PACKING CUSHION AND METHOD OF MANUFACTURING SAME

Abstract: The invention relates to a packing cushion made of chemical pulp fibre and to a method of manufacturing the packing cushion. The method is for manufacturing a packing cushion made of chemical pulp fibre and having a projecting structure. According to the invention, the projecting structure of the packing cushion comprising several projecting parts is formed of a wall of a solid-state packing cushion blank made of chemical pulp fibre.

Description: PACKING CUSHION AND METHOD OF MANUFACTURING SAME BACKGROUND OF THE INVENTION [0001] The invention relates to a packing cushion made of chemical pulp fibre and comprising a carrier structure having a projecting structure comprising several projecting parts. [0002] The invention also relates to a method of manufacturing a packing cushion made of chemical pulp fibre and having a projecting structure. [0003] Packing cushions are used in packings to protect the packed articles, such as electronic devices or other devices sensitive to vibration or other articles. [0004] Polyethylene or polystyrene are, for instance, known. These materials are, however, made of non-renewable natural resources and on the other hand, they are problematic in view of recycling. [0005] In addition, a packing cushion made of chemical pulp fibre is known. The present packing cushion is in its basic type one made of chemical pulp fibre. [0006] Known packing cushions made of chemical pulp fibre are, however, made of chemical pulp fibre in fluidized state, i.e. of a mixture of fluid and fibres, by feeding the mixture into a closed mould, in which the mixture obtains the shape of the packing cushion with its projecting structure, after which fluid is drained from the mixture to solidify the shape of the packing cushion. Egg cartons are manufactured in the above manner. The known solution in question does, however, have problems relating, for instance, to the structures required by fluidization and draining the fluid from the mould, and to energy requirements. A known packing cushion of chemical pulp fibre is made of recycled paper which may thus have ink remains or other harmful ingredients. BRIEF DESCRIPTION OF THE INVENTION [0007] It is an object of the invention to develop a novel packing cushion and method which provide a packing cushion which is easily manufactured with simple equipment and has good strength and cushioning properties. [0008] To achieve the above-mentioned object, the packing cushion of the invention is characterized in that the projecting structure of the packing cushion is a projecting structure formed of said carrier structure which is in solid state. [0009] To achieve the above-mentioned object, the method of the invention is characterized in that the projecting structure of the packing cushion is formed of a wall of a solid-state packing cushion blank made of chemical pulp fibre. [0010] The invention is based on using a solid-state blank. [0011] The packing cushion and method of the invention provide the advantage that less energy is needed and the equipment structures are simpler. Using first-run pulp as the raw material for the packing cushion according to a preferred embodiment of the invention means that the product composts easier after use, it is better suited for burning after use and it is better suited for re-pulping. BRIEF DESCRIPTION OF THE FIGURES [0012] The invention will now be described by means of preferred embodiments with reference to the accompanying drawings, in which Figure 1 shows a skeleton diagram of the manufacturing apparatus used in the method, Figure 2 shows a top view of a blank made of chemical pulp fibre, Figure 3 shows a side view of the blank of Figure 2 in the direction of the surface, Figure 4 shows a blank having shaped outer edges, Figure 5 shows a packing cushion having a projecting structure and made from the blank of Figure 4, Figure 6 shows a side view of Figure 5, Figure 7 shows a projecting-part press, Figure 8 shows the projecting-part press in the direction of travel of the blank when the press is in its low position, Figure 9 shows the projecting-part press perpendicularly transverse to the direction of travel of the blank when the press is in its low position, Figure 10 shows the projecting-part press in the direction of travel of the blank when the press is in its high position. DETAILED DESCRIPTION OF THE INVENTION [0013] First, reference is made to Figure 1 which shows the manufacturing apparatus used in the method. Some of the parts 1 to 6 in Figure 1 are necessary, others are optional parts according to preferred embodiments. Figure 1 shows a manufacturing line 10, on top of which a packing cushion blank 11 is placed. The blank 11 is a dry solid-state piece having a dryness of 92%, for instance, i.e. its moisture content is 8%. [0014] In a preferred embodiment, the apparatus comprises an evaporator 1 or another softening unit 1 with which the dryness of the blank 1 1 is slightly