On the basis of existing substances on the performance of the film, BOPP film important upgrade and improve control performance indicators is an important means of BOPP films to improve market competitiveness. Xia Min, let's take a look at the six directions of high performance of BOPP film:
4. Adjustable heat shrinkage rate
1. Long-term antistatic performance
During the use of BOPP film packaging, the static electricity of the film consists of the static electricity carried by the film itself and the static electricity generated by friction during the packaging process. The static electricity carried by the film itself is easier to control, but the static electricity generated during the packaging process is more difficult to control. The static electricity of the film will cause electrostatic adhesion, which has an adverse effect on cutting, conveying, folding film, etc., which may cause the film to operate on the machine. Therefore, if only the electrostatic value of the film itself is emphasized, and the static value generated during the packaging process is neglected, the detection performance of the film is good, but it always fails when the machine is running.
On general packaging machines, static electricity can be transferred by rapid conduction of metal or static eliminator. In addition, the environment with high humidity is also beneficial to the static elimination of the surface of the film. In the case of a relatively large electrostatic film or dry season (such as winter), the company can put the film into the packaging workshop in advance, adjust the humidity treatment in the packaging workshop, or use the water to wet the workshop floor or apply the wet towel to the film. The method of winding the end face to increase the humidity of the environment and easily eliminate the static electricity on the surface of the film.
2. Differential friction performance
BOPP film for box packaging is generally required to have different sliding properties, that is, the inner and outer layers of the film are required to have different coefficients of friction. During the packaging process, when the outer surface of the film is run on the metal parts such as the lower film passage, the forming wheel groove, the folding plate, the soldering iron, etc., the friction coefficient should be controlled at a low level, but since these metal parts are mostly at a high temperature of 50 ° C or higher Under the condition of running, the friction coefficient of the film increases with the increase of temperature, especially after 45 °C, the friction coefficient rises faster. Therefore, it is more important to control the thermal friction coefficient of the film under high temperature conditions. The film slides smoothly over the hot metal parts. The inner surface of the film is in contact with the paper during the packaging process, and the friction coefficient should be controlled to a slightly higher level, so that the positioning of the box product in the forming wheel and the film is good, and the folding quality of the film is improved, thereby obtaining a compact and crisp packaging effect. . Further research in this direction can begin with how to adjust the differential friction coefficient of the inner and outer layers to suit the needs of positioning and high-speed packaging.
3. Low temperature heat sealing performance
The heat sealing performance of the film is represented by heat sealing temperature and heat sealing strength, and the heat sealing temperature should generally be controlled between 85 and 110 °C. The film with a narrow heat sealing temperature range has a narrow temperature range for the adjustable heat seal on the packaging machine. If the set heat sealing temperature is slightly higher, the hot mouth will wrinkle; while the heat sealing temperature is set to be slightly lower, there will be problems such as tight sealing. Different packaging machines have different heat sealing conditions, and the same type of equipment requires different heat sealing temperatures in different operating environments. Therefore, the wide heat sealing temperature range makes the film have better heat seal adaptability, which ensures smooth operation on various packaging machines.
The special heat sealing materials used by film manufacturers are generally ethylene-propylene binary copolymers, ethylene-butadiene terpolymers and mixtures thereof. The melting points of the three heat-sealing materials are 135, 125, 115 ° C, which are gradually reduced. The trend, therefore, at 2.0 N/mm2 as the lowest heat seal strength of the film, their initial heat seal temperatures were lowered from high to low at 115, 105, 100 °C, respectively. The heat sealing ranges of the three heat sealing materials are: 115 to 150 ° C, 105 to 150 ° C, and 100 to 150 ° C. From the random copolymer to the mixture, due to the presence of multiple phases and the increase of ethylene content, the heat sealing range of the film is gradually increased. Therefore, in the film production formula design, different packaging speeds should use different heat sealing materials.
4. Adjustable heat shrinkage rate
For the BOPP film for cigarette packaging, it is generally divided into two types: ordinary type smoke film and heat shrinkable type smoke film. Ordinary cigarette film has low heat shrinkage performance, and the heat shrinkage rate should generally be controlled at 2% to 5%. It is generally used for small boxes of soft packs and strip boxes for cigarettes. The heat shrinkable smoke film has high heat shrinkage performance, and the heat shrinkage rate should generally be more than 7%. After packaging, the cigarette pack can be compact, have more uniform wrapping property, and can ensure the tightness of the cigarette pack for a long time without loosening. collapse. Its main feature is that it has excellent skin-packing effect, which overcomes the problem of loose wrinkles of the ordinary type of cigarette film on the hard-package film; in addition, the heat-shrinkable film adopts special processing technology and formula, so it has low-temperature heat shrinkage performance. And has better high-speed packaging performance.
