CA2127820C - Method for manufacturing panels and panels obtained thereby - Google Patents

Method for manufacturing panels and panels obtained thereby Download PDF

Info

Publication number
CA2127820C
CA2127820C CA002127820A CA2127820A CA2127820C CA 2127820 C CA2127820 C CA 2127820C CA 002127820 A CA002127820 A CA 002127820A CA 2127820 A CA2127820 A CA 2127820A CA 2127820 C CA2127820 C CA 2127820C
Authority
CA
Canada
Prior art keywords
fragments
thermoplastic resin
hot
panel
mass
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 - Fee Related
Application number
CA002127820A
Other languages
French (fr)
Other versions
CA2127820A1 (en
Inventor
Filippo Candela
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
SVILUPPO TECNOLOGIE Srl
Original Assignee
SVILUPPO TECNOLOGIE S.R.L.
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 SVILUPPO TECNOLOGIE S.R.L. filed Critical SVILUPPO TECNOLOGIE S.R.L.
Publication of CA2127820A1 publication Critical patent/CA2127820A1/en
Application granted granted Critical
Publication of CA2127820C publication Critical patent/CA2127820C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B27WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27NMANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUT ORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTING OF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL
    • B27N3/00Manufacture of substantially flat articles, e.g. boards, from particles or fibres
    • B27N3/08Moulding or pressing
    • B27N3/10Moulding of mats
    • B27N3/14Distributing or orienting the particles or fibres

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Wood Science & Technology (AREA)
  • Forests & Forestry (AREA)
  • Laminated Bodies (AREA)
  • Dry Formation Of Fiberboard And The Like (AREA)
  • Refrigerator Housings (AREA)
  • Securing Of Glass Panes Or The Like (AREA)
  • Casting Or Compression Moulding Of Plastics Or The Like (AREA)
  • Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
  • Panels For Use In Building Construction (AREA)
  • Conveying And Assembling Of Building Elements In Situ (AREA)
  • Joining Of Building Structures In Genera (AREA)

Abstract

Method for manufacturing panels by compressing fragments of bonded sheet material, such as thermoplastic resin coated cardboard, in a press at a temperature not lower than the softening point of the thermoplastic resin, comprising the addition of additives in the form of inert fillers or in the form of thermoplastic or thermosetting resins to modify the mechanical properties of the panel obtained and the addition of a layer of fine wood shavings on the outer face to improve its surface.

Description

Z~8~1~

"Method for manufacturing panels and panels obtained thereby"

This invention refers to a method for manufacturing panels in sheet form and the product obtained thereby.
There are known panels composed of incoherent material.s of various kinds, impregnated with suitable binders and then moulded in a press.
A typical example of application of this technique consists of panels composed of fragments of wood of suitable particle size, lmpregnated with thermosetting resin. This material is cold-preformed into the shape of a slab which is subsequently compressed into its final configuration in a heated mould, where the binder is polymerized. ~ :
Panels of this kind have extensive empty spaces inside them, due to the fact that the quantity of binding resin must be maintained within permissible limits from the economic and technolo~ical point of view. In certain applications their consequent poor mechanlcal strength and high hygroscopicity is not appreciated.
Likewise, there are known panels obtained by milling and suhsequently hot-pressing scraps and rejects of multilayered materials; the methods used for obtaining such panels are descrihed in patents DE-A 2.258.169 and DE-B 1.~51.374.
Due to the lntrinsic properties of the raw material used, these panels have an uneven surface which prevents them :
2~27820 ....