reduced. The dryness of the blank is preferably reduced by a few percent to make the shaping done in the apparatus 4 easier, especially if the blank is relatively large. The apparatus also comprises a cutting unit 2 with which the contours of the outer edge of the blank can be formed to achieve the shape in Figure 4. The apparatus in the preferred embodiment further comprises a device 3 adding an additive, such as a hydrophobizing agent, for instance glue, and its most important part, i.e. a press unit 4 or another corresponding unit 4 for producing a projecting structure 12 to the blank 11. The apparatus in the preferred embodiment further comprises a drying unit 5, i.e. a maturing unit 5, in which the glue or other hydrophobizing agent added earlier by the device 3 can be dried to achieve hydrophobicity. As a sixth part in the preferred embodiment, the apparatus comprises another cutting unit 6 for making openings or other additional weakenings to improve the cushioning properties of the packing cushion. The treatment device 3 can, instead of or in addition to the hydrophobizing agent, add an anti-corrosion agent and/or antistatic agent to the packing cushion blank. [0015] With reference to Figure 5 and item 130, the method in the preferred embodiment is, however, such that weakening openings 130 are formed before the projecting parts are formed, because cutting both before and after the forming of the projecting parts is then not needed. [0016] Figure 2 shows a preferably sheet-like packing cushion blank 11 from the top, i.e. as seen towards the surface of the packing cushion, whereas Figure 3 shows the blank of Figure 2 from the side, i.e. as seen in the direction of the surface. The packing cushion blank 11 is a preferably planar piece made of pulp stock, most preferably a sheet, for instance a sheet obtained from a sheeting machine in pulp production. The blank 11 is thus preferably made of pure pulp, most preferably first-run pulp, i.e. pulp made of pure wood or vegetable matter. Figure 4 shows a cut packing cushion blank 11 , to which a contour is formed by the cutter 2 of the apparatus of Figure 1. In the embodiment of Figure 4, a blank 11 has been formed, whose contour is cut in such a manner that the blank 11 can be made into a packing cushion having an outer structure with four projecting parts, as shown in Figures 5 and 6. To achieve the contour of Figure 4, the cutting of the contour can be done with a water cutter or puncher, which are illustrated by block 2 in Figure 1. In the preferred embodiment, the blank 11 can be treated by the device 3 with a hydrophobizing agent, such as glue, which later through maturing makes the packing cushion hydrophobic, i.e. moisture-proof, in which case the packing cushion only takes in moisture approximately 1 to 2% per weight. Instead, an untreated pulp material takes in moisture as much as 200% per weight, in which case the packing cushion would be useless. According to the applicant's observations, adding glue or another additive before forming the projecting structure 12, 121 to 124 is a better way than adding it after forming the projecting parts, because the dryness of the blank is reduced during additive treatment, i.e. the blank becomes slightly moist making the formation of the projecting parts easier. The evaporation or other softening done by the unit 1 , and the addition of additive(s) by the device 3 (by spraying or evaporating, for instance) increases the moisture content from 8 to 14%, for instance, whereby the moisture content increases by 6%, for instance, before the projecting parts are formed. The percentages may, however, differ from the above as necessary. [0017] In spite of the reduction of dryness during the pre- evaporation done by the unit 1 and the adding of additives by the device 3, the operation done in the unit 4 is dry-shaping. [0018] The following deals with the most essential part of the invention, i.e. the forming of the projecting structure to the blank. In the example of the figures, the projecting structure 12 has four elements and comprises projecting parts 121 to 124. The projecting parts 121 to 124 are preferably cone-shaped, preferably cup-like; it should, however, be said that 'cup-like' refers specifically to the external appearance of the projecting structure, because a cup-like projecting part can have weakenings, such as openings 130 through it, made by the unit 6, as in Figure 5. 