made from basalt; and   e) filaments made from metal wire, in particular made from steel.       

     Advantageously the individual filaments should have diameters in a range between 3 μm and 30 μm, advantageously between 4 μm and 20 μm and further advantageously between 6 μm and 10 μm and/or the compacted composite should have a diameter between 3 μm and 30 μm, advantageously between 4 μm and 20 μm and further advantageously between 6 μm and 10 μm and/or the compacted composite should have a diameter in a range between 150 μm and 10 mm, advantageously between 200 μm and 2 mm, particularly advantageously between 250 μm and 1.0 mm and/or the dried monofilament thread should have a diameter in a range between 120 μm and 10 mm, preferably between 160 μm and 1.6 mm, and particularly advantageously between 200 μm and 0.9 mm. 
     Furthermore the monofilament thread should be assembled from a number of individual filaments within the following ranges 100 to 3000, advantageously 150 to 2000, further advantageously 200 to 1000. 
     The employed resin can be selected from the group of the following resin types:
         a) Phenolic-formaldehyde resin;   b) Aminoplastic resin;   c) Epoxy resin;   d) Polyester resin;   e) ABS-resin;   f) Silicone resin; or   g) from a mixture of at least two of the preceding resin types.       

     According to an embodiment of the invention it is proposed that the resin includes a solvent portion, advantageously a water portion, between 10% and 70%, advantageously between 20% and 50%, further advantageously between 30% and 40%. 
     According to a particularly advantageous embodiment of the method according to the invention the solvent can be driven out of the coated and compacted composite through convection with forced air and/or through electromagnetic radiation, in particular infra red radiation or microwave radiation. Thus the temperature during the drying process should be preferably maintained in a range between 70° C. and 110° C., preferably between 80° C. and 100° C., in order to safely exclude undesirable crosslinking. 
     In order to improve adhesion of the resin at the individual filaments and to reduce introduction of air into the resin bath the individual filaments before coating with the resin can be heated to a temperature between 50° C. and 80° C., preferably between 60° C. and 70° C. 
     In order to obtain threads with particular properties and in order to optimize them with respect to plural requirements a first type of individual filaments can be arranged in an inner zone of the compacted composite of the individual filaments while another type of individual filaments is arranged in at least one outer zone that connects to the inner zone in radially outward direction. Optionally a thread of this type which includes a “core” and a “first jacket” can include another “jacket” radially further outside in the form of a second outer zone, wherein another type of individual filaments than in the first outer zone is arranged in the second outer zone. This way threads with optimum properties for various applications can be achieved, for example, for pure strength optimization, wear optimization, fire protection, heat insulation, noise insulation etc. For threads of this type with portions with different types of individual filaments defined relative to one another the boundaries between the respective zones should be formed by cylindrical surfaces which are arranged coaxial to a thread longitudinal axis. 
     The resin flow during the coating process is improved and thus air enclosures are prevented from remaining in the resin individual filament composite when the individual filaments are cleaned before coating, in particular washed in a bath with a cleaning liquid and/or are provided with a pre-coating that improves resin flow, wherein the particular filaments ( 45 ,  46 ,  47 ) are advantageously individually supported during cleaning. 
     The object is achieved by a device for producing a thread which includes a plurality of individual filaments, wherein the device includes the following features:
         at least one feed device for a plurality of individual filaments aligned parallel to one another;   a coating device through which the individual filaments respectively supported at a distance from one another are coatable at their enveloping surfaces with a flowable resin that includes a solvent and which is crosslinkable under the impact of at least one physical variable and/or one chemical substance;   a compacting device through which the cross-section filled by the plurality of individual filaments and the adhering resin can be reduced so that an composite can be produced which is made from the particular filaments and the resin continuously enveloping them, wherein the composite is free from gas enclosures;   a drying device through which the solvent included in the resin is drivable out of the compacted composite; and   a winding device through which the dried composite can be wound up with minimum tension so that the particular filaments are arranged without twist.       

     A device of this type facilitates performing the method according to the invention in a particularly simple manner. 
     Advantageously the coating device includes a container with a resin bath through which the plurality of individual filaments can be run individually. 
     In order to achieve good compacting results in a simple manner, the compacting device should include at least one nozzle whose cavity is frustum shaped. Advantageously at least the nozzle is arranged in the resin bath. 
