CA1070919A - Production of pile surfaced materials - Google Patents
Production of pile surfaced materialsInfo
- Publication number
- CA1070919A CA1070919A CA246,752A CA246752A CA1070919A CA 1070919 A CA1070919 A CA 1070919A CA 246752 A CA246752 A CA 246752A CA 1070919 A CA1070919 A CA 1070919A
- Authority
- CA
- Canada
- Prior art keywords
- backing
- heated
- polymer
- roll
- web
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H13/00—Other non-woven fabrics
- D04H13/02—Production of non-woven fabrics by partial defibrillation of oriented thermoplastics films
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C59/00—Surface shaping of articles, e.g. embossing; Apparatus therefor
- B29C59/02—Surface shaping of articles, e.g. embossing; Apparatus therefor by mechanical means, e.g. pressing
- B29C59/022—Surface shaping of articles, e.g. embossing; Apparatus therefor by mechanical means, e.g. pressing characterised by the disposition or the configuration, e.g. dimensions, of the embossments or the shaping tools therefor
- B29C59/025—Fibrous surfaces with piles or similar fibres substantially perpendicular to the surface
-
- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H11/00—Non-woven pile fabrics
- D04H11/08—Non-woven pile fabrics formed by creation of a pile on at least one surface of a non-woven fabric without addition of pile-forming material, e.g. by needling, by differential shrinking
Landscapes
- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Mechanical Engineering (AREA)
- Laminated Bodies (AREA)
- Treatment Of Fiber Materials (AREA)
Abstract
A process for producing pile surfaced materials in which a polymer and a backing web are fed to a substantially smooth surface heated to above the softening point of the polymer, the polymer being between the backing and the surface so that it is softened and adheres to said substantially smooth surface, withdrawing the backing web with the polymer adherent thereto from said surface so that fibrils or tufts of said polymer are drawn out between said backing and said surface, cooling said fibrils or tufts characterised in that the backing web is heated at a position prior to contacting position where the polymer contacts the heated surface from which it is drawn into fibrils or tufts.
Description
:~7~
The present invention relates to improvements in or relating to the productiorl of pile surfaced materials.
It has already been proposed to produce a pile on the surface of a synthetic polymeric material by pressing the material against the surface of a heated roll and separating the material ~rom the surface while cooling the material below its softening point. In this way fibrils are drawn out from the surface of the sheet and the cooling action ensures that the major part of each fibril remains integral with the thermoplastic material. In the preferred mode of operation of this technique cold air or another cooling medium is blown into the nip formed between the heated roll and the thermoplastic material as the thermoplastic separates from the roll. It has also been proposed to feed the thermoplastic to the roll as a sheek and to feed a backing material with the thermoplastic in such a way that the thermoplastic and the backing material bond together under the influence of the heated roll. Another suggestion has been to feed the material as a pre~ormed laminate with the . . ~ . .
; 20 ~ polymer between the backing and the heated surface. Such proposals and suggestions are described for example in UK
patent specifications 1378638, 1378639 and 1378640.
In some previous proposals such as UK patent specification 1169621 a pile surface is produced by forcing a thermoplastic into cavities in the surface of a roll and then separating the sheet from ~he roll so that the thermo-plastic that has been ~rced into the cavities is drawn lnto fibxilso This type of process suffers from the disadvantage ~ ~ !
"' ' ' ' ' . . . ' :
.' '. ' . ' ~ ~ ', . ' , . ': . . '~,;., ~ :
, /,. ' ' ' ' ' ~L0709~
that expensive equipment having accurately machined rolls is required and that the techniques cannot satisfactorily be used to produce short piles since the shallow cavities required for short pile would tend to be clogged with thermoplastic material. Furthermore, the nature of the pile (ie. the fibril density and length~ depends upon the depth and size of the cavities so that only ~ne type of pile may be obtained using one particular roller.
The present invention is concerned with a process i 10 in which fibrils are formed from a polymer between a substantially smooth surface and a backing web by introducing a polymer between the substantially smooth heated surface and the backing so that it is softened and adheres to the heated surface, and also bonds to the backing in the situation where the polymer and backing are introduced separately other than as a prelaminate. It is of course desirable that suGh a process be able to operate as quickly as possible and the present invention is aimed at speeding up such a process ~: and we have found that i~ the backing web is heated before the polymer contacts the heated sur-face the process may operate more quickly.
; The present invention thereore provides a process for producing pile surfaced material in which a polymer and a backing web are fed to a substantially smooth - 25 sur~ace heated to above the softening point of the polymer, ~ .
the polymer being between the backing and the surface so that it is softened and adheres to said substantially smooth -: ~ '' ,,' : . ' ' , ' . .
~C~7~
surface, withdrawing the backing web wi.th the polymer ?
adherent thereto from said surface so that ibrils or tufts of said polymer are drawn out between said backing and said surface, cooling said fibrils or tufts character-ised in that the backing web is heated at a position prior ~
' . to contacting position where the polymer contacts the heated ,.
surface from which it is drawn into fibrils or tufts.
In a preferred process the substantially smooth heated surface is a roller which is heated internally to . ,~
. lO a temperature above the melting point of the thermoplastic.
It is to be understood that within this specification the term substantially smooth'includes surfaces which have a satin finish'or have been shot or sand blasted but excludes surfaces in whi'ch'definite cavities are formed into which l~; 15 the polymer is forced to form fibrils since with cavited ~", ;~ , rolls it is not possible to obtain the wide range of pile ,~. types that can be achieved using the present invention.
i:. Examples of surfaces which fall within our definition '~
i,.. ' include polished metal surfaces such as steel or chrome ', 20 and satin finish metal rolls and sand blasted metal rolls :-, and the rolls may be coated with materials such as ,.: , polytetrafluoroethylene which modify the adheslon properties :' ,'~ of the surface. The substantially smooth surface may however ., :~';,~ be a continuous belt~ It is preferred that the polymer '~ 25 and backing web are pr~ssed into contact with each other ,' and into contact with the heated surface by a resilient ~', backing means, It has been found that this contributes ,' to the increasé in the speed at which the process may be !"~ .;.' ,. . .
