CHIPBOARD AND METHOD OF ITS MANUFACTURING

Abstract

 The chipboard consisting of organic particles of a synthetic resin composite, characterised in that it contains from 10 to 60% by weight of grounded composite, from 5 to 60% by weight of synthetic resin and from 10 to 85% by weight of organic particles, in particular wood and vegetable particles or fibres or compositions of these components. The object of the invention is also a method for manufacturing chipboard.

Description

[0001] The object of the invention is a chipboard consisting of organic particles, composite and synthetic resins, and its manufacturing process.

[0002] Document CN107206734A discloses a composite board consisting at least partly of a non-woven composite, wherein the non-woven composite comprises: natural fibre and/or dispersed glass fibre, ductile optical fibre, and 0 to 50% by weight of thermal hardening agents. The invention relates also to chipboard (PB), medium density fibreboard (MDF) and high density fibreboard (MDF-HDF), oriented strand board (OSB), laminated veneer lumber (LVL), plywood (PLW), and related materials.

[0003] The currently known solutions do not provide an adequate level of water resistance and thermal and electrical insulation of the board or electrical conductivity. Previous solutions require the use of 50 to 60% of binder in the form of epoxy and polyester resins.

[0004] A chipboard consisting of organic particles of a composite of synthetic resins according to the invention is characterized in that it comprises from 10 to 60% by weight of the particulate composite, from 5 to 60% by weight of the synthetic resins and from 10 to 85% by weight of organic particles, in particular wood and vegetable particles or fibres or compositions of these components.

[0005] Preferably, the composite is grounded to a 1D form, wherein in this form, the dimensions of the mixture of particles are: length of 1-4 mm, thickness up to 1 mm.

[0006] Preferably, the composite is grounded to a 2D form, wherein in this form the dimensions of the particles of the composite are: length of 5-200 mm, width of 1-30 mm, and thickness of 0.2-2 mm.

[0007] Preferably, the composite constitutes from 10 to 40% by weight of the chipboard. Preferably, the synthetic resins constitute from 5 to 20% by weight of the chipboard.

[0008] In another aspect, an object of the invention is a method for manufacturing chipboard, characterised in that:

1) the composite is grounded;

2) the ingredients from 10 to 60% by weight of grounded composite, from 5 to 60% by weight of the synthetic resins and from 10 to 85% by weight of the organic particles are mixed together;

3) the mixture is placed in a mould or on a moulding plate or on a forming belts at a temperature from 18 to 250°C;

4) a two-stage pressing is carried out at temperatures from 18 to 250°C, wherein the first step comprise alignment or arrangement of the filler and matrix particles and enable the degassing of the composite, while the second step comprise providing the final thickness at a temperature from 18 to 250°C and a pressure from 0.02 to 5 MPa.

[0009] Preferably, in order to manufacture a multilayer board, a mat is formed such that an outer layer containing from 0 to 60% by weight of the grounded composite is formed, then a middle layer containing from 10 to 70% by weight of the grounded composite is formed and then an upper outer layer containing from 0 to 60% by weight of the grounded composite is formed, wherein the proportion of the middle layer is from 50% to 90% by weight of the manufactured board.

[0010] Preferably, the composite is grounded to a 1D form, wherein in this form, the dimensions of the mixture of particles are: length of 1-4 mm, thickness up to 1 mm.

[0011] Preferably, the composite is grounded to a 2D form, wherein in this form the dimensions of the particles of the composite are: length of 5-200 mm, width of 1-30 mm, and thickness of 0.2-2 mm.

[0012] Preferably, the composite constitutes from 10 to 40% by weight of the chipboard . Preferably, the synthetic resins constitute from 5 to 20% by weight of the chipboard .

[0013] The object of the invention is represented below in an embodiment.

[0014] The chipboard according to the invention is manufactured as follows:

1) the composite is grounded;

2) the ingredients from 0 to 60% by weight of grounded composite, from 10 to 60% by weight of the synthetic resins, and from 0 to 90% by weight of the organic particles are mixed together;

3) the mixture is placed in a mould or on a moulding plate or on a forming belts at a temperature from 18 to 250°C;

4) a two-stage pressing is carried out at temperatures from 18 to 250°C, wherein the first step comprise alignment or arrangement of the filler and matrix particles and enable the degassing of the composite, while the second step comprise providing the final thickness at a temperature from 18 to 250°C and a pressure from 0.02 to 5 MPa.

[0015] The grounded composite used may be a glass-epoxy composite, glass-polyester composite, carbon-epoxy composite, or carbon-polyester composite, while glass and carbon fibres can exist simultaneously in a milled composite bonded with synthetic resins. The grounded composite originates from the recycling of wind turbine or yachts and boats composite propellers or composite panels or other composite structures and articles or is a mixture of composites of said or other origin.

[0016] In the case of multilayer boards, a mat is formed such that an outer layer containing from 0 to 60% by weight of the grounded composite is formed, then a middle layer containing from 10 to 70% by weight of the grounded composite is formed and then an upper outer layer containing from 0 to 60% by weight of the grounded composite is formed, wherein the proportion of the middle layer is from 50% to 75%, even up to 90%, by weight of the manufactured board.

