WO1980000936A1 - A process for producing plastic foils with increased surface friction - Google Patents

A process for producing plastic foils with increased surface friction Download PDF

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Publication number
WO1980000936A1
WO1980000936A1 PCT/SE1979/000221 SE7900221W WO8000936A1 WO 1980000936 A1 WO1980000936 A1 WO 1980000936A1 SE 7900221 W SE7900221 W SE 7900221W WO 8000936 A1 WO8000936 A1 WO 8000936A1
Authority
WO
WIPO (PCT)
Prior art keywords
plastic material
foil
extrusion
foils
stretching
Prior art date
Application number
PCT/SE1979/000221
Other languages
French (fr)
Inventor
N Karlsson
G Jonsson
G Carlsson
Original Assignee
Celloplast Ab
N Karlsson
G Jonsson
G Carlsson
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Celloplast Ab, N Karlsson, G Jonsson, G Carlsson filed Critical Celloplast Ab
Priority to DE2953283A priority Critical patent/DE2953283C1/en
Publication of WO1980000936A1 publication Critical patent/WO1980000936A1/en

Links

Classifications

    • 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
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/30—Extrusion nozzles or dies
    • B29C48/32—Extrusion nozzles or dies with annular openings, e.g. for forming tubular articles
    • B29C48/335—Multiple annular extrusion nozzles in coaxial arrangement, e.g. for making multi-layered tubular articles
    • B29C48/336—Multiple annular extrusion nozzles in coaxial arrangement, e.g. for making multi-layered tubular articles the components merging one by one down streams in the die
    • 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
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
    • B29C48/07—Flat, e.g. panels
    • B29C48/08—Flat, e.g. panels flexible, e.g. 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
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
    • B29C48/09—Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
    • 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
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
    • B29C48/09—Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
    • B29C48/10—Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels flexible, e.g. blown foils
    • 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
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/14—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the particular extruding conditions, e.g. in a modified atmosphere or by using vibration
    • B29C48/147—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the particular extruding conditions, e.g. in a modified atmosphere or by using vibration after the die nozzle
    • B29C48/1472—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the particular extruding conditions, e.g. in a modified atmosphere or by using vibration after the die nozzle at the die nozzle exit zone
    • 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
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/16—Articles comprising two or more components, e.g. co-extruded layers
    • B29C48/18—Articles comprising two or more components, e.g. co-extruded layers the components being layers
    • B29C48/21—Articles comprising two or more components, e.g. co-extruded layers the components being layers the layers being joined at their surfaces
    • 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
    • B29C2791/00—Shaping characteristics in general
    • B29C2791/004—Shaping under special conditions
    • B29C2791/007—Using fluid under pressure
    • 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
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/001—Combinations of extrusion moulding with other shaping operations
    • B29C48/0018—Combinations of extrusion moulding with other shaping operations combined with shaping by orienting, stretching or shrinking, e.g. film blowing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
    • B29K2995/0037—Other properties
    • B29K2995/0072—Roughness, e.g. anti-slip
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
    • B29L2023/00—Tubular articles
    • B29L2023/003—Tubular articles having irregular or rough surfaces