     In order to be able to produce threads with at least two zones with different types of individual filaments and thus to produce threads with combined properties, it is proposed that the compacting device includes an inner nozzle and an outer nozzle arranged coaxial thereto. Between a tip of the inner nozzle and an inner enveloping surface of the outer nozzle which includes a frustum shaped cavity, there is advantageously an annular gap. In this case, a plurality of individual filaments of a first type is configured to be run through an opening cross-section of the inner nozzle and a plurality of individual filaments of a second type is configured to be run through the annular gap between the nozzles. This way, a compacted composite can be generated at an outlet cross-section of the outer nozzle (combination composite) which includes an inner zone made from individual filaments of the first type and an outer zone made from individual filaments of the second type. In order to provide good cohesion of the individual filaments and subsequently high strength of the end product produced, the cavities between all individual filaments of both types are completely filled with resin and all individual filaments of both types extend parallel to another in the combination composite. 
     For fine tuning of the device during the compacting process, the outer nozzle can be movable in axial direction relative to the inner nozzle and can be fixatable in different positions. 
     According to the invention, the preferred portion of resin relative to the entire volume of the thread is between 2% and 15%, further preferably between 5% and 12%. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is subsequently described based on an embodiment of a device for performing the method and based on an embodiment of the thread according to the invention with reference to drawing figures, wherein: 
         FIG. 1  illustrates a longitudinal sectional view of the device; 
         FIG. 2   a - 2   c  illustrate a top view, a lateral view and a front view of a compacting device of the device according to  FIG. 1 ; 
         FIGS. 3   a  and  3   b  illustrate two perspective views of an outer nozzle with an inserted inner nozzle of the compacting device according to  FIG. 2   a - 2   c;    
         FIGS. 4   a  and  4   b  respectively illustrate a view of an exterior nozzle and of an inner nozzle of the compacting device according to  FIG. 2   a - 2   c;    
         FIG. 5  illustrates a cross-section through a thread with an inner zone and two outer zones; and 
         FIG. 6  illustrates an enlarged detail of  FIG. 5  with three adjacent individual filaments. 
     
    
    
     DETAILED DESCRIPTION 
     A device  1  as illustrated in  FIG. 1  for producing a thread  2  includes two unwinding devices A, two feed devices  3  and  4  for feeding respectively a plurality of monofilaments of two different types which are not illustrated individually, but only indicated by the lines  5  and  6 , a cleaning device R, a coating device  7 , a compacting device  8 , a drying device  9  that is only schematically illustrated and eventually a wind-up device  10  for winding up the monofilament thread  2 . 
     The unwinding units facilitate twist-free unwinding of the bundles of individual filaments so that in particular overhead unwinding is excluded. 
     The two feed devices  3  and  4  are slightly curved tubular elements  11  and  12  through which the individual filaments which are monofilaments are run in individually. The individual filaments are unwound twist-free by another winding device which is not illustrated but known in the art. 
     Initially the two bundles of monofilaments are run through a bath or a curtain with a cleaning fluid (primer) of a cleaning device R before they are subsequently fed to the coating device after the treatment. 
     The coating device  7  is formed by a container  13  in which a bath with flowable resin  14  is arranged through which the respective plurality of individual filaments of both types run. Thus, a submersion coating of all individual filaments takes place through a connection that is not illustrated, a level  15  of the resin bath is kept constant, and in particular the continuous consumption of resin during thread coating is compensated. 
     The compacting device  8  which is separately depicted in  FIGS. 2   a - 2   c  in three views includes an inner nozzle  16  and an outer nozzle  17  arranged coaxial thereto. Both nozzles  16 ,  17  are illustrated again in detail in different perspective views in  FIGS. 3   a ,  3   b  and  4   a ,  4   b.    
     The inner nozzle includes a frustum shaped outer enveloping surface  18  and an inner enveloping surface  19  which has a smaller cone angle. The inner enveloping surface  19  defines an inner cavity  20  of the inner nozzle  16 , wherein the compacting, this means the radial compression of the plurality of individual filaments which subsequently produce an inner zone of the thread  2  occurs in the inner cavity  20  up to an opening cross-section  22  arranged at a tip  21  of the inner nozzle  16 . 