[0017] The composite used to manufacture the board according to the invention may be ground to a 1D form, wherein in this form, the dimensions of the mixture of particles are: length of 1 mm, thickness up to 1 mm, or to a 2D form, wherein in this form the particle dimensions are: length of 5-200 mm, width of 5-30 mm and thickness of 0.2-2 mm. The grounded 2D and 1D composite is used to manufacture OSB - type chipboard , while the grounded 1D composite is used to make chipboard , fibre board, and MDF.

[0018] The grounded composite does not absorb the binder and therefore its use leads to reduced binder (resin) consumption-the resin applied to the particles does not penetrate into their interior so that its amount is less than would be necessary to cover an equivalent amount of wood or plant particles. Therefore, as a result of the lack of absorbability, the amount of resin needed to bond the particles of the composite board is less than an equivalent amount of wood chips.

[0019] As a result of grinding, the composite has uneven, rough/porous surfaces, which makes it easy to combine by entanglement with wood or plant chips.

[0020] Due to the specific weight of the composite, which averages 1800 kg/m³, it is optimal to use 10 to 40% by weight of the composite addition to the chipboard,
A maximum of 60% by weight of the composite content in the board is allowed.

[0021] The use of ground composite causes an increase in the hardness of the board, i.e. the more composite, the harder the board is.

[0022] The use of a higher content of ground composite in the outer layer of the mix causes an increase in its water resistance.

[0023] Generally available synthetic resins are used for bonding chips and composite. 5-20% of synthetic resin per board weight is sufficient for bonding chips and composite.

[0024] Depending on the type of resin, resin consumption can also be below 5% when using expensive resins.

[0025] The pressing temperature of the boards is from 18 to 250°C, at a pressure of 0.2-5.0 MPa.

[0026] The chipboard according to the invention has been tested to determine its physical and mechanical properties.

1. Object of the test

[0027] The object of the test was to evaluate the physical and mechanical properties of chipboard having a thickness of 16 mm, containing additives of composites derived from ground fragments of turbine propeller. The sheets did not have regular shapes and had numerous cuts and holes resulting from other tests. As described, on the provided sheets, the proportion of grounded fragments of turbine propeller was 10%, 20%, 30%, and 40%. The evaluation was performed together for all variants.

2. Basis for the evaluation of chipboard properties

[0028] The evaluation of the properties of the provided particleboard sheets was based on the relevant standards:

• static bending strength - PN-EN 310
• modulus of elasticity - PN-EN 310
• tensile strength perpendicular to board planes - PN-EN 319
• swelling to thickness after soaking in water - PN-EN 317
• moisture content - PN-EN 322
• density - PN-EN 323
• the flammability was determined on the basis of a methodology that allows to determine the degree of inflammability of wood and wood - based panels. Board samples having size of approximately 15 x 15 cm were dried for 24 hours at temperature of 102±3°C. After cooling, the samples were placed on a rack allowing the sample to be positioned at 45° relative to the substrate. A spirit burner was placed under the rack so that the distance between the wick and the sample was 5 cm. The flame under the sample was maintained for 3.5 min. After this time, the burner was extinguished, as well as the sample, if it burned with a strong fire. Test samples were weighed before determination and 5 and 60 minutes after determination. The loss of mass of the test sample was calculated on the basis of the difference in masses. Burning or glowing of the sample was observed during combustion of the sample and the time to ignition was recorded. After cooling, the size of the area destroyed by the flame was also determined using a planimeter. Furniture board (PB) having a thickness of up to 18 mm and a density of 650 kg/m³ was used as the reference board.

3. Summary of test results

[0029] The test results for the tested boards are shown in table 1. According to the data presented therein, the tested boards are characterized by an average static bending strength of 9.4 N/mm² and an average modulus of elasticity of 1910 N/mm². The tensile strength perpendicular to the tested planes is 0.21 N/mm². The tested boards deteriorates as a result of damage, delamination of the outer layer. By default, this type of board deteriorates in the middle layer, therefore an additional density profile of the delivered boards was realized. As can be seen from the data in scheme 1, the maximum density is shifted closer to the centre of the boards, so the weaker layers are closer to the outer zones, causing the boards to deteriorate in the layer made of microparticles.

