DE19856218A1 - Process for the injection molding of disc-shaped information carriers - Google Patents

Process for the injection molding of disc-shaped information carriers

Info

Publication number
DE19856218A1
DE19856218A1 DE1998156218 DE19856218A DE19856218A1 DE 19856218 A1 DE19856218 A1 DE 19856218A1 DE 1998156218 DE1998156218 DE 1998156218 DE 19856218 A DE19856218 A DE 19856218A DE 19856218 A1 DE19856218 A1 DE 19856218A1
Authority
DE
Germany
Prior art keywords
mold
information
information carrier
side
characterized
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.)
Withdrawn
Application number
DE1998156218
Other languages
German (de)
Inventor
Martin Eichlseder
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.)
KraussMaffei Kunststofftechnik GmbH
Original Assignee
KraussMaffei Kunststofftechnik GmbH
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 KraussMaffei Kunststofftechnik GmbH filed Critical KraussMaffei Kunststofftechnik GmbH
Priority to DE1998156218 priority Critical patent/DE19856218A1/en
Publication of DE19856218A1 publication Critical patent/DE19856218A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17Component parts, details or accessories; Auxiliary operations
    • B29C45/26Moulds
    • B29C45/263Moulds with mould wall parts provided with fine grooves or impressions, e.g. for record discs
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17Component parts, details or accessories; Auxiliary operations
    • B29C45/26Moulds
    • B29C45/263Moulds with mould wall parts provided with fine grooves or impressions, e.g. for record discs
    • B29C2045/2665Moulds with mould wall parts provided with fine grooves or impressions, e.g. for record discs using vacuum means for holding the disc on one of the mould walls during opening of the mould
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17Component parts, details or accessories; Auxiliary operations
    • B29C45/40Removing or ejecting moulded articles
    • B29C45/43Removing or ejecting moulded articles using fluid under pressure

Abstract

A method is described for producing a disk-shaped information carrier in an injection molding machine, in which the information carrier injected in a mold cavity has a negative pressure in the channels leading to a mold surface of a mold half, at least already during the part of the cooling time in which the largely solidified information carrier shrinks is maintained.

Description

The invention relates to a method for injection molding disk-shaped Information carriers according to the preamble of claim 1 and on a Vorrich to carry out the procedure.

In the production of disc-shaped information carriers, which are under the Label CD or DVD disks are commercially available on one side of the Information carrier small pits or grooves or a combination of Wells and grooves, which contain the information, by means of a matrix surface molded. The die surface, also called the stamper, usually consists of egg ner the nickel geometrical layer containing the pit geometries, with one of the two disk-shaped mold surfaces of the injection mold is occupied.

The information area of the finished information carrier therefore contains areas with Specializations and areas without specializations, one also speaks of pits and Country. There is a reading pulse from the reading laser when changing from a pit to a country is done, it is for an exact scanning of the information side of the information carrier it is important that the side walls of the pits are formed precisely and also when The demolding process remains intact.

The pit geometry of the die surface, however, acts like a toothing that fits into the Information side of the information carrier intervenes and its demoulding sword. This also has the disadvantage that when the material shrinks of the information carrier, one-sided tensions can arise in the gearing nen.  

As is known for example from DE-38 39 536 A1, the Demoulding when opening the tool on one or both sides of the IT on carrier compressed air between the mold surface and the associated surface of the In injected formation carrier. It can happen that due to under different liability in some areas on both sides of the information carrier, the demolding does not run uniformly and in the Detached areas of excessive tooth tension. When peeling these remaining surface areas can then damage all or a large part of the side walls of the pits, which are then called Clouds appear on the information carrier. In the same way due to damage to the side walls of the pits, the information quality of the In formation carrier are impaired.

The invention is therefore based on the object in the demolding process to avoid damage to the side walls of the pits of the information carrier.

This object is achieved by a method according to claim 1, which depend Current claims relate to advantageous embodiments of the invention.

The invention is based on the knowledge that with the definitive sub pressurizing only one mold surface in the cooling phase si is established that the shrinkage of the information carrier within the mold cavity of the information carrier enclosed by the mold surfaces ger only lifts off the side that is not under negative pressure.

