The choice of book cover material is a very crucial part of the process. Common types of book covers are fabric, PP, PVC, self-adhesive, paper and so on. Today we are going to talk about the quality control of the production of PVC book covers. PVC book covers account for a large proportion of the global market, it has the best fit with the book cover, the most flexible in many varieties of book covers, and at the same time has the characteristics of waterproof and durable.
When buying books covers from the market, you will find that the products often appear yellow in colour or wrinkled or sticky. Now we will talk about the handling of common problems in operation and teach you to choose a quality book cover supplier.
1.Temperature control
Temperature has a major impact on the performance of PVC materials and also on the future performance of the finished product. Whether it is the production of raw materials or the finished product, controlling the temperature is a primary condition. Summer temperatures and winter temperatures, rainy seasons or hot seasons, all have to be adjusted to the appropriate production temperature in accordance with the laws of nature. If the temperature is not adjusted properly, it can seriously affect the flexibility and shrinkage of the finished product at a later stage.
As an example, production temperatures are generally higher in winter than in summer. Because of thermal expansion and contraction, there is significant shrinkage when the product is placed at a lower room temperature after a high temperature. Therefore, in order to avoid excessive shrinkage, it is recommended to add drying lamp to the production control and to set the shape first.
2.Mould Size Control
As the size of paper products varies from country to country and city to city, it is necessary to know the local book sizes in advance in order to make the perfect book cover. For example, in Germany there may be more than 10 different sizes of book covers, each of which may only differ by as little as 5mm or even as little as 2mm. The size of the mould needs to be judged in the light of the weather, the shrinkage of the material and the size of the book before a decision can be made. Care must be taken to take into account the shrinkage in production and the influence of the weather at the time of production and the customer's local weather. The model made too large or too small will affect the size of the finished product.
3. Control the Amount of Powder Sprayed
To prevent the products from sticking together, the raw material needs to be powder sprayed, but the amount of powder spraying needs to be controlled. Too much powder will make the product opaque, too little will not separate it and the product will still stick easily.
4.Pressure control
Except for special book cover sizes (particularly large), production is generally largely automated, but the control of pressure regulation prior to automated production also requires special attention. Too much pressure can cause over-pressing, wrinkling and curling, resulting in an uneven product. Too little pressure will result in unclean torn edges and excessive material left in the corners, making the product less aesthetically pleasing, as well as problems with the ironed edges not being secure and easily tearing away.
5. Film roll control
Prevent wrinkling caused by inconsistent tension on both sides of the film roll. First choose a film with the same elasticity on both sides, then adjust the tension on both sides of the film to balance it and prevent wrinkling. When ironing the edges, control the machine pressure and temperature.
6. Labeling and Positioning Control
When using the automatic labelling machine you need to pay attention to the positioning of the label to be accurate and position the label well beforehand, then the machine can proceed smoothly. Once the positioning is not accurate, the whole batch of products will need to be reworked. In addition to the use of automatic labeling machine, sometimes also need to use manual labeling, manual labeling needs to pay more attention to the problem of positioning. Because of the speed, it is easy to stick crooked or far away from the original position. Therefore, it is necessary to use tips for positioning, such as using marker sizes on the operating table.
7. Conclusion
The most important point of quality control is actually to be attentive, to notice the problematic point of each link, pay attention to it, solve it and the problems will all disappear. After noticing every link and making it perfect, naturally there will be no problems and no quality issues. After 15 years of production, Mifia constantly sums up its experience and improves the machine problems in order to get the best product !