Table 1

Characteristics of tested chipboards
Plate properties	Unit	Requirements of EN 312∗	Tested		Control
humidity	%	-	8.53	0.28	-	-
density	kg/m3	-	695	28.9	653	17.85
fm	N/mm2	11	9.4	1.05	-	-
Em	N/mm2	1600	1910	233	-	-
Swelling	%	-	27.5	4.3	-	-
Absorbability	%	-	77.9	2.6	-	-
ft	N/mm2	0.35	0.21	0.06	-	-
Flammability
Loss of mass	%	-	3.81	-	5.38	-
Burnout depth	mm	-	8.35	-	9.02	-
Burnout surface	cm2	-	55.1	-	61.1	-

∗ - requirements for chipboards with unfinished surface - type P2 - boards for interior applications (including furniture) for use in dry conditions (thickness range > 13 to 20 mm), ∗∗ - standard deviation

[0030] The absorbability of chipboards not treated with additional hydrophobic agents is at the level of 27%-33%, and absorbability is from 60% to as much as 100%, therefore the swelling and absorbability values obtained for the boards tested should be considered satisfactory. As can be seen, the boards tested react better to fire. All evaluated properties for the evaluated boards are lower (better) than for the control board. Therefore, the evaluated board is a board who is less susceptible to fire than the control board

Scheme 1. Density profile

[0031] 

4. Concluding remarks, observations

[0032] The chipboards submitted for testing are characterised by good physical and mechanical properties. The values obtained indicate their high potential in the context of industrial production. The slightly lower values for static bending strength and tensile strength perpendicular to planes do not result from the additives used but from the way they are manufactured in the laboratory. The experience of the Department of Mechanical Wood Technology (pol. Katedra Mechanicznej Technologii Drewna) shows that the quality of a layer manufactured of microparticles under laboratory conditions, is usually much lower than the quality of this layer manufactured under industrial conditions. Since propeller fragments are added to the middle layer, it must be considered that a board so formed under industrial conditions will have even higher mechanical properties than a reference board manufactured entirely of wood chips.

5. Summary

[0033] Boards based on chips and particles or fragments resulting from the grounding of propellers represents new solutions to the current trends of reducing natural resources and phased eradication of raw materials throughout their life cycle. Composites derived from grounded propeller parts can be a valuable substitute for wood chips parts.

[0034] The use of a grounded composite increases the water resistance of the chipboard and the thermal insulation of the chipboard. The use of grounded composite increases the fire resistance of the board due to the non-combustible fibre content of the composite. The use of grounded GFK composite increases the electrical insulation of the chipboard. The use of grounded CFK composite provides the chipboard with an electrical conductivity.

[0035] The use of a ground composite reduces emissions of organic substances (VOC) especially from coniferous wood.

[0036] The use of grounded composites reduces the need for chemicals that reduce emissions of volatile organic compounds in finished boards. The use of ground composites reduces the amount of water required to prepare wood chips. The ground composite does not emit volatile organic compounds. The addition of ground composites reduces the swelling of the board due to moisture by as much as the percentage of composite in the board.

Claims

1. The chipboard consisting of organic particles of a synthetic resin composite, characterised in that it contains from 10 to 60% by weight of grounded composite, from 5 to 60% by weight of synthetic resin and from 10 to 85% by weight of organic particles, in particular wood and vegetable particles or fibres or compositions of these components.

2. Chipboard according to claim 1 characterised in that the composite is grounded to a 1D form, wherein the dimensions of the mixture of particles in this form are: length of 1-4 mm, thickness up to 1 mm.

3. Chipboard according to claim 1-2 characterised in that the composite is grounded into a 2D form, wherein the dimensions of the mixture of particles in this form are: length of 5-200 mm, width of 1-30 mm, and thickness of 0.2-2 mm.

4. Chipboard according to claim 1-3 characterised in that the composite constitute from 10 to 40% by weight of the chipboard.

5. Chipboard according to claim 1-3 characterised in that synthetic resins constitute from 5 to 20% by weight of the chipboard.

6. A method for manufacturing chipboard, characterised in that:

1) the composite is grounded;

2) the ingredients from 10 to 60% by weight of grounded composite, from 5 to 60% by weight of the synthetic resins and from 10 to 85% by weight of the organic particles are mixed together;

3) the mixture is placed in a mould or on a moulding plate or on a forming belts at a temperature from 18 to 250°C;

4) a two-stage pressing is carried out at temperatures from 18 to 250°C, wherein the first step comprise alignment or arrangement of the filler and matrix particles and enable the degassing of the composite, while the second step comprise providing the final thickness at a temperature from 18 to 250°C and a pressure from 0.02 to 5 MPa.

7. The method according to claim 6, characterised in that, in order to manufacture a multi - layer board, a mat is formed such that an outer layer containing from 0 to 60% by weight of the grounded composite is formed, then a middle layer containing from 10 to 70% by weight of the grounded composite is formed and then an upper outer layer containing from 0 to 60% by weight of the grounded composite is formed, wherein the proportion of the middle layer is from 50% to 90% by weight of the manufactured board.

8. The method according to claim 6-7 characterised in that the composite is grounded to a 1D form, wherein the dimensions of the particles in this form are: length of 1-4 mm, thickness up to 1 mm.

9. The method according to claim 6-8 characterised in that the composite is grounded to a 2D form, wherein the dimensions of the particles of the composite in this form are: length of 5-200 mm, width of 1-30 mm, and thickness of 0.2-2 mm.

10. The method according to claim 6-9 characterised in that the composite constitute from 10 to 40% by weight of the chipboard.

11. The method according to claim 6-10 characterised in that that synthetic resins constitute from 5 to 20% by weight of the chipboard.