, . . . . .
:::'. . :. ' .~ . . . .
.' :'. ' :
:., :. , ~97~ 9 operated which is thought to be because the resilient means ensures good contact between the polymer and the heated surface and the polymer and the backing web despite irregularities in the roll surface. It has been found that this may conveniently be achievecl by feeding the materials to the heated sur~ace arouncl a resilient co~ered lay-on roll.
It i5 also preferred that the thermoplastic be held against the heated surface by a pressure roll or ; 10 a belt during its contact therewith as well as at the point of initial contact. Whether a belt or roll be used it is preferred that it is resilient material to allow a predetermined amount of compression as the material is held against the heated surface with the backing material between the thermoplastic and the pressure roll or belt. A urther possibility is that the thermoplastic may be held against the heated surface by the tension in the backing material which bears against the thermoplastic to hold it against ' the heated surface. It is however preferred to use ancilliary means such as a roller or a belt particularly since the roller or belt will pick up heat due to its proximity to ; the heated roll and the backing material may be preheated by passi~g into con~act with the roller or belt.
The means which cools the fibrils is necessary to ensure that the fibrils which are drawn out from the sheet remain adhering to the thermoplastic and do not stick permanently to the heated surface. In addition it is important to have cooling to al~ow the process to be ,. .
, ., : ' ' . . , ::
:. :
:~7~3~
operated at increased speeds, for the production of any particular type of pile. A preferred method oE cooling is to use a jet of cold fluid e.g. air particularly which flows into the nip formed between the heated surace and the material as it moves away from the surface, cooling should be uniorm and thus the jet should extend across the total width of this nip. It has been found that the actual direction of the 3~et of cold air is important and it is also important to allow as free a circulation of the air as possible in the spacè between the heated surface and the material. Therefore it is preferred that the cooling air be directed from a narrow slit orifice of width less than l,-preferably less than 0.5 millimetre under a comparatively high pressure against the heated surface at a position just beyond the point where the pile separates from the surface ;
in such a way that the jet is deflected by the surface into this space. Thus the combination of the position and ;
direction of the cooling jet and the path the material takes as it moves away from the roll to a large extent determine the type of pile that can be obtained at any particular operating speed. The fibrils or tufts may also be cooled by directing a jet o coolant onto the side of the backing furthest away Erom the heated surace. This is particularly useful when the backing material is porous and the cooling gas passes through the backing material into the fibril forming area.
The path that the thermoplastic material .. j , .. , ~ .
.~
-:: :
' :~ ' ' ' ' . :: .. .
.: : . ~ ~ .
adopts as it leaves the heated surface is preferably con-trolled by withdrawing the material over a bar situated close to the heated surface as is described in British Patent Specifications 1378638, 137~639, 1378640 and Belgian Paten-t No. 807879. The particular path chosen depends upon the thickness and nature of the thermoplastic material and the type of product required.
It has been ~ound that small variations in the path of the material and thus a different pile structure may be achieved by simply altering the distance of the bar from the surace.
It is important that the bar be rigid to ensure uniform contact ~etween the sheet and the heated roll. Accordinglyr the shape of the bar should be chosen to provide both the required path of the sheet as it leaves the roll together with the necessary rigidity. The bar is therefore not necessarily of circular cross-section. This apparatus has the added advantage that it is extremely versatile as not only may the pile be altered by varying the distance of the bar from the roll but considerable . .
variations in product may be achieved by altering the size and x~ shape of the bar. In a further embodiment the bar may act as 20 an air knife which cools the thermoplastic, in this embodiment the bar is provided with a slot or holes through which cooling fluid such as cold air may be directed onto the web.
It has been found that in a process in which -khe pile is ;; formed against a substantially smoo~h sur~ace there are several .,, . ~ .
~ fac~ors which effect the speed at which J', ' `
. ~, . . .
.~' ' ' .
,~ - 7 -... . . .
~, .
3~, ,:i .
1a~7~9~
a catisfactory pile may be obtained. The optimum condltions for the production of any one type of pile depends upon the particular thermoplastic material.
Thus subject to other process variations it is preferred that the material be d~awn sharply away from the heated surface leaving as large a space as possible betwe~n the material and the surface so that a cooling fluid such as cold air be blown into this large space which allows for good circulation and escape of the fluid. The space between the material and the heated sur~ace depends upon the path or the material and hence the provision of a means which controls and reduces this radius of curvature and allows greater production speeds to be used. It has also been found that production rates may be further increased if the back of the web is cooled as it is parted from the heated surface! Accordingly, where the means which controls the radius of cur~ature of the sheet of thermoplastic as it moves away from the heated surEace is a rod around which the material is withdrawn it is preferred that it be internally cooled and/or be of a shape such that it can direct cooling gas such as cold air onto the back of the web.
The techniques of the present invention allows a further increase in the speed at which the process may be operated by heating the backing material at a postion before the polymer contacts the heated surface. The :: ' techniques of the present invention are particularly useful ,,~ ,, . , , .~ ' ! .' ' ' ' ' . : j ',' ' ' , '~ ' '` ' '`"' ' ' ' ' . ~ ' '~. ' ' .
. ' ~ ' ,, , ', ' . ' .
