DE102012017008B3 - Method for detaching mold of casting assembly for producing plastic lens e.g. spectacle lens, involves terminating predetermined breaking point of plastic lens for releasing casting molds of casting assembly from plastic lens - Google Patents

Abstract

The method involves producing a plastic lens (23) having a predetermined breaking point (25) by curing of a casting resin in a casting assembly (20). The predetermined breaking point of the plastic lens is terminated for releasing the casting molds (21,22) of the casting assembly from the plastic lens. An independent claim is included for casting assembly for producing plastic lens.

Description

The invention relates to a method for detaching a casting mold from a plastic lens and a casting package.

In the manufacture of plastic lenses for z. B. spectacle lenses, a plastic lens with the aid of a liquid or viscous plastic monomer mixture, a so-called casting resin, poured in a casting package and then cured by a polymerization or polyaddition reaction. An associated casting package has two shell molds, so-called casting molds, to each of which the front or rear surface of the finished plastic lens is cast. The two molds can be sealed with a tape so that filling and closing of the casting package for the subsequent curing of the lens is possible. The edge of the plastic lens to be produced thereby terminates flush with the casting mold edge.

During the curing process, the volume of the casting resin is reduced, which can cause mechanical stresses within the plastic lens. Furthermore, after the curing process and the removal of the tape, the casting molds usually adhere strongly to the plastic lens and must be removed from the surface of the plastic lens by a specially developed demolding process.

The document US 2006/202367 A1 relates to methods and apparatus for separating molds for ophthalmic lenses at different speeds. This cast soft contact lenses, high-precision intraocular lenses u. Ä. Separated from the individual molds in which they are produced. By controlling several movement speeds of crushing fingers to improve the production of ophthalmic lenses and damage is reduced.

For demolding, ie for detaching the molds from the plastic lens, the casting package is first fixed in a device by a known method. Subsequently, a stamp is mechanically pressed into the edge of the plastic lens, so that the molds are released by deformation of the surface of the plastic lens.

A disadvantage of this method for demolding lies in the mechanical deformation of the plastic lens by the pressing of the punch. This can cause cracks or streaks in the plastic lens, which can be amplified by internal stresses generated during curing.

Furthermore, the local pressure exerted on the edge of the plastic lens to inhomogeneity in the plastic structure, which is often visible after staining of the lens as Färbefehler.

The invention is therefore based on the object to provide an improved demolding process for detaching a casting mold from a plastic lens, in which the above-mentioned disadvantages are reduced.

This object is solved by the subject matters of the independent claims.

• – Herstellen einer Kunststofflinse mit einer Sollbruchstelle durch Aushärten eines Gießharzes in einem Gießpaket und
• – Abbrechen der Sollbruchstelle von der Kunststofflinse zum Ablösen zumindest einer ersten Gießform des Gießpakets von der Kunststofflinse.

One aspect of the invention relates to a method for detaching a casting mold from a plastic lens, comprising the steps:

• - Making a plastic lens with a predetermined breaking point by curing a casting resin in a casting package and
• - Canceling the predetermined breaking point of the plastic lens for detaching at least a first mold of the casting package from the plastic lens.

In this case, a plastic lens is produced in a casting package. Already in the production of the plastic lens, a predetermined breaking point is produced, which, like the plastic lens itself, is cured from the casting resin and which can be integrally formed together with the plastic lens. The predetermined breaking point is formed as an extension of the actually produced plastic lens. Therefore, in the demolding of the plastic lens from the casting package, the predetermined breaking point of the plastic lens can be canceled so that the plastic lens itself is not damaged.

Casting molds of the casting package can be sealed with a tape such that filling and closing of the casting package for the curing of the lens is simplified. The edge of the plastic lens to be produced can be flush with the casting mold rim.

The predetermined breaking point provides a possibility to release in the curing of the casting resin resulting internal stresses in the plastic lens by the predetermined breaking point is discontinued as part of the cured casting resin of this. In addition, the predetermined breaking point can provide an outer approach surface, can be applied to the pressure on the cured casting resin, without causing damage to the actual plastic lens in the immediate vicinity of the printing area.

A u. U. resulting demolition edge, along which the predetermined breaking point is broken off by the plastic lens can be completely removed in a following on the demolding process grinding the plastic lens.

