A method for manufacturing of protective packaging

Abstract

 A method for manufacturing of protective packaging, comprising attaching a bubble wrap (202) to the surface of cardboard (201), comprising the steps of cutting a sheet from the bubble wrap (202), the sheet having a size equal to the rectangular form of the cardboard, applying by a gluing unit (106) adhesive substance (203) on the whole surface of the rectangular cardboard form, attaching and pressing the bubble wrap sheet (202) to the form (201), the bubble wrap sheet comprising rows of bubbles, drying the cardboard with attached bubble wrap, cutting a desired die-cut of the packaging (330) on a die (320) equipped with cutting blades (321) and making creasing lines by using pairs of creasing knives (322, 323), wherein the creasing knives (322, 323) of each pair are set parallel to each other at a distance (D) larger than a distance (d1) between the neighbouring bubbles in a row and smaller than the diameter (d2) of a single bubble.

Description

[0001] This present invention relates to a method for manufacturing of protective packaging.

[0002] Protective packagings are particularly useful for packing and securing parts, elements, products subject to mechanical damage, brittle materials and materials with sensitive varnished surfaces.

[0003] One of the common protective materials is bubble wrap. Bubble wrap is currently one of the most reliable means of protection for fragile products in transport and storage. However, bubble wrap is usually the internal layer of packaging, and the necessary protection of products for transportation requires external layer as well. Products wrapped in bubble wrap are usually put into cardboard packaging, which constitutes the final packaging for transportation.

[0004] There is also a type of packaging in the form of cardboard boxes with its internal protective layer made of bubble wrap attached to one of the box walls. For example, an American patent no. US6676011 features a packaging box resistant to mechanical impact and shocks. The box contains a protective bag made of bubble wrap and attached to the internal surface of one of the box walls. The bag has a hole for placing a packaged item through it. The box is additionally equipped with tightening bands to close up the filled bag.

[0005] Another patent, no. GB2283008, features an insulating paper box, consisting of the main part and stiffening part, between which an insulating layer is inserted. The insulating layer is a plastic resin foam, its role is to protect the product inside the box against any damage.

[0006] Another well known and widely used type of protective packaging is bubble envelope. Such envelope is described for example in the American patent description no. US20060113360 A1. The envelope is made of two panels: front and rear, joined at the bottom and side edges, whereas the panels have external and internal cushion layer made of bubble wrap. Such packages, however, cannot be used for all kinds of products, especially for large-size products.

[0007] The aim of the invention is the development of a new, alternative method of manufacturing protective packaging, which will facilitate the production of easy-to-use packaging which guarantees reliable protection of packaged products.

[0008] The object of the invention is a method for manufacturing of protective packaging, comprising attaching a bubble wrap to the surface of cardboard, comprising the steps of cutting a sheet from the bubble wrap, the sheet having a size equal to the rectangular form of the cardboard, applying by a gluing unit adhesive substance on the whole surface of the rectangular cardboard form, attaching and pressing the bubble wrap sheet to the form, the bubble wrap sheet comprising rows of bubbles, drying the cardboard with attached bubble wrap, cutting a desired die-cut of the packaging on a die equipped with cutting blades and making creasing lines by using pairs of creasing knives, wherein the creasing knives of each pair are set parallel to each other at a distance larger than a distance between the neighbouring bubbles in a row and smaller than the diameter of a single bubble.

[0009] Preferably, in selected areas a series of more than two creasing knives are used, set parallel to one another at a distance larger than the distance in a row between the neighbouring bubbles of bubble wrap and smaller than the diameter of a single bubble.

[0010] The advantage of the invention is the complete automation of the production process which allows for production of protective packaging in a continuous cycle. An important element of this solution is the movement of bubble wrap by means of the one conveyor belt, and the movement of cardboard by means of the second conveyor belt, over which the gluing unit is placed; by using the controller of the gluing unit the movement of both belts can be synchronized, whilst the sensor detects the presence of cut-off element of bubble wrap of a size corresponding to the cardboard form. The identical size of bubble wrap and form allows to attach the bubble wrap to a whole surface of cardboard form, which prevents the bubble wrap from tearing off the edge. Packaging manufactured accordingly to the invention is cheap due to the use of standard components connected in simple way. Thus manufactured flat cardboard with bubble wrap will allow the cut and introduction of folding line in a further process to obtain any shape of protective packaging for various purposes.

[0011] The present invention is shown by means of exemplary embodiment on a drawing, in which:

Fig. 1 presents the block diagram of the technological process of manufacturing protective packaging.

Fig. 2 presents a diagram of the technological line for gluing corrugated cardboard forms with bubble wrap.

Fig. 3 presents a diagram showing the method of joining cardboard and bubble wrap.

Fig. 4 presents a diagram of a sample die-cut obtained from a form with bubble wrap (bubble wrap form).