_9_ ~hen the polymer and backing are fed separately to the heated surface and are bonded together due to the heat from the substantially smooth surface melting the polymer.
To this end the backing material may for example pass around a heated roll such as the backing pressure roll if one is used, or it may be indirectly heated by for example passage under an infra-red heating lamp or through a heated air tunnel. It has been found however that a simple adjustment so that the backing passes around part of the circumference of the pressure roll results in a considerable in-crease in maximum speed at which an aersthetically pleasing material is produced; the pressure roll may be heated directly by internal heating or by contact with another heated surface or roll, Eor example the substantially smooth heated surface. The backing material may be heated from the front, or back or both and before and/or after being brought into contact with the polymer. The temperature to which the backing material should be heated depends upon the nature of the backing and the thermoplastic. It has been found however that providing the temperature is not so high that the thermo-.
plastic or the backing is clamaged the higher the temperature the faster the pro-cess may be operated.
In a preferred process the synthetic thermo-plastic material is in the form of ia film and may be any of thé well-known film forming materials. Examples of , suitable materials include polyolefines, particularly high and low density polyethylene, polypropylene and olefine `~ copolymers, polymers and copolymers of vinyl chloride polyrners and copolymers of styrene, polyesters and the various nylons~.
, ~ 1 ~
;. ~: , . - ~:
~! ~
r i~ , .
~ t7~39~ ~
The choic~ oE material will of co~rse depend on the particular type of product that is required and the uses to which it is to be put. - ! , The cholce ol backing material will depend upon the desired nature of the produc-t; The use of paper as a backing presents problems as compared with meshed backings such as fabrics and open-celled foams since the surface of the paper has few points at which it can key to the thermo-plastic and thus it is more difficult to achieve a good bond.
Furthermore, when using an open mesh backing such as a fabric the fibrils may be mor0 eEfectively cooled from the back by directing a cooling fluid through the backing into the fibril forming arèa. Thus, when using paper as a backing the material is pre~erably cooled from the front as it separates from the surface and the more effective the cooling the higher the speeds that may be used. A
preferred methbd of cooling is to blow cold fluid preferably air into the gap between the heated surface and the thermoplastic and thus good circulation and escape of the cooling fluid is important for high production rates.
The techniques of the present invention are very useful when paper is used as a backing. It is preferred to with-draw the material rom the roll over a rod at a sharp angle to provide a wide space for circulation of the cooling fluid.
Polyethylene and paper is a particularly suitable combination from which to produca backed pile surfaced products and the ` feedstock may be separate sheets of paper and polyethylene or polyethylene coated paper.
The temperature at which the heated surface should be held depends upon the nature of the thermoplastic j material. However, providing the temperature is not so --/c,~ ~
.' ~ ' ` ~L070~L9 high that the thermoplastic is adversely affected, the higher the temperature the higher the production rates -that may be used. For example, roll surEace temperatures between 160C and 180C are particularly suitable when processing low density polyethylene a-t speeds up to 5 metres/
minute, The higher the roll temperature and production speed the greater -the need to control the path of the material and cool the fibrils effectively to ensure that they separate from the heated surface at the desired point to give the required pile length. In addition with processes operating at these temperatures it is preferred to cool the back of the web as it is withdrawn from the roll surface even when using a backing such as paper which has a low porosity.
This back cooling improves the abrasion resistance of the pile and it is particularly preferred to draw the web from the roll over a suitably shaped internally cooled bar. In order that the invention may be more clearly under-stood preferred embodiments are described with reference to Figures 1 to 10 and the Examples, Figures 1 and 3 to lO are diagrammatic representations of the arrangements of the rolls, backing web and polymer in the various embodiments of the invention. Figures 2 illustrates an apparatus which does not fall within the scope o~ the present invention and is provided by way of comparison, Figure l illustrates a machine capable of operating the present invention and shows a backing web (l) being fed around a guide roll (2) into contact with a pressure roll ~3) having a resilient surace (4) and bein~ heated by thq heat picked up ~ pressure ro~ 3) from heated drum (8). The web (l) passes from the pressure roll to a lay on roll (5) also having a resilient surface (6); a film of thermoplastic (7) is also fed to the lay on roll so that it contacts the backing web and the two pass around the roll (5) to bring the thermo-.
V~9 plastic (7) into contact with the satin finished surface of , the heated drum (8). Both the backing and the thermoplasticpass around the drum (8) wi-th -the -thermoplastic against the surface of the drum, The hea-t from the drum melts the polymer which bonds to the backing and adheres to the surface of :
the drum~ The backing with the polymex bondad thereto is ~ '.
then withdrawn from the surface of the drum over a rod (9 so that fibrils are drawn out between the backing and the , drum, These fibrils are cooled by a stream of cold air directed from nozzle (10) so that they break away from the surface of the drum to yield the pile surface product (11)..
. The machines shown diagrammatically in Figures 2 J " to 4, 6 to 10, use numbers referring to the same features as in Figure 1~ In Figures 2 to 4 and 6 roll (3) is similarly , heated by contact with heated drum (8). The nomenclature used ~ ~ .
.` to describe the relative positions of the hot roll 3, guide rod 9 and air jet 10 is illustrated in Figure 5~ Position 12 denotes the position of surface temperature measuring device.
~ In Figures 7 to 10 roll 13 is backing heating roll~
,; 20 EXAMæLE
~ A film of green pigmented low density polyethylene, .~, , . ~ 6S microns thi.ck was continuously fed together with a backing of blended sulphite/sulphate paper of substance 70 gram per square metre into the apparatus as illustrated in Figure 3.
, The machine settings used according to Figure 5 were: :
X = 1,7 mm .; ., .
