PROCESS OF INCORPORATING A UNIT OR OBJECT BY MOULDING

Abstract: Process of incorporating one or more units or objects (1) into an article (2), such as a transport and storage container, a waste container, a pallet or the like made of a polymeric material and moulded in a moulding tool (3) provided with at least one mould cavity (4). The unit or object (1) is on at least one side provided with at least one undercut tenon (5) or at least one undercut groove (5'). The mould cavity (4) is provided with at least one undercut groove (10) or at least one undercut tenon (10') corresponding to and intended to be brought into engagement with an equal number of tenons (5) or grooves (5') provided by the unit or object (1). Fixation of the unit or object (1) in an open moulding tool (3) is obtained when the tenon (5) or groove (5') of said unit or object (1) is brought into engagement with the groove (10) or tenon (10') of said mould cavity (4). The moulding tool (3) is thereby closed, molten polymeric material supplied and the mould cavity (4) filled therewith. The unit or object (1) becomes an integrated part of the article (2) made of the moulded polymeric material.

Description: PROCESS OF INCORPORATING A UNIT OR OBJECT BY MOULDING The present invention relates to a process of incorporating one or more units or objects, such as various minor components, units, devices and the like into a moulded article, preferably an injection moulded polymeric article, such as a trans¬ port and/or storage container, a waste container, a pallet or the like. An injection moulding is most suitably performed using a moulding tools provided with at least one mould cavity. The objects are preferably selected among information carrying units and other identifying objects, such as smart cards, radio transmitters and/or receivers, micro processors and other units holding electronic and/or magnetic read/write information. Information carrying units can be characterised as memory units transmitting and/or receiving information for automatic identification of for instance container type, content, owner, destination, etc. Objects or units incorporated into the mate¬ rial are i.a. alternative to such identifying objects as adhesive labels and in various ways mechanically arranged labels and similar objects. Various identifying objects or units are today used on articles such as transport and/or storage containers within the food processing industry and on waste con¬ tainers. The identifying objects are most often labels and other memory units being externally arranged on said articles, which arrangement often includes rivets, clinch nails, clips, label holders, glue and adhesives. An external arrangement and an attachment as disclosed imply damaged or lost identifying objects due to con¬ tinuous handling, harsh treatment, ungenial weather conditions etc., with pendant loss of information. Incorporation of objects, such as various information carrying units, into poly¬ meric materials by injection moulding is by known procedures difficult or requires complex moulding tools having a number of additional moving parts. Furthermore, location and fixation of the object create problems, such as required minimum size (breadth and/or width), mechanical deformation and bad fitting or leakage between the object and the polymeric material. The shear stress during injection of poly¬ meric material is extensive and requires a firm fixation of the object or unit. Known methods used for fixation, during an injection moulding, of objects to be incorporated into a polymeric material include fixation by means of vacuum, fixa¬ tion by means of steps in the moulding tool, squeezing between two or more mould parts and/or moving or stationary holders such as racks, pins, bars, rods etc. arranged in the mould or in parts thereof. The European Patent Application 0 342 237 discloses a procedure, whereby an item to be incorporated into a polymeric material is fixed by means of moving holders being an integrated part of the moulding tool. The item is introduced into the open mould and fixed and held at the accurate position by moving forth the tips of the holders. The mould is then closed and the item is held by the holders during injection of the molten polymeric material. The last stages of the moulding cycle include moving the holders back away from the item to the same plane as the surface of the mould followed by an additional injection of molten polymeric mate¬ rial to fill holes caused by the holders. This procedure display above disclosed dis¬ advantages and in addition thereto an increased tendency to material cracking due to the additional injection resulting in differences in the material temperature, ma¬ terial thickness and shrinkage. Above discussed problems and drawbacks are through the present invention avoided and a simple and reliable process of incorporating a unit or object into a moulded polymeric material is provided. The process includes the use of a mould¬ ing tool without additional moving parts and hence no holes to be filled through an additional supply of polymeric material. The unit or object to be incorporated is on one