SHANGHAI FRANCOM ROTOMOLDING TECHNOLOGY CO.,LTD

把滚塑模具安装到滚塑机上需要注意些什么? What need to pay attention to install the rotational mold on the rotational molding machine?

不同的类型滚塑机，其模具托架结构也是不同的。常见的模具托架有方框式，圆盘蛛网式。摇摆机和大型的直火式的滚塑机的的模具托架又不相同，那是一种类似于混凝土搅拌机的一种结构。我们今天要说到的是小型的一般的滚塑机上滚塑模具的安装方法。模具托架上安装的滚塑模具是否恰当合理直接影响到滚塑制品的质量好坏。这也是滚塑工艺不可忽视的一部分重要内容。     1.滚塑模具的选择。同一台滚塑机上，如果条件许可(有足够数量的同种模具)，最好选择同一类型的模具;如果要同时生产不同类别的其它产品，选择滚塑模具时力求所要安装的模具体积大小相近，重量差别不要太悬殊，滚塑制品的厚度要求基本上一致。以免出现产品老化降解或残留塑粉的现象。因为不同的滚塑模具生产时所要求加工周期都是不同的。 2.滚塑模具安装的间隔距离。一个模具托架上要安装多少个模具，这个要首先计算好，模具之间要留有足够的距离，以免互相遮挡，利于热空气的传导，同时也便于开模、合模。 3.模具托架的重心把握。这一点一定要注意，如果托架一边重一边轻，滚塑机的转动就会受到影响，轻则造成制品厚薄不均，严重时，会损坏滚塑机。 4. 注意滚塑机烘箱的直径，模具安装时要计算一下回转范围，否则会带来不良后果。 5. 滚塑模具的固定。模具安装时既要考虑牢固性，也要顾及安装、拆卸的速度。 Different types of rotational molding machine, its mold bracket structure are also different.Common mould bracket has box type, the disc spider web.Rock and roll machine and large direct fire type machine mould bracket is not the same, that is a kind of similar to a structure of concrete mixer.Today we want to say to is a small plastic mold on the general rolling machine of installation method.Plastic mold of mould bracket is installed on whether proper to directly affect the quality plastic products.It is also important content plastic part of the process can not be ignored.    1. Choose for rotational mold.On the same rotomolding machine, if the conditions permit (with a sufficient number of the same mold), had better choose the same type of mold;If you want to produce different types of other products at the same time, the rotational mould when trying to choose to install the mold size, the weight difference is not too wide, thickness of the plastic products requirement basically consistent.Lest appear product ageing degradation or the phenomenon of residual plastic powder.Because the plastic mold production of different required processing cycle is different. 2.Rotational mould installation distance. A mold on the bracket to install how many mould, the compute first of all, to leave enough distance between mold, in order to avoid each other shade, conduction of hot air, also easy to open mold, mold clamping. 3. The mould bracket the center of gravity of the master.It is important to note that if the bracket light, while heavy rotational molding machine rotation will be affected, light products thickness, serious when, can damage roll machine. 4. Pay attention to the diameter of the rotomolding machine have oven, to calculate the rotary mould installation range, otherwise it will bring adverse consequences. 5. Also fixed rotational mould.Mould installation should not only consider soundness is also the speed of the installation, should remove.  

What is Rotational Molding?

Rotational moulding, known also as rotomolding or rotocasting, is a process for manufacturing hollow plastic products. For certain types of liquid vinyls, the term slush molding is also used. Rotational molding has particular advantages in terms of relatively low levels of residual stresses and inexpensive molds. Rotational molding also has few competitors for the production of large (> 2 m3) hollow objects in one piece. Rotational molding is best known for the manufacture of tanks but it can also be used to make complex medical products, toys, leisure craft, and highly aesthetic point-of-sale products. The process begins with specially developed and uniquely applied resins. They can include plastisols, polyethylene, polycarbonate, acetate butyrate, polyamide, elastomers, polyurethane, polypropylene, ethylene vinyl acetate and fluorocarbons. Some of the most advanced work is being done with cross-linked polyethylene and even nylon. The principle of rotational molding of plastics is simple. Basically the process consists of introducing a known amount of plastic in powder, granular, or viscous liquid form into a hollow, shell-like mold.The mold is rotated and/ or rocked about two principal axes at relatively low speeds as it is heated so that the plastic enclosed in the mold adheres to, and forms a monolithic layer against, the mold surface. The mold rotation continues during the cooling phase so that the plastic retains its desired shape as it solidifies. When the plastic is sufficiently rigid, the cooling and mold rotation is stopped to allow the removal of the plastic product from the mold. At this stage, the cyclic process may be repeated. The basic steps of (a) mold charging, (b) mold heating, (c) mold cooling, and (d) part ejection are shown in Figure below.