Definitions

  • films and foils of plastic material have been widely used in many fields.
  • One of the most important fields is the. packing industry.
  • These films and foils have several suitable properties, among others, that they are stretch- able but have a good strength, that they are insensitive to the influence of water and other liquids, and that they can readily be heat welded.
  • the finished foil or film will mostly have a very smooth and glossy surface.
  • plastic .mate ⁇ rials especially polyolefins
  • the stack may fall, as the fricition between the sacks is low. This involves risks of serious accidents.
  • the plastic foil produced in this way has a suitably increased surface friction, it has the dis ⁇ advantage, however, that it requires an addition of blowing agent.
  • blowing agents are not always phy ⁇ siologically acceptable and may make the use of the foil
  • this object is achieved by preparing a plastic foil or film by extrusion,
  • the dosage of plastic material to the foil or foils forming the outer layer or layers being controlled in the extrusion operation in such a ⁇ ay that the added amount of plastic material is insuffici-
  • the extrusion is preferably carried out as extru- ⁇ sion blowing of a laminated tube through two or more concentric slit nozzles and a subsequent blowing and stretching of the hose.
  • a plastic compound 6 is led from an extruder with a controlled dosage (not shown) to the slit die 2. As the added amount of the plastic compound 6 is too small to form a coherent layer when the extruded tube is blown out and stretched by the air bubble indicated by . 8, the outer layer will crack and give local deposits 7 of the plastic material. In this way, a rough surface will be obtained.
  • the produced laminated foil is further treated in a comp ⁇ letely conventional way.
  • it can be rolled up us a tube and be transported ⁇ as a roll to its final use.
  • the controlling of the supply of plastic material to the extruder die or dies forming the layer which in ⁇ creases the friction can be carried out in such a way that the added amount is too small to obtain a coherent " ' - " layer after the stretching so that the layer thus breaks.
  • P/ v WIFO ness of the finished foil can also be added to the star ⁇ ting material of the foil or foils forming the outer layers.
  • Such fillers are known to those skilled in the art. 5
  • a plastic material for the foil any thermoplastic material can be used which is conventionally usable for ⁇ extrusion of foils. Polyolefins are especially suitable and primarily the use of polyethylene is contemplated. The plastic material or materials forming the friction
  • plastic material forming the main foil can often be the same as the plastic material forming the main foil. However, this is not absolutely necessary, but other plastic materials can also be used, provided that they can be laminated with the main foil material.
  • the extruders are of the type known to those skilled in the art and the adjustment of the extruder providing a controlled dosage can be easily established on the ba ⁇ sis of simple preliminary tests.
  • the extrusion is carried out in conventional manner also in other respects.
  • Asperities may also here be formed on both sides of the foil.
  • a foil or film of plastic material showing a high surface friction without the necessity of adding any foreign, expensiv and toxic materials is produced accor-
  • the prepared foil material can therefore be used for packing of foodstuffs and other sensitive materials without any risks. This means con ⁇ siderable technical advantages and also an increased safety.

Abstract

Process for producing foils or films of plastic material with increased surface friction. According to the invention, two or more foils are extruded, laminated and stretched together, the supply of material (6) to the extrusion of the foil or foils which are to form the surface layer (7) being controlled in such a way that the amount of plastic material is insufficient to form a coherent layer when the laminated foil is stretched. In this way the surface layer (7) will break at stretching and give a rough surface with an increased surface friction.