face side provided with at least one longitudinal undercut tenon or groove. The object is in preferred embodiments provided with least one undercut tenon. The mould cavity of the moulding tool is provided with at least one undercut groove or tenon corresponding to the tenons or the grooves being parts of the unit or object, whereby tenons/grooves on the unit are brought into engagement with corresponding grooves/tenons in the open moulding tool. The unit is securely fixed and held by said grooves and tenons. The moulding tool is closed and molten polymeric material is supplied, preferably by injection, to the closed mould cavity, resulting in an incorporation of said unit or object into said polymeric material. The unit is, when the moulding cycle is com¬ pleted, an integrated part of the injection moulded article. In preferred embodiments wherein the unit or object is provided with at least one tenon, the length of a corresponding groove in the mould cavity exceeds the length of such a tenon, resulting in a small cavity above or beneath the tenon. This small cavity is during injection filled with molten polymeric material, whereby providing a securing heel or the like. The unit or object to be incorporated can, in various embodiments, be provided with one or more upwards and/or downwards directed pegs or the like, which pegs works as vertical fixation means. The mould cavity can alternatively be provided with one or more inwards directed pegs, heads, knobs or the like. The incorporated unit or object is in various preferred embodiments incorporated as a part of or adjacent a profile being an integrated part of the injection moulded article, such as an upper and/or lower rim or a reinforcing web, rib, etc. Incorporated units and objects include advantageously memory units such as smart cards, micro chips, radio transmitters and/or receivers, micro processors or other magnetic and electronic units being able to hold for instance analogue or digital read/write information. The process according to the present invention provides a facilitated incorporation of various units and objects into the polymeric material of injection moulded arti¬ cles. The process furthermore permits a high degree of flexibility with regard to type of unit or object as well as its location. A unit or object incorporated according to the present invention is, with exception for optional pegs and the like and minor portions of the tenons, entirely incorpo¬ rated into the polymeric material. Pegs etc. have preferably a size allowing them to be in level with the material surface, whereby no parts of the unit protrude, thus eliminating the risk of lost information due to damages on the unit or object or parts thereof The lack of joints resulting for instance from additional supply of molten polymeric material imply that any tendency to leakage between incorpo¬ rated unit or object and the polymeric material is non-existent or exceptionally small and negligible. These and other objects and the attendant advantages will be more fully under¬ stood from the following detailed description, taken in conjunction with appended drawings, wherein like reference numerals have been applied to like parts through¬ out the various Figures and wherein: - Figure 1 shows a side view of an embodiment of a moulding tool and a unit to be incorporated, in accordance with the invention, located in a mould cavity. - Figure 2 and 3 show seen from above two different embodiments of moulding tools and units located in mould cavities. - Figure 4 - 7 show various embodiments of units and objects to be incorporated according to the process of the present invention. Figures 4 and 5 are seen from above and Figures 6 and 7 are seen in a view showing a face side provided with one or more tenons. Figure 8 shows a unit incorporated adjacent an upper rim being an integrated part of a transport container. Figure 1 shows in a side view partially and schematically a crosscut of a mould¬ ing tool 3. A unit 1 being of a so called smart card type is located in its 3 mould cavity 4. The unit 1 has an upper part 7 provided with a peg 1 1 for vertical fixa¬ tion of said unit 1 . The unit 1 is furthermore provided with an undercut tenon 5 brought into engagement with a corresponding undercut groove 10 being a part of the mould cavity 4. The groove 10 has a length exceeding that of the tenon 5 resulting in formation of a cavity 9 above the tenon 5. The cavity 9 will during injection of a molten polymeric material be filled therewith, resulting in forma¬ tion of a securing extension 6 (see Figure 8) of the tenon 5. The unit 1 has in this embodiment a lower side 8, which side 8 lacks pegs or similar arrangements for vertical and/or horizontal adjustment. Figure 2 and 3 show seen from above partially and schematically crosscuts of moulding tools 3, wherein a unit 1 of the same type as shown in Figure 1 is placed in respective mould cavity 4. Figure 2 shows a unit 1 having an undercut tenon 5 and a mould cavity 4 having an undercut groove 10 and Figure 3 shows a unit provided with an undercut groove 5' and a mould cavity 4 having an un¬ dercut tenon 10'. The units 1 are