Top 18 Kraft Paper Properties You Should Know
Firstly, we will come to a simple understanding of Kraft Paper, Kraft paper has environmental protection, recycling, cost saving, and other characteristics, with the entire international market on the packaging environmental protection requirements are increasing, Kraft paper with high strength, environmental protection, etc. property, has become the preferred material for Kraft paper box packaging. And Kraft paper also has a feature, in the customs when the Kraft paper packaging materials do not need to provide additional testing.
Excellent characteristics of Kraft paper.
Kraft Paper as a packaging material, it is certainly necessary to have high-strength compression performance, because many products are to be transported by logistics, and transport process is very easy to appear some packaging problems, subject to a certain squeeze, the folding resistance, toughness of Kraft paper are very good.
And Kraft paper packaging in some industrial and agricultural can also be used, such as cement bags, fertilizer bags, these packaging used Kraft paper with high load, high strength, and has a certain degree of breath-ability. Of course, in the food industry packaging Kraft paper is also very popular, food grade Kraft paper performance is very superior, not only with moisture-proof or waterproof, and oil immersion, low temperature freezing, long expiration period and other characteristics. And compared to plastic, glass and other packaging materials, in the performance difference is not much, but the cost of food-grade packaging Kraft paper is much lower than the general packaging materials.
And food grade Kraft paper can be recycled and reused. Compared with bleached white paper, Kraft paper properties have many unique advantages. For home food packaging, such as barbecue food or homemade food, the Kraft paper Natural Brown color makes the packaging look warm and nostalgic. For example, a wooden style decoration rustic steak restaurant, takeaway food packaging with Kraft paper, even if not in the restaurant can also feel the style of the restaurant. The unique appearance of Kraft paper alone is also more prominent than the overall white packaging.
Food grade Kraft paper for food packaging.
In Kraft paper products there is a special needs of Kraft paper, that is food packaging Kraft paper, benefiting from the national attention to food safety, as food packaging materials the food packaging Kraft paper market demand continues to be increased, products continue to standardize, food packaging Kraft paper is currently characterized by almost all the use of full wood pulp production. As use of recycled pulp and can reach the food packaging Kraft level of the product has not yet appeared on the top of the market.
Food grade Kraft paper with more environmentally friendly properties than plastic and other packaging. Its performance is also very superior, moisture-proof waterproof, anti-oil immersion, low-temperature freezing, can delay shelf life and other substances. You can buy anti-oil Kraft bags for food packaging from our store. The cost of food-grade Kraft paper is relatively lower when the barrier effect is the same compared to packaging materials such as plastics and glass.
Food packaging Kraft paper currently mainly has yellow Kraft paper and white Kraft paper two occupy the main market share, the current market of such products are mainly concentrated in the quality of standards and testing reports are not complete features, but the use of food Kraft paper customers are mostly to pick up foreign orders users, and such customers often need food-grade reports more complete, So at present, the domestic food packaging Kraft paper production enterprises need to improve their own depth in the detection report, now different countries will require Kraft paper manufacturers to provide different food grade testing reports, such as the export of food-grade printing and packaging products in the United States will ask for FDA reports, And as a junior SGS report has been unable to meet the current market demand.
An important test index of food grade white Kraft paper properties are the content of fluorescent agent, the content of which is too high will be harmful to human health. Because without adding brightener, the whiteness of white Kraft paper is very difficult to achieve high whiteness. In order to achieve this whiteness, many Kraft paper manufacturers will add a large number of phosphor as a brightener in production. But phosphors are harmful to the human body, and long-term exposure can be a cancer-causing risk. Therefore, in the food packaging industry is absolutely forbidden to use the addition of phosphor white Kraft paper.
So what simple ways do we have in our daily lives to quickly detect whether the fluorescent content of white Kraft paper is exceeding the standard, and we can use these simple methods.
1. Use a currency detector to detect. This is a relatively quick and easy way, is that we will UV function of the currency detector directly to white Kraft paper irradiation, and then slow movement, if there is a clear fluorescence phenomenon, it shows that the white Kraft paper product fluorescent content is seriously exceeded, cannot be used in food packaging.