from being given an aesthetically perfect finish either by painting, or by applying a paper coating.
The scope of this invention is to obtain panels composed internally of scraps of multilayered materials and externally of fine particle-sized wood shavings. Said panels are consequently characterized by a low degree of hygroscopicity, limited swelling in water, good thermal and acoustic insulation, d.eriving from the first component material, and an excellent finish and even surface deriving from the second component material.
The method for manufacturing panels according to the ~- --invention is characterized by the fact that fine, particle-sized wood shavings, suitably mixed with resins, are distributed on the outside of a mass of fragments of sheet material composed of thermoplastic resin coated ~-~
cardboard, the composition thus obtained being compressed -in a mould at a temperature higher than the softening ;~
point of the thermoplastic material and higher than the polymerizing temperature of the resin used, and subsequently cooled.
The invention also refers to the panel obtained by such method.
During the course of this description, the term multilayered material, or bonded sheet material, refers to a composite material comprising a layer of cardboard and at least one layer of thermoplastic material on one of its outer surfaces.
Further layexs may also be present, such as for example a 3 ~1~71320 sheet of aluminium foil.
The use of these multilayered materialfi as the basic ingredient for preparation of the panels, offers the advantage of perfectly even distribution of.th~ plastic ~-material on each of the fragments and, consequently, within the mass of the panel itself, resulting in optimal ~.
adherence between the Gomponent fragments and a singularly . -compact structure of the panel thus obtained.
A further essential advantage of the invention lies in the fact that scraps of multilayered mater.ial are widely available and exceptionally low in cost, in that they can be obtained from material discarded from the manu~acture of boxes which use this material as a constituent.
The cost of disposing of these scraps weighs heavily on ~ .
the industries which make up these boxes, and so the cost ~: -of acquiring the scraps from which the fragments are made may even be zero, or compensated with the cost of conventional disposal.
The plastic layer of the bonded sheet material referred to herein consists of a sheet of polyethylene, even though the presence of other thermoplastic materials is not excluded.
To carry out the procedure according to the invention, the ~ ::
sheet material is broken up into fragments, preferably having minimum dimensions of not less than 2 mm and .
maximum dimensions of around 40 mm, of the most diverse shapes, from substantially circular to elongated in the :~
form of fibres. --xl~7~2n According to the experiments conducted by the applicant, a percentage of thermoplastic binding material suitable for forming the panel ranges from 5 to 15~ in weight of the fragments, and more specifically around 10~, which is the same order of magnitude as the percentage in weight of the thermoplastic fraction contained in ~ardboaxd-polyethylene or cardhoard-aluminium-polyethylene mu]tilayer ~heets, so that the use of fragments made from scraps of this material ensures an adequate quantity of bonding resin.
It may prove advantageous, however, to add additives to the simple fragments of multilayer materials on the market, such as those used directly for packagin~
foodstuffs in particular.
These additives may consist of an additional quantity of the same plastic material contained in the multilayer material, as well as other thermoplastic substances. The thermoplastic resin added to the fragments will have a sufficiently fine par~icle size so as to be suitably distributed throughout the mass, typically with a basic particle size not exceeding the average size of the fragments.
It was found to be advantgeous, in certain applications, to add other plastic materials of the thermosetting class, in order to favourably affect the properties of the panel, and to facilitate the technique of forming the mass to be introduced into the mould, as well as to enable the panel to be removed easily from the mould. Synthetic resins which can be polymerized by adding a cataly~t may also be 212~820 used.
To form the two outer layers, use is made of wood shavings with a particle size ranging from 0.25 to 1.2 mm, with the - - addition of ureic resin or, preferably, melar,linic resin, which gives better characteristics in terms of hygroscopicity and limited swelling.
Special care should be taken in preparing the initial slab, since it is essential to ensure a certain amount of compenetration between the wood shavings and the fragments of cardhoard in order to prevent detachment of the surface layers composed of wood shavings from the support composed of fragments of multilayered material.
The thickness of the layers of wood shavings may vary from 0.3 to 1.5 mm. -It was found that the panels are formed satisfactorily when the initial slab is subjected to pressure.s in the region of 15-25 kg/cm2 and heated to a temperature ranging ,from 120 to 1~0C. The length of time that the fragments must remain under compression between the hot plates of the press varies according to the final thickness of the panel, in order to ensure a sufficientiy even distri~ution of the temperature throughout the mass. It has proved to be advantageous, for example, to keep the panel under the heated press plates for a period ranging from 15" to 30"

per millimetre of thickness of the panel obtained.
Whençver a thermosetting resin or a resin polymerized by catalysis is used as an additive, it was found that, in the time required for polvmerization and cross-linking of ~ ;

