Papermaking can be traced to about ad 105, when Ts&#;ai Lun, an official attached to the Imperial court of China, created a sheet of paper using mulberry and other bast fibres along with fishnets, old rags, and hemp waste. In its slow travel westward, the art of papermaking reached Samarkand, in Central Asia, in 751; and in 793 the first paper was made in Baghdad during the time of Hārūn ar-Rashīd, with the golden age of Islāmic culture that brought papermaking to the frontiers of Europe.
For more metalized paper manufacturerinformation, please contact us. We will provide professional answers.
By the 14th century a number of paper mills existed in Europe, particularly in Spain, Italy, France, and Germany. The invention of printing in the s brought a vastly increased demand for paper. Through the 18th century the papermaking process remained essentially unchanged, with linen and cotton rags furnishing the basic raw materials. Paper mills were increasingly plagued by shortages; in the 18th century they even advertised and solicited publicly for rags. It was evident that a process for utilizing a more abundant material was needed.
In a book was published that launched development of practical methods for manufacturing paper from wood pulp and other vegetable pulps. Several major pulping processes were gradually developed that relieved the paper industry of dependency upon cotton and linen rags and made modern large-scale production possible. These developments followed two distinct pathways. In one, fibres and fibre fragments were separated from the wood structure by mechanical means; and in the other, the wood was exposed to chemical solutions that dissolved and removed lignin and other wood components, leaving cellulose fibre behind. Made by mechanical methods, groundwood pulp contains all the components of wood and thus is not suitable for papers in which high whiteness and permanence are required. Chemical wood pulps such as soda and sulfite pulp (described below) are used when high brightness, strength, and permanence are required. Groundwood pulp was first made in Germany in , but the process did not come into extensive use until about . Soda pulp was first manufactured from wood in in England, and in a patent was issued in the United States for the sulfite pulping process.
A sheet of paper composed only of cellulosic fibres (&#;waterleaf&#;) is water absorbent. Hence, water-based inks and other aqueous liquids will penetrate and spread in it. Impregnation of the paper with various substances that retard such wetting and penetration is called sizing.
Special 67% offer for students! Finish the semester strong with Britannica.
Learn MoreBefore , paper sheets were sized by impregnation with animal glue or vegetable gums, an expensive and tedious process. In Moritz Friedrich Illig in Germany discovered that paper could be sized in vats with rosin and alum. Although Illig published his discovery in , the method did not come into wide use for about 25 years.
Discovery of the element chlorine in led to its use for bleaching paper stock. Lack of chemical knowledge at the time, however, resulted in production of inferior paper by the method, discrediting it for some years. Chlorine bleaching is a common papermaking technique today.
Prior to the invention of the paper machine, paper was made one sheet at a time by dipping a frame or mold with a screened bottom into a vat of stock. Lifting the mold allowed the water to drain, leaving the sheet on the screen. The sheet was then pressed and dried. The size of a single sheet was limited to the size of frame and mold that a man could lift from a vat of stock.
In Nicolas-Louis Robert in France constructed a moving screen belt that would receive a continuous flow of stock and deliver an unbroken sheet of wet paper to a pair of squeeze rolls. The French government recognized Robert&#;s work by the granting of a patent.
The paper machine did not become a practical reality, however, until two engineers in England, both familiar with Robert&#;s ideas, built an improved version for their employers, Henry and Sealy Fourdrinier, in . The Fourdrinier brothers obtained a patent also. Two years later a cylinder paper machine (described below) was devised by John Dickinson, an English papermaker. From these crude beginnings, modern papermaking machines evolved. By paper coated by machinery was being made for use in the printing of halftones by the new photoengraving process, and in Carl F. Dahl invented sulfate (kraft) pulp in Danzig, Germany.
Although the paper machine symbolizes the mechanization of the paper industry, every step of production, from the felling of trees to the shipment of the finished product, has also seen a dramatic increase in mechanization, thus reducing hand labour. As papermaking operations require the repeated movement of large amounts of material, the design and mechanization of materials-handling equipment has been and continues to be an important aspect of industry development.