2. Sunlight irradiation method, the method of low accuracy, because the sun itself contains ultraviolet light, if you can see fluorescent substances, but also that the white Kraft paper fluorescent agent exceeded the standard. This method is said to be less accurate because if we can see fluorescent substances in the sun, it shows that the white Kraft paper product fluorescent agent has been seriously exceeded. In fact, sometimes fluorescent agent content exceeding a certain range we can not see in the sun, so it is generally not recommended to use this method.
3. Naked eye observation method. The so-called naked eye observation method is that we directly look at the whiteness of white Kraft paper. Generally speaking, the whiteness of food grade white Kraft paper is relatively low, even some yellowish. If the white Kraft paper on your hand is as white as the A4 copy sheet, it goes without saying that this white Kraft paper can be clearly judged to be non-food grade.
Color classification of Kraft paper
1. Natural color Kraft paper is brown, color is relatively dim, its surface impurities are also more obvious, generally used as the outer layer packaging, mainly play a dust-proof, moisture-proof, shockproof effect.
2. Single-sided smooth Kraft paper, on the basis of the original sheet, has a face through the original pulp coating processing, coating this side of the surface smooth and bright, yellow-brown, can be printed color. And the other side is basically the same as the original color Kraft paper, there are impurities.
3. Double-sided Smooth Kraft paper, full wood pulp Kraft paper, two faces are relatively smooth and bright. Color brown can be printed multi-color, both sides have a full wood pulp coating, has toughness. Belonging to high-grade double-sided box board paper, imported double-sided Kraft paper generally with some physical characteristics are better than domestic.
4. White Kraft paper is a double-sided white Kraft paper, can be divided into domestic white cowhide and imported white cowhide. Generally speaking, white Kraft paper is also divided into white and ultra-white, ultra-white sometimes called high white Kraft paper. According to the performance of the paper in detail divided down and flame-retardant white Kraft paper, high-humidity strong white raft paper, waterproof white Kraft paper and non-ash white Kraft paper. For some packaging printing products, can also be drenched film, paper lamination, embossing, dyeing processing food grade and so on.
5. There are two kinds of yellow Kraft paper, one is two face color is pure bright yellow, that is, refined Kraft paper. The other is a double-sided yellow Kraft paper with stripes. Both of these types of paper belong to high-grade Kraft paper, the price is relatively expensive.
6. Black Kraft paper, gram weight lower black Kraft paper, gram weight higher called black Kraft cardboard. Also divided gray bottom single black cardboard, single-sided transmittance darker cardboard, double-sided transmittance darker cardboard, all wood paddle black cardboard.
Suitable for photo albums, photo frames, gift boxes, jewelry boxes, mobile phone boxes, shoe boxes, stationery, clothing tags, notebooks, desk calendars, handbags and horn speakers electronic gaskets and handicraft packaging etc. You can see the post Top 10 Kraft Boxes Types and Advantages.
Kraft paper color differences caused in production
We all know that Kraft paper is made of wood pulp, part of Kraft paper is made of all wood pulp, the other part of Kraft paper is made of recycled pulp. This is the basic one of properties. Whether it is all wood pulp made of Kraft paper or recycled pulp made of Kraft paper, after the finished Kraft paper came out, each batch of Kraft paper will always have a color difference.
So people notice why the color of Kraft paper in different batches is different, why this happens, in fact, the reason is very simple, because the production of Kraft paper raw materials can not be completely on the same tree material. So the production batch is different, the production season is different, at the same time the production machine is also different, so they produce the Kraft paper each batch will not be the same. Then this situation, will lead to Kraft paper color will have some deviation, but the impact will not be too large, good manufacturers produced Kraft paper color in each batch can reach 99% consistent.
White Kraft paper and Brown Kraft paper difference.
White Kraft paper is a kind of Kraft paper, Kraft paper is divided into brown Kraft paper and white Kraft paper, white Kraft paper can mainly be used for printing, there is a certain whiteness, many printing plants will apply this kind of paper to print, and brown Kraft paper is generally used for packaging more. It may be asked, what is the difference between white Kraft paper and ordinary brown Kraft paper, in addition to color? In fact, many aspects can be used as a comparison, the above mentioned that the color and use are actually different, and their production materials, it is certainly not the same. Ordinary brown Kraft paper is generally made of wood pulp. White Kraft paper is made of bleaching wood pulp, its core, bottom pulp are made of color wood pulp, so that's the difference between them.