[0012] Bubble wrap (in the form of tape wound on a roll) is put on the unwinder 101 whilst full-size (600 x 500 mm to 1600 x 1100 mm) corrugated cardboard formats are placed on the feeder 102. The diameter and width of the bubble wrap roll depends on the settings regarding the width of the coated cardboard form. The forms are made of corrugated three-layer, five-layer or seven-layer cardboard.

[0013] Afterwards, the bubble wrap tape, mounted on pneumatic expanding spindle, is unwound from the roll using the unwinder 101 to the tape feeding unit 103, which unwinds the tape by slightly stretching it. During the setting cycle, the tape unwinding is secured by the spindle drive motor with transmission, whilst during the work cycle the unwinding is forced by a device cooperating with the unwinder 101. The motor is synchronised with the drive of the feeding unit 103, which prevents uncontrolled unwinding of tape. The unwinder 101 has speed governor used to adjust the rotational speed of the expanding spindle depending on the changing pull tension of bubble wrap tape between the unwinder and the bubble wrap feeding unit. The unwinding speed is adjusted by control rolls located on the body of the unwinder, at the external diameter after placing the bubble wrap.

[0014] The next step includes delivering of the tape by the feeding unit 103 to the cut off unit 104, where the stretched and unwound tape is cut into sheets. The cut off unit provides horizontal and vertical adjustment for the appropriate setting of the cutting blade. After receiving the signal from the tape length counter and adjusting the pneumatic distributor, the piston of the rodless cylinder moves perpendicularly to the bubble wrap tape edge, cutting the predetermined section of the bubble wrap. After cutting the tape and pressing the microconnector, the piston rod of the cylinder remains in the home position to the moment of receiving a second signal from the length counter.

[0015] A route measure unit, comprised in the cut off unit, is equipped with a rotary impulse transmitter to generate impulses necessary to measure the length of cut sheets of the bubble wrap tape and to measure the speed of tape movement. The unit is installed on the base frame in front of the cut off unit. The linear speed and the length of the cut of bubble wrap tape for the forms are controlled by the operator and displayed on a counter installed on the main control panel.

[0016] The cut-off bubble wrap sheets are transported to the gluing unit 106 using the conveyor belt 105. Concurrently, the conveyor belt 105 connects the bubble wrap sheets to corrugated cardboard forms cut to the same size. The correct setting of bubble wrap tape sheets in relation to the corrugated cardboard forms facilitates the use of electronic activation and control system, which operates along the whole conveyor belt and gluing line sections. The conveyor belt 105 is composed of two belts allowing the travel of cut-off bubble wrap sheets in the upper part of the device, where they are cut off and transported to the feeding-gluing line located at the lower part. The bubble wrap sheets adhere to the surface of conveyor belts thanks to vacuum pumps sucking the air from the belt surface and thus ensuring the adhering in vertical position and in connection with the upper conveyor belts. The bubble wrap feeding unit may be adjusted both horizontally and vertically by means of its mechanical adjustment control. The horizontal travel allows aligning with the line located below, whilst the vertical travel provides introducing the device to the area of the device for feeding cardboard forms (cross-operation).

[0017] Concurrently, together with bubble wrap sheets, the gluing unit 106 receives cardboard forms from the feeder 102. The feeder 102 is composed of two conveyor belts. The first belt allows the travel of cut-off cardboard forms from the loading station to the feeder beneath the glue rollers. The second belt transports the cardboard through the glue rollers and cut-off bubble wrap sheet discharge station. Cardboard form adheres to the surface of conveyor belts thanks to a vacuum pump sucking the air from the belt surface and thus ensuring the removing of lower form. The number of forms is governed by a photocell system, which stops the bubble wrap feeding process if no cardboard forms are present. The side walls at the loading station, mounted on upper slides, in a beam screwed down to the frame tied to the body, are designed to lead the cut-off cardboard forms. A scale is drawn on the beam, which facilitates the setting of side walls in order to limit the input of cardboard forms. A motor with transmission and cogged belt, generating rotation for conveyor belt shafts, are mounted on the side wall bracket. Work parameters, i.e. motor speed and form feeding frequency, can be set on the operating panel.

[0018] Forms and bubble wrap sheets transported to the gluing unit 106 are glued together with adhesive substance, preferably vinyl polyacetate. The method of joining the form 201 and bubble wrap sheet 202 is presented in Fig. 3. The gluing unit delivers glue to the roller unit and covers the cardboard forms 201 with a glue layer 203 in order to attach cut-off bubble wrap sheets 202 to its surface; the bubble wrap sheet is attached at the bubble side. The glue is transported from the glue tank to the area of connection between the rollers and cardboard form 201, using pumps. Ball valves allow power cut-off to a selected nozzle. Switching on the power of the gluing unit, including switching the pump and electromagnet of the glue valve, triggers the delivery of glue to the gluing area on rollers, in the amount specified on the panel. The amount of glue should be limited to the necessary minimum ensuring the right course of the gluing process. The gluing unit is controlled using the operator's panel and keyboard located on the front wall of the control panel. With their assistance one can increase and decrease the amount of glue delivered on the glue rollers (feeding frequency). Excess glue is carried away to the tank by a pipe system.