Although modern inventions and engineering have transformed an ancient craft into a highly technical industry, the basic operations in papermaking remain the same to this day. The steps in the process are as follows: (1) a suspension of cellulosic fibre is prepared by beating it in water so that the fibres are thoroughly separated and saturated with water; (2) the paper stock is filtered on a woven screen to form a matted sheet of fibre; (3) the wet sheet is pressed and compacted to squeeze out a large proportion of water; (4) the remaining water is removed by evaporation; and (5) depending upon use requirements, the dry paper sheet is further compressed, coated, or impregnated.
The differences among various grades and types of paper are determined by: (1) the type of fibre or pulp, (2) the degree of beating or refining of the stock, (3) the addition of various materials to the stock, (4) formation conditions of the sheet, including basis weight, or substance per unit area, and (5) the physical or chemical treatment applied to the paper after its formation.
The company is the world’s best high quality Metallized Paper labels supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.
Metal manufacturing is essential for all areas of the economy. Because of their strength, stiffness, and long-term durability, metal components are used in applications from appliances to construction parts and car body panels. Traditional metal manufacturing techniques include forming, casting, molding, joining, and machining.
Sheet metal forming involves various processes where force is applied to a piece of sheet metal to plastically deform the material into the desired shape, modifying its geometry rather than removing any material. Sheet metals can be bent or stretched into a variety of complex shapes, permitting the creation of complex structures with great strength and a minimum amount of material.
Sheet metal forming is the most cost-effective forming procedure today for manufacturing parts in large quantities. It can be highly automated in factories or, at the other end of the spectrum, manually operated in metal workshops for small series parts. It is a versatile, consistent, and high-quality procedure to create accurate metal parts with limited material waste. From metal cans to protective housing for hardware, parts created by sheet metal forming are found everywhere in our daily lives.
In this article, learn the basics of sheet metals, the various sheet metal forming processes, and how to reduce the cost of sheet metal forming with rapid tooling and 3D printed dies. For a detailed overview and the step-by-step method, watch our webinar or download our white paper.
Sheet metal refers to thin, flat metal pieces that are formed by industrial processes. These can be extremely thin sheets, considered foil or leaf, to up to 6 mm (0.25 in) sheets. Pieces thicker than 6 mm are considered plate steel or "structural steel.&#; Sheet metal thickness is normally specified in millimeters around the world, while the US uses a non-linear measure known as the gauge. The larger the gauge number, the thinner the metal sheet.
A sheet metal blank for forming a blade guard for an electric saw.
Sheet metal is widely used in the manufacturing of cars, aircraft, trains, hardware enclosures, office tools, furniture, house appliances, computers, machine components, beverage cans, and in construction (ducts, gutters, etc.).
Plate metal is generally used in applications where durability is more important than weight, for example in larger structural parts of ships, pressure vessels, and turbines.
Many different metals can be processed into sheet metal, including aluminum, steel, brass, tin, copper, nickel, titanium, and for decorative purposes, also gold, silver, and platinum.
Sheet metal work stock is normally rolled and comes in coils that can be cut and bent into a variety of shapes.
Sheet metal forming includes treatments such as bending, spinning, drawing, or stretching implemented by dies or punching tools. Forming is mostly performed on a press and parts are formed between two dies.
The sheet metal forming process is straightforward:
A sheet of metal is cut out from a stock metal to create individual blanks.
The blank is placed in the forming machine in between two tools.
Subjected to the high forces of the machine, the upper die (also known as the punch) pushes the sheet metal around the matching lower tool and bends it in the desired shape.
Process workflow for sheet metal forming.
As a downside, sheet metal forming is an equipment-intensive operation. The procedure requires machinery and specialized tools that are part-dependent. As shown above, the tool&#;also referred to as the form or die&#;is the part of the forming machine acting to bend the sheet.
Typically, manufacturers produce their forming tools out of metal by CNC machining in house or outsourcing to service providers. This upfront tooling is expensive and generates significant lead times.