     The outer nozzle  17  includes a cylindrical outer enveloping surface  23  with shoulders and a frustum shaped inner enveloping surface, whose cone angle in turn is greater than the cone angle of the outer frustum shaped enveloping surface  18  of the inner nozzle  16 . With a continued movement of the individual filament fiber bundles of both types into the inner cavities  20 ,  25  of both nozzles  16 ,  17 , the respectively effective annular and circular cross-section is continuously reduced starting with the respective inlet cross-sections  26 ,  27  of the two nozzles  17 ,  16 , which provides the compacting effect for the individual filaments. 
     At an outlet cross-section  28  of the outer nozzle  17 , a monofilament thread  2  is provided at the end of the compacting process, wherein the monofilament thread  2  has a relatively tight arrangement of individual filaments in its cross-section, wherein the intermediary cavities between the individual filaments are completely filled with resin  14  and do not include any gas enclosures at all. 
     It is important that the individual filaments which subsequently form the outer zone of the thread  2  initially move into the device  1  through the tubular element  11  of the feed device  3  as a fiber bundle with approximately circular cross-section which is subsequently flat and loosened up. In the portion of the annular cavity between the inner nozzle  16  and the outer nozzle  17 , viewed in axial direction of the nozzles  16 ,  17 , the outer individual filaments are wound about the outer enveloping surface  18  of the inner nozzle  16  (distribution in circumferential direction). As a result, the outer monofilaments at the latest in the portion of the opening cross-section  22  of the inner nozzle  16  viewed in cross-section form a closed ring which completely envelops the individual filaments which are approximately arranged in a circular shape in cross-section, wherein the individual filaments exit from the nozzle  16  and form the subsequent inner zone of the thread  2 . 
     The exterior cone angle of the inner nozzle  16  is about 1.5° to 2.5°, preferably 2.0°, and the inner cone angle of the inner nozzle  16  is approximately 10° to 15°, preferably approximately 12°. The inner cone angle of the outer nozzle is approximately 15° to 20°, preferably approximately 18°. 
     In the drying device  9 , the monofilament thread  2  formed as described supra is dried using microwaves and/or hot air convection, this means in the present case that the water based solvent for the resin  14  is removed from the resin  14  so that its viscosity increases, the gluing properties and thus the cohesion of the individual filaments is improved. However, a drying is only provided in the physical sense and no chemical crosslinking of the monomers of the resin  14  occurs. 
     After leaving the drying device  9 , the thread  2  is stabilized far enough and thus has no “gluing” properties anymore, so that it can be wound up on the winding device  10  onto corresponding spools  29 . It is important for the method according to the invention that the individual filaments, in the present case of both types, are not twisted with one another in any step of the production process. During the entire production method, the parallel, this means unidirectional, orientation of all monofilaments is maintained, which also applies for the “finished” thread  2  wound up on the spool  29 . 
     Based on the  FIGS. 1 and 2   a  through  2   c , it is evident that the inner nozzle  16  is attached at a first nozzle support  30 . The outer nozzle  17  is attached at a second nozzle support  31  and namely threaded with an outer threaded section  32  into an inner thread section  33  of the nozzle support  31  interacting therewith. This facilitates providing a horizontal movement of the outer nozzle  17  along the double arrow  35  in the course of rotating the outer nozzle  17  about an axis  34 . This facilitates adjusting the compacting partners individually. From the figures it can furthermore be derived that both nozzle supports  30 ,  31  are bolted together with a base plate  36 , wherein the base plate  36  is arranged on a base surface  37  of the container  13 . The nozzles  16 ,  17 , the nozzle supports  30 ,  31  and the base plate  36  as well as the connecting bolts are made from stainless steel. The same applies for the container  13  and the tubular elements  11  and  12  of the supply devices  3  and  4 . 
     As can be derived from  FIGS. 3   a  and  3   b  and  4   a  and  4   b , the inner nozzle  16  includes a tubular rear portion connected to its frustum shaped front portion, wherein the tubular rear portion connects to the front portion at a shoulder  38 . The rear portion which has an opening cross-section  39  facilitates inserting a respectively adapted expended borehole cross-section  40  of a tubular nozzle holder  41  into the inner nozzle  16 , wherein the nozzle holder  41  in turn is connected with the nozzle support  30 . 
     Through the device  1 , a thread  2  can be produced whose circular inner zone includes approximately 100 to 2,000 individual filaments made from carbon. An outer zone with annular cross-section arranged about the inner zone in turn includes 100 to 2,000 individual filaments made, for example, from glass or ceramic. The diameters of both filament types can be in a range between 5 μm and 25 μm, preferably between 8 μm and 20 μm. Advantageously the individual filaments of one type all have identical diameters and also all filament types can have the same diameter. 
