JPS6324844A - Cylindrical article of thermoplastic film having inner surface coating - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to thermoplastic film tubes, particularly food containers, which have improved adhesion to the food product due to an internal coating, and Concerning methods of manufacturing things.

Thermoplastics, preferably vinylidene chloride (PVD), are selectively used as containers for sausages.
The film tube of C) is such that the food adheres poorly to its inner surface and therefore separates from the tube during the fat and meat boiling process, resulting in so-called settling-out. It has the disadvantage that it occurs. Also, when thermoplastic cylindrical containers are used as containers for cheese, it is advantageous that the cheese composition sticks to the container as tightly as possible and that the material of the container does not shift much when the cheese is cut into slices. be.

It is therefore an object of the present invention to treat thermoplastic cylindrical containers, in particular sausage containers, in such a way that the containers have improved adhesion to their contents, preferably cheese or sausage meat. .

According to the invention, therefore, it has an inner coating of a vinylidene chloride copolymer containing at least 50, preferably at least 80% by weight of vinylidene chloride, said coating containing a finely dispersed inorganic mold release agent. A characterized thermoplastic tubular film, preferably a PVDC tubular film, particularly a food product container, is provided.

Further, according to the present invention, immediately after extruding the film tube, the inside is cooled with an aqueous suspension in which an inorganic demolding agent is suspended, and the excess suspension is sucked out from the inside. If necessary, the cylindrical object is cooled from the outside in a water bath, and residual liquid stuck to the cylindrical object is removed using a squeezing roll.
The interior is then at least 50, preferably at least 8
The thermoplastic cylindrical container of the present invention is coated with an aqueous dispersion of a vinylidene chloride copolymer containing 0% by weight of vinylidene chloride, and then the water in the dispersion is removed by squeezing rolls again. A manufacturing method is provided.

The method of the invention is preferably carried out as shown schematically in FIG. 1 to produce tubes of film of thermoplastic resin, preferably PVDG.

In this method, a suspension of demolding agent is first introduced into a double-walled stirring vessel (1) while stirring at a constant speed. The liquid in the receiver (1) can be cooled to keep the temperature of the liquid constant during the manufacturing process so that the extrudate is cooled uniformly. The suspension is introduced into the freshly extruded tube (4) from the annular die of the extruder (3) using the pump (2a). At the same time, the second pump (2b) sucks and removes excess suspension. The extrudate, which is substantially in a molten state, is cooled from the outside in a water bath (5);
The interior is cooled by a temperature-controlled suspension. The water is squeezed out by a pair of squeezing rolls (6), while the demolding agent remains attached to the inner wall of the cylindrical object. After passing through a pair of squeeze rolls (6), the tube is internally coated between the two pairs of squeeze rolls (6 and ?) with an aqueous internal coating dispersion based on vinylidene chloride copolymer. .

This dispersion was introduced into the cylindrical body by opening another pair of squeezing rolls (7). A pair of squeezing rolls (7
), the water in the inner coating dispersion is completely removed from the tube.

The film tubes treated according to the method of the invention not only can be opened successfully without sticking in the subsequent step, ie filling with sausage meat or cheese compositions, but also can be opened without any subsequent boiling or No fat or juices are separated during the testing process;
The sausage meat or cheese adheres satisfactorily to the tubular container.

The aqueous suspension used immediately after extrusion of the film tube is a finely dispersed, usually inorganic, demolding agent, such as talc, calcium carbonate or 5iO2, with an average particle size of 1 to 30 mm, preferably has 5 to 20 voices. 20~
In addition to 60, preferably 30 to 40 parts by weight of a demolding agent, the suspension also contains known suspension aids.

Since the process of the invention is preferably carried out continuously, the suspension containing the demoulding agent may contain, for example, sorbitol monooleate, glycerol monostearate or sorbitol monopalmitate. 05-0
．． It can be introduced into the interior of the tube of film still substantially in the molten state at a rate of 8 strokes/min, preferably 0.15 to 0.5 strokes/min.

The aqueous coating dispersion contained inside the tube between the two pairs of squeeze rolls (6 and 7) contains 50-9B, preferably 90-94% by weight of vinylidene chloride, 3.5-9B, preferably 90-94% by weight. 40
．． Preferably 4-6% by weight of ethyl acrylate and 0.5% by weight.
A copolymer of 5 to 10, preferably 2 to 4, acrylic acid is included. This aqueous dispersion preferably has a solids content of 20 to 80. Preferably it is 40 to 60% by weight.

EXAMPLE PVD III with customary additives is melted at 135° C. in an extruder. The melt is formed into a cylinder through an annular die (diameter 47,750 mm) and introduced into a water bath.
The temperature of the water bath is 20°C. The interior is cooled in a first stage by an aqueous suspension of demolding agent that is forced into the interior of the tube from a storage tank. The demolding agent suspension has the following composition.

Water 82% by weight Talc 17.8% by weight Sorbitan monolaurate 0.2% by weight In the 9th drawing process in which a suspension of demolding agent is forced into the inside of the cylindrical object below the die using a pump device, the tube is Flatten the mixture and squeeze out the water. In a second step, the tube thus produced is filled with a pvnc suspension between two pairs of squeezing rolls. This dispersion contains 84% by weight of VDC, 12% by weight of ethyl acrylate, and 12% by weight of acrylic acid.
A 50% by weight aqueous dispersion of vinylidene chloride copolymer comprising 4% by weight.

The cylindrical film thus produced can be opened without any auxiliary means, and has very good adhesion to sausage meat when used as a container for boiled sausages.

In order to obtain a uniform coating on the inner surface during the long manufacturing process, the PVDC dispersion is changed every 3 to 5 hours.

The thermoplastic film thus produced can be filled with the sausage composition according to the usual method and boiled under normal conditions.Results of peel tests when using PVDC dispersions at various operating times. is as follows.

Percentage of the product covering the length of the sausage meat cylinder until the peel test is performed (m)
%

[Brief explanation of the drawing]

Claims (1)

[Scope of Claims] 1. It has an internal coating based on a vinylidene chloride copolymer containing at least 50% by weight of vinylidene chloride, and the coating contains a finely dispersed inorganic mold release agent. A thermoplastic cylindrical container. 2. The cylindrical container according to claim 1, wherein the thermoplastic resin is polyvinylidene chloride. 3. A cylindrical container according to claim 1 or 2, wherein the inner coating contains 0.25 to 0.35 g of a finely dispersed inorganic demolding agent, preferably talc, per m^2. 4. Immediately after extrusion, the inside of the film tube, which is in a substantially molten state, is cooled with an aqueous suspension in which a normal inorganic mold release agent is suspended, and the suspension is removed from the inside of the tube. The cylindrical material is also cooled from the outside in a water bath, the remaining liquid stuck to the cylindrical material is removed using a squeezing roll, and then the inside of the cylindrical material is filled with vinylidene chloride copolymer. 4. Process for producing thermoplastic cylindrical containers according to claims 1 to 3, characterized in that they are coated with an aqueous dispersion based on coalescence and then the residual liquid is removed again by squeezing rolls.