Application methods for pad printing technology in plasitc bottle cap area

There are two types of bottle caps: one type is plug-in,the other type is round rotary。generally speaking ,plug-in bottle caps are not normally required to install repeatedly, and it has more complex shapes, mainly completes some functional action,for example,spray.At present,it is used for this plastic bottles,such as Shower Gel, Hair care products , Pesticides and so on. Rotating circular caps are more common,and it has wider using area. In addition to the bottle caps protect the products from the environmental impact, but also plays transfering some important information function. for example ,Taiwan Uni-President tea drink, Shanghai Portola package plastic bottle cap and so on.

So it is very important to ornament bottle cap. This article is discussed printing word or trademarks on surface of the rotary cap.

Pad printing is the first choice for printing plastic bottle cap

When customers received orders for printing on the bottle caps, the first thought is the pad  printing process. Pad printing process is a unique printing which developed with screen printing, It is similar to rubber stamp which we often use in our daily lives.Pad printing adopts independent relationship which is between printing plate and printing stock, No matter how strange shape of the printing stock, it can complete very good.Screen printing which is called "universal printing" is difficult to complete many tasks ,but pad printing can complete it very good.

Adopting pad printing for bottle caps have a few advantages,and other printing progress can’t reach it.

　　(1)it is very convenient to change products,and it is very easy to making plate

　　(2) Less investment. Comparing with the other printing equipment,pad printing equipment is the least in investment.

　　(3)  It is strength adaptability .The shape of pad plastic head can be changed arbitrarily, This enhances the adaptability for shape of printing stock greatly .It is suitable for printing kinds of bottle caps which have different size and different appearance. According to our survey,about 80% bottle caps’ diameter are not larger than 40mm. That is to say,a pad printing machine which steel plate is 100*100mm can completes 80% bottle caps printing  

Essential factor for pad printing plastic bottle caps

1.Printing ink

It is very important to choose printing ink during pad printing plastic bottle caps.The materail of bottle caps are most PP or PE,choice of ink must match the material of printing stock.when you choose printing ink,please note the below two points:

　　(1) Some printing ink added sclerosant, this improves ink adhesion effect,but increase operation difficulty,so you’d better not to adopt this method except customter’s special requirement.

　(2) You’d better to choose pad printing ink instead of screen printing ink.Screen printing ink has good levelling,but pad printing ink has better colloidal.The drying speed of screen printing is slow,but pad printing is fast. Although solvent type screen printing ink can be used for pad printing,but the printing effect is less than special pad printing ink.If it needs to use UV ink, even should not selecte UV screen printing ink,just because its worse transfer.If you must use screen printing UV ink,you should add a certain amount of gelling agent in it.

2. pad plastic head

At present, generally we do not attach choosing plastic head in domestic,but choice of plastic head is very strict when pad printing. During printing bottle caps, round plastic head is very universal.When you choose plastic head ,please pay attention to the following two points.

(1) In the mesh image transfer printing process. yellow, magenta, cyan,this three color chooses plastic head which has same hard and same shape,but black color should choose harder plastic head

(2) please choose the plastic head which has good autostrip,this plastic head draws formula highlights of offset printing rubber sheeting,it can improve printing quality on PP or PE

3.Printing plate

For the manufacturer who attaches importance to pad printing qualitry for bottle caps,it is an advisable choice to adopt resin gravure. This kind printing plate is made from nylon polymer, it doesn’t need corrosion working procedure,this is propitious to control quality.At pressent, resin gravure is used widely in pad printing machine which is produced by occident

4.Cost

The printing area of bottle cap is small, this is why some people do not have to worry about its costs. However, as market competition intensifies,we should pay attention to reduce costs .This is why lots of manufacturer adopt pad printing instead of Flexography for printing bottle caps.

At present,the cheapest single color pad printing machine is about RMB10000,and it contains steel plate,clamps and plastic head.If you adopt this equipment, bottle cap single printing costs is generally not more than 1 cent(RMB).If you adopt fully automatic pad printing machine,the cost is cheaper .