The predetermined breaking point can be formed filigree that it breaks easily when force from the plastic lens, after which air can penetrate into a gap formed by it, change tensions inside the cured casting resin and the molds can be easily detached from the product to be produced, the plastic lens ,

Due to the fact that the plastic lens itself is not directly pressurized with this method at any point, damage to the plastic lens during removal from the mold is avoided.

The casting package can have a first and a second casting mold, by the shape of which the front or rear side of the plastic lens to be produced is determined.

When breaking the predetermined breaking point, at least the first of the casting molds is released from the plastic lens, in addition, the second casting mold can also be detached from the plastic lens together with any other casting molds of the casting package that may be present.

The plastic lens may be formed as an optical lens for a spectacle lens. The plastic lens may have a convex and a concave side, or two convex or two concave sides. Alternatively, the plastic lens may also have a flat side. The casting package can be designed as a reusable casting package with which a plurality of identical plastic lenses can be successively formed. The predetermined breaking point can be formed as an extension of the plastic lens, in particular as a spoiler on the plastic lens.

In one embodiment, the predetermined breaking point is formed in an outer region of the casting package. The outdoor area refers to a point on the casting package that limits the casting package. Thus, by the predetermined breaking point, the casting package outwardly limiting engagement surface is provided for a force acting on the outside of the casting package.

According to one embodiment, the predetermined breaking point is formed in a recess of the first casting mold of the casting package. In this case, in the first mold, a recess is formed, is poured into the resin during the manufacture of the plastic lens, which hardens together with the plastic lens as a predetermined breaking point. The shape of the recess determines the shape of the predetermined breaking point. Thereby, the predetermined breaking point can be given a predetermined shape.

According to one embodiment, by pressing a wedge on the casting package and / or the plastic lens, the predetermined breaking point is broken off by the plastic lens. The wedge is used to exert force on the predetermined breaking point. The wedge can have different shapes. For example, the wedge may be formed with a straight cutting edge or with a cutting edge adapted to the diameter of the plastic lens. Preferably, the wedge is formed with a wedge tip, so that the force can be applied selectively to the predetermined breaking point when breaking the predetermined breaking point. The pressing of the wedge can take place abruptly or the wedge can be carefully attached to the edge of the casting package, whereupon pressurization via the wedge to the predetermined breaking point can be increased slowly until breaking off the predetermined breaking point. By using a wedge to break off the predetermined breaking point, the necessary force can be targeted at a predetermined location on an outer region of the casting package.

In this case, the wedge can be pressed onto the casting package substantially radially with respect to the center point or the center axis of the plastic lens. A plastic lens is normally formed substantially circular. Towards the center of the lens therefore means towards the center of the circular lens, which may be arranged for example in a concave lens surface outside the actual plastic lens.

More specifically, the plastic lens is formed substantially cylindrical, wherein the cylinder bottom and / or the cylinder roof may be concave, convex or flat. Also, the casting package together with the plastic lens cured therein is substantially cylindrical and has the same cylinder axis as the plastic lens. The cylinder axis corresponds to the center axis of the casting package and the plastic lens. When pressed, the wedge is oriented in such a way that a wedge tip of the wedge points in the radial direction substantially perpendicularly to the cylinder axis of the plastic lens and defines a pressing direction by the direction vector of the force transmission.

In this case, the wedge on its wedge tip have an at least 10 mm wide pressure surface. Preferably, the pressure surface of the wedge tip is 15 mm to 25 mm wide. Since the plastic lens itself is usually circular in shape, when breaking off the predetermined breaking point, only a small part of the pressure surface of the wedge tip attaches to a circular segment of the casting package. A wedge width of about 20 mm (that is, the wedge at its wedge tip has a pressure surface of about 20 mm wide perpendicular to the Aufdrückrichtung) proves to be particularly favorable to the wedge quickly and without a lengthy adjustment of the wedge alignment.

The wedge can be adjusted before pressing on the casting package. For example, the wedge may be biased in a height-adjustable device. The broad surface of the wedge tip, so the pressure surface, can be arranged along a horizontal direction. An adjustment of the wedge before breaking the predetermined breaking point allows a targeted attachment of the wedge or the wedge tip to the predetermined breaking point.

In this case, the wedge can be stored flexibly, which protects the mold. The wedge can z. B. with a clearance of up to 2 mm perpendicular to the Aufdrückrichtung be stored. Such a bearing can be achieved for example with a spring, in particular with a spiral spring bearing. When breaking the predetermined breaking point by pressing the wedge, the wedge itself perpendicular to the Aufdrückrichtung, for example up or down, avoid, which is particularly helpful in a slight misalignment of the wedge and helps to protect the plastic lens and the mold to be produced. The Aufdrückrichtung is the direction of the force vector, in the breaking of the predetermined breaking point, a force is exerted by the wedge on the casting package.