ZlZ782~) the resin, the polyethylene melts to improve the aggregating action between the resin and the fragments of multilayered material, resulting in a singularly compact and sturdy product.
Resins of the most diver.se kinds have proved useful in manufacturing panels according to the invention, such as for example phenolic resins (phenol-formaldehyde, cresol-formaldehyde, phenol-furfural), amino-plasts (urea-formaldehyde, melamine-formaldehyde), polyesters (phthalic, maleic), epoxy, vinyl, acrylic, polystyrene, polyolefin and isocynate.
The mechanical properties and compactness of the end product can be improved by the addition of fillers of various different materials of suitable particle size, in widely varying percentages, typically from 5 to 10~, such as cellulose, cotton staple, sawdust, fibre glass, kaolin, calcium carbonate.
The addition of paraffin to the wood shavings and the use of melamine glues reduces the hygroscopicity and moisture expansion of the material.
The addition of monoammonium phosphate dispersed in the mass in percentages of 8-15~ makes it possible to obtain a substantially fire-proof product.

This exemplificative indication obviously does not in any way limit the choice of inert fillers which can in any case be added during the formation of the panel according to the inventlo~ to give it any desired specific ~ . - , .......... .. . - -.. . ,.. ., ,.,,, ,. . , , ~ . .

: ~, . . ~''; '" . ' ,, 2~278;~0 characteristics.
The procedures for carrying out the method according to the invention will be more clearly evident from the following practical example.

E X A M P L E

100 kg of dry ureic resin were treated with 52 kg of water - to obtain a milky suspension to which ammonium chloride was added up to a percentage ranging from 2 to 3%
(approximately 2.8 kg). -~
720 kg of fragments obtained by triturating scrap~ of multilayered materials (cardhoard, aluminium and polyethylene) were added to approximately 53 litres of thls mixture.
After having been vigorously stirred in appropriate apparatuses referred to as "resinators", this mixture was ,evenly distributed over a layer of previously resinated fine wood shavings. ~ -The upper surface, composed of fragments of resinated multilayered material, was also covered with a further layer of resinated fine wood shavings.
The operation of distributing the three alternate layers ~ -was carried out by means of special distributing machines referred to as "moulding machines" placed in succession above a conveyor belt.
The slab thus formed was cut into suitably si~ed modules with a specific weight of approximately lOO0 kg/m3, which 2~;~782(~

were then introduced between the hot plates of a gang press.
After having reached the softening point of the polyethylene in the core of the panels, the press plates were cooled to reduce the temperature of the panels to below the softening point, while keeping the panels constantly subjected to a specific pressure higher than the pressure exerted by the water vapour at the same temperature, during the heating and cooling phases.
The panels were subsequently removed from the press, cut transversally and longitudinally and then smoothed.
In view of the relatively low thermal conductivit~ of the material compacted to form the panel, it may be advantageous to preheat the mass before introducing it into the mould, thereby reducing the length of time it must remain inside the hot press for the core of the panel to reach the temperature required for the thermoplastic resin to soften and for polymerization of any thermosetting binder that may be used.
The preheating temperature must obviously be below the point which causes the thermoplastic resin to soften to such a degree as to cause it to run or to adhere excessively on contact, which could negatively affect the distribution of the resin within the mass.
It was also found that a high degree of moisture in the scraps of multilayered material, as is generally the case, may negatively affect the properties of the panel, and especially its compactness.

~ 21Z7820 A further feature of the manufacturing method according to this invention is consequently that of subjecting the fragments after milling to pre-drying in order to reduce the moisture content to values below 4~., preferably around 2%. The drying can easily be carried out under a stream of hot air.
In addition or as an alternative, also in order to speed up production and achieve hetter dimensional stabilization of the product, after the heating phase and after having exceeded the softening point of the raw material, the panel can be cooled under pressure, with release of any vapour that may have formed in the mass of mater~al.
To compress fragments of multilayered materials use can be made, in particular, of the currently known single or multiple-die presses. In particular, the cycle can be carried out with:
a) three single-die presses in line, the first of which , presses hot, the second re-presses hot and the third cools and stabilizes the product;
b) two single-die presses, the first of which heats and the second cools and stabilizes the product under pressure;
c) multiple-die press with hot/cold cycle;
d) continuous press with hot area upstream and cold area downstream.
On account of their compactness, the panels lend ;~
themselves satisfactorily to machining and surface finishing.

