What is processing paper?
For example, when making a decoration cake, put ingredients in a cup made of cooking paper, and bake the sponge cake in the oven. After that, the cup made of cooking paper will not be needed, so it will be peeled off before the next decoration step. The cup made of the cooking paper is a kind of processing paper.
In this sense, processing paper is a function product that plays an essential role in the manufacturing process of various materials, such as helping the formation of shapes, but becomes unnecessary as a final product.
Processing paper shall adhere to the following strict conditions.
■Because processing paper is used together with the finished product, the condition of its surface in contact with the product will directly affect the quality of the final product.
■Exposure to severe conditions such as high heat in the manufacturing process shall not change the dimensions, etc.
■The ink printed on processing paper can be peeled off smoothly when used as a product.
Types and applications
One kind of processing paper is called release paper or release film, whose major function is to securely protect the adhesive surface of adhesive products, such as seals and labels, until they are used to fulfil their actual application. By applying release agents such as silicone to the paper or films, they become release paper and release film that can be removed cleanly from the adhesive surface.
Though release paper and release films are ultimately peeled off and discarded, the requirements are high with regard to appropriate peeling power changing with types of adhesives, thickness, and strength suitable for printing and punching processes, and ways of sticking to facilitate easy peeling.
②Release paper for synthetic leather
Release paper for synthetic leather (casting paper) is used in the manufacturing process of synthetic leather where vinyl chloride and polyurethane are used as raw materials. While acting as a support to the synthetic leather being produced, it can also help shape the leather surface. In other words, it works to fulfil the function of pattern papers. Apply a release agent to the surface of the paper and form uneven patterns with an embossing roll. Apply resins such as vinyl chloride or polyurethane onto the process paper to bond it with the base cloth. Once dried, the patterns can be transferred by peeling the paper off.
Therefore, what is required is not only properties like peeling performance, but also creative designs. The sales of such release paper can be greatly influenced by the quality of designs. The applications of release paper for synthetic leather can be diversified, such as shoes, automobile seats, and so on.
③Release paper for carbon fiber composite materials
Carbon fiber composite materials are often used in making golf club shafts, fishing rods, etc. When manufacturing these products, sheets of carbon prepregs are used as intermediate materials by fixing carbon fibers with resins. During this process, release paper is used as a mounting sheet.
Carbon prepreg is an intermediate material that is made by impregnating the carbon fiber into epoxy resin, etc. and wind it up without being cured. Carbon prepregs come in many types depending on different combinations of fiber base material and resins.
④Processing paper for foamed polyurethane
By using this processing paper, raw materials shall not infiltrate into the processing paper, the surface shall be kept covered until the next process, and the production line shall not be contaminated.
⑤Casting processing paper for soft urethane slab mold
It is a kraft paper with plastic film attached to the urethane side and is divided into two types: peel-off type and non-peel-off type.
⑥Casting processing paper for polyurethane foam
This is used for manufacturing polyurethane foam. The casting paper is in the form of a square plate called a slab and is linked with a conveyor. The reaction liquid whose raw material is polyurethane will flow onto the paper and become foamed and cured. The surface of the paper can be coated with a release agent or laminated with resins such as polyethylene.
After foaming, the resin laminated on the surface of the casting paper will be transferred to the polyurethane foam. The casting paper can be peeled off from the base paper and become recyclable.
⑦Processing paper for urethane skin layer
This is used in the lamination process of coatings and fabrics for urethane films used as the exterior and interior of winter clothes, as well as thin film resin layers such as base material for plasters. It contributes to materials and clothes related to the medical industry.
⑧Processing paper for PVC foams
This is used as transfer printing paper for foamed PVC sheets and has been rapidly popularized as a substitute for expensive flooring materials. This foamed PVC sheet is manufactured by applying a mixture of molten vinyl chloride resin and foaming agents onto the processing paper to make it hardened and foamed.
Patterns such as wood grains printed on the surface of the processing paper can be transferred onto the surface of the finished products, making it possible to show various designs.
⑨Processing paper for punching process
When producing films, double-sided tapes, cushions, etc., paste the materials of double-sided tapes and various films onto the base sheet separator® with a laminator, then punch the material with a die press machine.
In this industry, in addition to films, double-sided tapes, and the film materials that become final product themselves, an interlayer paper is used between the products, which peels off the scraps and does not adhere to double-sided tapes. These films, single-sided tapes, and slightly adhesive films are not final products, but are used between different processes.
⑩Processing paper for ceramic capacitors
As for ceramic capacitors, apply paste-like ceramics to the release film and remove it once dried. Due to the film thickness required for capacitors in recent years, defects in release films can affect products' performance.
Carrier tapes are used to transport electronic components, such as highly integrated circuits. They belong to one type of industrial processing paper. Carrier tapes require high paper density and strength between layers to avoid the generation of fine paper powders, etc.
⑫Glass fabric non-woven cloth
Low-density glass fabric non-woven cloth can easily penetrate various resins. Furthermore, because of the excellent corrugate processability to process materials on waves, it is suitable as a base material for corrugated filters. It is used for roofing materials, ceiling materials, incombustible wall materials, surface materials, flooring materials, and mosquito coil inlays.
⑬Processing paper to print patterns on concretes
Special patterns that can delay the setting of the concrete are printed on the paper. For example, put the processing paper on the inside of the concrete wall mold, pour in fresh concrete, and wash it after the concrete sets. By doing this, only the inside of the concrete where special ink is used will be exposed and the patterns will appear on the surface.
When building and renovating hotels, resort facilities, and large stores, the exterior walls of such facilities shall not only be functionally superior in strength, durability, and workability, but also creatively designed. In this sense, the application value of this processing paper is believed to be high.
⑭Processing papers for food cups
Paraffin-applied glassine paper is used here. Used for cups of food, such as sweets, bread, and cakes, the management of foreign substances to be detected by foreign substance detectors, etc. must be thorough in the manufacturing process.
⑮Processing papers for food processing
The paper is used as base paper for steaming bread, meat buns, sweets, etc. When separated from food, it shall have an adequate peeling property.
⑯Processing paper for medical uses
It is a release paper used for plasters, etc. Depending on its application, it shall be able to change the base material, thickness, peeling force, etc. They can also be used as hygienic materials, such as plasters, release papers for body warmers, and poultices.