In this case, the mold surface carrying the die surface is preferably provided with a lower pressure applied. The complete detachment from the opposite side due to the shrinkage of the material can still be caused by compressed air be supported.  

In a preferred procedure of the invention, on the one hand, preferably the mirror side, detached and on the information side by Un the entire surface of the information carrier is recorded by an in its edge rich acting force according to the requirement of the negative pressure Mold surface (die surface) detached that a progressively controlled Transfer line sets. This ensures that no partial areas are incongruent peel off trolled.

The force is advantageously via a on the outer contour of the disc-shaped attached to the information carrier attacking form ring, creating an equal shaped-acting detachment can be accomplished along a ring line that from the circumference radially inwards until the information carrier is completely detached gers progresses.

The method according to the invention is preferably used in the production of disk-shaped information carriers instead of a mirror on one side side and on the other side have the information area. The negative pressure This is preferably done on the information page.

However, the method according to the invention is also used in the production of disks shaped information carriers applicable, in which both sides information area Chen have. Such information carriers can, for example, with two disc-shaped information carriers are glued, the mirror sides of which are outside lie, so that a total of a disc-shaped information carrier with four inside Information areas can be produced. Basically after that also more than four information areas on a disc-shaped information carriers can be accommodated.

An embodiment of the invention will be explained with reference to the accompanying drawings tert. It shows:  

Fig. 1 is a partial view of a closed injection mold having a representation of the information carrier to be sprayed in and cooled in nichtabgekühlter form,

Fig. 2 shows the partial view of a closed, filled with molten injection molding form,

Fig. 3 shows the injection mold of FIG. 2, in a partially opened position and a detached from a molding surface of the disc-shaped information carrier

Fig. 4, the injection mold according to Fig. 3 with information information in replacement and

Fig. 5 shows the opened injection mold with the molded and partially demolded information carrier.

The partial section shown in Fig. 1 shows a first mold half 1 of the mold 2 egg ner injection molding machine. The mold surface 3 of this mold half 1 is provided with a poli ture and represents the mirror side. The mold half 1 is opposite the mold half 4 , which shows a die surface 5 consisting of a galvano layer, the surface of which is designed according to the pit geometry. The mold half 4 is held by two sleeve parts 6 and 7 , between which there is a channel 8 which is connected to a vacuum unit (not shown). The mold cavity 9 enclosed by the two mold halves 1 and 4 is filled by an information carrier 10 .

The information carrier 10 is in the illustration according to FIG. 1 in the lower region in a state in which the melt mass has barely cooled down and in which the still less solidified melt mass of the information carrier 10 lies on the surface 3 , the mirror side. In the upper area of the illustration of FIG. 1, the molten mass of the information carrier 10 is substantially cooled and solidified, and has detached the molten material from the mold surface 3 due to the shrinkage S. The detached surface of the information carrier 10 represents the mirror side 11 thereof. The opposite side is the information side 12 of the information carrier 10 on which the pit geometry of the die surface 5 has emerged as a negative shape. The depressions, the pits 13 , are shown in extreme magnification for the purpose of clearer illustration. The areas of the information page 12 that are not occupied by pits 13 are designated by country 14 . When the information page 12 of a completely finished information carrier 10 is scanned with the reading laser (not shown), the transition point from a pit 13 to the land 14 is registered as an information unit. So that the transition point can be clearly detected by the reading laser, it is important that the side surfaces 15 of the pits 13 are shaped precisely and are not damaged by the die surface 5 during the subsequent demolding process.

, FIGS. 2 to 5 based on partial regions of a dargestell th injection mold in half section illustrates the flow of Entformungvorgangs for the disc-shaped information carrier 10.

Fig. 2 shows a closed injection mold, the mold cavity of which he most mold half 1 , the second mold half 4 and a mold ring 16 is closed. The mold ring 16 is arranged in the first mold half 1 slidably. The mold cavity is completely filled with melt via the sprue bushing 17 . There is a compressed air duct 18 between sprue bushing 17 and first mold half 1 . The second mold half 4 carries the die surface 5 (stamper) and is itself arranged on the sleeve parts 6 and 7 , between which there is the channel 8 connected to a vacuum unit Un. Inside the sleeve part 7 there is an ejector pin 20 .