= 2,0 mm . d = 0,6 mm ~; r = 3,0 mm a = 40 .. ~ . .
: .
,.
., ~ , .' ~ . .
..
.~ . ` .
1~70~9 The temperature of roll (8)i wcls rn~intained at 170C as measured at p~sition 12. A constant air flow was supplied at 420 Nm3/h from the jet (10) througll a gap of width 0,2 mm over a breadth of 740 mm. The speed at whicll the film and ~acking were ed to the web and the speed of rotation of the hot roll were gradually increased until the product ceased to exhibit a visually attractive pile. This speed was found to be 3,5 m/min.
No lamination of the film to the backing appeared to have occured due to the heat imparted to the backing by roll 3 because in a sample of film/backing cut from the web around roll 5 before contact with roll 8, the film could be peeled from the backing. For comparison, a film oE green pigmented low density polyethylene 65 microns thick was fed together with a backing of blended sulphite/sulphate paper of substance 70 grams per square metre into the apparatus illustrated in Figure 2 wlth the same machlne settings. Machine speed was gradually increased but the product ceased to exhibit a visually attractive pile at a speed of only 2,5 m/min.
The low density polyethylene film and the blended sulfite/
sulfate p2per backing used in Example 1 were fed into the apparatus illustrated in Figure 4, the machine settings were the same as in Example 1.
The machine speed was gradually increased until the product ceased to exhibit a visually attractive pile which was found to occur at a speed of 5 m/min.
: ~ .
- ~/3 ~ ~
.
;3 ' .
~7~9~.~
EX~MPLE 3 A film of non-pigmented low density polye-thylene, 150 microns thick was fed to~ether with a backing of bleached Kraftpaper of weight 120 grams per square metre into the apparatus illustrated in Figure 3.
The machine set-tings according to Figure 5 were:-X = 6,1 mm Y = 4,9 mm d = 2,0 mm r = 10 mm a= 28 The temperature of r-ol~ (8)lwas maintained at 160C as measured at position 12. A constant air flow of 360 Nm3jh was supplied from nozzle 10 through a gap o~ width 0,2 mm over a breadth of 800 mm. The speed of the machine was gradually increased until the product ceased to e~hibit a visually attractive pile. This speed was found to be 1,85 m/min. As in Example 1, no lamination of film to the . . i . .
backing appeared to have occurred due to heat imparted by roll 3.
-~ 20 For comparison, the low density polyethylene film and bleached Kraftpaper backing were fed into an apparatus as shown in Figure 2 using the same machine settin~s. The machine speed was gradually increased until the product ceased to exhibit a visually attractive pile. This speed - 25 was found to be only, 1,4 m/min.
, ,. . -" . : -.. - . . . .
~'.: ' :
, . .
.
'~ ' ' ' ' .
i: _ J~f_ ~tJ"~
7(~9~.~
E~XAMPLE 4 The procedure of Example 3 which used apparatus illustrated\in Figure 3 was repeated using the same c.onditions but using apparatus illustrated in Figure 4. The maximum speed at - S which an aesthetically pleasing ~ile surfaced ma-terial could be produced was 2.7 m/min.
In the above Examples, the piIe-surfaced materials produced on Apparatus illustrated in Figures 3 and 4 appeared to have ~ -greater resistance to abrasion than that of comparative materials produced on the Apparatus illustrated in Figure 2.
In Figures 1,3,4,6,7 and 9 the backing web ls heated from the back, but in Figures 8 and 10 the backlng web is heated from the front.
,~ ' . ' .
' ~ ' ' 1 ' ;
., . -~; ' ~
.
. . .
,,,, _ / ,~
;,~
~. ~r~
The present invention relates to improvements in or relating to the productiorl of pile surfaced materials.
It has already been proposed to produce a pile on the surface of a synthetic polymeric material by pressing the material against the surface of a heated roll and separating the material ~rom the surface while cooling the material below its softening point. In this way fibrils are drawn out from the surface of the sheet and the cooling action ensures that the major part of each fibril remains integral with the thermoplastic material. In the preferred mode of operation of this technique cold air or another cooling medium is blown into the nip formed between the heated roll and the thermoplastic material as the thermoplastic separates from the roll. It has also been proposed to feed the thermoplastic to the roll as a sheek and to feed a backing material with the thermoplastic in such a way that the thermoplastic and the backing material bond together under the influence of the heated roll. Another suggestion has been to feed the material as a pre~ormed laminate with the . . ~ . .
; 20 ~ polymer between the backing and the heated surface. Such proposals and suggestions are described for example in UK
patent specifications 1378638, 1378639 and 1378640.
In some previous proposals such as UK patent specification 1169621 a pile surface is produced by forcing a thermoplastic into cavities in the surface of a roll and then separating the sheet from ~he roll so that the thermo-plastic that has been ~rced into the cavities is drawn lnto fibxilso This type of process suffers from the disadvantage ~ ~ !
"' ' ' ' ' . . . ' :
.' '. ' . ' ~ ~ ', . ' , . ': . . '~,;., ~ :
, /,. ' ' ' ' ' ~L0709~
that expensive equipment having accurately machined rolls is required and that the techniques cannot satisfactorily be used to produce short piles since the shallow cavities required for short pile would tend to be clogged with thermoplastic material. Furthermore, the nature of the pile (ie. the fibril density and length~ depends upon the depth and size of the cavities so that only ~ne type of pile may be obtained using one particular roller.