In this case, the wedge on its wedge tip by 5 ° to 35 ° relative to the pressing direction inclined wedge surfaces have. By so inclined surfaces, a slight lifting of the plastic lens with the second mold can be carried out when breaking the predetermined breaking point, which facilitates the detachment of the first mold from the plastic lens and supports. In particular, the wedge tip can also have wedge surfaces inclined by 15 ° to 25 ° with respect to the pressing direction.

According to one embodiment, the predetermined breaking point is formed along a circular arc of the plastic lens of at least 10 mm in length.

Usually, the entire circular arc of the plastic lens or cylinder jacket of the plastic lens forms an outer region of the casting package. Therefore, the arrangement of the predetermined breaking point on the circular arc and / or cylinder jacket of the plastic lens is advantageous because the predetermined breaking point is located there on an outer region of the casting package. In order to provide a sufficient surface for a wedge, for example, the predetermined breaking point extends at least over 10 mm along the arc of the cylindrical surface of the plastic lens. Preferably, the predetermined breaking point extends from 20 mm to 30 mm along the circular arc of the cylindrical surface of the plastic lens. In particular, the predetermined breaking point can also be formed along the entire circular arc of the cylindrical surface of the plastic lens. This is particularly advantageous in terms of production and also facilitates alignment of the casting package prior to breaking off the predetermined breaking point relative to a wedge.

According to one embodiment, the predetermined breaking point is formed on a first optical side surface of the plastic lens. In particular, the predetermined breaking point can be formed on a convex side of the plastic lens. By breaking off the predetermined breaking point, it is therefore particularly possible to detach the convex casting mold as the first casting mold of the casting package. Alternatively or additionally, a predetermined breaking point on the opposite side, ie generally the concave lens side, an additional predetermined breaking point can be provided. Usually, however, detachment of the first mold on a first side of the plastic lens also facilitates the subsequent detachment of the second mold on the opposite side of the plastic lens, since the stress ratio that has arisen during the curing process changes.

According to one embodiment, the predetermined breaking point is formed at least 1.5 mm away from the plastic lens into the casting mold of the casting package. In particular, the predetermined breaking point can also point into the casting mold approximately 0.5 mm to 2.5 mm away from the plastic lens. As a result, a sufficiently large contact surface is provided on the cylinder jacket of the plastic lens, on which a force can be exerted on the predetermined breaking point from the outside, for example via a wedge tip.

According to one embodiment, the predetermined breaking point is formed with an angled tip of 10 ° to 50 °, in particular from 20 ° to 40 °, so that the tip of the predetermined breaking point facing away from the plastic lens. In this case, the predetermined breaking point may have the shape of a pointed extension pointing away from the plastic lens. Such a shaped predetermined breaking point can be particularly easy to mold during curing of the casting resin and also provides sufficient attack surface for a force application ready.

Another aspect relates to a casting package for producing a plastic lens by curing a pourable into the casting package casting resin. The casting package has a first casting mold and a second casting mold. In this case, a recess is formed on at least one of the two casting molds in an outer region of the casting package such that in the production of a plastic lens with the casting package in the recess a predetermined breaking point of the plastic lens is curable. The shape and the dimensioning of the recess determines the shape and dimensions of the predetermined breaking point.

The invention will be explained in more detail with reference to embodiments shown in FIGS. Individual features shown in the figures may be combined with features from the embodiments shown in other figures. Show it:

1 in a schematic sectional view of a casting package in a Entformvorrichtung according to the prior art;

2 in a schematic sectional view of a section of 1 ;

3 in a schematic sectional view of an embodiment of a casting package in a Entformvorrichtung;

4 an enlarged section of the 3 and

5 an enlarged section of the 4 ,

In 1 is a casting package in a schematic sectional view 10 shown in a demolding device 2 is inserted. The casting package 10 has a first mold 11 and a second mold 12 on, which are spaced from each other. In a space between the first mold 11 and the second mold 12 a casting resin was poured in and cured to a plastic lens 13 train. The casting package 10 is with its concave side at the bottom of the Entformvorrichtung 2 hung up. In this case, one end of the substantially circular or cylindrical casting package is against a block 4 demolding device 2 supported. At one the block 4 opposite end of the casting package 10 is a stamp 3 demolding device 2 arranged.