'Cone-shaped' refers especially to tapering, and thus in addition to a circular cone, the cone- shape should be understood to include among other shapes a pyramid-like shape. There may be one or more projecting parts. [0019] The forming of the projecting structure 12, 121 to 124 is preferably accomplished by pressing, i.e. the unit 4 in Figure 1 is a press in a preferred embodiment. In a preferred embodiment, after the projecting structure is formed, maturing, i.e. drying, takes place in the unit 5 to achieve the desired hydrophobicity, i.e. to make the packing cushion moisture-proof. The drying can be done in a convection oven 5, for instance. [0020] In a preferred embodiment, the method is such that before forming the projecting structure 12, 121 to 124, the packing cushion blank is treated with an anti-corrosion agent, such as VCI. This prevents the packing cushion from causing corrosion to the article in the packing cushion. In a preferred embodiment, the method is such that before forming the projecting structure, the packing cushion blank is treated with an anti-static agent, such as EDM. This prevents the packing cushion from producing static bursts causing damage to the article in the packing cushion. [0021] In a preferred embodiment, the packing cushion is treated with a hydrophobizing agent, anti-corrosion agent and anti-static agent at the same time. This is done for instance by making a liquid mixture containing all three agents. The treatment is preferably done by spraying with the device 3. Collective treatment simplifies the method and equipment. [0022] In a preferred embodiment, the dryness of the dry blank was already reduced somewhat during evaporation or softening in the unit 1 , i.e. its moisture content was slightly increased. The above-mentioned additive treatment with the device 3 preferably further reduced the dryness somewhat. [0023] An embodiment of the press 4 is shown in Figure 7. In Figure 7, the press comprises a support structure 41 and a press structure 50 moving in relation to it and a male press-counterpart 60. The moving press structure 50 comprises a moving part 500, a fastening piece 51 and a changeable press head 52 fastened to it. The fastening piece 51 has return chambers 53 which, when moving downward, press a spring 54, located between the support structure and return chamber, together to enable a movement and a corresponding return movement. [0024] When the moving part 500 is moved downward, it moves the press head 52 and the structures fastened to it towards the press counterpart 60. The packing cushion is in the area between the press head 52 and the counterpart 60. The tip of a contact part 55 in the press head 52 touches the packing cushion blank and sets it into place. When the movement continues, the contact part 55 goes inside the press head 52 by means of its spring 56, and the press head 52 can press the blank between a female chamber of the press head 52 and the male press-counterpart 60. [0025] A preferred embodiment of the invention uses a smooth carrier structure as the blank, because its use is less expensive and simpler. A corrugated carrier structure is thus not used, in which the corrugation of the blank would be intended to allow, due to the tensility of the blank, to create all projecting parts at the same time. The preferred embodiment of the invention thus functions by creating the projecting parts one at a time. This way, only one press is required and not as many as there are projecting parts. This saves equipment costs. As shown in Figures 8 to 10, the equipment comprises means 101 , 102 for providing the reciprocal movement of the packing cushion blank and the part 52, 60 forming the projecting parts. The means 101 makes a z movement, i.e. in z direction moves the part forming the projecting parts in relation to the packing cushion blank 111. The means 101 is a servo motor, for instance. The means 102 is a transporter or a conveyor, such as a chain conveyor, which makes an x movement, i.e. moves the packing cushion blank 111 in relation to the part 52, 60 forming the projecting parts. A transporter 500 provides a y movement, i.e. the actual press movement for forming the projecting parts. The equipment parts are in the support structure 100 as in a portal. The blank in Figures 8 and 10 has a different height as in Figure 9. [0026] With reference to Figure 9 in particular, in the preferred embodiment of the invention, the method and packing cushion are such that the projecting parts formed of the carrier structure are in a matrix form in such a manner that there are consecutive projecting parts 11 a to 11d in a first direction and consecutive projecting parts 11d to 11g in transverse direction to the first direction. This produces a structure of several small-sized projecting parts, i.e. a more even support. There may also be a common projecting part, such as 11d, for these mutually transverse directions. The transversal direction is preferably right-angled, i.e. 90 degrees. [0027] With reference to Figures 8 to 10, in the preferred embodiment, the position of the blank 111 is substantially vertical, because the position is then one that can also be used in other steps, such as in the hydrophobizing treatment of the blank. [0028] It is obvious to a person skilled in the art that while technology advances, the basic idea of the invention can be implemented in many different ways. The invention and its embodiments are thus not restricted to the examples described above, but can vary within the scope of the claims.

