DE1222425B - Sealing of plastic containers - Google Patents

Description

Plastic Container Sealing The invention relates to use of rigid plastics produced by injection molding with controlled cooling, such as linear polyethylene or linear olefin that consists of a rigid mold core and consist of a relatively soft, deformable surface layer, for a new, airtight and rigid engagement connection between container and lid, whereby the soft, deformable surface layer creates a tight seal is created, and in particular the container on its open side a circumferential one Has edge that interacts with the circumferential edge of the lid.

Injection-molded olefin plastics such as linear Polyethylene, with controlled cooling for the production of a rigid mold core and a relatively soft, deformable surface layer are known. A well-known linear polyethylene, a low pressure polyethylene, also exhibits at at elevated temperatures up to 1000 C considerable residual strength with high internal toughness on. In the case of the invention, this state corresponds to that of the rigid molded body core. It is also known that the crystalline, which determines the strength and the toughness Proportion of low-pressure polyethylene depends on the cooling rate, d. H. that with rapid cooling the proportion is lower than with slow cooling. So it is a kind of plastic heated to 124 to 1270 C in this temperature range loses its crystalline structure, quickly brought to a low temperature, so the crystallization of the plastic molecules cannot start in time and a plastic treated in this way retains its amorphous part for the most part Character at. The plastic surface most exposed to temperature influences will thus be considerably softer than that which is only subjected to a gradual cooling Core.

It is also known to make containers with lids made of soft, deformable material To produce polyethylene or polystyrene with a high density. To with a slip lid made of rigid film for placing on glasses a bad fit and damage the edge of the lid due to the different and irregular diameters of the It is known, for example, to avoid glasses on the inside of the lid rim to weld on a strip of soft foil or to attach it in some other way. In the case of lids with a threaded edge, a reinforcing strip made of hard or soft foil should be used be attached, which is provided before or after with the thread. These known type of seal or composite construction Plastics with an embedded Interlayer has an unprotected arrangement and is different working conditions subject. The result is that, over time, they can easily become dislodged loosens, throws, and wanders, resulting in an uneven and imperfect seal leads to the sealing surfaces.

The invention is based on the object of an effective and reliable Create seal for plastic container with lid. This is done according to the invention achieved in that at least one of the two cooperating parts of one differently cooled moldings made in the injection molding process with controlled Cooling is made of rigid plastics. This increases the sealing effect made a surface problem while the rigidity and strength of the gasket is guaranteed by the hard mold core. It will be effective and reliable Seal created.

According to a characteristic of the invention is the rigid plastic a linear or isotactic propylene. This has the advantage that the Consists of a single molded piece of linear or isotactic plastic Lid seal turns into a built-in seal on the one with the container edge in Touching part of the edge of the lid leads.

In the drawing, the expedient embodiments of the invention shows, FIG. 1 is a perspective view of an embodiment according to the invention in the form of a container in any desired configuration and a snap-on cap closure over the top edge of the container includes, the type of loosening of the lid indicated in dashed lines is; F i g. Figure 2 is an enlarged partial section on the plane 2-2 of Fig. 1; F i g. 3 is a view similar to that of FIG. 2 shown in the a modified embodiment of the lid and the container is shown, wherein another type of sealing connection is provided between the parts; Fig. 4 is a partial section in the plane 4-4 of FIG. 2, in which the touching and not contacting surfaces of a sealing connection between a lid and a container are shown.

In the drawing, numeral 10 denotes a container of any one Designates shape and design that is suitable for receiving a lid.

The execution sees the use in the example shown a relatively rigid snap-on lid, which is for the purpose of a hermetic Sealing must have the effect of a seal. For this purpose is the lid made of a polyethylene produced under low pressure, which has the physical Having properties of rigidity between opposing faces thereof and also resilient, soft and resilient, opposing surface layers owns that do not peel off. In fact, it exists under low pressure plastic material made of polyethylene at the same time from a core of rigid and solid material and a jacket or surface layers of soft, deformable material, as is inherent in polyethylene produced under high pressure is.

The cover, generally designated by the reference number 11, as shown in FIG F i g. 1, 2 and 4 consists of a pressed-in middle part 12, which is connected to a raised rim enclosing an inverted trough, which has an upper edge 13 and a side wall 14, the upper aisle of the upper edge 13 to the middle part 12 by an outwardly and upwardly inclined, circumferential wall part 15 is formed.

On the inner surface of the side wall 14 of the surrounding the trough Bordes are provided above and below oppositely inclined surfaces 16 and 17, which limit a thickening 18. The inner surface 16, which is attached to the underside of the Edge 13 is conveniently rounded, as at 16 a in F i g. 2 is indicated to the expanded for the purpose of a hermetic seal Edge part 19 of the container and the rounded edge 20 of the same to receive. Included is the inside diameter on the top surface 16 on the inside of the side wall 14 somewhat smaller than the corresponding outer diameter at the widened edge 19 of the container.