Description

A PROCESS FOR PRODUCING PLASTIC FOILS WITH INCREASED SURFACE FRICTION
Films and foils of plastic material, especially polyolefins such as polyethylene, have been widely used in many fields. One of the most important fields is the. packing industry. These films and foils have several suitable properties, among others, that they are stretch- able but have a good strength, that they are insensitive to the influence of water and other liquids, and that they can readily be heat welded.
In conventional manufacture of plastic film or foil by extrusion, the finished foil or film will mostly have a very smooth and glossy surface. For most plastic .mate¬ rials, especially polyolefins, this means that the sur¬ face of the foil has a very low friction, particularly when two foils of the same kind are rubbed against each other. For certain applications, e.g. in automatic packing machinery, this can be an advantage, but in many other cases the low friction is a serious disadvantage. For example, when filled sacks of polyethylene foil are stacked, there is a great risk that the stack may fall, as the fricition between the sacks is low. This involves risks of serious accidents.
Attempts have already been made to master this problem by laminating a plastic foil with one or more other foils of such a material or of such a design that the surface friction is increased. Thus, it is known, for example, from US patent 4 045 270 to blow extrude a laminated tube, where the main foil of polyethylene is provided on one or both sides with a layer of a plas-tic material which has been made porous by means of an added 5 blowing agent. At the blowing and stretching of the tube after the extrusion, the porous plastic layer will be stretched so that the cells in the material will break.. In this way, a coarse, net-like surface will be obtained h?ving a considerably increased friction.
10 Although the plastic foil produced in this way has a suitably increased surface friction, it has the dis¬ advantage, however, that it requires an addition of blowing agent. Such blowing agents are not always phy¬ siologically acceptable and may make the use of the foil
15 impossible in the food industry, where there must be a complete safety against foreign and injurious materials migrating from the packing material to the .-packed food¬ stuff.
The disadvantage indicated above is eliminated by
20 the present invention and a plastic foil with increased surface friction is obtained which does not contain any foreign additives.
According to the present invention, this object is achieved by preparing a plastic foil or film by extrusion,
25 lamination and stretching of two or more foils or films of thermoplastic material, the dosage of plastic material to the foil or foils forming the outer layer or layers being controlled in the extrusion operation in such aι ay that the added amount of plastic material is insuffici-
30 ent to form a coherent layer after the stretching.
The extrusion is preferably carried out as extru- ^ sion blowing of a laminated tube through two or more concentric slit nozzles and a subsequent blowing and stretching of the hose.
35 Due to this, the outer layer will crack at the
OM l λ - IF s et
? rst"retchi-ng and form a rough surface so that the surface 'J Z-friction is increased in the finished foil. DSΓL"' :'■ A.n example of how the invention is carried out is s'-:r::shown in the drawing. Here a sectional view of an extru- sion head 1 with two annular, concentric slit dies 2 and • ' 3 is sho'wn schematically. A plastic compound 4, which is -°" plasticized by heat, is led from a conventional extruder (not shown) through the inner die 3 and is extruded to the tube foil 5. A plastic compound 6 is led from an extruder with a controlled dosage (not shown) to the slit die 2. As the added amount of the plastic compound 6 is too small to form a coherent layer when the extruded tube is blown out and stretched by the air bubble indicated by .8, the outer layer will crack and give local deposits 7 of the plastic material. In this way, a rough surface will be obtained.
After the inflation and'stretching operation, the produced laminated foil is further treated in a comp¬ letely conventional way. Thus, it can be rolled up us a tube and be transported^as a roll to its final use.
Of course it is also possible to use three con¬ centric slit dies and to control the supply of plastic compound to the innermost and outermost die in the way indicated above. The result of this will be an increased surface friction on both sides of the foil.
The controlling of the supply of plastic material to the extruder die or dies forming the layer which in¬ creases the friction can be carried out in such a way that the added amount is too small to obtain a coherent " '-" layer after the stretching so that the layer thus breaks.
It is also possible to control the supply in such a way that it is made intermittent. This will provide a more markedly rough surface of the foil. Moreover, fillers or fibers giving this plastic material inferior flowing properties and consequently increasing the surface rough-
O FI n
P/v WIFO ness of the finished foil can also be added to the star¬ ting material of the foil or foils forming the outer layers. Such fillers are known to those skilled in the art. 5 As a plastic material for the foil any thermoplastic material can be used which is conventionally usable for ■ extrusion of foils. Polyolefins are especially suitable and primarily the use of polyethylene is contemplated. The plastic material or materials forming the friction
10 increasing surface layer can often be the same as the plastic material forming the main foil. However, this is not absolutely necessary, but other plastic materials can also be used, provided that they can be laminated with the main foil material.
15 . The extruders are of the type known to those skilled in the art and the adjustment of the extruder providing a controlled dosage can be easily established on the ba¬ sis of simple preliminary tests. The extrusion is carried out in conventional manner also in other respects.
20 The process of the invention has been described in the foregoing with reference to extrusion blowing of.a tube, which is a preferred embodiment. However, it is to be noted that the advantages of the invention can also be obtained in the extrusion of foils through straight
25 "slit dies and a subsequent lamination and stretching. By a controlled dosage to the extrusion nozzle providing the surface layer, it is also here achieved that the surface layer will contain an insufficient quantity of material to give a coherent layer after stretching, and
30 will instead crack and give a rough surface. Asperities may also here be formed on both sides of the foil.
A foil or film of plastic material showing a high surface friction without the necessity of adding any foreign, expensiv and toxic materials is produced accor-
55 ding to the present invention. The prepared foil material can therefore be used for packing of foodstuffs and other sensitive materials without any risks. This means con¬ siderable technical advantages and also an increased safety.