The present invention is concerned with a process i 10 in which fibrils are formed from a polymer between a substantially smooth surface and a backing web by introducing a polymer between the substantially smooth heated surface and the backing so that it is softened and adheres to the heated surface, and also bonds to the backing in the situation where the polymer and backing are introduced separately other than as a prelaminate. It is of course desirable that suGh a process be able to operate as quickly as possible and the present invention is aimed at speeding up such a process ~: and we have found that i~ the backing web is heated before the polymer contacts the heated sur-face the process may operate more quickly.
; The present invention thereore provides a process for producing pile surfaced material in which a polymer and a backing web are fed to a substantially smooth - 25 sur~ace heated to above the softening point of the polymer, ~ .
the polymer being between the backing and the surface so that it is softened and adheres to said substantially smooth -: ~ '' ,,' : . ' ' , ' . .
~C~7~
surface, withdrawing the backing web wi.th the polymer ?
adherent thereto from said surface so that ibrils or tufts of said polymer are drawn out between said backing and said surface, cooling said fibrils or tufts character-ised in that the backing web is heated at a position prior ~
' . to contacting position where the polymer contacts the heated ,.
surface from which it is drawn into fibrils or tufts.
In a preferred process the substantially smooth heated surface is a roller which is heated internally to . ,~
. lO a temperature above the melting point of the thermoplastic.
It is to be understood that within this specification the term substantially smooth'includes surfaces which have a satin finish'or have been shot or sand blasted but excludes surfaces in whi'ch'definite cavities are formed into which l~; 15 the polymer is forced to form fibrils since with cavited ~", ;~ , rolls it is not possible to obtain the wide range of pile ,~. types that can be achieved using the present invention.
i:. Examples of surfaces which fall within our definition '~
i,.. ' include polished metal surfaces such as steel or chrome ', 20 and satin finish metal rolls and sand blasted metal rolls :-, and the rolls may be coated with materials such as ,.: , polytetrafluoroethylene which modify the adheslon properties :' ,'~ of the surface. The substantially smooth surface may however ., :~';,~ be a continuous belt~ It is preferred that the polymer '~ 25 and backing web are pr~ssed into contact with each other ,' and into contact with the heated surface by a resilient ~', backing means, It has been found that this contributes ,' to the increasé in the speed at which the process may be !"~ .;.' ,. . .
, . . . . .
:::'. . :. ' .~ . . . .
.' :'. ' :
:., :. , ~97~ 9 operated which is thought to be because the resilient means ensures good contact between the polymer and the heated surface and the polymer and the backing web despite irregularities in the roll surface. It has been found that this may conveniently be achievecl by feeding the materials to the heated sur~ace arouncl a resilient co~ered lay-on roll.
It i5 also preferred that the thermoplastic be held against the heated surface by a pressure roll or ; 10 a belt during its contact therewith as well as at the point of initial contact. Whether a belt or roll be used it is preferred that it is resilient material to allow a predetermined amount of compression as the material is held against the heated surface with the backing material between the thermoplastic and the pressure roll or belt. A urther possibility is that the thermoplastic may be held against the heated surface by the tension in the backing material which bears against the thermoplastic to hold it against ' the heated surface. It is however preferred to use ancilliary means such as a roller or a belt particularly since the roller or belt will pick up heat due to its proximity to ; the heated roll and the backing material may be preheated by passi~g into con~act with the roller or belt.
The means which cools the fibrils is necessary to ensure that the fibrils which are drawn out from the sheet remain adhering to the thermoplastic and do not stick permanently to the heated surface. In addition it is important to have cooling to al~ow the process to be ,. .
, ., : ' ' . . , ::
:. :
:~7~3~
operated at increased speeds, for the production of any particular type of pile. A preferred method oE cooling is to use a jet of cold fluid e.g. air particularly which flows into the nip formed between the heated surace and the material as it moves away from the surface, cooling should be uniorm and thus the jet should extend across the total width of this nip. It has been found that the actual direction of the 3~et of cold air is important and it is also important to allow as free a circulation of the air as possible in the spacè between the heated surface and the material. Therefore it is preferred that the cooling air be directed from a narrow slit orifice of width less than l,-preferably less than 0.5 millimetre under a comparatively high pressure against the heated surface at a position just beyond the point where the pile separates from the surface ;
in such a way that the jet is deflected by the surface into this space. Thus the combination of the position and ;
direction of the cooling jet and the path the material takes as it moves away from the roll to a large extent determine the type of pile that can be obtained at any particular operating speed. The fibrils or tufts may also be cooled by directing a jet o coolant onto the side of the backing furthest away Erom the heated surace. This is particularly useful when the backing material is porous and the cooling gas passes through the backing material into the fibril forming area.
The path that the thermoplastic material .. j , .. , ~ .
.~
-:: :
' :~ ' ' ' ' . :: .. .
.: : . ~ ~ .
adopts as it leaves the heated surface is preferably con-trolled by withdrawing the material over a bar situated close to the heated surface as is described in British Patent Specifications 1378638, 137~639, 1378640 and Belgian Paten-t No. 807879. The particular path chosen depends upon the thickness and nature of the thermoplastic material and the type of product required.
It has been ~ound that small variations in the path of the material and thus a different pile structure may be achieved by simply altering the distance of the bar from the surace.
It is important that the bar be rigid to ensure uniform contact ~etween the sheet and the heated roll. Accordinglyr the shape of the bar should be chosen to provide both the required path of the sheet as it leaves the roll together with the necessary rigidity. The bar is therefore not necessarily of circular cross-section. This apparatus has the added advantage that it is extremely versatile as not only may the pile be altered by varying the distance of the bar from the roll but considerable . .
variations in product may be achieved by altering the size and x~ shape of the bar. In a further embodiment the bar may act as 20 an air knife which cools the thermoplastic, in this embodiment the bar is provided with a slot or holes through which cooling fluid such as cold air may be directed onto the web.
