Application of plastic film auxiliaries
Plastic film products are widely used for their advantages of light weight, thin shape, low price, easy to carry and change shape.
Especially in food and daily necessities packaging, agricultural covering materials, etc., the quantity and quality of plastic film products are constantly improving, and the functional requirements for new film materials are also increasing. To improve the quality of the film and enhance its functionality, simply relying on the change of the resin matrix and the improvement of the molding process can not meet the needs of market development, adding various functional additives has become a simple and efficient means to achieve the functionalization of the film.
Biaxially stretched film materials have been playing an important role in film packaging, and biaxially stretched polypropylene (BOPP), polyester (BOPET), nylon (BOPA) and other applications are increasingly widespread. Traditional PVC film is widely used in various vegetable and fruit preservation, long-term frozen food packaging, microwave baking food packaging, electronic components packaging conductive film. In addition, the production of products such as cast polypropylene (CPP) and cast polyethylene (CPE) is also large. The additive products with the above packaging film materials mainly include antistatic agents, smoothing and anti-adhesion agents, stiffeners, heat stabilizers, antioxidants and barrier agents, etc.
Antistatic agent
Industrial antistatic agents are mainly single compounds or compounds of non-ionic and ionic surfactants. According to whether the hydrophilic group in its molecules can be ionized, it is divided into ionic and non-ionic types, and ionic types are divided into cationic types, anionic types and amphoteric types. The antistatic principle is to use its hydrophilic base to absorb water vapor in the air on the plastic surface, or to form a conductive layer on the surface to reduce the surface resistance value.
Cationic antistatic agent has excellent antistatic performance, but it is usually poor thermal stability, easy to decompose and discoloration under high temperature processing conditions, and is generally only used in PVC products. The anionic antistatic agent can not be used for thin film products because it will affect the transparency.
Non-ionic antistatic agent has the characteristics of low toxicity, good thermal stability, and is not easy to cause plastic aging, which makes it become the main internal additive antistatic agent in packaging materials. The main varieties are fatty acid polyol esters, fatty acids, alcohols, amines of ethylene oxide admixtures and other products.
Smooth and anti-sticking agent
Modern plastic processing is developing in the direction of automation, high-speed and high-quality. The faster the processing speed, the easier it is to generate static electricity due to friction, and the easier it is to adhere between the film (plastic products), which seriously hinders the high-speed extrusion; The better the transparency of the film, the higher the processing temperature, the easier the agglomeration and adhesion. Therefore, highly efficient smoothing agents and anti-adhesive agents play an extremely important role in plastic production and automated packaging.
Domestic common varieties of smoothing agents are amines (oleic acid amine and erucic acid amine), soap (calcium stearate, etc.) and organosilicone (silicone). The latter is liquid, inconvenient to add and expensive. Although soap products are cheap, the effect is not ideal, and the amount of addition is large, and it can not be used in medium and high-end products. The common smoothing agents in packaging films are mostly amines, such as oleate amines used in LDPE films; Erucate amine for PP films.
And the anti-adhesion agent is also called the opening agent, generally inorganic fine particles, such as: silica and so on. However, because the refraction coefficient of the traditional inorganic opening agent is different from that of the base resin, it often affects the fog degree. The newly developed polymer particles as opening agents have solved this problem.
Stiffener
Stiffening agent for packaging materials, also known as stiffening agent, is mainly used in BOPP heat shrink film for tobacco to improve the crispness of BOPP film, improve the appearance of packaged goods, so as to enhance the value of goods. At present, the advantage and disadvantage of stiffening agent is mainly measured by examining the degree of improvement of elastic modulus of film. For tobacco BOPP heat shrink film, the performance requirements of the manufacturer for the stiffener also include: can not affect the film fog degree and other mechanical properties, reduce the heat sealing temperature.
At present, the research and development of stiffeners are mainly concentrated in two fields. One approach is to alloy PP with polymer containing rigid chain segments in the structure to improve the elastic modulus of BOPP. Commonly used polymers are: polycyclopentadiene and so on. The other way is to implement hardening according to the principle of promoting nucleation, through the existence of fine particles to play the role of heterogeneous nucleation, promote and improve the crystallization of PP, make its grain uniform and fine, to improve the rigidity of the product. Under the influence of this idea, the application of using organic nucleating agents to achieve stiffening has been developed.
Antioxidant
Because of the particularity of its application, such as packaged food, cosmetics, etc., the hygiene requirements of antioxidants are high, although many common antioxidants have been tested for toxicity, but the application is still difficult to avoid worrying. Vitamin E, a new antioxidant, has excellent thermal oxidation resistance and no toxic side effects, which is favored by the packaging products industry.
Blocking agent
In order to prevent all kinds of gas through the film and extend the storage period of the packaging material, the market demand for new barrier packaging films is increasing. In addition to the use of good barrier resin and SiOx vapor surface deposition treatment, adding a certain amount of barrier agent is also an important means to obtain new high barrier packaging materials.
Our Products：
https://www.potop-polymer.com/biaxial-stretcher/biaxial-film-stretcher-manufacturers.html
