| PVDC (polyvinylidene chloride) is one of the best plastic package materials with high barrier property in the world. PVDC smear film is usually called K smear flim which is made by daubing a coat of thin but continuous and compact PVDC on the surface of a chosen film. The company where I'm working has a PVDC product line introduced from Japan and it can produce smear films and dry composite films.In this research, adopting PVDC smear processing developed K-BOPP and K-BOPET tobacco package films with different thickness. It was also studied that the effect of the processing condition including different substrate, different adhesive , different smear emulsion, different smear dosage and different drying temperature on the mechanical property, barrier property and processable property of PVDC smear films in order to provide some evidence for their processing.The main contents are as follows.(1) In order to solve the technique problem that K-BOPP can't take good effect on the crimple-resistance of tobacco product package with dark color because of its weak solvent-resistance, the product K-BOPET with BOPET as its substrate was developed, whose crimple-resistance duration is longer than 6 months. This product had obtained the country patent of invention.(2) Because the price of PET is relatively high, a kind of 15 μ mBOPET was produced and substituted for 20 μ mBOPET by improving processing condition. As a result, the production cost was reduced effectively and the quality of the product was also kept.(3) A kind of transparent strip tobacco package film with 28 μ mBOPP as its substrate was developed by choosing smear dosage and drying temperature in order to replace the exterior packaging of the fourth or fifth -class cigarette. This product was firstly invented by my company, which supplied the gap of our country and its property exceeded the business criterion of quality. It was evaluated by a tobacco corporation that the packaging expense of one box of tobacco was reduced by 61.15 yuan after using this product, that is , about 611.5 yuan will be saved if the annual output is 100,000 boxes.(4) The printing strip packaging film was developed on the basis of transparent strip tobacco film in order to meet customers' demand for the color and pattern. During production, we overcame the difficulty that the printing tobacco film couldn't be processed by corona by reason of its metal color. After taking a series of measures, we directly coated the PVDC on the printing surface and found the optimal coating dosage by control experiment. This product is applying for the country patent of invention now.(5) In precoating procedure the PU adhesive was replaced by water-soluble adhesive, which improved the working environment, eliminated the possibility of fire risk caused by organic solvent, reduced waste and diminished cost.(6) In main-coating procedure the imported product was replaced by home PVDC whose performance was comparable to the imported one after being processed with some method but the production cost was greatly lowered. Because of this measure, about 500,000 yuan is saved for the corporation every year.(7) The dry composition processing was briefly discussed in the way of the preparation of adhesives, the control of the smear dosage, the choosing of the drying temperature , the control of the tension and so on.(8) The common problems and their resolvents in smear , dry composition and heat seal processing were collected and summarized from protracted experience.
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