White Kraft Paper food Packaging has many advantages, the specific summary of white Kraft food Packaging is more in line with health, environmental protection, more economical cost savings etc.
White Kraft Paper Packaging for food is more environmentally friendly. White Kraft paper is produced by full wood pulp production, food grade white Kraft paper usually comes from artificial forest farm, rather than natural forest farm, because artificial forest farm is usually the use of artificial forest and sustainable regeneration, and white Kraft paper can be fully recycled and reused.
Economical cost savings. White Kraft paper as a food grade packaging Kraft, affordable, in the conversion of packaging will not increase the cost of packaging, is a more ideal packaging used.
Eco-friendly Recycled Kraft paper.
We know that Kraft paper is environmentally friendly packaging, one is because Kraft paper can be recycled and reused, and the other reason is that some Kraft paper is made from recycled waste pulp environmental-friendly Kraft cardboard. The main difference between recycled Kraft paper and ordinary Kraft paper is in raw materials. Recycled Kraft paper is made of recycled pulp, while ordinary Kraft made of original raw wood pulp.
It is precisely because recycled Kraft paper uses recycled pulp, and recycled pulp often contains a large number of impurities, so in physical Kraft paper properties and quality of recycled Kraft paper than the original wood pulp Kraft paper is slightly weaker. Some recycled Kraft paper printing will also appear ''drop powder'' phenomenon. Therefore, in the market on the packaging performance and safety and hygiene requirements are usually use of original wood pulp Kraft paper, while the general packaging used to use recycled Kraft papers.
Recycled Kraft paper products are not because the use of raw materials used waste material is not high-grade, in fact, recycled Kraft paper on the grade is also divided into excellent grade, A class, ordinary level three levels. Highest level of recycled Kraft paper to meet the packaging needs of high-end products.
However, from the standpoint of environmental protection, recycled Kraft paper will use recycled pulp two times, greatly reducing the excessive use of forest resources. And because it is the use of recycled pulp, so the price of recycled Kraft paper is also cheaper.
About the weight of Kraft paper (grams per square meter )
When it comes to Kraft specifications of weight, if not a paper producer or often dealing with paper people generally do not know what is the weight of paper, and sometimes some customers say they need to buy Kraft paper, I asked him how many grams he needs, he does not understand what I mean, I will change the way to ask, how thick of the Kraft paper do you want? In fact, the weight of paper refers to grams per square meter of the paper, the easiest way is to cut Kraft paper into one meter multiplied by a meter of the specification, said, the weight called out is called grams is also called gram weight. In fact, G/SM is only a measurement method, and has nothing to do with Kraft paper properties and quality. The thickness of Kraft paper with different gram weight is also not the same.
The grams of Kraft paper can be measured by micrometer or caliper or measuring instrument, etc., you can also use the hand rubbing this piece of paper can also probably know the thickness of this piece of paper is also how many grams. The thickness of Kraft paper depends on paper weight, the higher the grams, the thicker paper, to buy Kraft cardboard as long as applicable for your product, do not care much about the thickness of papers.
If the use of thin Kraft paper, sometimes to produce packaging products hardness is not enough, it means that it can not be in the printing process to maintain a smooth, and then affect the production efficiency of the printing plant, but also affect the printing quality. The thinner the paper in printing will reduce the production speed of the printing press from 14,000 printing/hour to 10,000 printing/hour, so that the production efficiency of the printing plant will be reduced by 30%, so the specific use of thick paper is based on the characteristics of what you do is not the thicker the better or the thinner the better. Printing well-performing Kraft paper, can ensure the smooth running of printing, papers must have sufficient hardness, printing out the effect to meet customer requirements.
Personalized Kraft paper food packaging is the transmission of brand concept.
Personalized Kraft paper food packaging can promote the transmission of brand ideas. As consumers in the store to buy food, in the case of not knowing the taste, often choose to buy those with attractive product packaging, and the use of personalized food-grade Kraft paper packaging often gives people a unique visual effect, and easy to attract consumers' attention.