5. High gloss, low haze
In addition to ensuring that the film can be properly packaged on the machine, the most important function of the BOPP packaging film is the appearance of the bright package. Although the human eye is a direct tool for evaluating the optical properties of a film, and the final evaluation of the user is only intuitive, from the perspective of quality management, it is not enough to control by visual alone, because of lighting conditions, observer mood, Even the angle of observation will affect the visual effect. In order to obtain reliable and realistic quality assurance, objective, measurable parameters are required to quantify the appearance. Starting from the basic principle of optics, two important quantitative indicators of optical properties of BOPP films, namely gloss and haze, have emerged.
Gloss is used to evaluate the visual effect of the film surface. The more light that is directly reflected from the surface of the film, the higher the gloss. The light reflected by the high-gloss surface is highly concentrated and can clearly reflect the image; the light reflected by the low-gloss surface is diffusely reflected in all directions, and the image quality is lowered. Therefore, the surface of the BOPP film should have a high surface flatness, and the high gloss can bring a bright visual effect to the cigarette packet. Haze is a measure of the percentage of light that is transmitted from a direction of incident light that is greater than a certain angle of light. When scattering at a small angle, the contents of the package are relatively clear; the scattering angle is large and the inconsistency will result in a decrease in contrast, the contents of the package are ambiguous, and the lower haze can show the clear and vivid logo pattern of the outer casing of the product.
6. Stiffness, wear resistance, etc.
In addition to the properties mentioned above, stiffness is also an important property of BOPP films. In the index control process of the film product, the stiffness is not directly measured, but is reflected by the elastic modulus. The greater the modulus of elasticity, the higher the stiffness. When the film stiffness is high, high folding quality can be obtained during the packaging molding process, and a good heat sealing effect can be achieved in a short pause time. High stiffness is a prerequisite for increasing the speed of packaging and is suitable for high speed packaging machines with automatic shifting.
At present, a technical problem that BOPP film urgently needs to solve is to improve the surface scratch resistance of the film. Although some research has done some work to improve the hardness of the matrix PP, the problem has not been fundamentally solved. Some manufacturers have introduced anti-wearing BOPP. The film, after comparative analysis, actually only slightly reduced the surface scratches. In-depth study of the root cause of the scratch on the surface of the film, as well as the negative effect of anti-adhesive particles on the surface scratch resistance, is an important direction for the high performance of BOPP film in the future.
Pyrite (S48)
Place of Origin: Henan Luoyang, China
Pyrite, Iron pyrites , pyrites lump, Ferro sulphur, Pyrites powder.
Product Description:
Detailed introduction: Pyrite translated into the Iron pyrites or pyrites lump, also can be called Ferro sulphur. Luanchuan Hengkai Metallurgical pyrite Co., Ltd. specialize in the production and sales of high-grade pyrite (FeS2)/ Ferro sulphur, Has the rights of import and export operation.
The products are mainly exported to East Asia, South America, Western Europe, Australia and Taiwan markets. We are China's major exporters of pyrite, "Hengkai Metallurgical " is the first brand of high grade pyrite export. Products are widely as increase sulfur agent used in smelting and casting, fillers of grinding wheel's abrasive, soil conditioner, as the adsorbent of heavy metals in wastewater, filler of core-spun yarn, lithium battery cathode materials, by the user praise and trust.
Quality:
S: 48%min, FE: 42%min, SIO2: 3.0%max, PB: 0.1%max,
ZN: 0.1%max, AS: 0.1%max, . C: 0.3%max, CU: 0.2%max,
H20: 1.0%max, SIZE: 95%min
Granularity: (0-3)mm/(3-8)mm/(3-15)mm/(15-50)mm or other particle size.
Packing: 25KG/500KG/1000KG/BAG or 1000KG/BAG or other packaging.
Note: if there are special requirements, the product can be customized according to clients` requirements.
Crystal Pyrites pyrites lump Rough Copper Pyrites Natural Mineral Specimen
LUANCHUAN COUNTY HENGKAI METALLURGICAL MATERIALS SALES CO.,LTD , https://www.pyritechina.com