It has been found that in a process in which -khe pile is ;; formed against a substantially smoo~h sur~ace there are several .,, . ~ .
~ fac~ors which effect the speed at which J', ' `
. ~, . . .
.~' ' ' .
,~ - 7 -... . . .
~, .
3~, ,:i .
1a~7~9~
a catisfactory pile may be obtained. The optimum condltions for the production of any one type of pile depends upon the particular thermoplastic material.
Thus subject to other process variations it is preferred that the material be d~awn sharply away from the heated surface leaving as large a space as possible betwe~n the material and the surface so that a cooling fluid such as cold air be blown into this large space which allows for good circulation and escape of the fluid. The space between the material and the heated sur~ace depends upon the path or the material and hence the provision of a means which controls and reduces this radius of curvature and allows greater production speeds to be used. It has also been found that production rates may be further increased if the back of the web is cooled as it is parted from the heated surface! Accordingly, where the means which controls the radius of cur~ature of the sheet of thermoplastic as it moves away from the heated surEace is a rod around which the material is withdrawn it is preferred that it be internally cooled and/or be of a shape such that it can direct cooling gas such as cold air onto the back of the web.
The techniques of the present invention allows a further increase in the speed at which the process may be operated by heating the backing material at a postion before the polymer contacts the heated surface. The :: ' techniques of the present invention are particularly useful ,,~ ,, . , , .~ ' ! .' ' ' ' ' . : j ',' ' ' , '~ ' '` ' '`"' ' ' ' ' . ~ ' '~. ' ' .
. ' ~ ' ,, , ', ' . ' .
_9_ ~hen the polymer and backing are fed separately to the heated surface and are bonded together due to the heat from the substantially smooth surface melting the polymer.
To this end the backing material may for example pass around a heated roll such as the backing pressure roll if one is used, or it may be indirectly heated by for example passage under an infra-red heating lamp or through a heated air tunnel. It has been found however that a simple adjustment so that the backing passes around part of the circumference of the pressure roll results in a considerable in-crease in maximum speed at which an aersthetically pleasing material is produced; the pressure roll may be heated directly by internal heating or by contact with another heated surface or roll, Eor example the substantially smooth heated surface. The backing material may be heated from the front, or back or both and before and/or after being brought into contact with the polymer. The temperature to which the backing material should be heated depends upon the nature of the backing and the thermoplastic. It has been found however that providing the temperature is not so high that the thermo-.
plastic or the backing is clamaged the higher the temperature the faster the pro-cess may be operated.
In a preferred process the synthetic thermo-plastic material is in the form of ia film and may be any of thé well-known film forming materials. Examples of , suitable materials include polyolefines, particularly high and low density polyethylene, polypropylene and olefine `~ copolymers, polymers and copolymers of vinyl chloride polyrners and copolymers of styrene, polyesters and the various nylons~.
, ~ 1 ~
;. ~: , . - ~:
~! ~
r i~ , .
~ t7~39~ ~
The choic~ oE material will of co~rse depend on the particular type of product that is required and the uses to which it is to be put. - ! , The cholce ol backing material will depend upon the desired nature of the produc-t; The use of paper as a backing presents problems as compared with meshed backings such as fabrics and open-celled foams since the surface of the paper has few points at which it can key to the thermo-plastic and thus it is more difficult to achieve a good bond.
Furthermore, when using an open mesh backing such as a fabric the fibrils may be mor0 eEfectively cooled from the back by directing a cooling fluid through the backing into the fibril forming arèa. Thus, when using paper as a backing the material is pre~erably cooled from the front as it separates from the surface and the more effective the cooling the higher the speeds that may be used. A
preferred methbd of cooling is to blow cold fluid preferably air into the gap between the heated surface and the thermoplastic and thus good circulation and escape of the cooling fluid is important for high production rates.
The techniques of the present invention are very useful when paper is used as a backing. It is preferred to with-draw the material rom the roll over a rod at a sharp angle to provide a wide space for circulation of the cooling fluid.
Polyethylene and paper is a particularly suitable combination from which to produca backed pile surfaced products and the ` feedstock may be separate sheets of paper and polyethylene or polyethylene coated paper.
The temperature at which the heated surface should be held depends upon the nature of the thermoplastic j material. However, providing the temperature is not so --/c,~ ~
.' ~ ' ` ~L070~L9 high that the thermoplastic is adversely affected, the higher the temperature the higher the production rates -that may be used. For example, roll surEace temperatures between 160C and 180C are particularly suitable when processing low density polyethylene a-t speeds up to 5 metres/
minute, The higher the roll temperature and production speed the greater -the need to control the path of the material and cool the fibrils effectively to ensure that they separate from the heated surface at the desired point to give the required pile length. In addition with processes operating at these temperatures it is preferred to cool the back of the web as it is withdrawn from the roll surface even when using a backing such as paper which has a low porosity.
This back cooling improves the abrasion resistance of the pile and it is particularly preferred to draw the web from the roll over a suitably shaped internally cooled bar. In order that the invention may be more clearly under-stood preferred embodiments are described with reference to Figures 1 to 10 and the Examples, Figures 1 and 3 to lO are diagrammatic representations of the arrangements of the rolls, backing web and polymer in the various embodiments of the invention. Figures 2 illustrates an apparatus which does not fall within the scope o~ the present invention and is provided by way of comparison, Figure l illustrates a machine capable of operating the present invention and shows a backing web (l) being fed around a guide roll (2) into contact with a pressure roll ~3) having a resilient surace (4) and bein~ heated by thq heat picked up ~ pressure ro~ 3) from heated drum (8). The web (l) passes from the pressure roll to a lay on roll (5) also having a resilient surface (6); a film of thermoplastic (7) is also fed to the lay on roll so that it contacts the backing web and the two pass around the roll (5) to bring the thermo-.