In addition to personalization, food packaging is more safety-conscious than general packaging, it is necessary to ensure that food packaging Kraft paper and food contact non-toxic. For such reasons, all food packaging put forward higher requirements with Kraft paper.
And packaging conveys not only "attraction", but also a brand and concept. For brands, a good packaging (such as the use of personalized Kraft packaging) is ultimately designed to win the attention of consumers in the first place on supermarket shelves, prompting them to finally purchase. In order to achieve this goal, brands must convey the uniqueness of the product when they advertise. And in the commodity packaging must highlight the personalized things, whether the color or packaging material should be different from the peer. Only in this way can consumers see the ads after the next visit to the mall again because of personalized packaging caused resonance, stimulated to create the impulse to buy.
Packaging factory choose what kind of Kraft paper is better for printing?
Printing plant requirements for printing materials are relatively high, because each printing product its function and use is different, so it will have different requirements for its appearance and quality. There are two main aspects of the quality of Kraft paper for differential printing.
One is to check the quality of its appearance, including looking at the surface of Kraft paper whether there is dust, stains, holes, creases, cracks, light transmittance points, fiber groups, corner neatness and so on. These will directly affect the quality of Kraft paper properties and printing effect.
Second, for the internal quality of Kraft paper, to understand including the physical properties of Kraft paper, chemical properties, absorption performance, optical properties, surface properties, printing performance and other more professional knowledge.
In addition, the water content of Kraft paper is one of the important factors that will affect Kraft paper printing. If the water content of Kraft paper is too high, it will be easy to wrinkle when printing. For some Kraft paper with poor uniformity and rough surface. In printing due to the paper ink absorption is large, easy to penetrate, so it is best not to choose too deep color for printing Kraft papers.
What paper does a Kraft notebook usually use?
In general, ordinary notebook pages use between 400 or 500 grams of paper make cover, the inside page is used in 70 grams or 80 grams of ordinary paper. Because of the better physical properties of Kraft paper, it is generally possible to use lower grams of brown Kraft paper and white Kraft paper to meet the requirements. Generally, if you use Kraft paper to make the outer page, you can choose 400 grams or 450 grams Kraft paper. And for inside page, you can choose between 50 grams or 70 grams of Kraft paper to meet the demand.
The brown Kraft paper, which is usually used to make the outer pages of the notebook, is specially treated, while the brown Kraft paper on the inner page is smoother and the color is lighter. Light color mainly plays a better role in protecting the eyes, paper smoothness is mainly to have a better writing effect Kraft paper properties. White Kraft Paper, American Bull card, refined Kraft paper, writing papers, etc. are all Kraft paper for notebooks production.
Use Kraft paper to make brand printed brochure.
Traditional craft to do brochures often use art paper, but art paper is not environmentally friendly, does not conform to the current many products to promote the concept of environmental protection. In order to highlight the characteristics of the product, at the same time with the outside of the product publicity, the vast majority of the market now production brochures more and more use of Kraft paper, with Kraft paper to do brochures have a lot of advantages of Kraft paper properties.
First, if the product needs to highlight the product quaint, natural characteristics, you can choose the color of all wood pulp Kraft paper to do the brochure, the color of Kraft paper itself unique classical color, with the unique tattoo of wood pulp, will give people a simple, elegant feeling, see the brochure can be associated with the characteristics of the product.
Second, if you need to highlight the product is green, environmentally friendly characteristics, you can choose recycled Kraft paper to do the cover of the brochure.Recycled Kraft paper itself represents environmental protection, in full compliance with the concept of product promotion.
Third, if the product is for customers in US and the European countries, then the choice of recycled Kraft paper is even more right, because in US and the European countries environmental protection concept deeply rooted in the country, see the use of recycled Kraft Paper production brochure, first of all will be associated with the product, brochure is still so, the product is not to mention.
The use of brochures in the actual production process, we need to according to the product's promotion concept to choose the brochure production materials. This will allow you to take out in a large number of goods, grasp the details of product production, will be highly recognized by the market.
The introduce of bamboo pulp Kraft paper.
