包装机有立式和卧式之分，立式又有连续式(也叫滚轮式)和间歇式(也叫合掌式)之分，成袋有三边封、四边封、背封，还有一出多列的包装设备。茶叶包装设备品种繁多，各设备之间的差异也很大。在实际使用复合膜卷材时，会遇到各种问题，本文详细分析热封问题的产生原因，供参考。
packaging machine with vertical and horizontal, vertical and continuous type (also called roller type) and intermittent (also called crossing their type), three bags of edge-sealing, four edge sealing, back sealing, there are more than a column packing equipment. tea is a great variety of packaging equipment, has a very big difference between various devices. in actual use composite film coil, will encounter all sorts of problems, this article detailed analysis of causes of the heat sealing problem, for your reference.
低温热封性主要是由热封层树脂的性能所决定，同时也与压力也有关系，一般挤出复合时挤出温度较高，电晕处理过强或薄膜停放过久都会降低材料的低温热封性能。热粘性用于描述热封后未充分冷却固化时，热封层熔融面耐外力剥离的强度：这种外力在自动充填包装机中常常发生。因此茶叶自动包装用的复合膜卷材，应选择热粘性良好的热封材料。抗污染热封性又称夹杂内容物热封性，是指热封面粘附内容物或其它污染物时仍能够热封的性能。复合膜根据不同的被包装物、不问的包装机械和不同的包装条件(温度、速度等)来选择不同的热封树脂，不能千篇一律地采用一种热封层。对耐热性差的包装，应选用低温热封材料。对于重型包装应选用热封强度高和机械强度高、冲击性能好的热封材料。对于高速包装机，应选用低温热封和热粘强度高的热封材料，对于粉剂、液体等污染性较强的产品应选用抗污染良好的热封材料。
low-temperature heat sealing is mainly determined by the heat sealing layer of the resin performance, at the same time, it also has relations with pressure, normal extrusion composite extrusion temperature is higher, corona treatment too strong or film too long will reduce the material of low temperature heat sealing performance. not fully cooling after hot viscosity is used to describe heat sealing curing, heat sealing layer of molten surface resistance to the strength of the stripping force: the force often occur in the automatic filling packing machine. tea automatic packaging composite film coil, therefore, should choose good thermal viscous heat sealing materials. heat sealing pollution resistance is also called the mixed contents heat sealing, is refers to the thermal cover adhesive contents or other contaminants can still heat sealing performance. composite film according to the different packing materials, don't ask, don't packaging machinery and packaging conditions (temperature, speed
漏封是由于某些因素存在，使本应通过加热融熔结合的部位，没有封上。漏封一般有如下几种原因：seal leakage is due to some factors, make the combination should be melted by heat, no seal. leak sealing generally has the following several reasons:
①热封温度不够。同一包装材料在不同的热封部位要求的热封温度不同，不同的包装速度要求的热封温度不同，不同的包装环境温度要求的热封温度也不同。包装设备纵封和横封要求的热封温度不同，同一块热封模，不同部位的温度也可能不一样，这些都是在包装中必须考虑的问题。对于热封设备来说，还存在一个控温精度的问题，目前国产包装设备其控温精度较差，一般都有：10~c的偏差，就是说，如果我们控制的温度为140％的话，实际上在包装过程中其温度是在130—150~c之间。许多公司的气密性检查，都采用成品中随机抽样来检查，其实这并非是一种好的方法。最可靠的方法是在温度变化范围内的最低温度点取样，而且应连续取样，使样品能足够覆盖模具纵横向的各部位。heat sealing temperature is not enough. the same heat sealing parts of the packaging material in the different requirements of heat sealing temperature is different, different packing speed required heat sealing temperature is different, different packaging environment temperature heat sealing temperature is different also. longitudinal sealing and transverse sealing packaging equipment for heat sealing temperature is different, the same piece of heat sealing mode, the temperature of the different parts might not have the same, these are all problems must be considered in the packaging. for heat sealing equipment, there is a temperature control precision of the problem, the current domestic packaging equipment the temperature control accuracy is poorer, generally are: 10 ~ c deviation, that is to say, if we control the temperature of 140%, actually in the process of packaging its temperature is between 130-150 - c. many company seal check, use random sampling ? in finished products
②封口部位受污染。在包装的填充过程中，包装材料的封口位置常常被包装物所污染，污染一般又分为液体污染和粉尘污染。解决封口部位受污染的问题可以通过改进包装设备，使用抗污染、抗静电的热封材料等方法来解决。the sealing parts contaminated. in the process of packaging of filling, sealing position of packaging materials are often contaminated by packing materials, pollution in general is divided into liquid pollution and dust pollution. can solve the problem of sealing parts contaminated by improving packaging equipment, the use of pollution, antistatic, heat sealing materials and other methods to solve.
③ 设备和操作方面的问题。如热封模夹有异物，热封压力不够，热封模具不平行等。equipment and operation aspects. as a foreign body heat sealing mold clamp, heat sealing pressure is insufficient, heat sealing mould is not parallel, etc.
④包装材料的问题。如电晕过面，热封层爽滑剂太多而引起热封不良等。the problem of packaging materials. such as corona, heat sealing layer smooth agent too much and cause poor heat sealing, etc.