V~9 plastic (7) into contact with the satin finished surface of , the heated drum (8). Both the backing and the thermoplasticpass around the drum (8) wi-th -the -thermoplastic against the surface of the drum, The hea-t from the drum melts the polymer which bonds to the backing and adheres to the surface of :
the drum~ The backing with the polymex bondad thereto is ~ '.
then withdrawn from the surface of the drum over a rod (9 so that fibrils are drawn out between the backing and the , drum, These fibrils are cooled by a stream of cold air directed from nozzle (10) so that they break away from the surface of the drum to yield the pile surface product (11)..
. The machines shown diagrammatically in Figures 2 J " to 4, 6 to 10, use numbers referring to the same features as in Figure 1~ In Figures 2 to 4 and 6 roll (3) is similarly , heated by contact with heated drum (8). The nomenclature used ~ ~ .
.` to describe the relative positions of the hot roll 3, guide rod 9 and air jet 10 is illustrated in Figure 5~ Position 12 denotes the position of surface temperature measuring device.
~ In Figures 7 to 10 roll 13 is backing heating roll~
,; 20 EXAMæLE
~ A film of green pigmented low density polyethylene, .~, , . ~ 6S microns thi.ck was continuously fed together with a backing of blended sulphite/sulphate paper of substance 70 gram per square metre into the apparatus as illustrated in Figure 3.
, The machine settings used according to Figure 5 were: :
X = 1,7 mm .; ., .
= 2,0 mm . d = 0,6 mm ~; r = 3,0 mm a = 40 .. ~ . .
: .
,.
., ~ , .' ~ . .
..
.~ . ` .
1~70~9 The temperature of roll (8)i wcls rn~intained at 170C as measured at p~sition 12. A constant air flow was supplied at 420 Nm3/h from the jet (10) througll a gap of width 0,2 mm over a breadth of 740 mm. The speed at whicll the film and ~acking were ed to the web and the speed of rotation of the hot roll were gradually increased until the product ceased to exhibit a visually attractive pile. This speed was found to be 3,5 m/min.
No lamination of the film to the backing appeared to have occured due to the heat imparted to the backing by roll 3 because in a sample of film/backing cut from the web around roll 5 before contact with roll 8, the film could be peeled from the backing. For comparison, a film oE green pigmented low density polyethylene 65 microns thick was fed together with a backing of blended sulphite/sulphate paper of substance 70 grams per square metre into the apparatus illustrated in Figure 2 wlth the same machlne settings. Machine speed was gradually increased but the product ceased to exhibit a visually attractive pile at a speed of only 2,5 m/min.
The low density polyethylene film and the blended sulfite/
sulfate p2per backing used in Example 1 were fed into the apparatus illustrated in Figure 4, the machine settings were the same as in Example 1.
The machine speed was gradually increased until the product ceased to exhibit a visually attractive pile which was found to occur at a speed of 5 m/min.
: ~ .
- ~/3 ~ ~
.
;3 ' .
~7~9~.~
EX~MPLE 3 A film of non-pigmented low density polye-thylene, 150 microns thick was fed to~ether with a backing of bleached Kraftpaper of weight 120 grams per square metre into the apparatus illustrated in Figure 3.
The machine set-tings according to Figure 5 were:-X = 6,1 mm Y = 4,9 mm d = 2,0 mm r = 10 mm a= 28 The temperature of r-ol~ (8)lwas maintained at 160C as measured at position 12. A constant air flow of 360 Nm3jh was supplied from nozzle 10 through a gap o~ width 0,2 mm over a breadth of 800 mm. The speed of the machine was gradually increased until the product ceased to e~hibit a visually attractive pile. This speed was found to be 1,85 m/min. As in Example 1, no lamination of film to the . . i . .
backing appeared to have occurred due to heat imparted by roll 3.
-~ 20 For comparison, the low density polyethylene film and bleached Kraftpaper backing were fed into an apparatus as shown in Figure 2 using the same machine settin~s. The machine speed was gradually increased until the product ceased to exhibit a visually attractive pile. This speed - 25 was found to be only, 1,4 m/min.
, ,. . -" . : -.. - . . . .
~'.: ' :
, . .
.
'~ ' ' ' ' .
i: _ J~f_ ~tJ"~
7(~9~.~
E~XAMPLE 4 The procedure of Example 3 which used apparatus illustrated\in Figure 3 was repeated using the same c.onditions but using apparatus illustrated in Figure 4. The maximum speed at - S which an aesthetically pleasing ~ile surfaced ma-terial could be produced was 2.7 m/min.
In the above Examples, the piIe-surfaced materials produced on Apparatus illustrated in Figures 3 and 4 appeared to have ~ -greater resistance to abrasion than that of comparative materials produced on the Apparatus illustrated in Figure 2.
In Figures 1,3,4,6,7 and 9 the backing web ls heated from the back, but in Figures 8 and 10 the backlng web is heated from the front.
,~ ' . ' .
' ~ ' ' 1 ' ;
., . -~; ' ~
.
. . .
,,,, _ / ,~
;,~
~. ~r~
Claims (9)
1. A process for producing pile surfaced material in which a thermoplastic polymer and a backing web are fed to a substantially smooth surface heated to above the softening point of the thermoplastic polymer, the polymer being between the backing and the surface so that it is softened and adheres to said substantially smooth surface and the backing, with-drawing the backing web with the thermoplastic polymer adherent thereto from said surface so that fibrils or tufts of said thermoplastic polymer are drawn out between said backing and said surface, cooling said fibrils or tufts characterised in that the backing web is heated at a position prior to contacting position where the thermoplastic polymer contacts the heated surface from which it is drawn into fibrils or tufts.