     The resin  14  in the present case is made from a silicon resin mix. The resin “WS 40” distributed by Wacker Chemie AG, Munich, Germany, is suitable in particular. 
     Crosslinking the silicon resin is performed at a later point in time when the finished thread  2  is unwound from the coil  29  again and processed into a semi-finished product or end product (textile fabric or three dimensional structure) and thus the final configuration of the component is defined. The crosslinking temperature is above 140° C., wherein advantageously a pressure of up to 500 N/mm 2  is applied. Finishing the non-crosslinked thread  2  is not an object of the instant application. 
     The alternative thread  2 ′ according to  FIG. 5  has a three zone configuration compared to the thread  2  produced by the device  1 . An inner zone  42  is enveloped by a first outer zone  43  that is shaped like a circular ring in cross section, wherein the first outer zone in turn is enveloped by the second outer zone  44  in radially outward direction wherein the second outer zone  44  also is shaped by a circular ring in cross section. In the case illustrated in  FIG. 5  the individual filaments  45  of the inner zone are formed by carbon fibers, the particular the filaments  46  of the first outer zone  43  are formed basalt and the individual filaments  47  of the second outer zone  44  are formed from silicone. It is appreciated that the illustration of the individual filaments  45  through  47  with reference to the provided number in the respective zone is not to scale. As stated already with reference to the thread  2  as a product of the device  1  advantageously at least approximately 100 individual filaments are provided in the inner zone  42 . Accordingly there are typically more individual filaments in the two outer zones  43 ,  44 , this means between approximately 500 and 1500 as a function of the selected layer thicknesses. 
     The thread  2 ′ like all threads produced according to the method according to the invention is characterized by very high packing density of the individual filaments  45  through  47  in all three zones. Intermediary spaces  48  which are illustrated in  FIG. 6  at three individual filaments  47  which are pointed out in an exemplary manner have a typical spandrel shape (triangular shape with curved sides) in cross-section. In practical applications there are thin intermediary layers made from resin also in the portion of imaginary contact lines  49  or contact surfaces which improves the strength of the composite made from individual filaments  47  and resin for subsequent crosslinking of the resin. For individual filaments  47 , which define the thread  2 ′ in outward direction, there is resin  14  also in a portion which is defined by the dashed line  50  about the individual filaments  47  and also in the spandrels  51  formed between adjacent individual filaments  47 . Overall, resin consumption is minimized for the method according to the invention or threads  2  and  2 ′. 
     Aramide, in particular para-aramide monofilament due to its high price is used in particular when the strength properties or the ratio of strength and mass is important (aerospace and security applications, etc.). Glass fiber is a cost-effective material with sufficient properties. When there are stringent requirements with respect to temperature resistance, ceramic- or basalt-fibers can be used. Abrasion resistant monofilaments are typically used in the outer zone. Monofilaments with high tensile strength are typically used in the inner zone. 
     REFERENCE NUMERALS AND DESIGNATIONS 
       1  Device 
       2 ,  2 ′ Thread 
       3  Feed device 
       4  Feed device 
       5  Line 
       6  Line 
       7  Coating device 
       8  Compacting device 
       9  Drying device 
       10  Winding device 
       11  Tubular element 
       12  Tubular element 
       13  Container 
       14  Resin 
       15  Level 
       16  Inner nozzle 
       17  Outer nozzle 
       18  Outer enveloping surface 
       19  Inner enveloping surface 
       20  Inner cavity 
       21  Tip 
       22  Opening cross-section 
       23  Outer enveloping surface 
       24  Inner enveloping surface 
       25  Inner cavity 
       26  Inlet cross-section 
       27  Inlet cross-section 
       28  Outlet cross-section 
       29  Spool 
       30  Nozzle support 
       31  Nozzle support 
       32  Outer thread section 
       33  Inner thread section 
       34  Axis 
       35  Double arrow 
       36  Base plate 
       37  Ground surface 
       38  Shoulder 
       39  Opening cross-section 
       40  Borehole section 
       41  Nozzle support 
       42  Inner zone 
       43  First outer zone 
       44  Second outer zone 
       45  Individual filament 
       46  Individual filament 
       47  Individual filament 
       48  Intermediary space 
       49  Contact line 
       50  Line 
       51  Spandrel 
     R Cleaning device