In 2 is a schematic sectional view of the section of 1 shown enlarged, in which the punch and the stamp facing the outside of the casting package are shown. The casting package 10 is essentially circularly symmetrical. Here is the casting package 10 so in the Entformvorrichtung 2 inserted that a lens outer surface 13A radially from the center of the plastic lens 13 away to the outside. The lens outer surface 13A is the stamp 3 facing. The Stamp 3 can against the lens outer surface 13A be beaten, so that during the curing process resulting stresses inside the plastic lens 13 solve and the plastic lens 13 easier from the two molds can be triggered.

This can cause damage or distortion in the plastic lens 13 come.

In 3 is a casting package in a schematic sectional view 20 shown in a demolding device 50 is inserted. The casting package 20 has a first mold 21 and a second mold 22 on. Between the two casting molds 21 and 22 is a plastic lens 23 hardened. The casting package 20 as well as the plastic lens 23 are substantially circularly symmetrical with respect to a center axis M of the casting package 20 educated. The casting package 20 and the plastic lens 23 are formed substantially cylindrical, wherein the cylinder axis of the casting package and the plastic lens coincides with the central axis M.

In the in 3 the embodiment shown is the first mold 21 formed as a convex mold half, the second mold 22 is designed as a concave casting mold. That means the first mold 21 for forming a convex optical lens outer surface of the plastic lens 23 is provided and serves, and the second mold 22 for forming a concave optical lens outer surface of the plastic lens 23 , The first mold 21 , the plastic lens 23 and second mold 22 are arranged one above the other in the direction of the center axis M. Here is the first mold 21 arranged at the bottom.

At a first outer end of the first mold 21 is the first mold 21 on a storage 51 supported. At one of the storage 51 opposite arranged second outer end of the casting package 20 lies the first mold 21 on a control head 54 on. The control head 54 is by means of a set screw 53 height adjustable, so that on the control head 54 resting outer end of the casting package 20 is designed adjustable in height.

In 4 is shown in a schematic sectional view of the outer end of the Gießpakets that on the actuator head 54 rests. The control head 54 has a circulation 55 on, which is designed flat. On the pad 55 is the bottom of the casting package 20 on, in 4 the bottom of the first mold 21 , In the first mold 21 is a recess 21A formed in which the plastic lens 23 having a broadening or an extension, namely a predetermined breaking point 25 , The breaking point 25 is made of the same material as the plastic lens 23 formed of cured casting resin such as a cured monomer mixture.

For example, materials needed to make a lens with refractive index n = 1.5, 1.6, or 1.67 can be used.

The breaking point 25 is along the whole circular arc of the plastic lens 23 , the center axis M encircling 360 ° around the casting packages 20 trained (shown in 3 as a predetermined breaking point on both sides shown in the sectional view). The breaking point 25 protrudes from the plastic lens 23 out. In this case, the predetermined breaking point forms 25 an extension of the plastic lens 23 in the first mold 21 into it. The breaking point 25 does not protrude from the essentially circularly symmetrical casting package 20 out, but in the recess 21A the first mold 21 into it. The casting package used in the invention 20 has the same external dimensions as the casting package 10 , this in 1 is shown.

A lens outer surface 23A the plastic lens 23 is where the storage 51 opposite outer end of the casting package 20 designed so that it becomes a wedge 56 demolding device 50 has.

When curing the plastic lens 23 in the casting package 20 Material stresses and adhesions may occur in such a way that the first mold 21 and / or the second mold 22 only hard from the cured plastic lens 23 let it peel off.

For demolding, so the detachment of the molds from the plastic lens, the wedge 56 in Aufdrückrichtung A on the lens outer surface 23A the plastic lens 23 pressed. The Aufdrückrichtung A is aligned perpendicular to the central axis M in the radial direction. The wedge 56 itself is also aligned along its longitudinal axis in Aufdrückrichtung A. At one end of its longitudinal axis, the wedge points 26 a wedge tip, the lens outer surface 23A is facing. The lens outer surface 23A is formed in an outer region of the casting package.

The wedge tip of the wedge 56 is preferably formed with a printing area of 15 mm to 25 mm wide (in 4 perpendicular to the plane of the drawing) to provide an easy-to-adjust and sufficient force transfer surface when the wedge is pressed. When canceling the predetermined breaking point 25 touches the wedge tip of the wedge 56 the breaking point 25 not over the entire surface, but only with a fraction of its pressure surface.