2. A process according to Claim 1 in which the backing web is paper.
3. A process according to Claim 1 in which the substantially smooth heated surface is the surface of a roll.
4. A process according to Claim 1, 2 or 3 in which the polymer and backing web are fed separately to the heated surface.
5. A process according to Claim 1, 2 or 3 in which the polymer is in the form of a film.
6. A process according to Claim 1, 2 or 3 in which the backing web is heated from the back.
7. A process according to Claim 1 in which the polymer and backing web are pressed into contact with each other and into contact with the heated surface by a resilient backing means.
8. A process according to Claim 7 in which the resilient backing means is a pressure roll.
9. A process according to Claim 7 or 8 in which the backing web is heated by contact with the resilient backing means before being pressed against the polymer and into contact with the heated surface.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8224/75A GB1543163A (en) | 1975-02-27 | 1975-02-27 | Production of pile surfaced materials |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1070919A true CA1070919A (en) | 1980-02-05 |
Family
ID=9848339
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA246,752A Expired CA1070919A (en) | 1975-02-27 | 1976-02-27 | Production of pile surfaced materials |
Country Status (12)
| Country | Link |
|---|---|
| JP (1) | JPS51116274A (en) |
| AU (1) | AU1122976A (en) |
| BE (1) | BE838841A (en) |
| CA (1) | CA1070919A (en) |
| DE (1) | DE2607325A1 (en) |
| ES (1) | ES445601A1 (en) |
| FR (1) | FR2302182A1 (en) |
| GB (1) | GB1543163A (en) |
| NL (1) | NL7601981A (en) |
| NZ (1) | NZ180039A (en) |
| SE (1) | SE7602505L (en) |
| SU (1) | SU733519A3 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB8822674D0 (en) * | 1988-09-27 | 1988-11-02 | Tate & Lyle Plc | Preparation of acylated sucrose derivatives |
-
1975
- 1975-02-27 GB GB8224/75A patent/GB1543163A/en not_active Expired
-
1976
- 1976-02-17 NZ NZ180039A patent/NZ180039A/en unknown
- 1976-02-19 AU AU11229/76A patent/AU1122976A/en not_active Expired
- 1976-02-23 BE BE164551A patent/BE838841A/en unknown
- 1976-02-23 DE DE19762607325 patent/DE2607325A1/en not_active Withdrawn
- 1976-02-25 JP JP51019843A patent/JPS51116274A/en active Pending
- 1976-02-26 NL NL7601981A patent/NL7601981A/en not_active Application Discontinuation
- 1976-02-26 FR FR7605446A patent/FR2302182A1/en active Granted
- 1976-02-26 SE SE7602505A patent/SE7602505L/en unknown
- 1976-02-27 ES ES445601A patent/ES445601A1/en not_active Expired
- 1976-02-27 CA CA246,752A patent/CA1070919A/en not_active Expired
- 1976-02-27 SU SU762328354A patent/SU733519A3/en active
Also Published As
| Publication number | Publication date |
|---|---|
| JPS51116274A (en) | 1976-10-13 |
| FR2302182B1 (en) | 1979-08-24 |
| BE838841A (en) | 1976-08-23 |
| ES445601A1 (en) | 1977-06-01 |
| GB1543163A (en) | 1979-03-28 |
| DE2607325A1 (en) | 1976-09-09 |
| AU1122976A (en) | 1977-08-25 |
| FR2302182A1 (en) | 1976-09-24 |
| NZ180039A (en) | 1978-03-06 |
| SU733519A3 (en) | 1980-05-05 |
| SE7602505L (en) | 1976-08-28 |
| NL7601981A (en) | 1976-08-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0156471B1 (en) | Process and apparatus for forming a continuous web, particularly polymeric film, and material produced by the process | |
| US3557407A (en) | Apparatus for surface forming sheet material | |
| US5098636A (en) | Method of producing plastic fibers or filaments, preferably in conjunction with the formation of nonwoven fabric | |
| US3983278A (en) | Method of making a thermoplastic pile sheet | |
| US4359442A (en) | Process for the twin-web hot embossing of thermoplastic film | |
| US3692618A (en) | Continuous filament nonwoven web | |
| KR100235419B1 (en) | Process for making moldable, tufted polyolefin carpet | |
| US5202077A (en) | Method for removal of substrate material by means of heated pressurized fluid stream | |
| US4189336A (en) | Method of forming pile products by tack-spinning and heat treatment therefore | |
| US3696183A (en) | Forming a pile on an article | |
| US4636417A (en) | Fibrous reticular sheet material | |
| US4451419A (en) | Apparatus and process for the production of pile surface articles | |
| MXPA04006738A (en) | Heat treated profile extruded hook. | |
| GB2114052A (en) | Polypropylene spunbond fabric | |
| US6991758B2 (en) | Method of making a web having good breathing properties | |
| EA001177B1 (en) | Embossed fabric | |
| GB2115343A (en) | Producing a polypropylene spunbond fabric | |
| US6136124A (en) | Process for producing a structured, voluminous nonwoven | |
| US3660555A (en) | Method of bonding nonwoven textile fabrics | |
| EP1313899B1 (en) | Filament production method and apparatus | |
| US4854996A (en) | Method and apparatus for producing multilayer panels | |
| CA1070919A (en) | Production of pile surfaced materials | |
| US4815714A (en) | Process for the manufacture of microporous film | |
| US3976820A (en) | Process for the production of pile surfaced articles | |
| CA1045323A (en) | Apparatus and process for the production of pile surface articles |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |