How much do you know about Biaxially oriented film production process?

SUMINO BOPP FILM MAKING MACHINE

The film will be oriented during processing, which is generally divided into horizontal and vertical directions. Due to different processing techniques and parameters, the orientation is also different. For example, blown film has both longitudinal traction and lateral inflation, the relative vertical and horizontal orientation is relatively balanced, and the mechanical properties in the two directions are relatively balanced. For casting, there is only longitudinal traction, but no transverse inflation. Therefore, the longitudinal orientation is greater than the transverse direction, and the mechanical properties in the two directions are obviously different. For example, the longitudinal tensile force is large, but the tear strength is very low. Uniaxially stretched film (MDO) uses the speed difference between the rollers to further stretch the film in the longitudinal direction, thereby improving the stiffness, transparency, and certain mechanical properties of the film. At this time, the longitudinal orientation is much greater than the transverse direction. If transverse stretching is carried out on this basis, it is what we usually call bidirectional orientation (BO). Two-way stretching can be completed in one step, commonly known as synchronous stretching; it can also be completed in two consecutive steps, commonly known as asynchronous stretching. If the orientations in the two directions are equal, the resulting film is isotropic in performance; if the orientation in one direction is greater than the orientation in the other direction, the film is anisotropic in performance.

SUMINO BOPP FILM MAKING MACHINE----MDO

SUMINO BOPP FILM MAKING MACHINE-----TDO

In order to obtain effective orientation, the polymer is best stretched at a temperature lower than the melting point, and at the same time, there should be enough heat during stretching to allow the molecules to move. The higher the temperature, the faster the movement speed of the molecules, the shorter the relaxation time, and the less orientation actually occurs. After stretching, the film will be cooled and set to obtain thermal stability. Ideally, sufficient orientation is obtained by cooling before the stretched molecules relax.

SUMINO BOPP FILM MAKING MACHINE---Process Flow Chart

After the plastic film is biaxially stretched, the tensile strength and elastic modulus are significantly increased, and the mechanical strength is significantly improved. In addition, heat resistance, cold resistance, transparency, gloss, air tightness, moisture resistance and other properties have also been improved, and it has a wide range of uses. The polymer materials that can be used in the production of biaxially oriented films are: polypropylene, polyester, polystyrene, polyamide, polyvinyl alcohol, EVOH, polyvinylidene chloride, polyethylene and so on. Among them, biaxially oriented polypropylene (BOPP) film is mainly used for packaging food, medicine, clothing, cigarettes, etc., and is widely used as the base material of composite film and electrical film; biaxially oriented polyester (BOPET) is used in addition to tapes and floppy disks. In addition to various industrial uses such as, film, etc., it is also widely used in packaging for retort food, frozen food, medicine, cosmetics, etc., with excellent stiffness and scratch resistance; biaxially oriented polystyrene (BOPS) is mainly used for food packaging And toys and other packaging; Biaxially oriented polyamide (BOPA) is mainly used for various vacuum, aeration, retort sterilization, liquid packaging and other purposes. It has the best toughness and good gas barrier properties.

The main forming methods of biaxially oriented film are flat film method and tube film method. The film produced by the flat film method has good quality, high thickness precision and high production efficiency. The tube film method has low equipment investment and small footprint, but the product thickness accuracy is poor, and the production efficiency is low. It is limited to the production of special products such as polypropylene heat shrinkable film and cigarette packaging film. The flat film method can be further divided into two methods: stepwise biaxial stretching and simultaneous biaxial stretching. The step-by-step biaxial stretching method has mature equipment and high linear speed, which is currently the mainstream of the flat film method. However, the production of the same fabric biaxial stretching method is limited due to the expensive equipment. As the industry has higher and higher requirements for the quality of film products, this not only puts forward requirements for the polymer material itself, but also puts forward higher requirements for the further development of film production technology and equipment. Biaxial stretching technology can improve the quality of the film from the process. Although the technology has a higher threshold, it is believed that there will be more room for development in the future.

Membrane is a technical service platform focusing on the upstream and downstream industrial chain of thin films. The platform takes plastic film forming formula technology as the core, and through built-in algorithms, provides professional online formula guidance, cost estimation, performance comparison, data query, market information, human resources, film testing and Brand promotion and other services.

Company Profile

Nanjing Sumino Precision Machinery Co., Ltd. is a high-tech enterprise integrating scientific research, production and sales. It has always adhered to the business philosophy of integrity, equality, and customer benefits. In order to better improve the quality of equipment, it has entered a more professional and standardized Production track. We have established independent research and development technologies for seven categories of equipment including plastic sheet material, casting, bi-stretching, non-woven non-woven meltblown cloth, laminating film composite, recycled granulation environmental protection recycling system and coating machine manufacturing system. The center and production department provide a full set of professional technical solutions to meet the special needs of each customer. Among them, the biaxially oriented film manufacturing system includes: BOPP biaxially oriented film manufacturing system, PVC biaxially oriented shrink film production line, PET biaxially oriented film production line, BOPA biaxially oriented film production line, BOPA biaxially oriented film production line, etc.

Company Address: No. 11, Kaifeng Road, Moling Street, Jiangning District, Nanjing City, Jiangsu Province

Sue

International Business Development Department Manager

Nanjing Sumino Precision Machinery Co.,Ltd

Add: Kaituo Road No.11, Jiangning Distract, Nanjing, China.
Tel: +86 025-51839686
Fax: +86 025-51839687
Mob/Wechat/Whatsapp: +86 177 1241 3069

Email: suqian@susumino.com

Web: sumino.en.alibaba.com / www.susumino.com/ www.njsumino.com