Before demolding, the wedge becomes 56 facing lens outer surface 23A by means of the adjusting screw 53 and the control head 54 adjusted so that the breaking point 25 level with the wedge tip of the wedge 56 is arranged. The wedge 56 itself is not height adjustable, but fixed on the Entformvorrichtung 50 stored. This is a burden of height adjustment when pressing the wedge 56 on the casting package 20 avoided.

The wedge 56 is on a coil spring 52 stored so that it has a mechanical game in the vertical direction. This can make the wedge 56 be slightly deflected during the pressing in the vertical direction and thereby protect the mold. To achieve this storage with a game, the wedge is 56 from a screw 57 permeated stored on which the coil spring 52 is arranged. One end of the spiral spring 52 presses a surface of the wedge 56 downward. The game of the wedge 56 is directed up and down, so perpendicular to the Aufdrückrichtung A and parallel to the central axis M of the casting package 20 , The spiral spring 52 is chosen so that the wedge tip of the wedge 56 up to 2 mm in a direction parallel to the central axis M is mounted deflectable.

As well as the breaking point 25 level with the wedge point of the wedge 56 aligned, becomes the wedge tip of the wedge 56 in Aufdrückrichtung A on the lens outer surface 23A the plastic lens 23 pressed until the predetermined breaking point 25 breaks off from the plastic lens. It is not necessary that the breaking point 25 completely from the plastic lens 23 breaks off, especially not at a plastic lens 23 completely circular peripheral breaking point. As well as a fraction of the predetermined breaking point 25 from the plastic lens 23 breaks off, inner tensions dissolve in the plastic lens 23 or between the plastic lens 23 and the first mold 21 or the second mold 22 , Air can penetrate into the resulting intermediate gap and the first mold 21 dissolves from the plastic lens 23 , When Aufdrückvorgang the plastic lens 23 with the second mold 22 from the wedge 56 be easily raised, reflecting the game of the wedge 56 is favored and causing a detachment of the first mold 21 from the plastic lens 23 he follows.

By changing the stresses in the plastic lens 23 can be the second mold 22 usually easy z. B. with compressed air from the plastic lens 23 detach or blow off.

Pressing on the wedge 56 on the breaking point 25 may be as a gradual increase in pressure or as a sudden impact or belching of the wedge 56 against an outer surface of the casting package or the plastic lens.

In 5 is a section of 4 shown enlarged in a schematic representation. The breaking point 25 is in cross section through the casting package 20 formed with a point that is in a recess 21A the first mold 21 points in and their surfaces are inclined against each other by a point angle α. Point angle α can be from 10 ° to 50 °, in particular be designed substantially as a 30 ° angle.

An outer surface of the predetermined breaking point 25 is formed in an outer area of the casting package, as part of the lens outer surface 23A , This outer surface of the predetermined breaking point extends over an outer surface length L at which the wedge tip of the wedge 56 when canceling the predetermined breaking point 25 can start. The outer surface length L of the predetermined breaking point 25 may be formed from 0.5 mm to 2 mm long, in particular substantially 1.5 mm long. Larger outer surface lengths L are technically possible as well, but consume more casting resin.

The wedge tip of the wedge 56 has wedge surfaces which are formed inclined relative to the pressing direction A by a wedge surface angle β of 5 ° to 35 °.

After demolding, ie the detachment of the casting package from the plastic lens, the product, ie the plastic lens, is usually sanded on the edge. In this case, when breaking the predetermined breaking point resulting sharp edges can be sanded, as well as remains of the predetermined breaking point, the demolding of the plastic lens 23 were canceled.

By adjusting the wedge 56 before pressing the wedge can targeted to the breaking point 25 the plastic lens 23 be pressed without damaging the molds. This increases the life of reusable casting molds of the casting package.

Since in this process the product is mechanically deformed only at the predetermined breaking point and the fracture site is ground off after removal from the mold, there are no cracks, streaks or coloring errors of the plastic lens. In the in the 3 to 5 embodiment shown, the convex-sided mold, so the first mold dissolves 21 by breaking off the predetermined breaking point 25 ,

To the demolding device 50 for different product diameter, ie diameter of the plastic lens 23 and thus the casting package 20 in order to adjust the central axis M, a rotary wheel can be provided that as a bearing 51 serves and which is adjustable to different product diameter. Furthermore, the penetration depth of the wedge 56 be adjustable.