Bamboo pulp Kraft paper is a kind of Kraft paper product which is widely used in recent years. In general, we classify bamboo pulp Kraft paper into the refined Kraft paper product category, so what are the advantages and disadvantages of bamboo pulp Kraft paper, and what are the common uses.
Due to the rapid growth of bamboo materials used in bamboo pulp Kraft paper, Kraft paper products produced from this raw material are very extensive in the source of raw materials, and the growth rate is very fast relative to coniferous trees. Therefore, bamboo pulp Kraft materials relatively less impact on the environment, which is the advantage of all bamboo pulp Kraft paper. In addition, bamboo pulp is softer than other slurry, and the finished Kraft paper products are more flat and delicate than other Kraft paper products, with better feel and visual feel Kraft paper properties.
Because bamboo fibers are softer than coniferous fibers, we will find that, in the same number of grams, the stiffness and hardness of all bamboo pulp Kraft paper is slightly worse than the use of full coniferous pulp Kraft paper, so it is said that bamboo pulp Kraft paper in the use of certain restrictions.
Because the hardness and stiffness of the whole bamboo pulp Kraft paper are relatively poor, but the color of the whole bamboo pulp Kraft machine and the smoothness of the paper is very good. Therefore, all bamboo pulp Kraft paper is more suitable for boutique packaging, high end packaging and other fields.
Characteristics and application of coated Kraft paper.
Coated Kraft paper stock is often used in printing. It is a Kraft paper that is very popular with people in the printing industry. Coated Kraft paper is made by a layer of coating added to the paper surface by using coating technology. After adding the coating, its printing effect will become very good, can be comparable with art paper, white cardboard. Compared to ordinary Kraft paper, coated Kraft paper can print a more beautiful packaging product, this is one of coated Kraft paper properties.
Coated Kraft paper also has a very high compression resistance, tear resistance. Can replace corrugated cardboard packaging, commonly used in auto parts, household appliances and other packaging. And has moisture-proof and anti-freezing function, so it can also be used for cold drinks that need to be refrigerated, frozen food outside packaging. Swedish coated Kraft paper is a food-grade Kraft paper produced by all wood pulp, which can be used for packing with food, medicine or fast food boxes.
Coated Kraft paper although the printing effect, physical properties are very good, but it also has obvious shortcomings. Because coated Kraft paper there is a layer of coating, so after printing Kraft paper ink absorption capacity will be blocked by the coating, drying time will be much longer, it takes about 20 seconds. Therefore, its printing efficiency will be lower, and easy to appear decolorization and other printing quality problems.
Electrostatic phenomenon caused during Kraft paper printing.
Kraft paper is used in a variety of printing, especially in dry weather, Kraft paper in printing will produce static electricity, resulting in the inability to continue printing. So is there a way to solve the problem of electrostatic electricity generated by Kraft paper?
In the printing process, Kraft paper is transported under the friction between the conveyor tape and the press wheel when it is separated in the pile of papers. Between paper and paper, between paper and machine, always in a state of friction. The charge generated during friction. When the charge gathers, Kraft paper carries an electric charge. When Kraft paper with the same polar charge, Kraft paper is mutually exclusive, resulting in printing overprinted is not allowed to be out of touch with paper. When Kraft paper has a different kind of charge, resulting in double sheets as well as multiple sheets, overprinted is not allowed and so on. The surface of the paper with static electricity is also easy to adsorb some paper hair and dust, so it is important to eliminate the static electricity of the paper when printing.
Kraft paper eliminates electrostatic method, one is to use electrostatic eliminator elimination. The electrostatic eliminator used in the printing press has an inductive electrostatic eliminator, a high-frequency high-voltage electrostatic eliminator, and is installed to the best near the drum.
The second is to improve the humidity in the printing shop. The production of electrostatic is related to the humidity of the operating environment, the general workshop humidity is less than 40%, easy to appear static electricity. So when printing, sprinkle some water around the pile of paper and the machine, or use an air humidifier to adjust to improve the humidity in the printing shop to avoid the generation of static electricity. The third is to carry on the humidification treatment to the Kraft paper. When the water content of Kraft paper is low, it is easy to bring static electricity.