[0019] Cardboard forms joined with bubble wrap are then transported with the help of belt conveyor 107. During the transport of ready glued forms, controlled pressure is invoked from above using pressing tape, for the successful course of gluing process preventing the possibility of mutual displacement. The transporter is made of welded base and movable upper frame. The lower base contains rollers driven by a motor with transmission and covered with a plastic belt on which the cardboard forms with bubble wrap attached are transported. The upper frame is equipped with several sets of self-aligning rollers covered with plastic tape. The pressure depends on the pneumatic system of lifting and dropping the frame, programmed at the control panel. Change of the form size does not require replacement of the technological equipment or changes in work parameter settings. The transporter is controlled using the main panel.

[0020] The next step involves transport of the bubble wrap forms using the transporter 108 with drying unit in a closed, heated casing. The drying unit accelerates the gluing process before the joined forms leave the production line for the outlet table 109. The transporter is composed of welded base and movable upper frame. The frame is lifted and dropped by pneumatic system and controlled using the control panel. The lower base contains rollers driven by a motor with transmission and covered with plastic belts on which the cardboard forms with bubble wrap attached are transported. The upper casing has a heating unit with a blower. Change of the form size does not require replacement of the technological equipment or changes in work parameter settings. The transporter with drying unit is controlled using the main panel, as with the pressure transporter.

[0021] During the last step ready bubble wrap forms leaving the production line are placed on the outlet table 109. The outlet table 109 is equipped with a lifting mechanism. The lifting and dropping of the table is possible thanks to a motor with a transmission. The presence of a specific number of bubble wrap forms is signalled by optical sensors. This signal actuates dropping of the table to specified value, which allows for further loading until the maximum limit is reached. When the pallet is fully loaded with forms, it is pushed down the roll conveyor to the unloading station, from where it is transported to the outlet station with a forklift or pallet jack.

[0022] Thus prepared forms coated with bubble wrap are cut on the die 110 into target shapes. Afterwards, the folding lines are creased and/or perforated.

[0023] Fig. 4 presents a sample die-cutting of packaging using the method according to the invention, demonstrating the raw forms with bubble wrap 310, the die 320 and the obtained die-cut 330 respectively. The die 320 has cutting blades 321 for cutting through the forms and creasing knives 322, 323 for making creasing lines. The creasing knives 322, 323 are different from typical creasing knives in a way that for each creasing line a pair of knives 322, 323 is used. The knives are set parallel to one another at a distance D larger than the distance d1 in a row between the neighbouring bubbles of bubble wrap and smaller than the diameter d2 of a single bubble. Such creasing knives guarantee that the width of the creasing lines which are not parallel to a bubble line 211 (in the picture the bubbles are set in horizontal lines) is at least equal to the width of one bubble 211. In the sample die-cut 330 the grey colour represents the bubbles 331, 332, 333 which have been punctured by cutting or creasing knives. As can be seen, the horizontal line of bubbles 333 has a width of a single bubble. The vertical lines of bubbles 331, 332 have a width of approx. one and a half bubble, as the bubbles set next to one another along the vertical line have been punctured. Thanks to the above, each creasing line is accordingly wide and the packaging is easy to assemble. In the areas where bubbles are undesired, for example in the bubble area 334 - a side glue flap, more than two parallel creasing knives 324 can be used, set parallel to one another at a distance D larger than the distance d1 in a row between the neighbouring bubbles of bubble wrap and smaller than the diameter d2 of a single bubble. Such set of knives 324 is used to puncture all bubbles in a given area so that flat surface can be obtained and also to facilitate folding this area in the direction of the neighbouring areas, for example to join them.

[0024] After the necessary cuts, creases and/or perforations on the die 110 have been made, the die-cuts are glued and folded, using the folder-gluer 111, to their functional, box forms. The method also allows for an alternative way of joining die-cuts, with more than just gluing.

Claims

1. A method for manufacturing of protective packaging, comprising attaching a bubble wrap (202) to the surface of cardboard (201), characterized by comprising the steps of:

- cutting a sheet from the bubble wrap (202), the sheet having a size equal to the rectangular form of the cardboard,

- applying by a gluing unit (106) adhesive substance (203) on the whole surface of the rectangular cardboard form,

- attaching and pressing the bubble wrap sheet (202) to the form (201), the bubble wrap sheet comprising rows of bubbles,

- drying the cardboard with attached bubble wrap,

- cutting a desired die-cut of the packaging (330) on a die (320) equipped with cutting blades (321) and making creasing lines by using pairs of creasing knives (322, 323), wherein the creasing knives (322, 323) of each pair are set parallel to each other at a distance (D) larger than a distance (d1) between the neighbouring bubbles in a row and smaller than the diameter (d2) of a single bubble.

2. The method according to claim 1, wherein in selected areas a series of more than two creasing knives are used, set parallel to one another at a distance (D) larger than the distance (d1) in a row between the neighbouring bubbles of bubble wrap and smaller than the diameter (d2) of a single bubble.

Drawing