Sheet Extrusion line
片材挤出线
analyThe most commonly ud plastic materials are:PP(polypropylene),PS(polyester),PET(polyester-phthalate),PE(polyethylene).retire
通常所采用的塑料原料包括PP(polypropylene),PS(polyester),PET(polyester-phthalate),PE (polyethylene).
After producing the foil and winding it on reels,the final articles(trays,boxes,containers,etc)are obtained by the thermoforming process in a proper machine where,through hot moulds,
在片材生产出来了并收卷后，最终所需的制品（托盘、盒子、容器等等）在合适的机器中热模成型而得
the finished items are formed and cut out,meanwhile the remaining part of the foil(the skeleton)is milled in flakes.igbt是什么意思
最终的产品为成型后切出，同时残余的片材部分（废片）给破碎成碎片
3)Advantages of the co-extrusion technology-cost reduction of the produced articles
共挤技术的优势-制成品的成本削减
The extrusion line described in the previous paragraph produces a foil made from the melting of one kind of plastic material,such as PP or PET or PS.
在前述段落里所描述的挤出生产线所谈论生产的片材都是指由一种塑料原料熔融成型所得，如PP或PET或PS
If the articles are dedicated for the food packaging,in the European Countries the safety and healthy rules normally state that the plastic material in contact with the food must be100%virgin type.So,no recycled material is allowed,even if clean or without any kind of pollution,like the flakes coming from the thermoforming process above described.This restriction pos the big question of how to manage the scraps that must be nt for the waste recovering or the pelletizing process in order to make again virgin pellets.In any ca this situation generates high production costs for the food packaging articles.
如果制品是用于食品包装，按欧盟安全和健康标准的要求，接触食品的塑料必须100%为新料，即，不允许使用回收料，即使是干净或者没有任何污染的，比如从上述热成型过程中所产生的废片。这个规定导致了一个很大的问题即如何处理这些废片，这些废片需要送到废料回收系统或者再造粒以重新成为新料。在任何情况下这些均将导致食品包装制品的高昂的制造成本
The co-extrusion technology was developed to avoid above problems,as it enables the production of multi-layer geometry foils where the recycled material is normally extruded in the centre and the
virgin ones in the skin layers.
共挤技术即为发展来解决这些问题，因其使得生产多层结构的片材，其中回收料通常为中间层挤出而
新料作为皮层挤出，成为可能
Co-extrusion is obtained by means of a proper distributor(Feed Block)that builds the desired geometry of the different layers.
共挤通过采用合适的分配头（喂料块）来实现不同层的几何结构的分配
4-layer Feed Block scheme
多啦a梦全集四层喂料分配块结构
whispering
The most common co-extruded foil is made of three layers,“A-B-A”geometry,where“A”is the skin layer obtained with100%of virgin material and“B”is the core layer obtained with recycled material in flakes.Obviously,the extrusion line must be fitted with two extruders,one for the“A”layer and the other for“B”layer.
This technology reduces the costs of the final products.
最常见的共挤片材为三层,’A-B-A’结构，这里‘A’是指由100%新料挤出制成的皮层，而’B’则是由回收的碎片料获得；很明显的，挤出线应该配两台挤出机，一台用于挤‘A’层，另一台挤’B’层。
此项技术大幅降低了最终产品的成本
Three-layer co-extrusion
三层共挤线
(1)–Extruder挤出机“B”
控制器英文(2)–Extruder挤出机“A”
白雪公主剧本(3)–Three-layer Feed Block三层共挤喂料块
(4)–T-Die T型模头
(5)–Calender压延机(Roll-stack)
4)Advantages for the Environment(recycling and waste reduction)
环保上的优势（回收及减少废品）
One of the main advantages for the environment is the possibility to produce the foil by using the flakes coming from thermoforming recycling as described in the previous paragraph instead of nding them to the waste disposal.
对环境而言，一个主要的好处是象前段所说的通过使用从热成型过程中出来的碎片回收料来生产片材而不是将他们废弃处理
Another advantage is described in the following.
另一个好处则是
Throughout the last years PET food packages have become very popular thanks to the best technical properties of this material compared to other plastic materials,like PS or PP.PET is more transparent,has higher mechanical strength and resistance,better barrier qualities.For the reasons PET is also the main material ud for the production of bottles for soft drink beverages.As said before regarding the health rules all bottles are manufactured with100%of virgin pellets. Considering the size of this market there is a big quantity of bottles destined to the waste recovering systems(rubbish rervoir).Thanks to the co-extrusion technology it is possible to produce PET foils by using the flakes coming from the post-consume PET bottle recycling system for the core layer.So,all of the bottles that would have otherwi been destined to ground disposal thus making pollution and creating cost for their management,become now good quality raw
material at cheaper prices for food packaging manufacturing.
在过去的这些年里，由于PET材料相对于其它塑料物料，如PS或PP的优良的技术特性，PET更透明，有着更高的机械强度和屈服特性，更好的阻隔性能等等，PET得到广泛的应用。也因为这些特性，PET在软饮料瓶的生产上也是主要的材料。如前所述，按健康规定，这些所有的瓶子均必须由100%的新料生产而成。考虑到市场的庞大规模，有着极其巨量的瓶子应送至废品回收处理（垃圾焚烧场）。而由于共挤技术，使得采用这些废弃的PET瓶回收的碎片来生产共挤芯层成为可能。所以，所有这些瓶子有着比投入垃圾场制造污染更好的选择即用来成为制造食品包装的优质且廉价的材料
非生活必需品
PET foil co-extrsuion
PET片材挤出
5)PET extrusion with last generation twin screw extruders-power consumption(energy saving)
最新一代双螺杆挤出机在PET片材挤出上的应用-节能
考研成绩什么时候出PET is a hygroscopic material.At atmosphere condition it absorbs humidity.During the extrusion
process the humid material is subject to the hydrolysis chemical reaction that affects the mechanical
studyabroadproperties of the extruded foil.For this reason the common technology needs to dry the material with a high level of power consumption.
PET是一种吸湿性材料。在大气条件下，会吸潮。在挤出工艺中，这种潮湿的物质将起水解反应严重影响所挤出片材的机械性能。因此，通常的技术需要消耗大量的能量来干燥物料
PET drying unitPET干燥装置
