CN105437686A

CN105437686A - PA/TIE/PE/EVA/PVDC/EVA/PE seven-layer co-extruded deep-drawing film

Info

Publication number: CN105437686A
Application number: CN201410425519.4A
Authority: CN
Inventors: 须建
Original assignee: DANDONG QUANDE HIGH-TECH PACKAGING Co Ltd
Current assignee: DANDONG QUANDE HIGH-TECH PACKAGING Co Ltd
Priority date: 2014-08-26
Filing date: 2014-08-26
Publication date: 2016-03-30

Abstract

The invention discloses PA/TIE/PE/EVA/PVDC/EVA/PE seven-layer co-extruded deep-drawing film. The film comprises PA, TIE, PE, EVA, PVDC, EVA and PE in order from outside to inside. The film is advantageous in that the EVA layers are disposed at two sides of the PVDC layer so as to overcome an adhesive-containing defect, the drawing depth reaches 6 cm, and the film is used for product packages having deep-drawing high-strength requirements, and can be used for light packages of meat products and packages of marine products and dairy products.

Description

PA/TIE/PE/EVA/PVDC/EVA/PE7 layer co-extrusion deep drawn film

Technical field

The present invention relates to packaging material field, is a kind of film specifically, is more specifically a kind of co-extrusion film.

Background technology

Be expressed into by a kind of raw material on Manufactured another kind of film in the processing of film or be mutually bonded to together by Manufactured different types of film and become plural layers, this product is called composite membrane.The material great majority of composite membrane are plastics, but also can paper using, metal forming (being generally aluminium) or fabric etc.The basic demand of composite membrane is exactly will have good gluing between layers to ensure the overall mechanical property of packing.In addition, composite membrane is used for packaging for foodstuff, will use binder in the processing of composite membrane, and the selection of its solvent and gluing technique etc. all will meet corresponding sanitary standard requirement.

Co-extrusion film has most of feature of composite membrane, owing to being by hot melt combination without the need to binder between layers, therefore relatively reliable to the wholesomeness of packaging for foodstuff co-extrusion film.

Coextruded film has the feature of stretching in process, can corresponding raising intensity after plastic tensile, also the plastic material such as nylon, metallocene PE can be added in centre, make it possess and exceed general plastics packed combined strength bination, there is not delamination phenomenon, flexibility is good, and heat sealability is excellent.

PVDC, formal name used at school is " polyvinylidene chloride ", and it is a kind of nonpoisonous and tasteless, safe and reliable high barrier material, except the general performance with plastics, also has the feature such as oil resistivity, corrosion resistance, can be widely used in the industries such as packaging for foodstuff.

The PhilipKwok of Dow Chemical company, the JosephDooley of SteveJenkins and Bin Dun engineering company discloses following content in its paper " new technology of processing high-barrier PVDC ": PVDC can bear the heat time of 6-8 minute within the scope of 150-170 DEG C, and when 210-220 DEG C, bear deficiency of time 30 seconds; And the co-extrusion material heating-up temperature of the application is: PE:160-170 DEG C; EVA:160-180 DEG C; PA binding agent is at 200 DEG C, and PA will ensure that its levelability is minimum also shaping at 220 DEG C.Therefore, co-extrusion stretched film structural design must consider heating temperature and the heated time problem of different materials.

Chinese Patent Application No. 201220654117.8 discloses a kind of PVDC composite membrane, and this patent is a kind of composite membrane, is not a kind of co-extrusion film.

GB/T28117-2011 discloses some PVDC co-extrusion films, but the PVDC co-extrusion film disclosed in this standard has a common feature, and the neighbouring layer being exactly PVDC layer all adopts TIE, and TIE is a kind of binder resin, and its structure does not overcome the defect of composite membrane.

Summary of the invention

For solving the problems of the technologies described above, the open a kind of 7 layers of co-extrusion stretched film of the present invention, are followed successively by from outside to inside and are followed successively by PA, TIE, PE, EVA, PVDC, EVA, PE from outside to inside.

7 layers of co-extrusion stretched film of the present invention adopt the multi-layer co-extruded mould of a kind of PVDC to prepare, and described mould has multiple annular or taper stem stem, and described stem stem periphery arranges multilayer for extruding the mold layer of different materials; The runner extruding outlet from molten thermoplastic entrance to annular is set in described mold layer; PVDC extruding layer arranges multiple runner be connected with extruder, and multiple runner forms helical form form in center; The runner of described PP, PE, EVA, takes one-to-two, two point four, and the labyrinth type of four point eight is without dead angle runner.

Advantage of the present invention is: 7 layers of co-extrusion stretched film of the present invention, and PVDC layer both sides are EVA, only contain TIE in the side of PVDC layer, and PVDC has high-barrier function, therefore, use not containing side and the Food Contact of TIE, overcome the foregoing defect containing adhesive; Stretching depth reaches 6cm, requires that the packing of product uses for deep drawn high strength, can be used for meat products and gently packs and marine product, dairy products packaging.

Accompanying drawing explanation

Fig. 1 is the structural representation of 7 layers of co-extrusion deep drawn film;

The runner schematic diagram that Fig. 2 is PVDC mold layer;

Fig. 3 is one-to-two, two point four, and the labyrinth type of four point eight is without dead angle runner schematic diagram.

Detailed description of the invention

Illustrate the present invention below in conjunction with accompanying drawing, the structure of 5 layers of co-extrusion stretched film as shown in Figure 1, is followed successively by PP or PE, EVA, PVDC, EVA, PE from outside to inside.The present invention adopts the multi-layer co-extruded mould of a kind of PVDC to prepare, and as shown in Figure 2 and Figure 3, described mould has multiple annular or taper stem stem, and described stem stem periphery arranges multilayer for extruding the mold layer of different materials; The runner extruding outlet from molten thermoplastic entrance to annular is set in described mold layer; PVDC layer 203 adopts the runner 2031 of multiple entry to design, and 3 runners 2031 form helical form form in center; The raw material of PVDC each extruder in forming process is made just to complete shaping in 1/3 to circumference.Also the passage of other quantity can be adopted, as 2,4 etc., specifically can according to settings such as the thickness of film, the numbers of plies.

Claims

1.PA/TIE/PE/EVA/PVDC/EVA/PE7 layer co-extrusion deep drawn film, is characterized in that: be followed successively by PA, TIE, PE, EVA, PVDC, EVA, PE from outside to inside.