When the paper with static electricity is serious, it is necessary to stack the paper into a more humid environment for a period of time, but to prevent excessive moisture caused the ' lotus leaf edge ' phenomenon.
What will cause poor tensile forces of Kraft paper?
The quality of the finished product will be directly affected by the good or bad of Kraft paper tension. When a finished product is made, whether it is durable or not is to see the tension of Kraft paper, then what is the cause of the poor tensile force of Kraft paper properties?In fact, this reason is caused by many aspects.
It is known that Kraft paper is made of all wood pulp or recycled pulp. Under normal circumstances, all wood pulp made of Kraft paper is better tensile force than recycled pulp made of Kraft paper. Second, the same wood pulp made Kraft paper, the craft is not the same, then the tensile force is different. If there is any material added to the Kraft paper, then the result is completely different. The quality of Kraft paper can also be expressed in terms of material. If the wood used is very good, then the Kraft paper made from will be very good.
The tensile force of imported Kraft paper is very good, because the general import of Kraft paper is made of all wood pulp, and many imported Kraft paper is required to be printed, and made into a lot of durable finished products, so imported Kraft paper will generally with good tensile force.
The evenness of quality Kraft paper.
Today's market for Kraft paper products and raw materials is becoming increasingly chaotic. Some customers in the purchase of Kraft paper is very pay attention to the physical properties of papers, such as breakage resistance, tightness, extrusion, folding resistance and so on. In fact, these physical Kraft paper properties are related to the evenness of Kraft paper.
The evenness of Kraft paper is closely related to the quality of Kraft cardboard, because the raw material of a piece of paper is fiber, and evenness is the uniformity of the fibrous tissue of the paper. The paper can be seen in the place of the bright light. Kraft paper has a good degree of evenness and will have a lot of advantages. In the printing aspect of the poor evenness of paper, the surface smoothness is relatively poor, ink absorption and tightness will be uneven, such inhomogeneity is bound to disrupt the evenness of the printing screen and reduce the quality of printed products.
Evenness is so important, but it is not easy to control when producing paper. Many factors can lead to changes in uniformity at the time of production. The lack of pulping is an important factor affecting the poor evenness of Kraft paper, and the longer the fibers, the easier it is to gather together. The lack of pulping can easily lead to fiber forming, resulting in uneven distribution of paper fibers, serious impact on the quality of paper.
What factors affect the hardness of Kraft paper?
The same gram weight of Kraft paper may have different hardness paper properties, which is mainly due to the original solid of the pulp. As we all know, the raw material of Kraft paper is plant fiber, the trunk part of the tree has the highest content of wood fiber, so the production of Kraft paper hardness is the highest, that is, we often say pure wood pulp Kraft paper.
However, recycled Kraft paper will add bark, rags and other materials, hardness will be lacking. So the hardness of Kraft paper depends on the content of wood fiber, the higher the content of the paper hardness is better. Different varieties of tree fiber content is not the same, different areas of the tree fiber content is also different, so the pulp produced after the production of Kraft paper hardness will be different. To reach the same hardness, it is best to use the same batch of Kraft paper.
The difference between FSC certified Kraft paper and 100% recycled Kraft paper.
The difference between FSC certified Kraft paper and 100% recycled Kraft paper is mainly reflected in the use of raw materials, that is to say, two kinds of Kraft paper products are using different types of raw materials, its products themselves are not very different.
FSC certified Kraft paper usually uses the original wood pulp as raw material for papermaking, while 100% recycled Kraft paper uses the recycled pulp as raw material for paper making, which is the biggest difference between the two. FSC belongs to the forest Green Certification range, with tractability, each FSC certified Kraft paper can be traced back to the raw material from which forest farm.
FSC Kraft paper and 100% recycled Kraft paper at the same point Is that they all embody the concept of environmental protection, first of all, the pursuit of environmental protection, FSC Kraft paper is usually made by artificial forest wood as raw materials, 100% environmentally friendly recycled Kraft paper is the use of recycled pulp as raw materials, but both have environmental characteristics.
Above introduced 18 basic Kraft paper properties knowledge that you should know about Kraft paper. We don't sell Kraft paper, but you can shop Kraft paper gift boxes and Kraft bags made from refined Kraft paper from our store.