fixed in the mould cavities 4 by bringing the tenons 5 and 10' into engagement with respective groove 10 and 5'. Figure 4 and 5 show seen from above schematically crosscuts of units and ob¬ jects 1 to be incorporated, in accordance with the present invention, into an ar¬ ticle 2 made of a polymeric material. The unit 1 shown in Figure 4 is provided with two undercut tenons 5 intended to be brought into engagement with corre¬ sponding grooves 10 (see Figure 2) and the unit 1 shown in Figure 5 is provided with two grooves 5' intended to be brought into engagement with corresponding tenons 10' (se Figure 3). Figure 6 shows in a front view schematically one embodiment of a unit 1 being oval and provided with two upwards directed pegs 1 1 and two downwards coni¬ cal tenons 5. The pegs 1 1 are used for vertical fixation of the unit 1 in a mould cavity 4 (se Figure 1 - 3). Figure 7 shows in a front view schematically one embodiment of a unit 1 being hexagonal and provided with a V-shaped undercut tenon 5. The unit 1 has a design resulting in a cavity 9' inside the "V". The cavity 9' is filled with molten polymeric material and a securing heel consisting of polymeric material is thus formed. - Figure 8 shows a partial view of an injection moulded article 2 made of a poly¬ meric material, in this case a transport container, in which a unit 1 is incorpo¬ rated. A dashed line indicates the unit 1 and its position. The unit 1 is an integrated part of the article 2 and is incorporated adjacent an upper rim 12. The unit 1 is provided with two conical undercut tenons 5. The tenons 5 is levelled with the surface of the polymeric material and is thus not entirely incor¬ porated, but not protruding. Securing extensions 6 are formed above the tenons 5. The extensions 6 are formed in the same way as disclosed under heading Fig¬ ure 1. While particular embodiments of the invention have been shown, it will be under¬ stood, of course, that the invention is not limited thereto since many modifications may be made, and it is, therefore, contemplated to cover by the appended claims any such modifications as fall within the true spirit and scope of the invention.

Claims: CLAIMS 1. Process of incorporating one or more units or objects (1) into an article (2), such as a transport and/or storage container, a waste container, a pallet or the like made of a polymeric material and moulded, preferably injection moulded, in a moulding tool (3) provided with at least one mould cavity (4) characterised in, that i) the unit or object (1) on at least one side is provided with at least one undercut tenon (5) or at least one undercut groove (5'); ii) the mould cavity (4) is provided with at least one undercut groove (10) or at least one undercut tenon (10') corresponding to and intended to be brought into engagement with an equal number of tenons (5) or grooves (5') provided by the unit or object (1); iii) fixation of the unit or object (1) in an open moulding tool (3) is obtained when a tenon (5) or groove (5') on said unit or object (1) is brought into engagement with a groove (10) or tenon (10') in said mould cavity (4), whereby the moulding tool (3) is closed and molten polymeric material is supplied and the mould cavity (4) filled therewith; iv) the unit or object (1) becomes an integrated part of the article (2) made of said moulded polymeric material. 2. Process according to claim 1 c h a ra c te ri s ed i n, that the unit or object (1) is provided with at least one undercut tenon (5) and that the mould cavity (4) is provided with at least one undercut groove (10). 3. Process according to claim 2 c h a ra c t e r i s e d i n, that the groove (10) has a length exceeding that of the tenon (5), whereby a cavity (9) is formed above or below the tenon (5), which cavity (9) during supply of mol¬ ten polymeric material is filled resulting in a securing extension (6) of the te¬ non (5). 4. Process according to claim 2 or 3 c h a racte ris ed i n, that the unit or object (1) is provided with one or more pegs (11), heels or the like for vertical fixation of the unit or object (1) before and during supply of molten polymeric material. 5. Process according to any of the claims 1 - 4 c h a r a c t e r i s e d i n, that the mould cavity (4) is provided with one or more pegs (11), heels or the like for vertical fixation of the unit or object (1) before and/or during supply of molten polymeric material. 6. Process according to any of the claims 1 - 5 c ha racterised i n, that the unit or object (1) is incorporated adjacent a profile, such as an upper or lower rim (12) or a reinforcing web, girder or rib, being an integrated part of the moulded article (2). 7. Process according to any of the claims 1 -6 ch a racteris ed i n, that the unit or object (1) is or includes at least one smart card, micro chip, radio transmitter and/or receiver, micro processor or other magnetic and/or electronic medium being able to hold analogue and/or digital read/write infor¬ mation.

Inventors: CARLSSON ROBIN, CARLSSON, ROBIN
Applicants: CARLSSON ROBIN, PERSTORP AB, CARLSSON, ROBIN
Application year: 1995
Main classification: B29C45
IPC codes: B29C33, B29C45