In the process step according to FIG. 3, the first mold half 1 is retracted, whereas the mold ring 16 remains in the stop on the second mold half 4 and, with its undercut 16, encloses the outer contour of the information carrier 10 solidified from the melt. The retraction of the mold 1 according to Fig. 3 is a detachment operation of the information carrier 10 from the mold surface 3 vorausge addressed, wherein on the one hand the information page was kept 12 of the information carrier 10 by vacuum pressure via the channel 8 on the die pad 5 and the replacement of the information carrier 10 from the mold surface 3 since by that the melt volume for the information carrier 10 has shrunk ge and 18 compressed air was pressed between the Formoberflä surface and the information carrier 10 via the compressed air channel.

In the subsequent process step according to FIG. 4, the compressed air present via the compressed air duct 18 is switched off and the shaped ring 16 is retracted, the negative pressure remaining effective. The disc-shaped information carrier 10 held in the undercut 19 on its outer contour is bent and therefore progressively separates from the outside of the die surface 5 from the inside. The negative pressure remains effective until the information carrier 10 is completely detached from the die surface 5 .

In the process step according to FIG. 5, the information carrier 10 is completely detached from the second mold half 4 and, after the central sprue has been removed, part (not shown) can be removed from the mold.

Claims (7)

1. Process for the injection molding of disc-shaped information carriers with a mirror and an information side or with two information pages in which the melt is injected into an mold cavity enclosed by two mold halves of a mold and, after a cooling time following the injection process, the mold is opened and opened at an injection molding unit the compressed air for separating the information carrier from the mold surfaces forming the mirror and the information side or the two information sides is introduced via channels leading through the mold halves to the mold surfaces , characterized in that at least already during the part of the cooling time in which a shrinkage of the largely solidified information carrier ( 10 ) takes place in the channels ( 8 ) of a mold half ( 4 ), a negative pressure is maintained.
2. The method according to claim 1, characterized in that on the side of the information carrier ( 10 ), which lies opposite the side which is subjected to negative pressure, the information carrier ( 10 ) over the entire surface by pressurizing the mold surface ( 3 ) of the mold half ( 19th ) is replaced.
3. The method according to claim 1 or 2, characterized in that in a mirror and an information page having information carrier ( 10 ), the negative pressure on the information side ( 12 ) of the information carrier ( 10 ) forming the mold surface (die surface ( 5 )) is maintained .
4. The method according to any one of claims 1 to 3, characterized in that the disc-shaped information carrier ( 10 ) is held on its outer edge by a movable in the opening direction of the mold ring ( 16 ), the information carrier ( 10 ) after its complete detachment on the side opposite the side subjected to negative pressure, progressively detaching radially from the outside to the side subjected to negative pressure.
5. Device according to one of claims 1 to 4, characterized in that at least the leading to a mold surface of a mold half ( 4 ) channels ( 8 ) are connected to a vacuum unit.
6. Device according to one of claims 1 to 5, characterized in that the channels ( 8 ) are arranged radially inside the die surface ( 5 ) to form the information side ( 12 ) of the information carrier ( 10 ).
7. Device according to one of claims 1 to 6, characterized in that the mold cavity in the edge region of a in a mold half ( 1 ) slidably arranged mold ring ( 16 ) is limited, in which the outer contour of the information carrier ( 10 ) forming undercut ( 19 ) is formed.
DE1998156218 1998-12-05 1998-12-05 Process for the injection molding of disc-shaped information carriers Withdrawn DE19856218A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE1998156218 DE19856218A1 (en) 1998-12-05 1998-12-05 Process for the injection molding of disc-shaped information carriers