As a result of the training described above, you can use the lid Press 11 over the edge of the container and let it snap into place, with the inside of the wall 14 continues to expand on the outer surface of the Edge 20 of the container pushes on. Removing the lid 11 from the container 10 is facilitated by the gap 21 between the inclined inner surface 17 and the outer surface of the side wall of the container 10 is provided. By inserting of the thumb into the space 21 and by exercising an outward and upward movement Directional pressure, the cover 11 can be easily removed. Taking off the Lid is further facilitated by the loading train on the wall 14 of the Trough enclosing board joint-like acting, rounded board part 16 a, and Although this form of training also forms the reason for the ease with which the lid 11 can be slipped onto the container 10.

As shown, an essential characteristic is the texture of the surface layers 22 and 23 of the container 10 when this from under low Pressure made polyethylene is molded, as well as in the texture of the opposite Surface layers 24 and 25 of the lid 11, which is made of low pressure Polyethylene is molded. It turns out that in molded products from under low pressure polyethylene, be it by injection, blowing, vacuum or in some other way, an arrangement of the molecules is going on through the properties on the surface, which are related to compliance and Softness differs from the texture of the core, as mentioned above. Any such Surface layer is used when it is used for the purpose of a der metischen sealing another surface is brought into contact, as in the case of FIG. 2 shown Compound, in an effective manner as a seal against the adjacent, proportionate rigid parts and thereby enables a good hermetic seal and a lighter Bringing together and loosening the connected parts.

If different materials are used for the container 10 and the lid 11 should be chosen, it is appropriate to the lid 11 from under low pressure molded polyethylene. However, both parts can also be made from under low pressure polyethylene.

In addition, it is not necessary that the parts in their entirety Starch consist of low pressure polyethylene. It can also a pressed or warm applied surface layer made of under low pressure Manufactured polyethylene is provided at selected points on the parts to be connected will.

In Fig. 3, a container and a lid are shown, which are shown in FIG can be handled in the usual way and have similar characteristics as the Execution according to FIG. 1 and 2.

The container 26 is provided with a straight edge portion 27 and the The outer and inner surfaces of the container are designated by the reference numerals 28 and 29. The lid is indicated generally by the reference numeral 30 and has a central one Part 31 and a raised shelf enclosing a trough with an inner wall 32, an outer wall 33 and an upper connecting wall 34, as well as an outwardly protruding one Flange 35 which adjoins the lower edge of the outer wall 33. The exterior respectively.

Inner surfaces of the lid are denoted by the reference numerals 36 and 37. The flange 35 is used as a point of attack for the fingers when putting on and taking off of the cover 30 related. To lose weight, an upward pressure is applied to the Underside of the flange exerted to the wall 33 by bending outward from to solve the outer surface of the edge part and thus initiate removal.

As in Fig. 3, the inner surfaces of the trough walls act 32, 33 and 34 with the opposite surfaces of the rim portion 27 of the container 26 together to create a hermetic seal. When everyone is in touch kicking parts the connection made under low pressure Polyethylene, the sealability is doubled. This also applies to the Execution, which is shown in FIG. 1 and 2 is shown. If only one of the in touch stepping parts is made of low-pressure polyethylene the effect that of a simple poem.

The use of the spray process with controlled cooling produced rigid plastics thus essentially refers to a detachable, Hermetically sealing connection of two releasably joinable parts, e.g. B. one Container and a lid, in which the surfaces that come into contact of bodies made of polyethylene produced under low pressure, these Body are either designed as a support on the parts to be joined or are formed by these parts themselves. Furthermore, those are pretreated accordingly Plastics except for making the connection of a container to a lid also on pipes, bottles, couplings and other tubular or non-tubular shapes Parts applicable, for which detachable caps or parts are required, which are caused by frictional forces, be held together by threads or in some other way. It should be noted that that the term "sealing" in the description and claims for each type of connection applies in the case of parts for the purpose of a liquid-tight seal can be releasably connected to each other, as well as the threaded, clamp and snap connections includes.

The plastics used also include polymeric products from compounds of olefins that do not belong to the ethylene, z. B. propylene and copolymers of the same, provided that such polymeric products are in-house societies the polymers or copolymers of ethylene under the general name Have "polyethylene", as it is after working under low pressure processes as mentioned above.

Claims (2)

Claims: 1. Use of in the spray process with controlled Refrigerated manufactured rigid plastics, such as linear polyethylene or linear Olefin, which consists of a rigid mandrel and a relatively soft, deformable one Surface layer exist for a new, airtight and rigid engagement connection between the container and the lid, whereby through the soft deformable surface layer a tight seal is created, and in particular the container its open side has an all-round edge that with the all-round edge Lid edge cooperates, d a -characterized in that at least one of the two interacting parts (10, 11) made of a molded body that has been cooled differently consists of the aforementioned rigid plastics. 2. Seal according to claim 1, characterized in that the rigid Plastic is a linear or isotactic propylene. Considered publications: German utility model no. 1,678,680; French Patent Nos. 963 119, 1 107 745; U.S. Patents No. 2,606,586, 2,614,727, 2,695,645, 2,740,444; Journal »Kunststoffe«, issue 10, Born in 1955, p. 412: "The new polyethylene".