Materiais especiais: soluções em tecnologia de corte para estampagem a quente de papéis de diferentes materiais

The slitting quality of hot stamping paper directly determines the effect, production efficiency and cost control of the final hot stamping product. Hot stamping paper of different substrates has huge differences in physical and chemical properties, so it is necessary to adopt a targeted slitting process. Here are detailed solutions for three common materials.

1. Core principle: first identify the material, then cut it

Before formulating a slitting plan, it is essential to fully understand the properties of each material and its impact on the slitting process.

2. Targeted solutions for slitting technology

1. PET hot stamping paper slitting scheme

• Tool configuration:

◦ Blade Type: High-quality tungsten carbide (WC) or ceramic-coated circular knives are preferred. It is essential to maintain extreme sharpness and wear resistance.

◦ Tool angle selection: Use a smaller edge angle (such as 30°-45°) to achieve a clean and clean shear cut, avoiding material hair caused by squeeze cutting.

◦ Tool holder setting: Suspended slitting (flying cutting) is used to avoid wear and tear in direct contact between the bottom roller and the blade, and can reduce heat build-up.

• Tension control:

◦ Set a medium-high and stable tension. Due to the anti-stretch nature of PET, it can withstand large tensions to ensure tight and neat winding.

◦ Use a high-precision magnetic powder clutch or servo motor control system to ensure a smooth transition from unwinding to unwinding tension curves.

• Key process parameters:

◦ Speed: It can adapt to medium and high speed slitting.

◦ Pressure: Minimize pressure to reduce tool wear and heat generation while providing clean cut-off.

◦ Environment: Strictly control the temperature and humidity of the workshop (such as 23±2°C, 50%±5%RH) to reduce static electricity. A static eliminator (such as an ion air rod) must be installed.

• Quality inspection focus:

◦ Whether the section surface is smooth and burr-free.

◦ Whether the winding is neat, and whether there is a string edge or collapse phenomenon.

◦ Use a magnifying glass to check whether the coating on the cut edge has come off due to overheating.

2. OPP hot stamping paper slitting scheme

• Tool configuration:

◦ Blade type: A sharp plain alloy steel circular knife is sufficient, as the material is softer.

◦ Tool angle selection: The blade angle can be slightly larger (such as 45°-55°) to avoid the knife being too sharp and "biting" too deeply.

◦ Tool holder setting: It is recommended to use gasket type slitting (soft knife sleeve), that is, a plastic or paper gasket is placed under it, which can effectively reduce the phenomenon of edge adhesion and curling.

• Tension control:

◦ Low tension control is adopted. This is the core key to the success of OPP slitting.

◦ The starting tension should be very small, only to ensure that the material is flattened. Using the taper tension control function, the tension should gradually decrease as the coil diameter increases to prevent the inner layer from being compressed and deformed.

◦ The guide rollers must operate flexibly to ensure absolutely uniform tension transmission.

• Key process parameters:

◦ Speed: Medium and low speed slitting is recommended to provide sufficient response time for the tension control system.

◦ Pressure: Light pressure, just enough to cut off the material.

◦ Environment: Temperature, humidity and static electricity also need to be controlled. OPP is prone to curling, and a stable environment is essential.

• Quality inspection focus:

◦ Whether the film roll is flat after slitting, and there is no curling phenomenon such as "ruffles" or "chrysanthemum hearts".

◦ Touch the cut edge with your hand to see if it is smooth and non-sticky.

◦ Check whether there is any invisible tensile deformation caused by excessive tension (it can be preliminarily judged by comparing the length before and after slitting).

3. Laser film hot stamping paper slitting scheme

• Tool configuration:

◦ Blade Type: High-gloss, mirror-treated round blade. The blade itself must not have any scratches or rough spots.

◦ Tool Angle Selection: Similar to PET, sharp edge angles are required for quick shearing.

◦ Tool holder setting: Suspended slitting (fly cutting) must be used. The blade is absolutely prohibited from touching any metal bottom rollers. The surface of all passing rolls and guide rollers should be high-finish anodized aluminum or chrome plating, or even wrapped in a protective film.

• Tension control:

◦ The tension setting is between PET and OPP, which requires a high degree of stability and no fluctuation. Any small tension runout can cause slight misalignment of the laser texture, affecting the visual effect.

◦ Servo motor drive is preferred to ensure excellent synchronization of speed and tension.

• Key process parameters:

◦ Speed: Medium speed is preferable, and stability is not purely efficient.

◦ Pressure: Precisely controlled minimum pressure to ensure cut-off.

◦ Environment: Ultra-clean environment requirements. The equipment should be equipped with a dust removal device, and the operator should wear gloves to prevent sweat and dust from contaminating the surface of the product.

• Quality inspection focus:

◦ Observe from multiple angles under a specific light source to check whether there are any scratches or scratches on the entire film surface during the slitting process.

◦ Check whether the gloss and brightness of the laser effect are consistent with those before slitting.

◦ Check the straightness of the slitting edges to ensure that the pattern direction is consistent.

3. General recommendations and equipment configuration

1. Equipment Basics:

◦ Investing in a slitting machine with independent servo tension control system, high-precision correction device and taper tension control function is the prerequisite for realizing "special material use".

◦ The device should be able to flexibly switch between "fly cut" and "pad cut" modes.

2. Human Element:

◦ Operators must be trained to be able to skillfully adjust equipment parameters according to different coils.

◦ Develop the habit of "trying small rolls first": Every time you change the material type or batch, first try cutting with small coils, adjust to the optimal parameters before mass production.

3. Maintenance and Care:

◦ Daily maintenance of blades is crucial. A strict blade cleaning, inspection, and grinding system must be established. After slitting different materials, the residue on the tool groove and guide rollers should be cleaned up in time.

resumo

The cutting concept of "special materials" requires us to no longer regard hot stamping paper as a general material, but according to the unique personality of its substrate, it is refined like a precision craft. Through the troika of precise tool selection, subtle tension control and clean production environment, the slitting quality of each type of hot stamping paper can be maximized, thus laying a solid foundation for subsequent high-quality hot stamping.