v;~ ~t~ "~

~ 212~1~2~

The panels obtained according to the invention lend themselves to a wide range of applications in the most diverse fields. In addition to the conventional uses for . ~. products of this kind, they can also be su.itable for uses which call for resistance to passive stress, in view of their good mechanical strength. Moreover, due to their low degree of impregnability and expansion in water, the panels according to the .i.nvent.ion can be used in the building industry.
Lastly, it should be pointed out that the utilization of scraps of multilayered materials is an aspect of considerable importance, since at present they d~ not prove to be of any practical use and are extremely difficult and expensive to dispose of, while they can be made into panels having the same character1stics in terms of finish as the known panels manufactured with particle ~:
board and can consequently be subjected to the same finishing techniques as the latter.

Claims (16)

1. Method for manufacturing a panel which method comprises compressing a composition of fine particle-sized wood shavings, suitably mixed with resins, distributed on the outside of a mass of fragments of sheet material composed of thermoplastic resin coated cardboard, in a mould at a temperature higher than the softening point of the thermoplastic material and higher than the polymerizing temperature of the resin used, and subsequently cooling to yield said panel.
2. Method as claimed in claim 1, wherein said fragments are subjected to drying before being hot-pressed, to decrease their moisture content to values below 4%.
3. Method as claimed in claim 1, wherein said fragments are subjected to drying before being hot-pressed, to decrease their moisture content to values below 2%.
4. Method as claimed in any one of claims 1 to 3, wherein said fragments are subjected to preheating at a temperature lower than the softening point of the thermoplastic resin, before being hot-pressed.
5. Method as claimed in any one of claims 1 to 4, wherein upon completion of the hot-compression phase, the compressed material is cooled under pressure until it reaches an internal temperature lower than the softening point of the thermoplastic resin.
6. Method as claimed in any one of claims 1 to 5, wherein said fragments are compressed with pressure values ranging from 15 to 25 kg/cm2.
7. Method as claimed in any one of claims 1 to 6, wherein the hot-compression phase has a duration ranging from 15 to 30 seconds per millimetre of thickness of the finished panel.
8. Method as claimed in any one of claims 1 to 7, wherein thermoplastic resin is added as an additive dispersed in the mass of fragments of multilayered material.
9. Method as claimed in claim 8, wherein the thermoplastic resin is present in percentages ranging from 5 to 15% by weight of the fragments.
10. Method as claimed in claim 8, wherein the thermoplastic resin is present as about 10% by weight of the fragments.
11. Method as claimed in any one of claims 1 to 7, wherein thermosetting resin is added as an additive dispersed in the mass of fragments of multilayered material.
12. Method as claimed in claim 11, wherein the thermosetting resin is added as an additive in percentages ranging from 5 to 15% by weight of the fragments.
13. Method as claimed in claim 11, wherein the thermosetting resin is added as an additive in percentages ranging from 5 to 10% by weight of the fragments.
14. Method as claimed in any one of claims 1 to 13, wherein an inert filler is added as an additive dispersed in the mass to the fragments of multilayered material.
15. Panel obtained by hot compression of two layers of fine particle-sized wood shavings, suitably mixed with resins, bonded by moulding to the outside of a mass of fragments of sheet material composed of cardboard and thermoplastic resin-bonded material.
16. Panel as claimed in claim 15, manufactured according to one or more of tie claims from 1 to 14.
CA002127820A 1993-08-06 1994-07-12 Method for manufacturing panels and panels obtained thereby Expired - Fee Related CA2127820C (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ITMI93A001786 1993-08-06
IT93MI001786A IT1265062B1 (en) 1993-08-06 1993-08-06 METHOD FOR THE CONSTRUCTION OF PANELS AND PANELS SO OBTAINED

Publications (2)

Publication Number Publication Date
CA2127820A1 CA2127820A1 (en) 1995-02-07
CA2127820C true CA2127820C (en) 2000-03-14

Family

ID=11366786

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002127820A Expired - Fee Related CA2127820C (en) 1993-08-06 1994-07-12 Method for manufacturing panels and panels obtained thereby

Country Status (14)