Driven by innovation, industries using metal components need more intricate parts with increased agility in fabrication means. Reconsidering tooling techniques can be a powerful lever for this.
Although large size parts such as car body panels are associated with heavy tooling, most metal workshops also produce all kinds of small units requiring lower bending forces. Replacing those metal tools with plastic parts printed in house for prototyping and low volume production can shorten development times and drive down production costs.
In-house 3D printing enables engineers to prototype metal parts and iterate tool designs in a matter of hours, achieving complex geometries while reducing reliance on outsourced providers. Professional desktop printers are affordable, easy to implement, and can be quickly scaled with the demand.
Different iterations of upper and lower dies manufactured with 3D printing for forming a replacement blade guard.
Manufacturers are already using stereolithography (SLA) polymer resins to substitute metal jigs, fixtures, and replacement parts in factories. In processes such as injection molding or thermoforming, using test molds in plastic is an effective practice to validate designs and solve DFM challenges before committing to expensive metal molds. Savings in material costs from metal to plastic are significant.
Watch the video to see how Shane Wighton from the Formlabs engineering team formed a sheet metal part using 3D printed tools for concept validation.
SLA 3D printing technology presents some interesting properties for sheet metal forming. Characterized by high precision and a smooth surface finish, SLA printers can fabricate tools with excellent registration features for better repeatability. Thanks to a broad material library with various mechanical properties, choosing a resin tailored to the specific use case can optimize the result of the forming. SLA resins are isotropic and fairly stable under load compared to other 3D printing materials. Plastic tooling can also eliminate a polishing step, as plastic dies do not mark the sheet as metal.
The mechanism is similar to the general sheet metal forming workflow. The difference lies in the design and print of the two-part tool made of upper and lower dies. The blank sheet is then placed between both plastic dies, and pressed with a hydraulic press or other forming equipment.
Process workflow for sheet metal forming with 3D printed dies.
White Paper
This research work tests and demonstrates the viability of SLA 3D printed dies to form sheet metal parts.
Download the White Paper
3D printing a tool for sheet metal forming in house can give flexibility to designers and engineers by reducing the lead time from weeks to a day.
For large volume production, prototyping the tool in plastic allows verifying the design before committing to an expensive metal tool. For short-run production, printed dies would save hundreds of dollars compared to outsourcing the part.
Here&#;s a cost and lead time comparison for the dies required for the metallic blade guard in our white paper:
ProcessEquipmentLead TimeMaterial Cost for 1 Final PartMaterial Cost for 50 Final PartsIn-house 3D printed toolForm 3, pressing machine, metal cutting equipment10-24 hours (tool print time and post-processing)$40 ($30 die + $10 sheet metal stock)$60 ($30 die + $30 sheet metal stock)Outsourced 3D printed toolPressing machine, metal cutting equipment6 business days$160 ($150 die + $10 sheet metal stock)$180 ($150 die + $30 sheet metal stock)Outsourced metal toolPressing machine, metal cutting equipment25 business days$460 ($450 die + $10 sheet metal stock)$480 ($450 die + $30 sheet metal stock)Outsourced metal partNone - fully outsourced15 business days$230$700White Paper
In this white paper, learn how to combine rapid tooling with traditional manufacturing processes like injection molding, thermoforming, or casting.
Download the White Paper
Rethinking toolmaking is a powerful way for reducing costs in metal manufacturing. Beyond the agility provided by prototyping expensive tools, 3D printed plastic dies can be efficient and affordable substitutes to expensive metal tools. For sheet metal forming, 3D printed tools offer multiple opportunities for applications from bent brackets to embossed parts, louvers, grille, and off the shelf set of dies for a press brake.
In our free white paper, we demonstrate how we successfully fabricated a metallic blade guard with the help of 3D printed plastic dies. We could potentially produce dozens of these parts with a single set of dies, bringing short-run production in house. Download the white paper now for the detailed case study and the step-by-step method and watch the webinar for specific design considerations and application examples.
Want more information on metallized paper supplier? Feel free to contact us.