The breaking point 25 is designed as a kind of spoiler and revolving around the casting package 20 along a circle segment of 360 ° around the plastic lens 23 trained around. The breaking point 25 is doing in the recess 21A the first mold 21 educated. Such a completely circumferential predetermined breaking point is particularly easy to produce and adjustable.

For placing the casting package 20 on the camp 51 and the control head 54 can the warehouse 51 be designed as an eccentric with an adjusting screw for different product diameters. The eccentric system, which can be designed as a revolver, does not necessarily have to be designed to be height-adjustable. A height adjustment of the outside of the casting package 20 that the wedge 56 is normally sufficient for the inventive method.

LIST OF REFERENCE NUMBERS

2

removal unit

3

stamp

4

block

10

casting assembly

11

first mold

12

second mold

13

Plastic lens

13A

Lens outer surface

20

casting assembly

21

first mold

21A

recess

22

second mold

23

Plastic lens

23A

Lens outer surface

25

Breaking point

50

removal unit

51

storage

52

spiral spring

53

screw

54

Deputy head

55

edition

56

wedge

57

screw

A

Aufdrückrichtung

M

central axis

α

Point angle

β

Wedge surface angle

L

Outer surface length

Claims (15)

Method for detaching a casting mold ( 22 ; 21 ) of a plastic lens ( 23 ), comprising the steps of: - producing a plastic lens ( 23 ) with a predetermined breaking point ( 25 ) by curing a casting resin in a casting package ( 20 ) and - cancel the predetermined breaking point ( 25 ) of the plastic lens ( 23 ) for detaching at least one first casting mold ( 21 ) of the casting package ( 20 ) of the plastic lens ( 23 ). Method according to claim 1, wherein the predetermined breaking point ( 25 ) in an outer area of the casting package ( 20 ) is formed. Method according to one of the preceding claims, wherein the predetermined breaking point ( 25 ) in a recess ( 21A ) of the first mold ( 21 ) of the casting package ( 20 ) is formed. Method according to one of the preceding claims, wherein the predetermined breaking point ( 25 ) by pressing a wedge ( 56 ) on the pouring package ( 20 ) and / or the plastic lens ( 23 ) of the plastic lens ( 23 ) is canceled. The method of claim 4, wherein the wedge radially to the central axis (M) of the plastic lens ( 23 ) directed towards the pouring package ( 20 ) is pressed. Method according to claim 4 or 5, wherein the wedge ( 56 ) has at its wedge tip an at least 10 mm wide printing surface. Method according to one of claims 4 to 6, wherein the wedge ( 56 ) before pressing on the casting package ( 20 ) and / or the plastic lens ( 23 ) is adjusted. Method according to one of claims 4 to 7, wherein the wedge ( 56 ) is stored flexibly. Method according to one of claims 4 to 8, wherein the wedge ( 56 ) has at its wedge tip at 5 ° to 35 ° relative to the pressing direction (A) inclined wedge surfaces. Method according to one of the preceding claims, wherein the predetermined breaking point ( 25 ) along a circular arc of the plastic lens ( 23 ) of at least 10 mm in length is formed. Method according to one of the preceding claims, wherein the predetermined breaking point ( 25 ) along the entire circular arc of the plastic lens ( 23 ) is formed. Method according to one of the preceding claims, wherein the predetermined breaking point ( 25 ) on a convex side of the plastic lens ( 23 ) is formed. Method according to one of the preceding claims, wherein the predetermined breaking point ( 25 ) at least 1.5 mm from the plastic lens ( 23 ) away into the first mold ( 21 ) is formed inwardly. Method according to one of the preceding claims, wherein the predetermined breaking point ( 25 ) is formed with an angled tip of 10 ° to 50 ° so that the tip of the predetermined breaking point ( 25 ) of the plastic lens ( 23 ) points away. Casting package for producing a plastic lens by curing a casting resin which can be introduced into the casting package, comprising - a first casting mold ( 21 ) and - a second mold ( 23 ); wherein on at least one of the two casting molds ( 21 ; 22 ) in an outer area of the casting package ( 20 ) a recess ( 21A ) is formed such that in the manufacture of a plastic lens ( 23 ) with the pouring package ( 20 ) in the recess ( 21A ) a predetermined breaking point ( 25 ) of the plastic lens ( 23 ) is curable.

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