Claims: CLAIMS 1. A packing cushion made of chemical pulp fibre and comprising a carrier structure having a projecting structure comprising several projecting parts, characterized in that the projecting structure of the packing cushion having several projecting parts is a projecting structure formed of said carrier structure which is in solid state. 2. A packing cushion as claimed in claim 1 , characterized in that the projecting structure is a projecting structure dry-shaped of the carrier structure. 3. A packing cushion as claimed in claim 1 , characterized in that the projecting structure is a projecting structure dry-shaped of the carrier structure by pressing. 4. A packing cushion as claimed in claim 1 , characterized in that the chemical pulp fibre of the packing cushion is at least in 80% first-run chemical pulp fibre. 5. A packing cushion as claimed in claim 1, characterized in that the projecting parts are cone-shaped. 6. A packing cushion as claimed in claim 1 or 5, characterized in that the projecting parts are cup-like. 7. A packing cushion as claimed in claim ^characterized in that the carrier structure is a smooth uncorrugated carrier structure. 8. A packing cushion as claimed in claim 1, characterized in that the projecting parts made of the carrier structure are in a matrix form in such a manner that there are consecutive projecting parts (11a to 11 d) in a first direction and consecutive projecting parts (11 d to 11g) in transverse direction to the first direction. 9. A method of manufacturing a packing cushion made of chemical pulp fibre and having a projecting structure, characterized in that the projecting structure of the packing cushion having several projecting parts is formed of a wall of a solid-state packing cushion blank made of chemical pulp fibre. 10. A method as claimed in claim 9, characterized in that the projecting structure is formed by pressing the packing cushion blank. 11. A method as claimed in claim 9, characterized in that before the projecting structure is formed, the packing cushion blank is treated with a hydrophobizing agent. 12. A method as claimed in claim 11, characterized in that the hydrophobizing agent is glue. 13. A method as claimed in claim 11 or 12, characterized in that the packing cushion comprising the hydrophobizing agent is matured to achieve hydrophobicity. 14. A method as claimed in claim 13, characterized in that the maturing is done after the projecting structure is formed. 15. A method as claimed in claim 9, characterized in that before the projecting structure is formed, the packing cushion blank is treated with an anti-corrosion agent. 16. A method as claimed in claim 9, characterized in that before the projecting structure is formed, the packing cushion blank is treated with an anti-static agent. 17. A method as claimed in claim 9, characterized in that before the projecting structure is formed, the contour of the outer edge of the packing cushion is formed. 18. A method as claimed in claim 17, c h a ra cte ri ze d in that the contour of the outer edge of the packing cushion is formed with water cutting or punching. 19. A method as claimed in claim 9, characterized in that before the projecting parts are formed, weakening openings are formed in the packing cushion blank in one or more locations where a projecting part is to be formed. 20. A method as claimed in claim 9, characterized in that the packing cushion blank to which the projecting structure is formed is sheetlike. 21. A method as claimed in claim 9, c h a ra cte ri ze d in that the packing cushion blank to which the projecting structure is formed is a smooth uncorrugated packing cushion blank. 22. A method as claimed in claim 9, characterized in that the projecting parts are formed one at a time.

Inventors: ALATARVAS KARI, SIIMES ASLAK, ALATARVAS, KARI, SIIMES, ASLAK
Applicants: ALATARVAS KARI, MASIJET OY, SIIMES ASLAK, ALATARVAS, KARI, SIIMES, ASLAK
Application year: 2001
Main classification: B65D81
IPC codes: B65D81