What are the key points for attention in the production of high temperature cooking bag and suction bag
① Arched phenomenon of nylon film
BOPA film can be produced by tube film drawing method or plane biaxial drawing method. The biaxially oriented nylon film produced by different methods has different bow effect, which has obvious influence on the printing precision of the film and the flatness of the packaging bag (including the appearance of the bag surface before and after boiling).
The specific method to detect the arched effect of nylon film is to measure the diagonal thermal shrinkage. The detection condition of heat shrinkage in the national standard is that we can also test the hygrothermal shrinkage of nylon film according to the actual use conditions of suction bag (such as 100 ℃ 30min). The smaller the difference of diagonal heat shrinkage rate, the better the balance of products; if the difference is less than 1.5%, there will be no warping during bag making.
② Market supply
BOPA film can be divided into printing grade and composite grade. Printing grade can be used for printing and laminating process, while suction bag composite grade is only recommended for composite process without printing. The thickness is generally 12 μ m, 15 μ m and 25 μ M. 15 μ m soft packaging composite film, 25 μ m for cold formed aluminum medicine packaging. Double sided corona film must be used when it is used for intermediate layer lamination and cooking.
③ Key quality requirements of BOPA film
a. If the flatness requirement is high, the synchronous stretching film with small bow effect should be selected.
b. The surface tension of the film is more than or equal to 50 Mn / m to ensure the adhesion fastness of the ink. The larger the processing value, the better.
c. Choose the film with good adaptability to relative humidity to ensure the overprint accuracy.
d. Choose the film type with smaller thermal shrinkage (hygrothermal shrinkage). www.dgbpk.com/
Dongguan Beite packaging materials Co., Ltd
Dongguan special bag, plastic bag, plastic bag, plastic bag