Country Link
EP (1) EP0637488B1 (en)
JP (1) JPH0768579A (en)
AT (1) ATE158220T1 (en)
CA (1) CA2127820C (en)
DE (1) DE69405665T2 (en)
DK (1) DK0637488T3 (en)
ES (1) ES2107740T3 (en)
FI (1) FI943636A (en)
GR (1) GR3025553T3 (en)
HU (1) HU215067B (en)
IT (1) IT1265062B1 (en)
NO (1) NO308513B1 (en)
PL (1) PL174630B1 (en)
SI (1) SI0637488T1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB0110873D0 (en) * 2001-05-03 2001-06-27 Hyperlast Ltd Burglar resistant materials
CN101065508B (en) 2004-11-26 2010-11-03 杰富意钢铁株式会社 Steel pipe having excellent electromagnetic properties and process for producing the same

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2686143A (en) * 1942-04-25 1954-08-10 Fahrni Fred Process for manufacturing a composite wooden board
GB1267918A (en) * 1968-07-23 1972-03-22 Amos Roy Paske Improvements in or relating to particle board
DE2622294A1 (en) * 1976-05-19 1977-12-01 Hubertus Schmid Composite board contg. wood chips and other waste - esp. with wood facings and core different materials
US4382108A (en) * 1981-12-21 1983-05-03 The Upjohn Company Novel compositions and process
CA2014089C (en) * 1989-07-21 1997-01-14 Vernon L. Lamb Apparatus and method for making pressboard from poly-coated paper using relative movement of facing webs

Also Published As

Publication number Publication date
NO942916D0 (en) 1994-08-05
NO942916L (en) 1995-02-07
PL304572A1 (en) 1995-02-20
ITMI931786A0 (en) 1993-08-06
ITMI931786A1 (en) 1995-02-06
EP0637488A1 (en) 1995-02-08
FI943636A (en) 1995-02-07
GR3025553T3 (en) 1998-03-31
DE69405665D1 (en) 1997-10-23
DE69405665T2 (en) 1998-04-09
ES2107740T3 (en) 1997-12-01
ATE158220T1 (en) 1997-10-15
JPH0768579A (en) 1995-03-14
FI943636A0 (en) 1994-08-05
IT1265062B1 (en) 1996-10-28
HU9402172D0 (en) 1994-09-28
HU215067B (en) 1998-09-28
SI0637488T1 (en) 1998-04-30
DK0637488T3 (en) 1997-10-27
CA2127820A1 (en) 1995-02-07
PL174630B1 (en) 1998-08-31
HUT71820A (en) 1996-02-28
NO308513B1 (en) 2000-09-25
EP0637488B1 (en) 1997-09-17

Similar Documents

Publication Publication Date Title
US3718536A (en) Composite board and method of manufacture
US5134026A (en) Process for manufacturing a compression-moulded synthetic resin object and fabricated material for use in said process
US3493527A (en) Moldable composition formed of waste wood or the like
US4111730A (en) Producing recycle composition paper flake board
US5624616A (en) Method for co-refining dry urban wood chips and blends of dry urban wood chips and thermoplastic resins for the production of high quality fiberboard products
CN101405318A (en) Carpet waste composite
US20080145619A1 (en) Cellulosic article having increased thickness
RU1836210C (en) Method of profiled plates manufacturing
US5374474A (en) Composite board and method of manufacture
JP2603905B2 (en) Manufacturing method of molded products
RU2755311C1 (en) Method for manufacturing wood-fiber panel
CA2127820C (en) Method for manufacturing panels and panels obtained thereby
US20230227655A1 (en) Process for Manufacturing Components from Reclaimed Textile Fabric Products
WO2022109118A1 (en) Composite building materials and methods of manufacture
EP0358119B1 (en) A method for the manufacture of fibreboards
SU1097505A1 (en) Method of manufacturing moulded articles from thermoplastic dispersions and wooden particles
WO1994026515A1 (en) Method for the preparation of board
RU2106243C1 (en) Article press molding method
RU2048289C1 (en) Method of manufacturing the wood-particle boards with two-sided facing
US20040032054A1 (en) Compression molded panels
JPS6145948B2 (en)
JPH10100115A (en) Composite fiber board and manufacture thereof
MXPA97008054A (en) Method for co-refining dry pieces of urban wood and mixtures of dry pieces of urban wood and thermoplastic resins for the production of high quality board products

Legal Events

Date Code Title Description
EEER Examination request
MKLA Lapsed