Claims

Claims
1. A process for producing a foil or film of plastic material with increased surface friction by extrusion, lamination and stretching of two or more foils of thermoplastic materials, characterized in that the dosage of plastic material to the foil or foils or films which are to form the surface layer or layers in the extrusion process is controlled in such a way that the amount of plastic material is insufficient to form a coherent layer after the stretching process.
2. The process as claimed in claim 1, characterized in that the extrusion is carried out as extrusion blowing of a laminated tube through two or more concentric slit dies and a subsequent inflation and stretching of the tube.
3. The process as claimed in claim 1 or 2, characterized in that the dosage of plastic material to the surface layer or layers is controlled in such a way that it is intermittent.
4. The process as claimed in any one of claims 1-3, characterized in that fillers or fibers reducing the flowability of the plastic material are added to the plastic material or materials which are to form the surface layer or layers.
5. The process as claimed in any one of claims 1-4, characterized in that the plastic material forming the surface layer is the same as the plastic material
OM forming the main foil.
6. The process as cla-imed in any one of claims 1-5, characterized in that the plastic material consists of polyolefin, especially polyethylene.
PCT/SE1979/000221 1978-11-01 1979-10-31 A process for producing plastic foils with increased surface friction WO1980000936A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE2953283A DE2953283C1 (en) 1978-11-01 1979-10-31 Process for producing a film or tube with increased surface roughness from plastic

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE7811311A SE414604B (en) 1978-11-01 1978-11-01 SET TO MAKE FILM OR FILM OF PLASTIC MATERIAL WITH INCREASED SURFACE
SE7811311 1978-11-01

Publications (1)

Publication Number Publication Date
WO1980000936A1 true WO1980000936A1 (en) 1980-05-15

Family

ID=20336236

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/SE1979/000221 WO1980000936A1 (en) 1978-11-01 1979-10-31 A process for producing plastic foils with increased surface friction

Country Status (8)

Country Link
AT (1) AT368439B (en)
CA (1) CA1131868A (en)
CH (1) CH652645A5 (en)
DE (1) DE2953283C1 (en)
FI (1) FI69776B (en)
GB (1) GB2043527B (en)
SE (1) SE414604B (en)
WO (1) WO1980000936A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0822052A1 (en) * 1996-08-02 1998-02-04 Société Anonyme dite: MESNEL Process and apparatus for manufacturing by extrusion a profile locally varying in cross-section
US6444080B1 (en) * 1997-02-05 2002-09-03 Mandzsu, Sen. Jozsef Process of roughening thermoplastic films and roughed plastic films
US7775716B2 (en) 2004-05-26 2010-08-17 Kee Plastics Ab Piping bag, blank for manufacturing a piping bag and method of manufacturing a piping bag

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0095849B1 (en) * 1982-05-20 1987-09-09 Stiksack STS S.A. Plastics film and bags and sacks therefrom
GR20090100422A (en) * 2009-07-28 2011-02-18 Γεωργιος Κωνσταντινου Λαγουδερης Thermoplastic film with flexible ribs - machine and method for the production of same

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FI63344C (en) * 1975-04-28 1988-05-03 Wiik & Hoeglund FOER FARING FOR FRAMING OF PLASTIC PLASTICS.

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
No relevant documents have been disclosed *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0822052A1 (en) * 1996-08-02 1998-02-04 Société Anonyme dite: MESNEL Process and apparatus for manufacturing by extrusion a profile locally varying in cross-section
FR2751913A1 (en) * 1996-08-02 1998-02-06 Mesnel METHOD AND DEVICE FOR MANUFACTURING BY EXTRUSION OF A PROFILE WITH LOCALLY VARIABLE SECTION, AND PROFILE THUS PRODUCED
US6444080B1 (en) * 1997-02-05 2002-09-03 Mandzsu, Sen. Jozsef Process of roughening thermoplastic films and roughed plastic films
US7775716B2 (en) 2004-05-26 2010-08-17 Kee Plastics Ab Piping bag, blank for manufacturing a piping bag and method of manufacturing a piping bag
US8322926B2 (en) 2004-05-26 2012-12-04 Kee Plastics Ab Piping bag, blank for manufacturing a piping bag and method of manufacturing a piping bag

Also Published As

Publication number Publication date
CH652645A5 (en) 1985-11-29
ATA903979A (en) 1982-02-15
FI69776B (en) 1985-12-31
SE414604B (en) 1980-08-11
SE7811311L (en) 1980-05-02
DE2953283A1 (en) 1980-12-18
GB2043527A (en) 1980-10-08
AT368439B (en) 1982-10-11
DE2953283C1 (en) 1985-02-28
CA1131868A (en) 1982-09-21
GB2043527B (en) 1982-10-06
FI793258A (en) 1980-05-02

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