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE1998156218 DE19856218A1 (en) 1998-12-05 1998-12-05 Process for the injection molding of disc-shaped information carriers
PCT/EP1999/009425 WO2000034024A1 (en) 1998-12-05 1999-12-02 Method for injection-moulding disk-shaped information supports
TW89100561A TW469216B (en) 1998-12-05 2000-01-14 Method for injection-molding disk-shaped information supports

Publications (1)

Publication Number Publication Date
DE19856218A1 true DE19856218A1 (en) 2000-09-28

Family

ID=7890131

Family Applications (1)

Application Number Title Priority Date Filing Date
DE1998156218 Withdrawn DE19856218A1 (en) 1998-12-05 1998-12-05 Process for the injection molding of disc-shaped information carriers

Country Status (3)

Country Link
DE (1) DE19856218A1 (en)
TW (1) TW469216B (en)
WO (1) WO2000034024A1 (en)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3839536A1 (en) * 1987-12-19 1989-06-29 Pioneer Electronic Corp Method and device for injection molding the carrier material for information storage disk and information storage disk
US5244606A (en) * 1992-06-08 1993-09-14 Galic Maus Ventures Faster cycling method and apparatus for optical disk removal from injection mold

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4449916A (en) * 1980-11-20 1984-05-22 Matsushita Electric Industrial Co., Ltd. Device for manufacturing information recording mediums
JPH0278036A (en) * 1988-09-13 1990-03-19 Ricoh Co Ltd Optical disk
JPH0493208A (en) * 1990-08-10 1992-03-26 Canon Inc Mold release method of flat molded product
JPH07156212A (en) * 1993-12-10 1995-06-20 Ricoh Co Ltd Mold and molding method
JP3310823B2 (en) * 1995-07-05 2002-08-05 松下電器産業株式会社 Foam plastic volume reduction device
JP3387727B2 (en) * 1996-04-11 2003-03-17 株式会社名機製作所 Disk forming die and disk forming method

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3839536A1 (en) * 1987-12-19 1989-06-29 Pioneer Electronic Corp Method and device for injection molding the carrier material for information storage disk and information storage disk
US5244606A (en) * 1992-06-08 1993-09-14 Galic Maus Ventures Faster cycling method and apparatus for optical disk removal from injection mold

Also Published As

Publication number Publication date
WO2000034024A1 (en) 2000-06-15
TW469216B (en) 2001-12-21

Similar Documents

Publication Publication Date Title
CA2228961C (en) Base curve mold designs to maintain hema ring/base curve adhesion
JP4781721B2 (en) Recovery method of ceramic core
KR0136374B1 (en) Injection molding die apparatus for use in the production of substrate of optical disk
US4880587A (en) Process for production of an injected molded part
US7044726B2 (en) Mold component and mold assembly
US5695706A (en) Injection molding method
EP1332033A1 (en) Method and device for producing thick-walled moulded parts
JP3976655B2 (en) Intermediate for optical recording medium, mold, molding machine, and method for producing optical recording medium
KR910001178B1 (en) Vertical injection apparatus
US5423705A (en) Flying disc with laminate surfacing
JP4845180B2 (en) Injection mold apparatus and injection molding method
DE3442023C2 (en)
KR100851708B1 (en) Resin-sealed mold and resin-sealed device
US5145630A (en) Direct gating into the lip of thin walled container
US7396575B2 (en) Molding die apparatus, method for disc substrate, and disc-shaped recording medium
DE19942153A1 (en) Manufacture of two-piece plastic assembly from a single die set
US20030194464A1 (en) Mold for molding the substrate of an optical disk
JP4081240B2 (en) Injection molding apparatus for manufacturing disc-type information recording carrier
US7186109B2 (en) Stamper holder, mold component, and mold assembly
JP2006150638A (en) Disk molding method and mold therefor
DE19749149B4 (en) Injection molding for thin moldings
US4453904A (en) Injection mold device for forming an article such as footwear
US5092758A (en) Disc molding apparatus
KR20090079849A (en) Hollow moldings having thin film on inner surface
GB2156264A (en) Moulding a thin-walled container

Legal Events

Date Code Title Description
OP8 Request for examination as to paragraph 44 patent law
8130 Withdrawal