Poor Weld

Stainless steel coil and sheet stock is unloaded and stored outdoors under protective cover. As it is needed, the coil stock is moved indoors by a forklift to one of six automatic tube mills where the sides of unrolled metal strips are curled up to form a continuous, cylindrical pipe. The seam of the resulting pipe is fused in an electric in-line welding operation. An abrasive saw is used to cut the continuously formed pipe to specified lengths sections of poorly welded pipe are cut away. 

Repair pinholes in glass or poorly welded or brazed metal parts. 

Poor Weld Lines Injection Pressure too Low Short Injection Time Low Melt Temperature Low Mold Temperature Incorrect Pad Size... 

Coated Marto and Rohsenow [31] Poor weld Irregular matrix of surface and reentrant cavities... 

The melt should be present at the appropriate temperature and pressure at each injection point to enable the desired flow pattern in the cavity. Unwanted phenomena such as poor welding lines, frozen-in orientations, or cooling stresses should be avoided. 

Previous studies [1,2] examined the welded dowel surface after pull-out from the substrate. In this work, the SEM study focused on the welded-joints (Eig. 6(a-d)). Figure 6(a) shows a poorly welded joint between the dowel inserted in the hole (left side) and the maple substrate (right side), whereas Fig. 6(b) presents a well-welded bond between the dowel (right side) and the maple substrate (left side). When examining in more details the micrograph for maple, one can see the absence of visible cracks at the interface between the dowel and the substrate, as... 

Figure 6. SEM micrographs of the welded joints (a) poorly-welded joint (30 x magnification) (h) well-welded joint (30 x magnification) (c) magnified view of (b) (800 x magnification) (d) well-welded joint with low tensile strength (1000 x magnification).

Short press times under the same conditions of pressure and temperatme as in (1) yield poor welding, or no welding at aU, in the veneers interphases. 

An appropriate solvent is essential to prodnce a strong weld. Although the process is generally robust, if too little or too much solvent is applied then a poor weld can result. Excess solvent can be allowed to evaporate before assembly of the joint. Good fit and smooth substrates help to give a strong weld. 

Fig. 28. Poor weld line (weak) pinch-off had knife edge relief angle was either too large or too small.

Welding techniques for joining the plastic sheets are critical. Each weld must be continuous, leak tight, and mechanically strong. Poor welding is a common cause of lining failure. 

Austenitic and duplex stainless steels are the major metallic materials of construction for white water service, particularly for the headbox, piping, and also for suction roll shells. Bronze, once widely used for forming wires and suction roll shells, is used less because of its inherently poor corrosion resistance in modern white water environments. Poor welding quality can undermine the corrosion resistance of stainless steels, especially if the thiosulfate and chloride levels are high. Corrosion under surface deposits including scales, pulp mats, or microbiological growths... 

TLCP can be used in small amounts to reduce the viscosity of many polymers [25] and reduced-viscosity products have been developed using PAEK [26]. Such blends might sometimes suffer from delamination and poor weld line strength depending on the amount of LCP used. 

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